Yohudi's Build log - Time to get stuck in

[yohudi]

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]

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]

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]

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]

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]

any updates?

[yohudi]

Originally Posted by ckm 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]

Hi yohudi. This is great, please keep it up. Nice pictures.

[yohudi]

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]

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]

Very nice. Its certainly coming along. This thread will be an asset to me later on when Im building a big machine. Thanks.

[cncfoam]

just posting so I can get updates when you update.

Looks good
Eric
cncfoam