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yohudi
05-17-2006, 11:07 PM
General Notes about this Log:
Ok, just a few quick notes before getting into the build. All info regarding aqquisition and cost relating to components can be found in my "DIY with quality components" thread.
http://www.cnczone.com/forums/showthread.php?t=17834.

I'm going to restrict this log to the actual build so as not to get sidetracked. I'll be happy to answer build related questions or take any comments or suggestions regarding the build here. If you see me doing something stupid, please please speak up BEFORE I maim or kill myself, I really would appreciate it ;) I have a reasonable electrics / electronics background from a misspent youth of music technology related pursuits. I've done a good bit of Band, P.A, stage-lighting, studio and computer related power and wiring. I've not killed anybody yet despite plenty of opportunity but I'm certainly NO EXPERT.

!!!! IMPORTANT !!!!

IF YOU DUPLICATE ANY OF THIS BUILD PLEASE BE AWARE THAT IT IS AT YOUR OWN RISK. I TAKE NO RESPONSIBILITY FOR INJURY OR DEATH TO YOURSELF OR OTHERS. I AM CERTAINLY NOT QUALIFIED TO STATE THAT ANY OF THE STEPS IN THIS BUILD ARE SAFE, SENSIBLE OR GOOD PRACTICE. YOU MUST PUT YOUR OWN SAFETY FIRST AND ASSUME THEY ARE NOT

Format and content:
I'm going to try and make this log the one I would have liked to have found when I was looking for information. There will be as much detail as I can sensibly include. As much of it as possible self-evident from the pictures and requiring minimum waffle from myself. It will be organized by the image content. It's easier to do than say so I'll get started.

Image: Cnt00_ Schematic.jpg:

Hopefully the resolution limits on files will keep the clarity in this. If not and you want a higer res version plz let me know and I'll send it.

Before I started powering, cutting or drilling anything I laid out the system as a schematic. It gives a comprehensive view of all the tasks and opportunity to check that components are located in a logical place in view of the connections they will recieve. It allows accurate calculation of connector types and numbers and ensures the possibility of upgrading the controller to 6 axis in the future by adding a BOB, PSU and 2 motor drives. Cutting drilling and fitting for ALL hardware must be done now to get all swarf and filings out the way before any components are fitted in the case.

I should at this point acknowledge the influence of many other's designs in this control setup particularly Madvac's. The AC distribution side in my controller is almost a straight lift from Madvac's and I'd be the first to admit it AND say thanks.

I made a point of trying to show the BOB connections clearly. The CNC4PC BOB is not documented to the extent that you can tell what it's fully capable of. There are no example layouts I could locate anyway.

I'd REALLY REALLY REALLY appreciate someone with good electronics knowledge having a look at this. Any electronics sillyness in my plans is already there in the schematic. I've tried to make it clear and self-explantory please let me know anything I may have missed. Hopefully the colours will still be clear on the uploaded version.

Image: Cnt01_RAID Case.jpg:

The RAID case as it arrived. With the various blanking plates and HD mounting hardware I'm pretty sure that this will hold everything for a 6 axis controller.

Image: Cnt02_Swtch_Leds_Lock.jpg:

Close up of the case front showing the existing swiches and LED's. The Switches are rated at 230VAC at 10AMPS nominal and 16 AMPS surge current. I'm planning on using these to switch the 50V DC PSU's independantly.

I don't know the LED type or voltage but I'd guess at 5v as it supposed to be an extension for a hard-drive activity LED. I'm looking at what I need to do to get these to indicate step and dir for 6 Axes. There are LED's on the BOB. If they are the same or similar it's shouldn't be hard to make this work. There are an additional two momentary switches and a resetable fuse to add to these switches. They should all easily fit in a single drive cover plate. The lock secures the doors/fans visible in the next picture and adds a good safety feature.

Image: Cnt03_Fans.jpg:

4 x 12v fans are built into the doors and have removable and cleanable filter. Will come in handy. Was mainly seeing the Hard drive array behind these fans and the other front panel features that decided me on this case as a good 6 Axis enclosure.

Image: Cnt04_ComponentsALL.jpg:

Overview ofcomponents to make initial 4 Axis controller. Pretty much all of this has to go in the enclosure. Will examine in detail below.

Image: Cnt05_PCBs_Relays.jpg:

A closer view of the PCB's and relays. The largest PCB is a CNC4PC C1 Parallel port interface card. 2 of these are required for 6 axis control if you want options like relay control and saftey charge pump. If you only need 6 axis motion, Limits, up to 3 axis home and Estop then a single BOB WILL do this.

The long thin PCB to the right is 5v/12v PSU. The small PCB in the centre is the safety charge pump and to it's left is one of the 5 AMP solid state relays. The Crydom relay is 240VAC at 25AMP rated, could switch on/off spindle and Vac together and leave 2 other relays free for other tasks like 2nd spindle etc. The black and grey relay next to the USB leads is the Onron 4 pole relay that will control AC distribution. The USB leads provide separate power to the PC side of the BOB. I have a second low volts PSU that I may use instead to cut down on leads entering the case.

Image: Cnt06_MS845.jpg: and Cnt07_MSD880_980.jpg:


Closeups of the 2 motor drive types and settings data. They are functionally identical with just the current rating being higher for the 980/880 type drive. I like the way the settings are adjusted via dip switch. A lot easier than soldering resistors to set current limits etc.

Image: Cnt08_Sundries.jpg:

The other items required to complete the controller. Now I've established the case switches will take the voltage and current required I won't need the illuminated rocker switches.

Image: Cnt09_Mockup PCBs.jpg:

Close up to demonstrate the PCB layout. I'll be grouping the various connections using heat-shrink tubing to keep everything neat and tidy when I've established that the controller works. There are 2 BOBs which doesn't show up as well as I'd have liked. They are stacked using PCB pillars to separate them.

Image: Cnt10_Mockup ALL.jpg:

An overview of all 4 axis components in the case. Motor drives and PSU's placed for optimum cooling. Thinking of changing this layout for actual construction. I could mount all the PCBs in a card type arrangement, just like a standard ISA or PCI card and then mount it vertically on the far left behind the motor drives. This would leave the space for an additional PSU, there is a spare case switch for this already. 2 additional motor drives will be of the MS845 type, without heatsink. There is ample space to fit these with the others. The wires to the left of the PSU board are the power leads to the case fans.


That's about if for the first entry. Next job is to MOD the case to my needs. Drill out for all switches, sockets, mains connectors and get them mounted. I'll make up my mind about the PCB layout at that point too. Might also sort out the actual mounting of 3rd PSU and adjustment of PCB layout to suit.

yohudi
05-26-2006, 11:50 PM
PCB Layout adjustments:
As mentioned in closing the last entry I decided to include the 3rd PSU from the outset. By doing this it means I only have to add 2 drives in the future and wire them to go fully 6 axis. In order to do this I had a fair bit of modification to perform on the basic case which should become self-evident as other aspects are discussed.


Image: Cnt12_50v9.9A_PSU_Pins.jpg:

First job of electronics build was to ID the inputs and outputs on the 50VDC 9.9Amp PSU's. They are originally designed for use with a standard molex connector. but the individual blade outputs readily accept spade terminals and is good firm connection. To be on the safe side I double insulated the unused pins with heat-shrink. I'll clean off the untidy marker pen with thinners if everything works OK.

Image: Cnt13_BOBs_Moved.jpg:

Relocated BOB's to a small shelf mounted on the rear panel. Made from a drive bay. The safety charge pump has also been relocated to the underneath of the shelf. Four screws securing mounting pillars are visible on the left of the picture.

Image: Cnt14_77v8A_PSU.jpg:

The reason for the adjustments. In 6 axis config 77v 8Amp PSU will drive 4 motors requiring 2 Amps each. Both 50v PSU's will then power 1 MAE motor each. MAE's need 7 Amps. Controller would need complete rebuild in future if 3rd PSU not included now. Mounted PSU as shown to balance the case. Case is VERY heavy now requiring support rails. Also visible are alterations to layout of other components.

Image: Cnt15_Assembled_S.jpg and Cnt16_Assembled_T.jpg:

Side and Top view of assembled components with all case mods complete. Front panel switches and fuse holders visible on left of picture. Sockets for drive outputs and limit inputs are next to BOB's on rear panel. Just behind toroid of 77v PSU are sockets for mains input and relay outputs. Top view shows 2 relays moved onto side of case. Pic also shows adjustment to motor drives to create clearance for front panel hardware.

Image: Cnt17_Wiring_A.jpg:

Wiring started. PSU's to Motor Drives, via front panel fuses. Front panel switches are wired and any AC distribution which will be inaccessible when rear panel is attached. Using terminal block on 77v PSU to connect AC Neutrals only. Will be no AC Live connection to 77v PSU until 6 axis required.

Image: Cnt18_Wiring_B.jpg:

Close up of AC distruibution from Omron relay. Wires running underneath 77v PSU plate will all be heat-shrinked for protection.

Image: Cnt19_Wiring_C.jpg:

AC distribution wiring completed. Thin black and red wires on top of 50v PSU's are BOB activate switch. Thicker wires are 5V supply to BOB's. Yellow heat shrink is 12v Fans and SChP power. Black heat shrink on right holds ground and switching connection to all relays. Brown wires on left with red tape are connections to AC Live, Neutrals are blue wires on lower left and green is earth from 77v PSU. Brown with green tape in centre of picture is from Omron relay for Estops.

Image: Cnt20_Wiring_D.jpg:

As is becoming evident my design is quite modular. This allowed a lot of work on front and rear panels to be performed away from the main case. Sockets for drive outputs, mains input and Estop are in the foreground. EStop is a modified IEC connector with one of the pins removed with RED heatshrink. All soldered connections have been insulated with heatshrink. Extra clear heatshrink on drive leads is to cover exposed braided shield and protect where they run close to a PSU smoothing capacitor.

Image: Cnt21_Wiring_E.jpg:

View of limit switch and SChP wiring. New charge pump position. Limits, Charge pump and USB power all wired to the BOB at this stage.

Image: Cnt22_Wiring_F.jpg:

Rough plate I bashed up out of unused bit of drive mount. Made with hammer and vice. Required to create some space between PSU transformer and these relay output sockets. Could be prettier but works fine ... also used to mount terminal block to share AC Live and Neutral connections.

Image: Cnt23_Fully_Wired.jpg, Cnt24_Rear_View.jpg and Cnt25_Front_Switches.jpg:

All wiring complete... should be a working controller at this point. Box to the right in top view is rails for case. Rear view shows all sockets. can just make out mod on Estop socket, pin removed and will block up matching hole on plug to make unique connection. USB power for BOB is on right. Front view shows mods to allow fuse and switch mounting.

Image: Cnt26_Test_Kit.jpg:

Components required to test the controller. Have to make two short motor leads, a set of test limit switches, a relay output lead and an example Estop circuit with switch and bulb.


Next job

Once the kit is completed I'll be able to test all controller functions on the bench before going any further. I'm setting up an old laptop to run Mach2 for testing purposes. That way if I've got something wrong and it eats a machine it won't be dual AMD processors that get destroyed.

to be continued........

yohudi
06-02-2006, 09:20 PM
Ok... had to happen so here it is..

pics of testing procedure to be added when I dl them from the camera.. but wanted to ask for advice 1st...In all that follows there has been no escape of the 'magic' smoke.. None of the PSU, motors, drives, or any other circuitry is showing any signs of heating at all.... but problem persists... any comments, thoughts, advice would be appreciated..

obviously have made up test-kit, performed testing in stages, confirming all functions checked out ok. Have arrived at motor testing only to hit weird prob. Hookup of motors is as per schematic... 1x 50v 9Amp PSU to 2 motors. MAE motor wants 7 amps and Nema23 wants just over 2 amps..

Jogging in Mach 2 produces smooth, controlled motion at expected speeds on nema23 motor but MAE motor sounds rough as a bears A!*e.. Motor tuning has no effect on roughness. Is NOT resonance.. sounds and looks like its running on gravel bearings. Stuttering badly is the best way I can describe the motion....

First thought was motor wiring.. it's 8 wire motor and had performed bipolar parallel linking myself so was 1st suspect.. but wiring is correct... this is confirmed later.

Next thought maybe poor connection in motor power chain.... measuring with meter confirms solid 42v DC coming from PSU.. below stated 50v but is solid.. didn't fancy taking the chance of putting meter (and me) in series to check PSU current output just yet....tested voltage at input to both motor drives and is solid there too. Tested every connection, wire, plug and sockets for continuity.. AOK all the way.

Voltage out of drive when motor is moving is strange ..seem to only get measurable voltage on one output phase on the MAE drive... thought maybe it was something to do with step/dir coming from BOB...

Signal step/dir from BOB tests out fine. Signal level of 4.6v... in sync with jogging.. displayed by LED's onboard BOB... same signal from BOB is driving nema23 fine..

Have duplicate PSU, Drives and motors... so switched to duplicate set of PSU and drives... but kept same motors in place.... Similar Problem exhibits, except now it's the same MAE motor that runs perfectly, can make it shake the bench it's fastened to if I tweak it up in motor tuning. No signs of any resonance or roughness, it sings... beautifully... rapid acceleration and deceleration... however, the nema23 doesn't move at all...

Seemed to me that maybe I may have had the misfortune to have had 2 defective motor drives supplied. 1 of each type.. but this seemed unlikely.. I began to suspect that the problem lies in the PSU. I thought I'd check by connecting 1 known working MAE +drive and 1 known working nema23 + drive to the same PSU...when I do this the problem with the MAE motor exhibits again.. while nema23 drives well as previously.

I've pulled out the PSU docs and I think that It's definitely some kind of current related problem. There is mention of the output voltage being resticted to 42.8v + or - 0.5v if the PSU detects itself to be in an unregulated state. This would tally with measured voltage out of PSU's.. both PSU's measure same voltage out... there's no information about what happens to the current level if this happens.

There are other inputs and outputs on the PSU but all DC outputs are the same at 41.5 to 42 volts. Docs mention some kind of 'Inhibit(Ucr)' function and the fact that the PSU puts out a 'system GOOD' voltage signal.. but there is no further information...

That's as far as I've got with it at the moment. Over the weekend I'm going to test the drives 1 at a time on each motor. If they run fine with 1 drive per PSU then I think it will be proof that the problem lies in the PSU output.. which I can then address....


like I said before.... any advice appreciated...

yohudi
06-05-2006, 11:05 PM
Happy to say I've located the root of the problem... faulty wiring.... that's all there is to it...

Broke the controller down to the point where I was sure the components left worked fine.. Discovered a couple of bad solder joints on the panel mount fuse holders in the process... these had tested ok for continuity but there was movement in the soldered joints.... remade these connections and made sure to use them in the rest of the testing below.

Switched to 80v 9Amp PSU for testing... The 50v PSU's will run unregulated but are originally designed for microprocessor applying voltage regulation... was not sure that this was not part of the problem...

Tested the motor drives in isolation... all drives function perfectly with 3 different motors. Adjustable current settings came in very handy here.... All motors getting great speed... lot's of torque... no heating of drives or motors even when running flat out... all very well behaved.

Going to retest with one of the 50v PSU's next.. see if the problems come back... I don't think so though.... Have had both types of motor and drive running fine off 50v PSU's... but had unknown faulty wiring present in motor power circuitry on 2 drives.. one of each type..

If all goes OK with the 50v test in isolation then I'll reassemble controller... checking all connections as I go.. do final test .. and then move on to the mechanicals....

yohudi
07-19-2006, 08:00 PM
Hello to those interested..

what's going on.. well there is progress... quite a bit.. but I haven't updated here in a while as I want to keep the log sequential.. I have a prob with that in that the vids I took of my controller testing are still in the camera..

I have to reconfig what will be the controller PC and pull a firewire card out of it to grab the footage onto this machine... however, I'm still backing up data from the Dual AMD rackmount to DVD before I go ahead with the reconfig.. I had about 300GB of data on the hard drive that I don't want to lose... that's about 80 burns.. plus the time required to organise it... I was going to grab the vids to the other machine, then Burn to DVD and transfer to this machine.. but as I've got to backup before I use the Dual AMD for the controller it seemed better to just get on with it.. that way I can show the actual setup that will be used..

apart from that I've just had some mechanicals made by a local engineering firm.... 90% of that went OK no probs.. but I need to get a couple of tweaks done on a motor mount and a gearbox adaptor for the nema 23 motors... the slide I had made for the Z Axis is sweet as a nut... with the router mounted I can raise the whole assembly by turning the ballscrew between finger and thumb.. so I know that the supernema's will have no probs at all....

have also been sidetracked by the missus... roped into building some accomodation for two ponies....once all that's sorted out then I'll be taking up the build again.... the things you have do to keep them happy...

stay tuned....

ckm
09-12-2006, 02:33 AM
any updates?

yohudi
09-12-2006, 06:00 PM
any updates?

Hi there and thanks for asking..... There is a lot of news re my build....

I've decided to get my machine to a functional 3 Axis setup before updating any further. That way I'll be able to assess cost/performance and include my conclusions and proof of functionality etc...

To this end I'm about 2 thirds of the way through the mechanicals, I only have the Z axis to attach and some motor/limit switch wiring to complete and it's a functional 3 Axis machine. I anticipate 3 axis completion in about 10 to 14 days.... got to fit it in around other work...

diarmaid
09-12-2006, 06:29 PM
Hi yohudi. This is great, please keep it up. Nice pictures. :)

yohudi
09-22-2006, 09:28 PM
Build_Log Update 03 - 08_08_06 :- Controller Testing -:

Well it's taken me a while to get round to this update, been mad busy and had loads of extra commitments to deal with also. The date above (08/08/06 is when I originally wrote this). Anyway here it is at last....

Mentioned previously that I thought I had a wiring problem... this boiled down to being a faulty terminal block on one of the drives. Think I may have over-tightned it at one point and thereafter it wasn't making a good connection. Support from Motion Control Ltd was very good and was advised how to go about repair, which so far appears to be successful. Once I had that prob sorted the rest of my testing was a pleasure.

A quick note about any video clips I put up. They are AVI, encoded using DivX 5.0 video codec and MP3 for audio where present. The current clips were shot without benefit of a tripod but clips are clear enough for purpose
here. I've had to .ZIP them as the board only accepts WMV or MOV media files. (EDIT : CAN'T GET THE ZIP TO GO UP !!! IS 4.98MB ONLY BUT STILL WON'T UPLOAD)


Image: Cnt27_TestSetup1.jpg - Cnt28_TestSetup2.jpg:

I originally planned on using an old laptop to test with but it couldn't run Mach 2 or Mach 3. Just got famous BSOD and reboot everytime. Decided to make use of another dual processor machine I had about the place. A dual PIII 600Mhz job with 1GB RAM. I'd read that Mach 2 can be a bit fussy on Dual processor macines as you can't really run them as "standard PC" and they run by defalt in ACPI mode, which the Mach 2 docs say it prefers not to do. Anyway thought it would be a truer test in relation to the real machine I will use.

In the 1st image it's possible to make out the test Estop lead and on top of the monitor you can make out the base of a small lamp. I used the lamp to test if spindle and vac relays were switching. The second image shows them a bit more clearly.

My Estop is part of the mains input circuit via a relay. On activation the Estop unlatches the relay and power is killed to everything.


Image: Cnt29_TestSetup3.jpg:

This image is a close-up of the BOB. The LED lit up on the right of the image just visible below the Earth lead/s is the power indicator for the "PC Side" power coming over USB. In this instance it's active so that's fine.

The LED lit up on the Left of the image is the indicator for the 5v enabling voltage the BOB requires, coming from the low voltage PSU. In this instance it's also an indicator of the health of the Safety Charge pump function.

The "enable" voltage is only supplied to the BOB if the separate SCHP relay get's 12Khz from Mach 2 and closes.

The LED is lit so that's all good also.


Image: Cnt30_TestSetup4.jpg:

I initially set up 4 motors to test but in the end I used just 1 nema 23 to test both the Z and A Axis functions. Saved me making up another lead.

Also visible in this image is the limit test setup I made. I wired both switches into the same 4 pin plug then split it to "home" and "summed limit" on the socket to BOB connections. Keeps the setup simple with a single lead for limits per axis. The Offlex cable I found has the cores clearly numbered throughout the length of the cable so this was a real help with all the wiring.


Image: Cnt31_BoBTest.jpg:

Closup of the BOB showing step and dir activity and output on the LEDs. Tested BOB in isolation without powering up motor PSU's. Any probs might mean having to poke about inside the case with the BOB powered up. Use of a meter maybe to check output voltages from BOB. Best to be safe when testing, especially with the lid off.

Tests showed LED activity corresponding with Mach 2 Jog controls and DRO activity so again all is fine.


Video: Cnt32_JogTest.avi

Video clip shows correct motor response and activity on 3 axes in response to jogging 3 axes in Mach 2. Have previously performed motor tuning on each axis to get highest motor speed with smooth running.


Image and Video: Cnt33_ProgRun1.jpg, Cnt34_ProgRun2.avi and Cnt35_ProgRun3.avi:

Having run all motors happily in isolation next test was to run a program cycle to ensure all motors will run simultaneously as would be required when machine is operational. Still shows the "roadrunner.tap" that comes with
Mach 2 as the Gcode source.

Cnt34_ProgRun2.avi is a short clip of all 3 axes running. Mach 2 is performing the locate programmed at the start of the roadrunner file.

Cnt35_ProgRun3.avi shows the motors under Mach 2 control as it runs the roadrunner file. Motion corresponds to Mach 2 DRO activity which is only test of motor control which can be made until machine is built.


Video: Cnt36_Limits.avi

Short clip showing correct response when limit switch is operated.


Image: Cnt37_Racked1.jpg and Cnt38_Racked2.jpg:

Having tested out OK the controller, 2 PC's and a KVM swich were installed in a tidy 10U enclosure I've had for a number of years. It's designed so that up to 4 1U modules can also be installed in the enclosure side. The slim white box at the side of the controller is a Compaq KVM swich mounted in the side as described. The last image shows the PC's added to the rack.


Next job

With the electronics and PC side of things out of the way for the time being it's time to hit the mechanicals.

I've recently had some components made as discussed in my accquisitions thread and I've updated that thread with some images of the actual parts.... hoping to have everything ready to start mechanical build by the end of this week beginning of next.....

to be continued........

yohudi
09-23-2006, 10:55 PM
Build_Log Update 04 - 23_09_06 :- Mechanical build -:


I haven't updated in a while but I have still been busy with the build... I've now completed the mechanicals to a basic 3 axis configuration to start with. If/when this tests out OK then I'll add the 4th 5th and 6th axes. I've got pretty clear ideas of how that will work very simply and will fit in with my "adaptable machining centre" goal very well.


Image: Mech01 - 3AxisBuild.jpg:

This image shows the current state of the build. Will detail how I got there below but thought should start with an idea of completed progress.


Image: Mech02 - EndsParts.jpg:

Extrusion, connectors, plates and adjustable feet required to construct Front Leg assembly. The rear leg assembly is identical except for the addition of a motor mount. I ordered all the extrusion pre-cut to specified and matching lengths. There were several reasons for this, the main ones being speed of building and accuracy of finished result.


Image: Mech03 - FootTapping.jpg:

M12 Tap used to create thread for adjustable feet. Machine will be braced to the floor after testing. Adjusters will be for levelling only


Image: Mech04 - FootTapped.jpg:

Height adjuster fitted. Process is repeated for each leg.


Image: Mech05 - LegGussets.jpg and Mech06 - BoschBracket.jpg:

Pre-fitting of gussets and brackets to cross-rails and braces. This allows the leg upright(s) to slide into position really easily. Cross-rails and braces were aligned to measurements derived from CAD as a starting point. Stiffening plates were added after final position was confirmed.


Image: Mech07 - FrontEnd.jpg and Mech08 - RearEnd.jpg:

Machine Sub-frame assembled. Think it's all pretty self-evident from the pictures as to what goes where. In the pics the 5 hole stiffening plates have been mounted at the frame ends and the 12 hole plates have also been setup with 48 T-nuts and bolts to accept the main frame sides.


Image: Mech09 - MainSides1.jpg and Mech10 - MainSides2.jpg:

These images show the main frame sides installed. In the second image the top crossrails have also been added. One of the main advantages of the 8020 frame method is very clear here. When the correct connecting elements are used there is infiite adjustment available at every joint.


Image: Mech11 - XMotor.jpg:

The completed X Axis motor assembly.


Image: Mech12 - XRails.jpg, Mech13 - XGuides1.jpg and Mech14 - XGuides2.jpg:

X Axis linear Guides and rails have been added. Used up over 80 M6 x 20mm allen bolts and T-Nuts to mount both rails, fortunately there were plenty of M6 T Nuts in the job lot of Bosch stuff I picked up on ebay. Using the T-Nuts helps a lot with keeping the rails centered and parallel. You have to watch the torque on the bolts too. It's important to keep to manufacturers spec if you want to get the performance you've paid for.


Image: Mech15 - XYTable.jpg:

The completed XY Table.


Images: Mech16 - Gantry1.jpg to Mech19 - Gantry4.jpg:

Overview of Gantry uprights and lower span with close-ups of assembly method. M12 studs were tapped into the ends of the lower span (as with the height adjusters earlier). I modified 2 of the 8 hole stiffening plates to accept the studs in the centre holes.

I used two 4 hole gussets each side to maintain rigidity and assist with an even transfer of force from the X axis ballscrew. Mech17 - Gantry2.jpg shows the clearance between lower span and main side rails (10 mm).


Images: Mech20 - Spans1.jpg to Mech24 - Spans5.jpg:

These images show method used to assemble gantry upper spans. I mounted the first span having pre-assembled the guides/rail and also having pre-assembled 4 x 8 hole gussets, two gussets to each end. I slid this into position derived from CAD. Next I added the Y Motor assembly including bearings and ballnut/screw.

I used the plate from the Y axis cradle I had made to check ballscrew height and alignment. I didn't have any problems here. The Y axis is built around my own custom parts, the engineering complied with my specs from CAD so this was a nice easy job. This aspect was also important for the fitting of the top span.

Prior to fitting the top span the Y cradle backplate was attached to the bottom set of guides and the ballnut mount. This was then wound away from the motor to the far end of the screw. The top span was fitted with the linear guides/rail and gussets pre-assembled. The motor end of the top span was located by resting on top of the motor mount. The far end was located so that the fastenings in the two top linear guides aligned exactly with the holes in the Y cradle backplate. All was secured and top guides were attached. Alignment and correct function of ballscrew was measured and confirmed.

Took the opportunity to test motion on X axis also. Gantry is getting quite heavy at this stage. Slides nice and freely along X axis but can already notice a good bit of inertia building up during motion. Y axis has similar smooth motion. Really glad I found brand new linear guides and rails.


Images: Mech25 - XScrew1.jpg to Mech29 - XScrew5.jpg:

Fitted the X axis ballnut/screw using following method.

Located X Axis ballnut mount to align with motor center. These were again my custom parts so were made to suit each other. Attached bearings to ballscrew ends. Fastened ballnut to mount and LOOSELY fastened ballscrew bearings to supporting profile, just nipped up. Attached coupling to motor end of ballcrew. Coupling was fitted over motor shaft but not tightened up.

Gantry was wound away from motor to far end of ballscrew. Checked ballscrew for horizontal and lateral alignment. Rotating ballscrew easily shows misalignment as causes coupling to flex. Adjust bearing location at motor end until lateral allignment is correct. Fasten bearing securely.

Loosened bearing off at gantry end of table to determine if height adustment was required at supporting profile. Adjusted out very slight height mismatch. Fastened down bearing securely. Any lateral alignment problems resolved as well during this process.


Image: Mech30 - ZMotor1.jpg and Mech31 - ZMotor2.jpg:

These images show the approach used for the Z Axis motor mount. I realised it was going to be easier to use the rear motor shaft to drive the gearbox. This meant drilling and tapping a couple of M4 holes into one of the cradle support arms, getting a new center collet to use with the smaller gear and filing a slot for clearance on part of the Z axis box.

The second image shows all this completed and Z motor mounted.


Image: Mech32 - ZAxis1.jpg and Mech33 - ZAxis2.jpg:

These images show the method of attachment to the Y cradle backplate


Image: Mech34 - ZAxis3.jpg and Mech35 - ZAxis4.jpg:

These images show the method employed mounting the Makita 3612 router to the Z slide.

I had to mod the router a bit (which was why I bought used one). Handles were removed and 10 mm was trimmed of the handle support lugs on each side. The plastic cover on the baseplate was also removed. The 3612 now fastens to the base of the Z slide usin 4 x M4 allen bolts. 2 x M6 Allen bolts also fasten through the sides of the Z slide into the threads formerly used for the handles. There are 2 lots of the side holes to allow for adjustment for tooling length if need be.


Image: Mech36 - ZAxis5.jpg and Mech37 - ZAxis6.jpg:

Z Slide attached (temporarily) to the Z Axis box. Still need to make actuator for limit switches but can now measure up for this and make to suit. Will need to remove slide to fit.


Image: Mech38 - ZAxis7.jpg and Mech39 - ZAxis8.jpg:

Z slide at full extension (in this configuration). I second pic end of the tool is 25mm above T slot. This is to allow for 25mm MDF Board. Overall travel on Z Axis is 220 mm. However this is not the end of the story. When I take the machine to 6 axis there will be 300 mm travel in Z axis.


Image: Mech40 - XEChain.jpg and Mech41 - YEChain.jpg:

EChain fitted to X and Y Axes prior to running cabling. Is better and neater this way as cables can be measured and located as job progresses.

Next job

Make motor connection leads. Locate and wire E stops and limits. Add MDF table top. TEST PERFORMANCE !!!

to be continued........

diarmaid
09-24-2006, 07:44 AM
Very nice. Its certainly coming along. This thread will be an asset to me later on when Im building a big machine. Thanks. :)

cncfoam
10-10-2006, 08:39 PM
just posting so I can get updates when you update.

Looks good
Eric
cncfoam

project5k
10-14-2006, 08:52 AM
whats the deal on thoes blue gears, where did you get them, how much slack is in them?

yohudi
10-19-2006, 09:43 PM
In the words of the great Austin Powers.. "YEAH BABY !!!!!!!".....Well almost !!

No pics with this info at the minute and just flagging up decent results during initial testing but will edit this and put in pics when I've finished up last bits of pre-cutting work.

Happy to say I've completed all wiring, plugged into the controller and away she went....... As machine isn't yet braced to the floor I've kept the travese speeds down to 25% of maximum just to check motion and limits. So far so good. All axes motion is SMOOTH with NO BINDING. Is a LOT of mass in the gantry so want the machine fastened down properly before I go any further. Was sooooo chuffed to see it move.. still smiling about it now..:rainfro: :rainfro: :rainfro: :rainfro: :rainfro: :rainfro: :rainfro: :rainfro: :rainfro:

will post pics and vids ASAP but just wanted to post results so far.


whats the deal on thoes blue gears, where did you get them, how much slack is in them?

project5k: Thanks for the interest. The gear box, including the gears came with the Z axis unit I bought from German Ebayer.... if you check the link below all info on my parts aqquisition and costing is there.....

http://www.cnczone.com/forums/showthread.php?t=17834

re slack: none that I can detect. There's absolutely 0 play in the Z axis even when coupled via the gear box. The guy who did the engineering on my custom parts remarked on how little play there was in the whole Z axis unit, I left it with him when he made my parts etc...

If I rock the cogs by hand I can't feel any give at all. Will only know for sure when I've had chance to do the dial-test indicator run as described in the mach2 manual. Will be 1st thing I do once I've braced to the floor and got the table on it....


Don't Touch That Dial !!!

nash
10-22-2006, 04:00 AM
Really cool machine.

I've been lurking and learning from all of you... This is a fabulous site. This is my first posting tho...

all the best

yohudi
01-08-2007, 08:54 AM
Really cool machine....

all the best

Nash: thanks for kind words..

have been soo busy since my last update here that I'm remiss in bringing the log up to date.... there has been continued progress.. motion test have continued and I've been programming some G code for the stuff I make (Kids ride-on toys etc).. ALL good so far, no major probs at all and my G code seems to be fine too.

I've generated the code using 3DS Max (my preferred modelling s/ware) and a plugin for it called CNCToolkit. CNCToolkit is excellent and because I have over 10 years 3DS modelling experience I can get a grerat deal out of it immediately.. can optimize my code and preview all tool motion directly in the 3ds environment.. the plugin follows 3ds vertex and spline priority rules so I can make it cut where I want, when I want really easily, or re-order the cutting of any part.. I'd recomend CNCToolkit to any 3ds max user...

re the build:

table top is on now..
is braced to floor...
have completed dust extractor and mounted all that..
I've bought in the last of the rotary tables I needed to go to 6 axis..
I've designed a bolt on plate/ carrier for the B and C axes....
Have come up with mod for Z axis slide to allow additional 100m travel in Z

all build progress completed about the middle of December last year.. since then I've had to focus on other things to the exclusion of everything else..

will post pics and vids when I get some time....

thkoutsidthebox
01-08-2007, 09:53 AM
Yes please do post pics, an overall one would be great.

Is there any flexing in your ballscrews?

What are the overall dimensions of your table? (I couldn't find it posted but haven't read the entire thread yet :) )

What is the working area now that its finished?

Do you have any problems with the 8020 flexing considering the mass of your gantry?

Is the 8020 difficult to assemble?

Do you wish you used steel tubing instead of 8020 and what are the advantages/disadvantages of this? ;) (Im planning to go with steel tubing but not sure why so many people use 8020)

What is your router model/make (I think it says Makita?) and what HP is it?

What speeds are you getting?

Did you order your e-chain from IGUS?

Who did you buy your ballscrews from and what was the total cost of them in the end?

Phew! Lots of questions. :o Great job on the machine....but need more pics to confirm its still in one piece!! :D

yohudi
01-08-2007, 08:15 PM
Is there any flexing in your ballscrews?

None that I can detect.. all motion is smooth with no binding, racking or screw whipping. This was one of main issues I had concerns over but so far so good and no problems to report. I've tried stopping one side of the gantry by pulling against it when in motion (slow motion that is... obviously you don't want heavy gantry running away with you at high speed).. it just pulled me
along with it..



What are the overall dimensions of your table?

What is the working area now that its finished?

Table dimensions are L = 2500mm (2.5 metres) W = 1574mm (1.574 metres)

Cutting area is 1.8metres x 1.4 metres

Gantry width is 1.8 metres.



Do you have any problems with the 8020 flexing considering the mass of your gantry?

Is the 8020 difficult to assemble?

Do you wish you used steel tubing instead of 8020 and what are the advantages/disadvantages of this? ;)

The 8020 (in my case it's UK metric equivalent) shows no sign of flexing anywhere.. I used the heaviest 80mm profile I could find for the longest rails and the gantry spans. Heaviest cross-sectional structure that is...

The 8020 is VERY easy to assemble.. that's one of it's main strengths. If you use the correct connection elements it's much easier, in fact it's the only way I'd consider going.. 8020 derives rigidity from the connection element/s used and the number/size of fastenings at each joint. It's great as long as you assemble it correctly... If you check my construction images you'll see what i'm getting at.

I wish there were a steel version of 8020... :D Would cost a damn sight less in the UK anyway... I investigated using steel framing.. it's all there in my aqquisition thread. It was attractive from the cost point of view but welding and working steel accurately is beyond my own abilities at the moment. This means I'd be paying someone else for a lot of the construction and assembly.

Also if you get 8020 from a reputable supplier who will CNC cut it to length/pallet ship then it's straight, square and dimensionally accurate to start with.

As the fastenings can slide in the 8020 slots you have infinite adjustment to get everything square/level and at the same time all those minute differences between calculated/measured and actual dimensions in components can be accounted for. A lot of the time when people quote you dimensions on components there a specified +/- factor. These can add up and cause you problems in final construction. There's always adjustment to accomodate this with 8020 which is not so easy to do with steel...

finally 8020 helps phenomenally with things like rail, ballscrew and bearing alignment. It's adaptable and forgiving and you can even make design changes and additions after build easily. 8020 just seemed to make the build so much easier and a more practical DIY project.


What is your router model/make (I think it says Makita?) and what HP is it?

It's a Makita 3612 BR model at 3 1/4 HP.. tops out at 23,000 rpm..

I bought this second hand as I knew I was going to cut up the handle retaining lugs to fasten it into my Z slide.. also was some question as to wether this would have the necessary poke to get up to decent cutting speeds.. so didn't want to cut a new one then find it wasn't up to scratch havig obliterated the warranty etc...



What speeds are you getting?

Have yet to determine max cutting speeds/depths.

Have only so far run at 20% feedrate and max cut of 9mm with 12mm bog standard cutter.. to make sure nothing is going to fly off and kill me or anyone else.

I get between 15 - 20 IPM cut at these settings, depending on stock being cut, but this is no way representative of what I should get in the end.... I'm waiting until I hit max performance before posting update/vids.. should be in next week or so as after xmas I can drop back onto build testing.

More than speed I've concentrated on accuracy and optimisation of my Gcode.. read a tag here that said first get good.. then get fast and that's been my philosophy from the outset.


Did you order your e-chain from IGUS?

No, I bought E Chain used from guy in germany.. was much less than to buy new...another ebay find.. but had to use german keywords to locate it...


Who did you buy your ballscrews from and what was the total cost of them in the end?

Ballscrews and matching ballnuts were from german ebayer.. call Akutrac or something like that.. can check if you need to know... he has good length 25mm ballscrews quite regularly.. some new some used... I bought 1 new and 1 used.. both in excellent condition although shipping/packaging could have been better.

If you use this guy then beware the stated specifications.. he's not that accurate and cannot tell a 2 start screw from a single thread. In my case the 2 start screw was exactly what I needed for such a long X axis.. but in all honesty this was luck rather than buying to spec...

final costs of ballscrews, nuts and bearings was £641.16 including VAT and £48.00 delivery charges


Hope the above is of some assistance.. asking questions is only way to make progress with decisions etc.. so no worries there. You can take it from me that machine IS still in one piece .. not about to break something I've spent so much time, effort and money on.. hopefully will have some more pics and vids up next week..

regards

yohudi
01-13-2007, 12:35 AM
will have some more pics and vids up next week..

regards

Have caught up on some testing and piccy taking today.... took some vids cutting at 60 Inches per minute with 6mm cutter. Have upped a pic of the part I cut with this post..

This is quite a crude conversion from the model as I'm still only running the demo of Mach2 with a 1000 line limit. The part program used is 527 lines of Gcode. Going to buy Mach2 now I think.. then can use more subdivisions on the splines to get smoother cuts. Also I'd originally designed the part to be cut with 3mm cutter but I wanted to run with larger diameter while testing.

I'm nervous of breaking cutters at the moment as I've only been using router bits .. have to keep it a bit on the mellow side as not sure what the smaller colleted bits can take.... I can tell by the way cutting went that 10mm cut at this speed would be no prob. I'm now running at about 30% of the MAX machine speed available with current motor settings. Next up is a run at some 18mm stock with larger diameter cutters.

Machine can be seen in motion at the URL's below, all on youtube.com as they are much too big to post here. streaming is not the best but they're ok if you view at the smaller size. If anyone wants the original clips to be certain of correct smooth motion I'll be happy to send them to you.. is about 100MB in total for all 3 original clips:-

Jogging: http://www.youtube.com/watch?v=tiIWU7H7iKI

Reference: http://www.youtube.com/watch?v=rIMY_xcw5qY

Cutting: http://www.youtube.com/watch?v=VoYoQwRnIKU

will be doing normal detailed update over the weekend taking up where I left off previously..

regards

Mr.Chips
01-13-2007, 02:38 AM
Just wondering how the 80-20 bolted construction holds up under the vibration, does it loosen over time? Did you locktite the bolts?

Have some of this material and was wondering how it holds up. It is a super material to build with and make adjustments to.

Since you are just completing your machine you may not have the answers, any 80-20 builders out there with this information.

Thanks
Hager

yohudi
01-13-2007, 08:56 AM
Just wondering how the 80-20 bolted construction holds up under the vibration, does it loosen over time? Did you locktite the bolts?

Have some of this material and was wondering how it holds up. ......

Thanks
Hager

Hi there, thanks for the interest..

I've threadlocked every nut and bolt on the machine with xtra strength RED threadlock. Also many of the 8020 supplied nuts come with either serrated faces to the mating surface or a very thin washer which has similar serrations on both faces. Once they've been torqued up they seem to hold OK.

I didn't apply threadlock to 8020 connectors until I'd checked out the machine as being square straight and level. Then I was able to go over all the nuts and bolts and loosen them one at a time, apply threadlock and then re-torque the fastening. Everything other than the 8020 connections was threadlocked during assembly as a matter of course.

I've had the machine in motion capable form for about a month to 6 weeks. I do check daily to see if anything has worked loose, so far so good...

hope this helps..

thkoutsidthebox
01-13-2007, 10:13 AM
Thanks for answering all my questions. Its much appreciated. :)

Just wondering, do you just screw your board down onto your, I think they were 2x1's, in the video? Or do you use some other form of hold down?

Watched your videos, thats fantastic, I dont know what else to say, it really is fantastic. :) Great machine. :banana:

Mr.Chips
01-13-2007, 02:39 PM
Hi there, thanks for the interest..

I've threadlocked every nut and bolt on the machine with xtra strength RED threadlock. Also many of the 8020 supplied nuts come with either serrated faces to the mating surface or a very thin washer which has similar serrations on both faces. Once they've been torqued up they seem to hold OK.

I didn't apply threadlock to 8020 connectors until I'd checked out the machine as being square straight and level. Then I was able to go over all the nuts and bolts and loosen them one at a time, apply threadlock and then re-torque the fastening. Everything other than the 8020 connections was threadlocked during assembly as a matter of course.

I've had the machine in motion capable form for about a month to 6 weeks. I do check daily to see if anything has worked loose, so far so good...

hope this helps..


Thanks for the detailed posting. I'm sure this will help many people that are thinking about 80-20 type construction.

Hager

yohudi
01-14-2007, 07:13 PM
Thanks for answering all my questions. Its much appreciated. ....Just wondering, do you just screw your board down onto your, I think they were 2x1's, in the video? Or do you use some other form of hold down?

ThkO..T..B

No prob re questions.. had lots of my own questions answered on the zone.. your latest will be answered l8r on in this update... also thanks for kind words.. any encouragement is much appreciated.


Thanks for the detailed posting. I'm sure this will help many people that are thinking about 80-20 type construction.

Hager

Mr Chips.. Likewise.. no probs with requests for details and thanks for kind words..

Having previously posted that I'm now performance testing and put up links to vids on youtube.com I'm completing the update of the log to explain how I got to testing stage.

Image: Wire01 - Earth.jpg to Wire04 - Echain.jpg

Routed all required cables through Echain and made good earth connection to the machine frame. All pretty evident from the pics I think. Where the leads exit the Echain I've used spiral wrap to keep the Motor and Limit wiring grouped by Axis and to provide protection. The thick black cable running up the gantry upright is the 240V feed to the spindle.

Image: Wire05 - Xmotor.jpg

Routed X motor lead using slots in 8020 to locate the wiring, another plus for this approach. Really easy to position wiring out of harms way and secure using cable-ties around the framing. Also means it's very easy to replace or re-route wiring in future.

Image: Wire06 - XLimit01.JPG to Wire09 - XLimit04.JPG

Decided to locate the X Axis limit and home switches at ends of the gantry lower span. Pics show triggering method using block attached to inside of framing.. X Limit 04.jpg is a clearer image of one of the blocks. Other images show routing of wires for X Axis switches. I had to use a junction box in the centre of the gantry because of the short leads supplied with the switches. They have a proprietary Telemechanique connector so was easiest way to get around this problem. Wire for Estop (orange wire) and Y motor can also be seen routed along the lower span of the gantry.

Attaching X axis limits to the lower gantry span gives the simplest, most accurate and reliable performance. It also allows the option of easily adjusting the home or limit position by moving the trigger block along the 8020 slot.. good old 8020 again !! In addition When the gantry is in the Home position this allows access to every part of machine wiring via the lid/hatch incorporated in the table top.

Image: Wire10 - Estop.jpg to Wire12 - Estop - Ymotor02.jpg

Close up of Estop location, attachment and wiring. Orange lead is just visible inside the 8020 slot. Machine also has a keylock EStop which is located by the computer/controller to provide protection from the operator position.

Wider views show wiring to the Y Axis motor. Another black plastic junction box accomodates the connection to the motor wires. The 2nd image shows Y Axis motor lead routed in 8020 slot. The white rings evident where the cables enter the box are my el cheapo strain relief method, using a cable tie tight to the flex, to prevent the cable moving in or out of the junction box.

Image: Wire13 - YLimits.jpg

I'd intended to use two Telemechanique limit switches on the Y axis but in the end I opted for a couple of micro-switches. They were lighter, easier to mount and perform just as well. Triggering is via an adapted 8020 90% connector fastened to the Y Axis plate, I filed the triggering edge flat.

Image: Wire14 - Z-Motor - ZLimits.jpg and Wire15 - ZLimits.jpg

Detail of Z Motor and Limit connections and view inside the connection box. 2nd image shows Z Axis switch trigger method, by block attached to top of Z slide. Similar block triggers the lower limit switch.

Image: Wire16 - Spindle.jpg

Pic shows connection for spindle using 240v IP44 Plug and socket. Eventually 5th and 6th Axis will sit on sliding plate similar to existing Z slide. Means I'll be able to go from 3/4 Axis config to 6 axis by unbolting existing Z slide and replacing with one carrying 5th and 6th axis. Will use similar plug in approach for the motors on these axes.

The reason behind the above is that some of my planned work requires cutting of multiple parts in quantity from larger stock as fast as possible. That would be using machine pretty much as it is with ability to run heavier cutters at estimated minimum of 80 to 100 IPM feedrates.

I also want to be able to carve/etch detail on stock and assembled pieces for customisation of product. I can then charge extra for this or build it into pricing as value feature. Carving letters and image detail will use smaller lighter spindle and 5/6 Axis setup to allow relief carving in one pass.

Image: Wire17 - Complete.jpg and X00 - LegBracing.jpg

A overview of full machine with all wiring and bracing to floor completed. A clean, tidy and safe job made a lot easier by the slots in the 8020.

I did the "YEAH BABY !!!" (see below) motion testing before I'd made the leg braces. Once the machine was capable of motion I wanted to make sure everything worked immediately.


In the words of the great Austin Powers.. "YEAH BABY !!!!!!!".....Well almost !!


I used the diagnostic page in Mach2 to ensure the Estops and Limits were all functional then powered up the motors and hit the jog buttons. Smooth groovey motion as mentioned already.

Mass and buildup of momentum in gantry suggested it would be wise to brace to the floor before going further with testing. Made the largest braces I could fit in the space available, better to overdo the bracing if anything.

Image: X01 - DustXParts.jpg to X04 - DustXAttach.jpg

Assembled the parts shown to create dust extraction hose of correct length. Had previously decided to route the hose by attaching to Echain with large cable ties. Seemed the easiest way to enable tracking with the cutter head. This can be seen clearly in rest of this image series.

I made the brush edge of the extraction hood using bog standard draught excluder strip. Measured around the Z Axis base and dust spigot and cut slots in the draught excluder to allow bends in correct places. Drilled Z base plate to match and screwed into place using threadlock on all fastenings.

The observant will also see that I've applied similar brush strips along the frame sides to act as covers for the XAxis guide rails.

Image: X05 - TableTop.jpg to X07 - TableStock.jpg

I was unable to source slotwall MDF without excessive delivery costs. Was also suggested to me that the slots would deteriorate really quickly if they were used to secure any type of serious clamping. Realised I'd have to come up with something else.

In the end I made up the tabletop as follows:-

used 2 layers of 20mm thick flooring grade chipboard. Bottom layer runs along the length of machine and top layer runs across i.e at 90% to bottom layer. I used PVA and suitably placed screws to unite the layers as top was assembled. Removed the screws when glue had dried. Top was secured to framing sides from above by screws through bottom layer of chipboard. Screws were then covered by top layer

I fastened to the table crossbracing from underneath the machine ensuring screws did not penetrate more than 30mm into the combined 40mm chipboard. The space at the rear free of ribs (see X03 - DustXAttach.jpg) is the access hatch. X06 - TableHatch.jpg shows this from below.

There was some light sanding required to remove any unevenness at joins. Did this carefully checking using straightedge to make sure table top remained flat. Sealed chipboard with 3 coats of polyurethane varnish to reduce any warping due to humidity.

Once varnish was dry I added the sacrificial ribs which are 20mm wide and 12mm thick with 4 counterbored screw holes per rib. Counterbore is 7mm deep. I opted for this approach as there will be a lot of through cutting in work I'm planning. As the ribs get cut away over time it's very easy to replace them and won't cost a great deal. I can also fill in the spacing between ribs with packing if I need to eliminate deflection in any given cut.

In testing I've secured small stock to the table simply using screws as in X07 - TableStock.jpg. I pre-drill checking that screws will not intrude on cutter path and that they pass through the ribs and into the tabletop. For larger sheets of stock the 8020 slots on the top edge of frame sides are still easily accessible along the full length of the framing. Use of these will still allow free travel of the gantry.

Image: X08 - RackConfig.jpg

Mach2 has run without problem on the dual PIII machine I've used during testing. However, this is an ACPI system. Mach2 manual says is better to use a non-ACPI system. I've built a 1.4Ghz AMD Athlon machine into the top 2U case with the 4 visible drive bays to allow for this should I need it. 2 systems mean I'll be able to convert and check Gcode without interfering with cutting.

Picked up a 1U slideout Dell TFT monitor and keyboard to reduce the required space when fully operational. It adds a bit of class too I think. KVM switch allows both systems to use this without problem. Keylock Estop is visible on top of rack, nice and handy when operating.

Image: X09 - Cutting01.jpg to X11 - Cutting03.jpg

Some pics taken during the performance testing. First 2 show the toolpath in Mach2 and last is pic of the cut part. Allowing for the fact that cutter used was 3mm oversize in diameter the part measurements match the toolpath to a point where I cant measure any discrepancy by eye, which is certainly good enough for woodworking. The vids I posted on youtube show this test in progress, the links are repeated below.

Jogging: http://www.youtube.com/watch?v=tiIWU7H7iKI

Reference: http://www.youtube.com/watch?v=rIMY_xcw5qY

Cutting: http://www.youtube.com/watch?v=VoYoQwRnIKU

Next job:

Next job is to get the 3 rotary tables I bought knocked up into 3 axis drives.

I have a neat idea for the 4th axis which will run parallel with the gantry spans and will be ajustable to cope with different stock length. 5th/6th will be mounted to Z Slide as mentioned earlier. I'll post the CAD renders for these when I get a minute.

Also plan on perfoming true costing of build to the 3 Axis stage. Oh and of course I'll be running/testing the machine further. Have to create the Gcode for multiple part runs from large sheet. This will probably be the next time I update with video, when I'm testing a multiple parts cut.

Would like to say a quick thanks at this point to all the people at the Zone who have shown interest in my build especially those who offered advice.

This machine would not exist were it not for the information I gleaned here. Madvac build springs particularly to mind as well as CNCfoam and all the other folks who steered me right in the beginning when my plans were a bit adrift (see aqquisitions thread).

Thanks are also due to Bruce at Range engineering in Chirk, UK who made all my custom parts. Kevin at Marchant Dice for supplying precut 8020 framing and ballscrew bearings. The folks at Motion Control, Bournemouth, UK were V helpful and their drives are certainly up to the job. Arturo Duncan (CNC4PC) supplied the BOBs, SCHP and other PCB's. My other suppliers were many and varied but each has helped in their own way so they all deserve a nod.

Development of machine will continue so keep on checking, won't be happy until I'm running all 6 axes...... Would encourage anyone reading this and thinking of building a machine to GET IT ON !!! You won't regret it !!!

Mr.Chips
01-14-2007, 07:53 PM
Yohudi,

You have so many quality pictures posted I almost hate to ask for one more.

But the next time you are taking pictures I would like to see a side view photo of the "Y" Axis (Vertical axis), I see the X and Y interchanged so much I never know which is which. Now "Z", I got that one down pat.

I want to see how you built it having two vertical pieces and how they are connected/braced together. Cannot see it clearly from the angle side shots.

Thanks
Hager

yohudi
01-14-2007, 08:21 PM
I would like to see a side view photo of the "Y" Axis (Vertical axis), ........ see how you built it having two vertical pieces and how they are connected/braced together. Cannot see it clearly from the angle side shots.

Thanks
Hager

Mr Chips...no probs.... will happily do that... in the meantime the CAD renders from my aqqisitions thread might help... see the three links below

Table (XAxis) : http://www.cnczone.com/forums/attachment.php?attachmentid=17631&d=1146304227
Gantry Front View (Y Axis) : http://www.cnczone.com/forums/attachment.php?attachmentid=17629&d=1146304227
Gantry Rear View (Y and Z) : http://www.cnczone.com/forums/attachment.php?attachmentid=17630&d=1146304227

If you then relate these back to the photos all should become a bit clearer.... I'll still up the side view next update to be sure tho..

regards

Danny

Mr.Chips
01-14-2007, 08:38 PM
Mr Chips...no probs.... will happily do that... in the meantime the CAD renders from my aqqisitions thread might help... see the three links below

If you then relate these back to the photos all should become a bit clearer.... I'll still up the side view next update to be sure tho..
regards
Danny

Thanks Danny,
That does make it clearer. Looking forward to more pictures.
Hager

thkoutsidthebox
01-15-2007, 08:26 AM
:cheers: Im just wondering about your dust extraction. That looks like a regular shop vac.
1) Does it have enough 'uumph' to suck all the chips out from the spindle area?

2) I notice your 4" is connected directly to the vac. Did you adapt the vac yourself to allow the 4" hose, or did it come like that?

3) Dont suppose you know what cfm its rated at?

Thanks. :)

yohudi
01-15-2007, 06:39 PM
:cheers: Im just wondering about your dust extraction. That looks like a regular shop vac.
1) Does it have enough 'uumph' to suck all the chips out from the spindle area?

2) I notice your 4" is connected directly to the vac. Did you adapt the vac yourself to allow the 4" hose, or did it come like that?

3) Dont suppose you know what cfm its rated at?

Thanks. :)

Hi there...

you're right it is a 1200w wet and dry vac.... I've no idea of the cubic capacity per minute..... the hose is 3 inch. I bought the vac first, measured the coupling and bought hose that would fit directly over it.. secured it with a hose clip of suitable diameter.

I do have a "pro" dust extractor on a trolley.. but it runs off a 3 Phase soft starter with a zero release switch and all that.. I would have to effectively break it open to have mach2 switch it on/off using a relay... and being honest I'm not that sure of my electrical skills to make it all work

I got the VAC in the pics for about £20 to £30 if I remember correctly... brand new and with warranty. thought for that kind of price I'd try it.. see how it went. if it's not up to the job then I'll use my normal extractor and switch it manually... if that was the case the the VAC in the pics is usable individually on most of the other machinery in the workshop, which I've already tried...

I can only speak for the tests I've run so far... and as you can see in the cutting video there's very little dust or chips left on the job or the table. Will only know for sure when I've run some more serious cutting or some deeper non-penetrating cuts. I think the use of the ribs on the table help a lot with the chips from through cutting anyway.... anything the vac doesn't get drops straight between the ribs...

basically as with most other things it's all a case of try it and see...

regards:wave: :wave: :wave:

eloid
02-24-2007, 10:19 PM
yohudi

can you show a close up of your ballscrew for you x, y axis
whats the outer diameter of the ballscrew..whats the model of it is ie specs
how may thread per rev etc

can u make video showing how fast can it go just homeing, without cuting
joggging back and forth from x to y and z

want to see the speed of these ballscrews lol

yohudi
02-26-2007, 08:59 AM
yohudi

can you show a close up of your ballscrew for you x, y axis

can u make video showing how fast can it go just homeing,

want to see the speed of these ballscrews lol

Hi there, thanks for your interest..

I will post close up images of ballscrews as you requested next time I send pics.. also vid of it homing.. all my motion calculations inc ballscrew and motor spec are in this thread

http://www.cnczone.com/forums/showthread.php?t=17834

It's the same one I sent in response to your PM. Just put it here in case others have similar questions.

Using the ref all function in Mach2 the diagnostics screen reports a blended motion rate of just over 5.6 metres per min (220 IPM). However I am restricting the motor speed at the moment to about 40% of their maximum capacity. If I ran them flat out then the mass of the gantry would definitely mean there would be some damage.

I've done quite a bit more cutting with the machine and had much repeated success through cutting 12mm (1/2 inch) thick birch plywood at 2540mm/min (100 IPM) with all cuts remaining dimensionally accurate. The tooling used for this was a titman 3/8ths twin flute router bit on 1/2 inch shank. I've just got some carbide fluted cutters so I need to run some test cuts with these to see if I can cut deeper or faster with them.

At the moment I'm developing and refining my GCoding to layout multiple parts on large sheets. Also I've been working on some carving cuts and also a layout of some of my product which will combine through cutting and carving.

I've no previous experience in GCoding so this is a trial and error process for me which can drag it out a bit. Some of my GCode files are hitting 7500 lines, so it's just as well I'm not writing them manually, although I do have to check them manually

will post images/video requested next time I get 5 mins...

regards

mhasting2004
04-28-2007, 05:03 AM
First off... awesome job!

I too am in the build/design stage of a large 8020 gantry router and this thread is just a goldmine of info. Much apreciated.

I'm making a 1.4x2.5M table with future plans like you to have a 4th axis rotary chuck for round stock work and a 5th and 6th axis on the Z for fancy work.
My design is somewhat driven by the parts I have as we decommissioned a lot of gear hear at work and I've been very lucky to get 90% of the components for nicks. But it does mean I have a problem as to whether to use the 2.5m ballscrew I have or not. Its a 5mm pitch 32mm dia bosch screw and nut which would be a bit slow but really accurate. I am still thinking of doing a dual belt drive system (similar to a rack and pinion with the belt not moving but the motors "climbing" along) yet this will be very fast and less accurate / strong...decissions decisions.

My main concern with the central screw design is that the table is unsupported for its full length.

Other points of debate are whether to have the gantry made from horizontally place 8080 extrusion with the Z axis carriage slung between them or vertically like your design. It would be stiffer in the X axis but less in the Z and a lot more resistant to skewing. Another factor is the THK ball slides I have look more intended for the load being placed above them rather than on the side.

One other thing I see alot of discussion on is the whip in a ballscrew... why do people drive the screw on these larger machines... drive the nut! Less inertia as the motor weight on the gantry is far less than the screw in these lengths. much less load on thebearings I would suspect also as the screw is fixed and held under tension and the bearings on the ball nut only need to resist the driven force. Just an idea.



One of the great advantages I see with the 8020 construction is if I do go for a dual drive and it doesn't pan out I can fairly easily rebuild in a new configuration.

As I have been lucky enough to get practically all the components very cheaply I want to get to proof of concept without too much $$ outlay plus I have people chomping at the bit to get this thing working so that they can start giving me jobs. So, is the dual drive belt idea feasible or a waste of time (I have the ball screw and would need to purchase the belts)and not the faster route to completion I think it may be.

Thanks

Mark

Robert M
04-29-2007, 12:28 PM
Hi Yohdi,

I second “mhasting2004” as this is very nice of you to take so much time detailling all your effort. As you so well pointed out in your Format & content, you have accomplish the mission ; “I'm going to try and make this log the one I would have liked to have found when I was looking for information.” Thank you for it !

I too in the same boat today as you where back in your early “newbie days” and even closer to mhasting2004 future built.
I’ve been “flirting” around some others design & type of Diy CNC’s for the past +/-6mo for some source of inspiration to make my own version too. Same here, got also inspired by MadVac but I would also include your too !!

I’m in to this hopping to achieve making what looks to become a 5’ x 10’ router table with a lathe (4<SUP>th</SUP> axis ) imbedded in the “ Y ” axis as a CNC Wood router / lathe combo.
For this type of design I figured no under mount gantry ballscrew type. Rack & pinion on both side will simplify the chassis design & making it stiffer !
No Aluminum base table because of the imbedded lathe chassis, but for sure the gantry will have some of it hopping to lighten it !

Anyway, All this to share some upcoming fun with some of you guys but also hopping to get from you some questions.
1) – Can you tell me in what software you drew those nice electrical plan of yours. Could your share those in their original format so I may use them as a base ?

2) – Why did you go with “Motion” for your motor drivers? Why not Greco, has it seem the popular choice ?

Excuse me for yet not totally read all ( both mains logs of your built) threads as to maybe my Q could be answered ?
Robert M

yohudi
05-19-2007, 10:29 PM
Hi there all,

News

I've been a bit busy over the past few months what with learning how to use my machine. It's more the GCoding that I've been getting my head around as most of my work is art and toy related as opposed to engineering or mechanical. It can be pretty difficult to Gcode some of the more freeform stuff.

I was using a plugin for 3DS Max called CNCtoolkit.. which is a great method of deriving GCode especially for 5 axis setups. However, I've recently bought Cut3D from Vectric. Being honest it's MUCH better for 3D object to GCode conversion for a 3 axis system like I have at the moment. It's a lot faster and MUCH more intuitive with the software doing a LOT more work.

Only other change I've made since I last posted is to swap out the Vac I was using for my main shop Vac. The little Vac was great on the thinner stock but just couldn't deal with thicker and higher speed cuts. Other than that all is as it was and still working fine etc.

To reply to those who have posted recently.... First of all Mark


First off... awesome job!

I too am in the build/design stage....... I have a problem as to whether to use the 2.5m ballscrew I have or not. Its a 5mm pitch 32mm dia bosch screw and nut which would be a bit slow but really accurate.......

First of all thanks for the kind words.... got a lot of inspiration and help from people at the zone myself.. it's nice to know that folks are getting something out of my own log at this stage.

re: your ballscrew conundrum.. One of the best bits of advice I got about my machine was from Ger21 here at the zone. He pointed out that the original 5mm pitch screws I was planning on using might be too slow for the amount/rate of travel I was intending.. he was 110% right about that. I'd have needed to run the motor flat out to get the kind of motion rates I'm using at the moment which would in turn have upped the potential for whipping problems.

I was lucky to pick up the 25mm (effective pitch) ballscrew on the X axis of my machine... The higher thread pitch means that for a given rate of travel the motor speed is MUCH reduced. I don't get ANY whip in the ballscrew at all, even when rapids hit 5 metres per minute. It also means I'm well in the lower range of motor speed so I get maximum torque from the stepper. I wouldn't worry that much about accuracy vs speed.

Most drives should give you the step multiplication to get high accuracy from higher thread pitch... and software pulse rate can always be stepped up to keep good speed within reach..


I am still thinking of doing a dual belt drive system (similar to a rack and pinion with the belt not moving but the motors "climbing" along) ......

For a ballscrew length of 2.5 metres then I'd tend to agree with you re: an alternative drive method. I'm not really qualified to comment other than my own build experience. My ballscrew is only unsupported over a length of 1.8 metres even though it's 2.0 metres long.

According to the official Bosch/Star/Rexroth datasheet, the maximum length for the screw/nut I'm using is stated as 3 metres, maximum rate of motion is stated as being 12 metres per minute. I would see what they say in their technical data for your screw/nut configuration and factor that into my decision making.


Other points....... whether to have the gantry made from horizontally.... or vertically like your design......

In respect of this I'd say that I tried many different configurations in the design process and settled on the one I'm using as a result of the following:-

1. I saw a similar design for a wood-cutter by CNCfoam posted here at the zone. He reported good results and no problems.... I took the approach that if it worked for him it would work for me and so far this has held true.

2. I checked the published info on the Bosch/8020 extrusions. If you commit to using the Bosch/8020 extrusion for framing then you MUST fasten it together appropriately.. 8020 derives it strength and stiffness from fastening methods employed. A lot of people skimp on the connection elements and fastenings... they can be expensive.


Another factor is the THK ball slides I have look more intended for the load being placed above them rather than on the side....

I considered this approach also... I was lucky to pickup brand new linear guide/bearings that are rated for "super heavy" load. Again I chased the tech data and discovered that I could use them top, side or even bottom mounted with little impact on performance. Side mounted made some other things easier so I went with that.


why do people drive the screw on these larger machines... drive the nut!.....

I did think about this and found a few "driven nut" systems out there. The commercial setups I saw all used special motors... no motor shaft with the ballscrew running smack dab through the the motor/nut combination.

Commercial setup was beyond my pocket... and I just couldn't see that anything I made or had made would give me the same rigidity and security of connection as a solid ballnut mount with a driven screw. At least not for anything like a similar cost.


One of the great advantages I see with the 8020 construction is ......I can fairly easily rebuild in a new configuration.
.....is the dual drive belt idea feasible or a waste of time......

I think you've partly answered your own question..... You have ballscrew and nut already. 8020 is easy to build and adjust if not right.

You could easily employ a frame design that would allow you to try the ballscrew setup you already have and then if you do have probs adjust fairly simply to your alternative "belt-drive" method or rack and pinion.

To be honest on a large machine if ballscrew/nut is problematical I'd think more of rack and pinion than belt drive. Large gantry = lots of mass. Don't know how well belts would work stopping something like this. A lot of the time it's stopping or changing direction quickly where drive mechanics give probs...

For my build I bought two identical X axis drives and steppers just in case I needed to go the rack and pinion route myself. So far I haven't seen any need to change any of the drive mechanics.

Hope at least some of the above is of some use to you..... best advice I can suggest to you is chase the tech data on any planned components. This will always shed a bit of light on your proposed usage...



Hi Yohdi,

Hi Robert..



I second “mhasting2004” as this is very nice of you to take so much time detailling all your effort..... you have accomplish the mission ;
“I'm going to try and make this log the one I would have liked to have found when I was looking for information.” Thank you for it !......got also inspired by MadVac but I would also include your too !!

Hi Robert.. thanks for your kind words.... I MUST say that in terms of mechanics, engineering and CNC in general I am not worthy of being mentioned in the same sentence as Madvac..... high praise indeed.... but nice to know the log is of assistance... regarding your questions:-


– Can you tell me in what software you drew those nice electrical plan of yours. Could your share those in their original format so I may use them as a base ?

I drew the original schematic in 3D Studio MAX. 3DSMAX has some excellent 2D drawing features. I could export the schematic to a DXF and send you that if you think it might be helpful to you. Alternatively I can render out the final output at a very high resolution and send you that. Either way you are more than welcome to use it.

I MUST point out that although I have had no problems whatsoever with my controller design or function I AM NOT QUALIFIED IN ELECTRONICS DESIGN OR ASSEMBLY. You would be using my schematic entirely at your own risk !!!


2) – Why did you go with “Motion” for your motor drivers? Why not Greco, has it seem the popular choice ?

I chose the "Motion Control" drives purely because I live in the UK. I looked for supplier of Gecko's in the UK who could offer swap-out warranty and immediate replacement from within the UK if I had problems. I was unable to find anyone to do this.

Most of the people I asked suggested I buy direct from Gecko in the USA. This would mean that any support or replacement was too far away as far as I was concerned. I looked for a UK drive manufacturer of equal power and quality to Gecko's and Motion Control had the best overall product IMHO. Also one thing I did like about Motion Control product range was the dip switch configuration. As I am new to all this I didn't trust myself to be adding resistors to current limit the Gecko drives

hope this helps you out.


All:-
I will add some more photos and a couple of more videos of machine in action in the not too distant future... I think it's always the same thing, once you have a machine built you shift focus to using it instead of taking photos etc. I invested a lot of money in this machine so concentrating on getting my own skill levels up to standard using it... I haven't forgot the help and encouragement I got at the zone.. so I will keep the faith and update as and when I have any news.. or if people ask questions etc.

Until then...TTFN my CNC brethren !!!

yohudi
06-03-2007, 06:40 PM
Definitive Performance Test:

I've finally arrived at a point where I can give the machine a run at something serious and give realistic assessment of speed, accuracy and repeatability. I've upped the gantry side pic Mr Chips asked for a while ago (00Gantry-YAxis-Side.jpg).

So, I'm just about to run my 1st detailed job and the machine starts playing up. Consistently losing accuracy along the y axis, losing or gaining over 5mm. Nothing had changed re any controller settings... came on quickly.. in between jobs....

Reset everything PC and controller wise. Then checked mechanicals... everything OK nothing moved or loose.. began to suspect ballnut/ballscrew on Y axis.. Is only major component I bought used.... could find no explanation so priced up a replacement brand new... £ 400+

Before laying out the large pennies decided to strip out the Y axis ballscrew and nut to examine it in isolation.... prove it's at fault. In process of doing the stripout was clear that the ballnut definitely had a different feel to it... very loose on the thread.. would run down the thread under it's own weight if held vertical... wasn't like this when it went in... Examined the ballnut which has adjustable preload. When I checked the preload the adjuster bolt definitely had play in it... not much .. about 1/6th of a turn before I felt any kind of bite.

Thought could do no real harm if I adjusted the preload so I couldn't easily turn the nut using my fingers.. then backed it off just enough so I could then turn freely. Held the ballscrew vertical and ballnut remained in place.. just like it used to be. Reassembled the Y axis and ran some quick tests. Accuracy right back where it was originally. Thought there's only one way to know for sure so I ran the job below....

Decided that if this was going to be any kind of test then I'd go out of my way to make it challenging enough to settle all doubt.. thought that in keeping with my show how it is approach I'd do it with decent pics etc.... also document my work method to see if anyone can suggest improvements to get more from the machine in less time etc....

What to Cut ? (01-HiresMesh.jpg + 02GCode.jpg)

I've recently bought Cut3D software from Vectric.. CNCToolkit is a great GCode generator but Cut3D is much more useful to me. Gives me GCode to the level of my design abilities without me knowing a great deal about CNC methods and practices. Having Cut3D meant I could use a serious model.

Cut3D slices the object and GCodes the slices depending on stock and specified tooling. The image Shows the full model and the 3 finishing paths generated. Getting the GCode is a matter of minutes.. I sized and sliced the model so the finished job would be 600mm x 450mm x 68 mm. A fair sized cut in order to test the machine fully.

Stock (03-Stock.JPG + 04Prepped.JPG)

Stock is 23mm "void free" birch ply but there are still voids in it. Wanted to run the cut on something that would put up a bit of resistance. MDF is the stock to use for a job like this as you get a much better finish. However, as I was testing the machine I wanted to cut some timber.

Stock has been cut 100 mm ovesize with centres marked. This gives me a good clearance and makes for easy location of fastenings. Fastenings are pre-drilled through the stock.

Setup (05Align.JPG - 07Reffed.jpg)

I use a laser line for fast alignment on the table. Job will be completed without removing so no realignment issues. If I cut job which is removed and returned to the table I align, fasten down and then block up to the corners of the stock. Goes back into same spot no problem..

By rights I should have merged the GCode to a single file, using offset stock positions. This would mean that on my large table I could have cut all 3 pieces in one setup. However, I haven't yet learned how to do this.. and so I setup 3 times for this job.. but takes a couple of minutes maximum and will add the missing skills to my reportoire ASAP.

I have the machine setup in Mach2 with stored locations for my tooling. This job has 50mm leeway in stock size so X and Y zero isn't a matter of life and death. I always check Z position on stock by using a sheet of paper and touching. When it's just gripped by the tooltip I back off 0.1mm remove the paper and check/update Z position.

The Cut. (08RToolpath.jpg - 18Stacked.jpg)

Spindle speed of 23000 r.p.m. and feedrate of 2540 mm per minute (100IPM) throughout.

Tooling was 12mm Endmill for all the roughing at 6mm cut depth. This was to allow for the various levels in the roughing. For finishing, 6mm ballnose was used on smaller pieces and 12mm ballnose on the largest. 8% stepover setting on each of the ballnose. Don't and won't see the benefit of this on plywood but was looking to thouroughly test machine over time. 8% stepover doubled the finishing time for all parts in effect. .

Total runtime including stock setups and tool changes was about 6 and a half to 7 hours for all 3 parts. With 15% finishing stepover would have been cut in about 4 hours max.

Machine performed well. No re-occurance of Y axis problem. I've put order of replacement ballscrew on hold. When I cut part3 (with the nose) I did a 2nd (unnecessary) finishing pass at 5% stepover setting.. needed to see if machine would make accurate 2nd finish path. Delighted to say no problems with anything and positioning remains accurate. I'm also happy that repeatability is more than adequate as there were no faults at all on the 2nd pass testing I did..

Had an issue with the roughing toolpath on the largest piece, see 17FinishedAll.jpg. Issue is software or model related and it didn't happen in any of the other 5 paths I ran. I must have clipped faces from the model by having the slice plane a little low, Cut3D would process these as gaps (I think). As a matter of interest I could have just run the finishing toolpath on this slice. 99% of this piece was cut from unroughed areas of the stock.

The faults I've circled on the largest piece come from the roughing pass for this piece and can be seen in being cut in the image 15Roughing1.JPG. The finishing pass for this piece expected stock to be left here and it wasn't.

Conclusions (19UthaStuff1.jpg + 20UthatStuff2.jpg

Well overall I'm pretty pleased. Machine performs as I'd hoped and has good accuracy and repeatability, certainly good enough for the kind of work I'm doing and planning. Reliability is my only issue at the moment, will have to keep an eye on the Y axis ballscrew.. but everything else seems to be OK a good few months since I finished the build. Hopefully it was just the preload adjustment had slipped on the Y ballscrew.. only time will tell.

I have previously used machine to make other large Items.. I've included pics of a couple of things. I produced the code for the ride-on stuff using CNCtoolkit.. However this method of coding was slow for me. I didn't know enough about accepted CNC procedures and approaches to get a decent workrate out of it.. more scratching head than cutting wood at times.

Cut3D has allowed me to instantly explore the full potential and performance of my machine so my workrate and production times will see vast improvements....

Can seriously focus on adding the 4th axis in near future.. hopefully 5th and 6th won't be too long either. Other tweaks will be mounting for smaller (detail) spindle/s.. Going to move the dust collector head to the front of the spindle plate... will be about 50% more effeicient there as will catch the chips as they are thrown off the tool.

Would be interested in any thoughts or comments re performance and or methods..... also any similar experiences re ballscrew preload etc.

Regnar
06-03-2007, 07:46 PM
Great work!!!!! Where do you get the plans for the motorcycle and donkey? Again great work I am truley looking foward to see more of you work!

walter
06-03-2007, 08:41 PM
Great thread!
_

yohudi
06-04-2007, 07:48 PM
Great work!!!!! Where do you get the plans for the motorcycle and donkey? .........

Regnar.. thanks for the kind words... encouragement is a big plus when it comes to keeping the log going.. nice to know that folks are still checking it out.

I made the plans for the motorbike and the donkey.. they are inspired and influenced by stuff I'd seen on the web, which I've then modified to suit my own inclinations etc. I had originally planned to make them by hand but CNC is much more cost-effective and better quality job.

hope this helps

....

yohudi
06-04-2007, 07:50 PM
Great thread!
_

Likewise.. thanks for the kind words.. glad you like my thread..

yohudi
06-04-2007, 08:03 PM
Well actually no I'm not kidding...

see the image and check out the link below.. then follow the link to the free download... also check some of the example and user gallery scans...

http://www.cs.tu-bs.de/rob/david.html

so what I'm thinking is... mount USB webcam to rear of gantry in fixed position. mount laser pointer/ line projecting device to Side of Z axis Facing rear. Make 90% corner I can stand object in front of...

program a smooth movement of the Y or Z axis to laser scan the object in one of 2 directions depending on object size... USB camera is held fixed and solid to get spot on footage of the scan.. david does the rest....

doesn't this mean that anyone with a CNC machine a laser pointer and a webcam can do the same ? ?

yohudi
06-19-2007, 08:18 PM
Decided to run my Test job again to check my understanding of the problems I had last time and to see that I had all these issues resolved.

I had mail from Tony at Vectric re: the problem I experienced. As a result of this test I'm 110% certain that I caused the roughing problem myself last time around.

I've put multiple job approach into regular working practice. Minimise setups and tool changes. Cut3D makes this easy. It's a simple but really useful feature. All in all I remain totally impressed with this software and the support also.

Anyway enough chewing the fat and on with the job...

The Model: Image- 01 - 3DPlaque.jpg

Problem last time was combination of the model structure and my settings in Cut3D. I'd scaled the model in the Z axis to fit on 3 pieces of stock. When combined with my slice settings in Cut3D this caused the roughing problem. This time I made alterations to the model to prevent problems and used stock that meant I could live with the native model aspect ratio in all axes.

01 - 3DPlaque.jpg shows alterations I made in 3DS MAX environment. A is the original mesh. B is the mask portion of the model after subdivision. This increases the resolution of the model, reducing the possibility of face destruction. C shows the addition of a simple frame made from boxes and squashed spheres. D is a viewport render of the model confirming it is intact, no incomplete faces.

Cut3D Processing: Image- 02 - Slice.jpg and 03 - Process.jpg

02 - Slice.jpg is part of the Cut3D processing. I've left the image large enough to read the model dimensions. I decided on 18mm slices to suit some chipboard offcuts I had left after I made the table top for my machine.

03 - Process.jpg shows the process of getting the GCode out for the slices. A and B show the calculated roughing and finishing paths respectively. C and D are previews generated to assist in checking the path.

Cut3D generates suitable paths for multiple setup if the origin position for each slice is suitably adjusted when processing. This is taken into account when generating GCode. Resulting output can then be cut and pasted together in any order. One setting.. so easy... just takes a little thought during processing.

The Multi-cut Setup: Image- 04 - Machine.jpg to 07 - Multi.jpg

04 - Machine.jpg, a picture of my machine, what else ;). Shows the multiple setup. Can also see the heavier duty dust extraction in use.

05 - Stock.jpg, the pieces prior to setup. I marked the position of the origin for each piece (the asterisk in a corner) and the fastenings. I usually allow a standard 100mm oversize on all stock and fastenings 25mm in from each edge. This allows 25mm clearance between fastenings and toolpath centreline wherever it might be in the stock.

06 - Align.jpg is first piece setup and aligned using laser line as normal. Get this right and the rest are really easy to setup.

07 - Multi.jpg shows all of the stock setup with roughing about to commence. The origins of the pieces are arranged to match the order and positioning I opted for when processing the individual slices.

The Combined Toolpath: Image- 08 - Toolpath.jpg

A shot of the Mach2 screen as roughing is nearly finished. Feedrate, speed and runtime are readable. Toolpath result of (careful) cut and paste from the Cut3D output. Found it useful to comment the individual sections. Mach 2 displays the comment so you know where you are in the combined run. The cut order I used was 4,3,2,1.

In the Rough: Image- 09 - Roughing.jpg and 10 - EndRough.jpg

09 - Roughing.jpg shows the machine a few seconds after 08 - Toolpath.jpg had been taken. I literally took 08 - Toolpath.jpg, walked to the front of the machine, took 09 - Roughing.jpg. If you look at piece 2, in the foreground with horns you, can see break through. This piece doesn't have the full 100mm oversize in the Y dimension. It was an offcut and was only 10mm oversize in Y.

10 - EndRough.jpg is a view of the completed roughing with the dust cleared away.

Finishing: Image- 11 - Finishing.jpg to 13 - CloseFinish.jpg

All fairly self evident here I think. Tool was 6mm and 12mm Ballnose and I varied the stepover with the size of the pieces. The nose piece (4) was 10%, the eyes and mouth piece(3) 8%. The larger pieces(2,1) were at 5% stepover.

I didn't combine the finishing paths. I did two passes on the larger pieces. One with 6mm ballnose, for detail, one with 12mm ballnose at 0.5mm lower Z for finish. 13 - CloseFinish.jpg is a close-up of one of the larger parts showing the finish after the 6mm ballnose pass. There is plenty of detail but the surface is a little rougher than I would like.

Assembly: Image- 14 - Cutout.jpg to 20 - Closeups.jpg

14 - Cutout.jpg and 15 - Stacked.jpg Show all the parts as they came off the machine. If you look closely in the area of the mouth remains of some of the tabs used are visible. No hand finishing of ANY sort at this stage.

16 - Glue1+2.jpg and 17 - Smoothed.jpg concentrate on pieces 1 and 2. The close up of the "ear" shows part alignment after glue has set and I've given it a quick rub along the join with 120 grade abrasive.

18 - MostlyDone.jpg shows fully glued up and after about 2hours worth of removing toolmarks etc

19 - Undercoat.jpg is after a final rub with 120 grade and a single coat of acrylic undercoat.

20 - Closeups.jpg is self explanatory.

Remarks:

Entire process from loading original mesh to photograph of final image was around 10 or 11 hours. About 6 hours related to computing and cutting (including extra pass on largest pieces). I think this settles any questions as to where the problems lay last time. Just a weird combination of model structure and settings I used.

As always would be interested in any thoughts, comment, tips, advice etc

TTFN amigo's

dsquire
06-20-2007, 03:33 AM
You are to be congratulated on the superb work that you have put into your CNC machine. I have only discovered this thread today and have spent a few hours reading and viewing most of the pictures. I too am a woodworker and have been planning a machine (probably not as big) and have been wondering about the 8020 aluminum. I now think that it is the way to go. I will continue to watch your posts as they have been very helpful and educational. I love your rocking horses even though the one has wheels.

Keep the router chips flying

Don

yohudi
06-20-2007, 03:22 PM
You are to be congratulated...... I have been wondering about the 8020 aluminum. I now think that it is the way to go..... I love your rocking horses even though the one has wheels.

Keep the router chips flying

Don

Hi there Don.. thanks for the kind words. If you're planning a machine I'd encourage you to go for it ASAP.. The satisfaction you'll get watching it work just can't be put into words...

Re: 8020. It was the only way to go for me.. it seemed the most sensible way to guarantee accuracy in a DIY build. I also liked the fact that you can tweak and add to the design afterwards, as in adding 4th 5th and 6th axes.

I should point out that I was lucky buy a vast amount of T nuts/bolts, connection elements and other fasteners well below cost. The amount of these you go through is surprising. If you go with the 8020 make sure you allow for connection and fastening costs.

Glad you like the ride-on toys.. I have a couple more different styles of rocking horse/toys to make also. To be honest I'll make anything I can model in 3D. My next post here will be based around a headboard I'm making for my daughter.

Best of luck with your planned build.. the sooner you start the sooner you'll finish.... so get the spanners out :)

Danny

mhasting2004
06-22-2007, 08:04 AM
Well my project is advancing and evolving slowly so I have a few more questions for those that have "boldly gone" before the rest of us.

What reduction gearing are you using on your Omega drive, what tooth profile and suppliers have you used.

I was looking at T5 then swapped to AT5 (25mm wide) as it has a better backlash spec but the price jumped three fold! HTD and STD were more difficult to source especially the pulleys but i have only checked a few Sydney based places.

I'm still sold on a belt drive system as my monster has evolved into a 1.4m x 2.6m 3axis router that can convert to a 4 axis hot wire with the removal of 2 pins which couple the independent motor drives to the gantry. I also plan to have a rotary axis down the center. The cutting bed can drop 450mm to allow a maximum 670mm foam block to be cut and is raised and lowered using air rams but locked and pinned in place at set heights (say every 150mm)

The only bits that I need to start bolting it all together is the belt drive components and the metal for the frame.

I am using 8020 extrusion for the bed, gantry and as a mounting place for the X (or is it Y) rails on top of the assembeld steel frame.


At $60 per meter (need about 8 meters) for the belt I want to make sure I'm getting the right profile for the job.

Any input will be greatly appreciated.

I know I;m repeating myself (and others ) but truely awesome job on your machine and cool stuff you've made with it so far.


Cheers

Mark

Ps Great link on the laser scanner/profiler.... its been added to the "put this somewhere on the machine" list

PPs i havent posted any CAD pics of the beast as untill I actually get more put together its a design in a state of flux and not "real" yet.

Tony Mac
06-23-2007, 11:58 AM
Fantastic work Danny and thanks for taking the time to document the project so logically and thoroughly.

I will be in touch soon.

Tony

ZipSnipe
06-24-2007, 02:24 AM
Yohudi, your project kicks ASS !!!! I like it!

yohudi
06-24-2007, 07:20 PM
Well my project is advancing and evolving slowly so I have a few more questions..........

What reduction gearing are you using on your Omega drive, what tooth profile and suppliers have you used.


Hi there Mark.. thanks for the compliments... regarding your belts and pulleys questions.. I think you have me mixed up with someone else.. my machine is ballscrew/nut on all 3 axes... being honest I haven't got a clue about belt drive..


I'm still sold on a belt drive system as my monster has evolved....

I know that evolving feeling.. sometimes it can be a component that's a bit special.. or something you can get for free... next thing you know you're tweaking the design to make it happen. Sounds like you've got something interesting in mind by the end. Lot of unique features.. and now with laser scanner of course ....

Re:the Drive system. I'm sure you've arrived at a decision that best meets your own needs. Unless you get credible advice one way or the other you have to build it and find out. As long as you leave some contingency it'll all work out as planned.. or via contingency plans..


The only bits that I need to start ..... is the belt drive components and the metal for the frame.

I am using 8020 extrusion ..... I want to make sure I'm getting the right profile for the job.

You should be able to discuss this with suppliers. Provided with your data they should be able to tell if a given profile will meet your needs under static load. How you plan on fastening it together makes a BIG difference to the dynamic load performance.

My own gantry mass is about 90kilos. The longest unsupported length is 1.8metres. The profile I used is 80mm square and is a "heavy" profile. There are more internal walls and the walls are thicker. The external mounting edges are also thicker. This easily handles static load.

I had good idea that it should beforehand as Cncfoam completed his all 8020 build before I started mine. Machine proportions were reasonably close.. so the relative loads would be similar.. I also planned larger size "heavy" extrusion to cope with the additional size. Cncfoam reported no problems and showed cuts made with machine etc.. I was encouraged by this. You should check his "A quick build" thread...


Great link on the laser scanner/profiler.... its been added to the "put this somewhere on the machine" list...

I found that link via the Vectric forum... When I decide where my 4th axis will attach then I'll be setting a permanent scanner up also.....

All the best with your build... looking forward to hearing how you get on...

All the best..

Danny

yohudi
06-24-2007, 07:36 PM
Fantastic work Danny and thanks.....
I will be in touch soon.

Tony

Tony: Hi Tony, thanks again for the kind words. Cut3D is still doing it for me. You're welcome re the info and pics.. look forward to hearing from you.


Yohudi, your project kicks ASS !!!! I like it!

ZipSnipe: I'm so glad you like... I think it's KICKASS too..:cheers:

yohudi
08-21-2007, 06:09 PM
Hello All....

Saw a posting on the vectric forum a few weeks ago that got me interested in developing a comprehensive and free method to create 3D models from bitmap sources. I use 3DSMAX myself.. but GMAX is capable of identical work in this area.. and costs nothing.. from turbosquid...

Essentially you build simple low-res gemetry to match the X and Y detail in the bitmap, adjust the z height of vertices to match the apparant 3D depth and then use a component in 3DSMAX/GMAX called Meshsmooth to generate a high-res smoothed mesh suitable for cutting. I've put up some pics.

comments/thoughts/questions welcome.

yohudi
09-02-2007, 04:56 PM
Thought I'd add pics of the completed job...

studysession
09-02-2007, 06:00 PM
Nice work!@

Drakkn
09-03-2007, 06:51 AM
Hi

Truly amazing build - I have just found it - wish I had found it earlier I may have changed the build I am on http://www.cnczone.com/forums/showthread.php?t=37139

Anyway what's the cutting area of your machine - oh I notice your are in the UK - anywhere near me - soon to be relocating to Barnsley South Yorkshire.

I am to make guitar bodies on my machine plus anything else that comes to mind in wood or aluminium.

Once again great build

yohudi
09-03-2007, 07:27 AM
Studysession

Thanks for kind words.....

Drakkn

Hi there. also thanks for kind words.. took a quick peep at your log.. you don't seem to be that far off the finished job yourself.... stick with it, 1st time yyou cut something you'll be well pleased.

Cutting area of my machine is 1.8 x 1.4 metres and I'm located in Shropshire.. about 4 miles from Oswestry...

Interesting that you are a guitar maker as I have a guitar job in the pipeline. Just doing the CAD now for a lapsteel guitar. The guy has based it on a design available from a buildyourguitar website. They have a handbuilt version but we will be refining the plan to take advantage of the CNC facilities....

Think basically I'll just be shaping the body and boring a few cutouts. It has a fretboard but this is just for position of the steel when playing.. there are no frets.. and no worries about action for same reason.

Only major issue I have is establishment of the "harmonics" line for pickup placement. Think we'll have to mount the bridge and pegs first. Then identify harmonics line after which we can machine for the pickup. The guy has all the bits/timber. Nice zebra wood fretboard and knobs to match... think the body will be beech... will post some pics here as job progresses..

Anyway.. stick at the build... it's well worth it in the end..

toneV8
09-03-2007, 12:39 PM
yohudi: Did you try machining aluminium on your machine.

yohudi
09-03-2007, 01:09 PM
yohudi: Did you try machining aluminium on your machine.


Hi there,

No i've never tried aluminium... I have been tempted as I have some 10mm and 20mm aluminium stock left over from build...

I wasn't sure if i'd need some kind of coolant which I'm not really set up for. I don't really know enough about metal machining at the moment.. so I'll investigate and maybe try it...

zoltan
09-03-2007, 01:14 PM
Hi,

Your are a very creative person. Great machine. Great work. I have followed your tutorial about 2D to 3D on vectric and must say Thank You. Super help for dimensional signs.

Zoltan

Drakkn
09-03-2007, 01:57 PM
Hi there,

No i've never tried aluminium... I have been tempted as I have some 10mm and 20mm aluminium stock left over from build...

I wasn't sure if i'd need some kind of coolant which I'm not really set up for. I don't really know enough about metal machining at the moment.. so I'll investigate and maybe try it...

Hi

I have done a bit of work with aluminium and have found that paraffin is good for a lubricant ,however a can of WD40 from your local motorist shop sprayed onto where you are drilling/cutting also does a great job.

yohudi
09-03-2007, 07:14 PM
Zoltan

Thanks for the very kind words... glad you found the tutorial helpful... if you have any further issues with bimaps to models then I'd be happy to help out if I can.


Drakkn
Thanks for the tip re the WD40.. as there happens to be a can on the shelf ... have to start looking through my cutters.... would be helpful to know what kind of spindle speed and feedrate you used on the ali. lowest I can go is about 12k rpm on the spindle.. and feedrate is adjustable obviously... Thanks in advance for any assistance.

Drakkn
09-03-2007, 07:59 PM
Cant help on the speed for cutting/maching aluminium as I was drilling holes at the time using my pillar drill - but also have used wd40 to drill holes using my power drill -cuts through like butter at quite a high speed.

toneV8
09-04-2007, 03:34 AM
I was just curious to know can machine hold machining aluminium.

If you try machining aluminium post pic to see result.

yohudi
09-12-2007, 05:51 PM
Well with all the talk of cutting aluminium.. I did a little search and found the url below....

I will be trying this very soon.. to make mount for a small detail spindle... need to be able to run cutters down to 1mm. Will secure as in CNCdudez pic below... he also has a do-able perspex vac table plan up there as well

http://www.cncdudez.com/kress.html

yohudi
09-14-2007, 05:51 PM
To anyone interested really...

Have previously mentioned working on a free method to equate to what the likes of visual scuplture can do by way of generating 3D vector models from raster clipart. I'm happy to say I have a fully working no-cost solution.. requiring NO modelling skills and MINIMAL knowledge and experience. As close to a load and Code solution as you will get for free.

Each of the models demoed below was generated directly from a bitmap in 10 mins or less and required nothing more serious than adjusting some value sliders.. NO modelling, NO geometry tweaking, NOTHING. ALL software used is FREE. Essentially you need an bitmap editor, GMax ... AND the method...

If I get enough interest from people I'm considering making an ebook detailing the method.. similar to the free PDF I've created previously. I 'm thinking of charging a small amount for the method, to justify the time it takes to create the ebook. If you want a taste of my cooking then download the free tutorial indicated in my sig.

A few people found that even the basic modelling in the free tut was a problem to them. This prompted me to pursue a non-modelling method which is very successful, take a look at the pics and see for yourself.. The Pvw series of images are cutting previews from Cut3D software.

If anyone thinks they may be interested in purchasing the non-modellers tutorial could you please let me know here or via p.m. If I get enough interest I'll get to work.. if not I'll know the demand is not there...

TTFN

EDIT: I've tried the method on a portrait sketch and a 3D render.. the cut 3D previews have been added... the blue model needs tweaks to the image to solve some minor problems but overall I think it's a winner...

yohudi
09-19-2007, 01:31 PM
Started as thread relating to bitmap to model conversion...

some new images related to the job below...

check it out if interested..

http://www.cnczone.com/forums/showthread.php?t=43622

CarveOne
09-20-2007, 05:48 PM
You might also want to try some hand lotion as a cutting lubricant. If it contains an ample percentage of lanolin it makes a very good tap cream for threading aluminum. I have a bottle of Desitin for extra dry hands that works well. Paint it onto the surfaces to be cut and it won't run off like WD40. WD40 is not as good but is easier to apply more when needed. Hand creams smell better than WD40 also.

CarveOne

yohudi
09-21-2007, 11:12 PM
You might also want to try some hand lotion as a cutting lubricant. If it contains an ample percentage of lanolin it makes a very good tap cream for threading aluminum. I have a bottle of Desitin for extra dry hands that works well. Paint it onto the surfaces to be cut and it won't run off like WD40. WD40 is not as good but is easier to apply more when needed. Hand creams smell better than WD40 also.

CarveOne

Hi there .. and thanks for the tip... will bear it in mind when I try and make the spindle mount. I'm only really going for an accurate hole in a plate.. so I shouldn't have any major prob with it... then again there's always usually something unexpected.... such excitement... don't know if I can take it.. :)

yohudi
09-25-2007, 06:45 PM
Have just put my new bitmap to model tut up at the yahoogroup in my sig..

If anyone is interested please visit the group. I'm asking a small contribution of £10.00 UK for the tut.. it's well worth it...

check this thread for details and examples of the models the method creates directly from a bitmap... with NO modeling and 0 experience

http://www.cnczone.com/forums/showthread.php?t=43622

ttfn amigos...

yohudi
09-28-2007, 05:00 AM
Hello all

For a limited time I'm hosting some free STL files, including those pictured below at my CNC_4_FREE Yahoo group. See the URL in my sig. The purpose of this is to promote the methods in my NEW bitmap to 2.5D model in 10 mins tutorial.

I would like people to take the opportunity to examine the files 1st hand and make their own assessment. If you never visit again after that then I don't have a problem with it.. as I say it's a promotional exercise.

If you are interested then feel free to access the group and take the files. There is additionally a FREE tutorial I made about 2 months ago, which is a good introduction to GMax software. This will walk you through the method of Box-modelling in GMax, a FREE version of 3DSMAX.

If you DO want to learn how to make the same type of models quickly and easily, with NO experience or modelling skills then info about this is up at the group.

The models pictured below are amongst the FREE download.. see what you think. There's a picture of the Ted on the Moon model cut and finished in an earlier post in this thread.

ttfn

Yohudi

planekrazie
11-12-2007, 08:36 PM
Nice

yohudi
11-13-2007, 02:05 PM
Nice

Hi there,

thanks for the kind word...

To anyone watching this thread really...

Will be adding 4th and 5th axis to my machine over the next couple of weeks... with usual pics and documentation...

Motor drives should be here tomorrow.. so starting the mechanicals for the 4th tonight..

when I've finished to additions I'll be compiling a price and spec list for the final job....

TTFN....

Yohudi...

planekrazie
11-13-2007, 08:17 PM
I cant wait to see how you set up the other 4th and the 5th axis.
Again Great work.
Steve

Mick40
11-13-2007, 08:48 PM
Yohudi- You rock, wow what talent!

Thanks for taking the time to share!
Mick

Drakkn
11-20-2007, 06:22 PM
Hi Danny
Any idea on how to sort out cable lengths for all of xyz axis - btw have posted your strings today.

Regards
Tony

yohudi
11-20-2007, 07:12 PM
Hi Danny
Any idea on how to sort out cable lengths for all of xyz axis - btw have posted your strings today.

Regards
Tony

Hi Tony,

Estop is on it's way also.. should arrive tomorrow..

In terms of Cabling. When I did mine I knew the routing I wanted as I'd worked it out as build progressed.

I fitted the E chain in advance... Made it easy to work backwards from the motors, and then just leave a bit of allowance when came round a curve or a corner..

Broadly speaking it's really only the Y and Z axis that are problematical.. as X motor is fixed...

For Y motor I ended up using about (1.75 x the X axis length) + (width of gantry) as my motor is the opposite side to where the controller sits.

For Z it was similar amount but was more like (1.75 x X axis length) + (1.75 x Y axis length) to allow sufficient travel.

I found was easier to keep it on the roll... route the cable.. then add the extra required to reach controller location and cut..

hope this helps

Danny.... (aka Yohudi)

Drakkn
11-22-2007, 08:45 AM
[QUOTE=yohudi;369018]Hi Tony,

Estop is on it's way also.. should arrive tomorrow..

Have just collected it from the post office - have to wire it in onto my board and then buy a load of cables fit the oldham coupling when it arrives then ready to setup mach3 ,have mad a sort of mdf mount for the T3 router which when machine is running ,the first thing i will make will me a complete aluminium z axis and ditch the mdf.Not far off now me thinks

yohudi
01-23-2008, 01:48 PM
Posted update to build log today... but in wrong post.... so I've added the pics and such here as this is where they should go really....

00ModelCut.jpg and 000Modelcut.jpg

Took these on finish cut of my Dragskull model.. made using methods in my bitmap to models tutorial

01Stripped.jpg

Table on machine after I removed old sacrificial strips to mount profile for A axis

02MountA1.jpg

Colin Doughty's prototype rotary axis mounted as an A Axis... Square should give idea of dimensions etc

03MountA2.jpg

4-Jaw Chuck mounted onto the rotary

04MountA3.jpg

The view down the table from the drive end

05MountA4

Completed Table setup.. Added heavier ribs as will now be used for fastening rather than just spacing off the table

06MountA5.jpg

View of the completed job from the tailstock end

will add more pics once I get time to sort them out

ttfn

Danny

slowbob
09-17-2008, 06:21 PM
Hi Danny,

I’m sure you get enough of me at cnc4free.org site, but I just finished reading this thread and have a question about using linear rails with 8020.

1st, did you mount and align them yourself. If so, did you mill an edge, butt against a straight edge or or … what? Could you please describe the alignment procedure?

2nd along the way in this thread someone asked if you used locktite (threadtite) and if things have loosened up. You had only been running the machine about 6 weeks and it hadn’t. Now that you have more time on this beautiful beast is it showing any signs of loosening up? Have you experienced any binding?

I’ve going to start with a small desktop using 28” rails (salvaged several sets off retools at work :wee: ) on both the X and Y axis so alignment should be easier than what you had to go through.

Thanks,
Bob

P.S. Thanks for running the CNC4FREE.ORG site, it has helped more than any other resource to learn CAD and CAM

yohudi
09-18-2008, 07:39 AM
Hi Danny,

I just finished reading this thread and have a question about using linear rails with 8020.......

1st, did you mount and align them yourself. If so, did you mill an edge, butt against a straight edge or or … what? Could you please describe the alignment procedure?

2nd along the way in this thread someone asked if you used locktite (threadtite) and if things have loosened up. ........ Now that you have more time on this beautiful beast is it showing any signs of loosening up? Have you experienced any binding?


Thanks,
Bob

P.S. Thanks for running the CNC4FREE.ORG site, it has helped more than any other resource to learn CAD and CAM

Hi Bob,

First many thanks re the +ve remarks about cnc4free.org... Was strange how it developed from the initial tutorial thing.. but it's there now and if it helps even just a few people get started earlier, or try something new then I think it's worthwhile..

re your questions:

1. Rail Alignment using 8020:- There were a couple of things I did to assist this and a couple of things about 8020 construction that helped too.

I had all the 8020 pre-cut using CNC and pallete shipped. Thought that even if there were slight inaccuracies in the suppliers cutting they would be consistent inaccuracies. This helped in keeping the framing quite true and avoiding distortion in the long sides when the cross-bracing was fastened in etc.

I used T-Nuts with a raised lug to assist in locating centrally in the slots. When I fastened the rails initially I checked for trueness using the mounting plates for the gantry as a reference point. As the rails on my machine are side-mounted gravity helps a lot. Didnt take much in the way of pressure to ensure each slot-nut was hard against the internal lip of the 8020 before fully tightening.

Machine design helped too... was another reason I went for side mounted rails. As long as the linear rails are true to each 8020 support and the supports are square and parallel, any slight discrepancy in actual rail height was accounted for when the gantry was built in situ.

2. Threadlock: Have noticed no issues with loosening or deterioration of hold on 99.9% of the machine. In use I've had 2 nuts drop off the gantry.. on inspection I'd missed hitting them with threadlock.. When I performed some dissassembly, to add the bedplate and Doughty Drive, I had to fight the fastenings a bit in places.. so I'm pretty confident in the overall security of the fastenings.. but I also continue to do a general check each time I run the machine

re: binding:- This was a concern building a machince as large as this but... touchwood... no binding problems have evidenced, even over time. I put this down to a few things.. robust ballscrew.. very large flange on ballnut.. custom ballnut mount professionally engineered to spec, large plate securing ball nut mount to gantry. I have run quite a few cuts where the head is at full extent to travel in +ve or -ve Y direction.. like when I cut the parts for ride on toys etc.. I usually throw 1/2 or 3/4 of an 8 x 4 ft sheet of ply on the table and leave the machine to get on with it.

I should say that this machine doesn't run flat out each and every day... I'm ususally running in 8 hour stretches probably every couple of days.. It has seen a good amount of use since I built it...

As always hope this helps

Danny

Khalid
09-18-2008, 08:17 AM
Thanks Danny for such a great website.. i visited many times in past, but didn't post here... Again thanks for ur great contribution:)

http://cnc4free.org

yohudi
09-24-2008, 10:53 PM
Thanks Danny for such a great website.. i visited many times in past, but didn't post here... Again thanks for ur great contribution:)

http://cnc4free.org



Hi there,

Many thanks for the kind words and glad that you found the site of some use.

regards

Danny

Khalid
09-25-2008, 01:41 AM
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