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bgolash
11-17-2004, 09:35 PM
Hi Group

I’ve been visiting the cnc zone website for a few months. During that time I’ve been reading many of the threads. There are so many talented people that visit the site I have learned allot here. It’s a certainty that I will have many questions for the members of the site.
So now,for better or worst the construction begins. I visited my favorite junk yard. I managed to find aluminum extrusions, Thomson block assemblies and the best find... A 36 X 80 I-beam base. eBay as usual seems to be place to find the expensive components. I found lead screw assemblies with the bearing blocks and purchased two sets. One complete set will be used for the Z axis. The other will be cannibalized for the bearing blocks which will be used on the X axis.
Note: ¾ dia .2 lead In addition, I procured four thk linear sets with 4 bearing blocks. I plan to butt these end to end for the Y axis. For the bearing assemblies I turned two blocks on my old south-bend lathe.
I’ve been working on the electronics for the project. I have one gecko 201 and an Automation Direct stepper. Since I am not an electronics expert to get started I purchased their 40 volt power supply. I haven’t had much success with the electronics part of this project. I did manage to get the stepper up and running. The problem is the motors spins at about 2 to 3 rps. I’ve played with the mach 2 tuning selection to no avail. Hope someone here can help me with this frustrating problem.
So frustrated with the electronics, I started to mount my Thomson 1.25 dia linear motion rails to the bottom of my frame. This required 48 bolt holes to be drilled in the aluminum frame. I got one rail mounted and then setup a measuring system to check the other x rail for parallel. I mounted a dial-indicator attached to an extrusion and linked it to two Thomson bearing blocks. I adjusted the blocks as tight as possible to eliminate any clearances. After about 5 hours I managed to get the two x rails within .001. As a test I mounted a 13 x 36 piece of MDF to the four bearing blocks .. clamped four wood clamps to secure the MDF and pushed the new assembly to test for any binding. It seemed OK but I did push on one side and the MDF did twist a bit. I hope that the machine will not see any offset loads because it did move .010.
In a few days I’ll receive another eBay purchase …more extrusions so I can finish the base. I do have the gantry ends roughed out. I think I`ll send them out to a machinist to square them up. I thought it might be a good idea to have the ends machined so I would have reliable references to mount the other components. Its getting late. I hope you`ll visit this thread again. I`m certain I`ll have endless questions.

Best Wishes, Barry

ViperTX
11-18-2004, 06:27 PM
Do you have any other information on the stepper....I'll chase down the Gecko 201 drawing. Can you describe how you have it hooked up....it is stepping in one direction and not just stuttering??

bgolash
11-18-2004, 07:14 PM
Hi ViperTX
I have one gecko 201 and stepper with a 40 volt power supply.
The motor I have is STP-MTR-34066.The motor and the power supply
are from Automation Direct. Motor specs 5 volt, 2.8 amp 410 oz*in
http://web3.automationdirect.com/static/specs/surestepmotors.pdf
I am using Mach2 but even with endless combinations with velocity
etc. The stepper only seems to move 2 to 3 revs per second.
I am using bob campbell`s breakout board. I tried the motor as XYZ
on the breakout board..all axes run but very slowly.
The wiring off the top of my head is step to step , direction
to direction and a com to and from the breakout broad to the gecko.
It seems to me the LED`s are working on the breakout. Someone mentioned
in another group that my old 450megahertz PC maybe too slow. I haven`t
tried using my 2.4 PC but will tomorrow.
Note: Mach2 has sample code and sometimes the motor just makes noise no
movement. I have run the stepper in manual mode with the joy stick and then
it will move at about 2 to 3 rps.

Thanks for the help..Barry

bgolash
11-18-2004, 08:48 PM
Hi all

I need to purchase a rolled ball screw. The length
is approximately 72 inches. Is a 5/8 diameter
large enough to minimize sagging or whip of the screw.

Regards Barry

ger21
11-18-2004, 10:04 PM
Hi ViperTX
I have one gecko 201 and stepper with a 40 volt power supply.
The motor I have is STP-MTR-34066.The motor and the power supply
are from Automation Direct. Motor specs 5 volt, 2.8 amp 410 oz*in
http://web3.automationdirect.com/static/specs/surestepmotors.pdf
I am using Mach2 but even with endless combinations with velocity
etc. The stepper only seems to move 2 to 3 revs per second.
I am using bob campbell`s breakout board. I tried the motor as XYZ
on the breakout board..all axes run but very slowly.
The wiring off the top of my head is step to step , direction
to direction and a com to and from the breakout broad to the gecko.
It seems to me the LED`s are working on the breakout. Someone mentioned
in another group that my old 450megahertz PC maybe too slow. I haven`t
tried using my 2.4 PC but will tomorrow.
Note: Mach2 has sample code and sometimes the motor just makes noise no
movement. I have run the stepper in manual mode with the joy stick and then
it will move at about 2 to 3 rps.

Thanks for the help..Barry

If it just makes noise and doesn't move, your acceleration may be set too high. Also, If your manually jogging the machine, it may not be able to go any faster. Try running some g-code and use the F word to set the speed you want.

bgolash
11-19-2004, 04:29 PM
Hi All

I believe all my problems are solved with the slow motor problem.
It seems as soon as I tried the motor with Mach2 on my 2.4 megahertz
PC everything seemed to work as I hoped it would. No luck with a old
450.
Regards Barry

ViperTX
11-20-2004, 06:30 PM
Barry, Check the wiring to the Gecko. The red motor wire should go to Phase A and the while mtr wire should go to Phase B. The green motr wire should go to Phase C and the black motor wire should go to Phase D.

Also since you have a 40VDC motor supply you should have a resistor of about 2500 ohms (pick a 3.3 K or so resistor....don't remember what is between 2.2 K and 4.7K0 in series with the step and direction inputs. Check that Term 10 (+5VDC) is connected to a 5VDC power supply....I'm not familiar with the breakout board, but it will most likely have a 5 volt source. Let me know what happens.
Paul

bgolash
11-23-2004, 08:42 AM
I checked over all the wiring. It seems fine.
Thanks for taking the time to help.



Barry, Check the wiring to the Gecko. The red motor wire should go to Phase A and the while mtr wire should go to Phase B. The green motr wire should go to Phase C and the black motor wire should go to Phase D.

Also since you have a 40VDC motor supply you should have a resistor of about 2500 ohms (pick a 3.3 K or so resistor....don't remember what is between 2.2 K and 4.7K0 in series with the step and direction inputs. Check that Term 10 (+5VDC) is connected to a 5VDC power supply....I'm not familiar with the breakout board, but it will most likely have a 5 volt source. Let me know what happens.
Paul

bgolash
11-24-2004, 01:33 PM
Hi Group

The machine base is comprised of aluminum extrusions and welded I -beams. The current view of the frame is upside down.
The Thomson 1.25 diameter rails are mounted underneath the frame. It seems this orientation to load is the worst from a design | load standpoint. The frame to a degree only allowed easy mounting with the current placement. The load of each block is 2000 pounds. The specs on the blocks indicate that when they are in an inverted orientation they must be de-rated by 50%. So I think I`ll be safe at 1000 pounds per block. The next step is to mount a Thomson 5/8 diameter ball screw with a length of 68 inches to the
frame. The machining I hope to do myself. I`m a bit concerned because the screw is case-hardened to a Rockwell 57. I was thinking about annealing the ends with a mapp torch while the part was spinning in the lathe. I`m a bit concerned that it might be possible with the heat to distort the screw. I purchased a ball screw assembly on eBay just to use the bearing blocks for the x axis lead screw. At 30 dollars for the assembly that definitely saved a lot of time to fab something in-house.
Once the machine has its x lead screw attached I`ll flip the machine over
and start on the gantry.

bgolash
11-24-2004, 04:03 PM
Hi Group

Here are a few more of the parts. I plan to use the lead screw pictured here for the Z axis. I have another lead screw that`s a carbon copy of the first. The second one I`ll use the bearing blocks for the X axis. The two aluminum turnings are bearing housing I turned for the Y axis. The IKO rails will be butted end to end for the gantry Y axis. It looks like making the machine
base was the easy part. Now for the detail work.

bgolash
12-11-2004, 07:29 PM
Hi Group

I machined the ball screw and did a mock up of the x axis.
At the moment all the parts are secured by clamps. I tried
the steppers with Mach 2 software and a Gecko 210 driver.
The power supply is from Automation Direct as is the stepper.
The stepper is the largest they sell 410 oz*in. The power supply
is 32 volts.
I have to admit, I thought I would be moving the x a bit faster.
The current speed is 60 ipm. The ball screw is a Thomson
5/8 diameter with a .2 lead. I did try to run the steppers faster
but the motor stalled. I did check the alignment of the gantry
and the ball screw and there was no bidding. I`m wondering
if the motor is just sized too small.


Best Wishes, Barry

ger21
12-12-2004, 08:32 AM
I don't have first hand experience, but I've heard that if you double your voltage you should roughly double your top speed. Maybe not what you wanted to hear. Is this the $99 motor they sell? #34066? There short description says it's 310oz-in, but the specs say 434oz-in. If you look at the torque curve chart on the website, you'll see that with 1/10 microstepping (What setting are you using?) this motor only has about 60oz-in of torque at 300rpm (60ipm). And at 375RPM, it only has about 25oz-in. It also has only just over 300oz-in holding torque, according to the chart. So it's looks like its really a 310 oz-in motor. They don't list the motors rated voltage (or the specs needed to determine it), so it's a bit hard to determine the Max voltage you could safely supply. You could measure the resistance of one of the coils, and the voltage rating should be 2.8a x resistance. More voltage should give you more speed, though. You might want to try something like this.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=36323&item=3858922482&rd=1

Compare this Vexta motor's torque curve compared to yours.
http://www.orientalmotor.co.jp/cgi-bin/WebObjects/UPOMStep.woa/wa/F3?typeNameId=1&modelName=PK296%2DF4.5A&seriesId=2PK&frameSize=85
When wired bipolar parallel, there is quite a difference in useable torque for motors with similar ratings.

Lastly, make sure you have absolutely no binding and everything moves freely.
Can you turn the leadscrew easily with your fingers without the motor? How hard is it to move the X without the leadscrew attached?

bgolash
01-17-2005, 08:41 PM
Hi Group

I`m in the middle of a 3 axis cnc that I hope will mill aluminum.
The height of the horizontal tube will be set at 5 inches above the work surface. I`m hoping that keeping the horizontal tube close to the work surface will minimize the cantilever load that would be present if the
axis was higher over the surface. At the moment the vertical tubes are
excessively long. The horizontal tube is a 4 x 4 with a 1/4 wall
thickness. The vertical tube will have gussets set at the bottom of
the tube to increase stiffness and a bottom plate that will bolt the
tube to the bottom gantry section
This design will allow me to add riser blocks under the plate in the
event that additional gantry height is needed. I hope this solution
will work. Any suggestions are appreciated.

Regards Barry

bgolash
03-21-2005, 08:09 PM
Hi Group

Progress on the Y axis has finally started taking shape. I used structural tube
for the uprights that support the 4 x 4 tube. The uprights were welded and then sent out to a machinist to mill the top and bottom surfaces of the uprights. At a price of $285.00
The 4 x 4 tube at a length of 54 inches was sent out to have 3 of the 4 tube surfaces banchard ground.This cost $250 .I thought this might help to have a flat surface to mount the iko preloaded rail assemblies. The ground faces did help to ease the installation of the rails.
They look to be within .001 of parallel. I did have a detail that looked like
a potential problem. I tried the rails by securing the four iko blocks to a 90 degree piece of plywood. It seemed that it took a great amount of pressure to move the blocks. I was concerned that the stepper motor would be unable to push the assembly. It seems that the ikos that I got on ebay had a #2 preload. This made them very stiff. The benefit I feel is this should make a very tight Y axis. I was still concerned the steppers might die when
they tried to push the mass. So just this weekend I machined the ball screw and mounted the motor. I had a automation direct 310 oz*in motor. I tried the Y axis with the motor and was very surprised that the motor could function without problems. Just as an additional test I placed a 4 x 10 x 12 granite surface plate on top of the ikos and again the motor had no problems. The speed is approx 200 ipm.
The 5/8 ball screw is looking to be a problem. It seems I have about three bent areas in the 50 inch length. At any speed the screw looks to be wiping. I guess I`ll have to straighten the screw but am not certain of the best method to remove the bent sections. I`d appreciate any advice
on this issue.

bgolash
03-26-2005, 07:26 PM
Hi Group

Just started prototyping the mounting bracket for the Z axis.
I have the overall width of the ikos blocks as 8.75. I hope
this will provide enough support for the movement without
affecting accuracy. I am constructing this as a sub-assembly.
The Z axis will be made on its own 1 x 9.75 x 18 aluminum
jig plate. Once the Z axis is complete it will be bolted to the
subassembly. I hope this will make it easy to align the axis
vertically.

bgolash
04-05-2005, 08:34 AM
Hi Group

I `ve got the X and Y complete and am working on the
Z. I`m not certain what I want to set as my Z height.
I wanted a machine that could machine aluminum and steel
I`m concerned about the Z plate moving down which is
supported on 3/4 Blanchard ground aluminum plate. I know
the longer I extend the axis the more potential vibration I
may have. The Z axis is 8.5 inches from the table. I would
like to add 1.5 high aluminum extrusions as a work surface or as a
secondary choice 1.5 MDF. So with a 1.5 work surface added
to the machine I`d have a working height of 7 inches. I`m wondering
if this might still be too much of an extension to keep the axis
rigid. I`m attempting to make the Z as rigid as possible. I have
a sub-assembly that`s made from 5/8 aluminum plate. This has
gussets for reinforcement. The Z axis will mount against this surface.
The Z axis itself is made with a 1 thick piece of ground plate and
THK 30 rails. The sliding blocks will be mounted to a piece of 3/4
aluminum plate. If necessary I can add pieces of steel or alumium to
the edges of the 3/4 plate for additional strength. I`m no expert in the
strengths of materials so I have no idea as to what is the best solution.

JavaDog
04-05-2005, 11:46 AM
Wow, that is a beefy looking machine! Coming together very nicely.
Perhaps I missed it, but what are you planning to use as a spindle?

bgolash
04-05-2005, 01:48 PM
Hi JavaDog

Good Question...I am uncertain as to what direction to go.
I`ve seen a spindle from the littlemachine shop for 249.00.
I have no idea if this would be a good investment.
I might try and build one but I don`t have any drawings to
use as reference material. I`d like the spindle to run from
300 to 10,000 rpms. That would allow me to machine wood
and metal. Any recommendations would be appreciated.

JavaDog
04-06-2005, 05:09 PM
Hi JavaDog

Good Question...I am uncertain as to what direction to go.
I`ve seen a spindle from the littlemachine shop for 249.00.
I have no idea if this would be a good investment.
I might try and build one but I don`t have any drawings to
use as reference material. I`d like the spindle to run from
300 to 10,000 rpms. That would allow me to machine wood
and metal. Any recommendations would be appreciated.

To be honest, I was curious, but I am not too knowledgable on spindles (I'm kinda a noob). I know I am just using a Porter-Cable Variable-Speed Router on my machine, but I don't have the need to go as slow (300rpm?!) as you...

bgolash
04-11-2005, 06:35 AM
Hi Group

The Z axis is nearing completion. I`ve had a difficult time
deciding on the amount of travel for the axis. My guess
is that 6 inches should be enough. If I have to I could increase
the travel in the future. I`m trying to keep the axis as rigid
as possible.
Details to finish include adding another nook ballnut for anti-backlash
and a faceplate of 3/4 thick aluminum.
PS..what travel did you set for your machine? Was it enough travel
for all your machining needs?

bgolash
04-12-2005, 05:17 PM
Hi
Just got this spindle on ebay. I hope to add a motor and step
pulleys to machine metal. My machine was intended for wood
but I have a interest in machining metal. I was hoping to drive
this spindle to accommodate the speeds needed for both metal
and wood. I`m not certain that can be done in a easy manner.
I`m thinking that I may need a router for wood and the new spindle
for metal.

-Spindle Housing is made from Steel
-Timing Belt Pulley Drive, #22L075MP Pulley
-Comes with 5/8" 5C Collet and Endmill
-Perfect for homemade lathe, mill, CNC projects
-Bearings are 6209Z with a light preload on them
-Bearing were press fit into housing and shaft was press fit into bearing ID's
-Overall length is 9.5", the housing O.D. is 4.5", bottom flange is .38" x 4.75" x 7.25"
-.56" diameter holes are centered on bottom flange at 2.5" & 5.75"
-The tools or workpieces are tightened in the collet with a standard 5C tightener (green handle) but it can be modified to fit your ap

JavaDog
04-12-2005, 05:31 PM
Hmm...that's pretty interesting. What RPM is that rated for? Any idea on the motor to drive it?

bgolash
04-13-2005, 10:19 AM
Hi

I think the bearings can run at 8,000 rpms. I found this
link that deals with a variable speed conversion of a
Bridgeport. I will follow the article and use a PMDC
motor.

http://truetex.com/dcdrv.htm

bgolash
05-03-2005, 05:43 PM
I`m finally done. Two Nook ballnuts are used for
anti-backlash.

JavaDog
05-03-2005, 08:22 PM
Nie looking Z-axis! Very clean and tight.

Get about 3in of travel out of that?

Bloy2004
05-03-2005, 08:31 PM
...that's a nice table it's resting on too !

bgolash
05-03-2005, 08:50 PM
It has a 6 inches of travel. I`m hoping that having
a shorter stroke will help minimize vibration from the
tool.

Nie looking Z-axis! Very clean and tight.

Get about 3in of travel out of that?

bgolash
05-03-2005, 09:05 PM
Hi Bloy
Thanks for the kind comments. That saw was the best investment
I`ve ever made for my cabinetshop.

S315 WS Sliding Tablesaw (3 phase only)
This is our best-selling saw with features that no other slider has. You get a real cast iron trunnion, separate scoring motor with external adjustment, separate miter fence, and a dial indicator for the tilt. These features and its low price make it the best 8ft saw on the market. Special price includes:

2 main blades
scoring blade
Specifications:
4.8hp- 1ph/ 9hp- 3ph
3/4hp scoring motor
Separate external adjustments
8-1/2' sliding table with swing arm support
Telescoping cross cut fence
Separate mitre fence
12” Main blade capacity
Scoring
5/8” arbor
Tilting arbor 0-45 degrees
50” rip capacity on a solid steel bar
Heavy cast iron trunnion
Net weight: 1530lbs




...that's a nice table it's resting on too !

bgolash
06-03-2005, 08:54 AM
Hi

I`ve begun the work on my spindle for the machine. The footprint
of the spindle is larger then I would like but I`m optimistic these factors
will not adversely affect machine function.
Motor take-up will be accomplished by a THK rail assembly and a
lead screw to set the belt tension. The motor is a 1 HP PMDC with
a variable speed controller running the spindle up to 2500 rpms.
I hope to add a second pulley group to take the spindle speed to
9000 rpms. This I hope should allow me to machine wood.

bgolash
06-08-2005, 10:27 AM
Hi
The spindle is done and mounted to the Z axis. The motor has a lead
screw incorporated to allow quick belt tensioning. I`m very happy with
the variable speed control and there seems to be no vibration from
the spindle. I do have a concern regarding the temperature of the
spindle. It gets warm after 10 minutes of operation.This occurs
at 2500 rpm. I plan to setup another combination of pulleys to allow
wood machining at 8 to 9000 rpms. Its my guess this will really heat
up the bearings.The spindle does have a light preload and the bearings
are a Chinese model. I may have to get a higher quality bearing for the spindle.
The big test will come soon when I start cutting some parts. I`m very
interested to see how accurate the parts will be.

bgolash
06-08-2005, 05:02 PM
Hi

I just ran the spindle and cut a few test pcs. The speed
was 2500 rpms in MDF but the cut was very good. I`m
very happy so far with the spindle.

bgolash
06-10-2005, 04:32 PM
Hi All

It seems the spindle is not going to be a trouble free system.
During my 35 minutes of routing, running the spindle at 1000 rpm
the bearings got so hot that they lost the press fit to the spindle. I noticed a
misalign of the timing pulleys, then noticed they didn`t move but
the spindle dropped down 5/8 of a inch. This is a major problem
but I think a collar mounted to the top of the upper bearing will
solve the spindle movement. I`m looking also to replace the bearings
but an not a expert in all the details of bearing selection.
Here are the specs on the current bearings
> Manufacturer: EBC China
> Part Number: 6209Z
> ID.................: 1.772
> OD................: 3.347
> Height............: .746
Its my guess that these bearings are a poor grade and that a higher
quality bearing might allow higher rpms and help to keep bearing
temperatures within reasonable limits. I am looking into ceramic
bearings but one salesmen didn`t think they were available in the
size needed. If anyone in the group has info on bearing selection I`d
appreciate your comments

ViperTX
06-10-2005, 04:55 PM
It could also be that the bearing bores are not aligned...I would try to thermocouple the bearing case to determine which one is heating up. Were they well lubricated? Check the bore alignment and check the diameter of the bore and the diameter of the bearing....the bearing could be pressed into too small an opening.

I guess the housing did not have a inside shoulder where the bearing fit? (nuts)

Al_The_Man
06-10-2005, 05:05 PM
Here are the specs on the current bearings
> Manufacturer: EBC China
> Part Number: 6209Z
> ID.................: 1.772
> OD................: 3.347
> Height............: .746


I would look and see you can get them in FAG or SKF, any bearing supplier should be able to oblige.
Al.

take a cut
06-10-2005, 05:08 PM
I would have to agree there must be a misalignment in the bearings most likely in the housing as the shaft would probably be machined in one setup and the housing may have been rotated in the lathe and not dialed up properly to align the bearings. Or i must ask was the housing welded to the plate before or after machining if after you probably have a bore that is out of round from the weld pull.

mxtras
06-10-2005, 05:34 PM
A 6209 bearing is common - should be no problem to find a replacement. I would replace the Z with an R, though. The Z is shielded, the R is sealed with a lip seal to keep out the dust. So a 6209ZR would have a shield on one side and a seal on the other (probably hard to find in stock) - so buy a 6209RR and yank one seal to lube it up the way you want. I would not recommend running just a shield (Z) that close to the dust.

I would also strongly suggest that you select a Electric Motor quality or better.

I can't imagine a decent bearing failing at 1000 RPM. It seems like it would have to have been either a really crappy bearing, contaminated, not lubed, misaligned or over loaded - did you try to preload it to remove slop? Is it possible you over did it? Just a thought. Standard deep groove ball bearing don't appreciate side loads too much, and a 6209 is a standard deep groove bearing.

I prefer KOYO for any precision bearing - they are the only bearings I put in the cases of my motorcycle motors - they spin 14,500 rpm.

Scott

ViperTX
06-11-2005, 01:29 AM
bgolash.....what have you found??

bgolash
06-11-2005, 06:04 AM
Hi
Nothing much to report. I was going to find a bearing that has
specs better then the original and have it replaced. I don`t have
an arbor-press so I have to send it off to a machinist. Before I have
him insert the bearings I`ll have him check the alignment of the
spindle bore.

bgolash
06-12-2005, 09:21 AM
Hi All
While I wait to resolve the spindle issue I have another spindle
related problem. It seems the weight of the motor is causing
the Z to drop when the stepper is powered down. I have a pneumatic
cylinder that has a 7 inch travel. I thought I might close off one of
its air intakes as that makes the cylinder move with resistance. I was not
certain if I`d ever get the right resistance so I decided on a different approach.
The new solution will not win any engineering awards but so far the new
pulley and spring combination is working. The Z still drops a few inches
from its fully raised position but does stop. This at the very least is a
temporary solution. It makes me feel better knowing the Z will not be able to
over-travel and stress the ballscrews by hitting against its bearing blocks.

bgolash
06-16-2005, 05:07 PM
Hi Group

I just did a upgrade of that spring counterweight design.
I purchased a gas cylinder from McMaster-Carr and added it to the
Z axis. Its working fine and it was a much better solution then
the spring.
Reducible-Force Gas Springs : http://www.mcmaster.com/nav/enter.asp?partnum=6465K4&pagenum=1067

bgolash
06-17-2005, 01:03 PM
Hi
I did a test and so far I`m optimistic I`ll be able to
mill some steel. I ran a four flute endmill in a piece of
cast iron at 3 ipm with a spindle speed of 300 rpms.
The cut was good considering my hold-downs are not
the greatest i.e. Wood Clamps. I checked the spindle
and very little vibration is transmitted to the Z axis.
The side cut was .032 and the bottom of the endmill
engaged about .032. I`ve never milled any metals before
so I was very conservative. The next attempt will be steel
when I purchase a real clamping arrangement.

bgolash
08-30-2005, 08:35 PM
Just finished the control panel. That was a very time-consuming step in the construction of the CNC. To siffen up the machine frame I added a piece of 1/4 thick plate steel which also provided a surface to mount the control panel and the variable speed drive for the spindle. The next step will be adding some 80|20 to create a work surface. I think I`ll just do part of the table in 80|20 and the rest of the surface in a double sandwich of MDF. I`d like to use all alumium but the cost is just too high. Time to go...I have to find some deals on ebay

Mike F
08-31-2005, 05:01 PM
Very neat!

I'm just in the process of planning my control box so it's good to see how others have tackled it. Are the dark objects to the right of the geckos cooling fans? If not, I can't make out anything else that resembles a fan.

I hope my wiring ends up as tidy as yours :)

Mike

cbass
08-31-2005, 09:20 PM
bgolash,

Just wanted to say congrats so far. Very nice looking machine. It's heavier duty than most DIY designs... Almost makes me wish I had made my own.

Carlo

bgolash
08-31-2005, 09:36 PM
Hi Mike F

Yes, I have two 115 AC fans running to cool the geckos. Other parts include two transformers, two momentary switches. The power on | off is completed by the use of a relay. The DC supply that feeds the geckos is run thru 7 amp fuses which have reverse biased diodes that protect the gecko drives in the event that a fuse is blown.
I also have a 12 DC LED panel light mounted to the top of the case.This helps to remind me of the status of the power to the system. During design I forgot to turn the power off before removing the motor wires. That was an expensive mistake. One gecko was DOA.

bgolash
09-25-2005, 07:38 PM
Hi All
I`m getting ready to mill the frame of the cnc. The surface of the
machine frame which is constructed with I beam aluminum wasn't
very flat.
I`ve used a high-speed router bit that`s 1 1/2 diameter. I just
did a test cut at 2800 rpms and a feed rate of 30 ipm. The feed and
speeds seemed OK....anyone have recommendations for different speeds,
feeds and cutters. I am going to use Mach3 and the teach wizard to
mill the surface. Once the frame milling is complete I`ll add some 80|20
1 X 3 X 44 for the work surface. Its a bit nerve-racking running the cutter
into your machine frame with limited experience.

bgolash
12-26-2005, 07:25 PM
Hi All

It never seems like there is a true end point to a DIY machine but I`m getting closer. I finished installing the aluminum diamond plates as a surface for the cable carrier system. There were a few moments when I went to slide my motor connectors thru the carrier and found that they just fit. Just a bit bigger connector would have caused some painful re-work. For those of you still to do this procedure its safer to run your wires then add any connectors after the wire run is made. It seems I got ahead of myself. Still to do is the main work surface. Part of the table will have 80|20 and the rest will be 1 inch MDF.

Regards Barry

cbass
12-27-2005, 03:34 AM
Good to see you're still at it!!!

Many start, few finish...


Carlo

bgolash
02-12-2006, 09:00 PM
Hi
I am in the process of converting my x axis to a servo. I was having problems with the axis losing steps. As a result, I decided to upgrade to a servo. I believe the problem was the size of the stepper. At 286 oz*in, the torque was most likely the source of the problem. During the upgrade, which included the construction of a new mounting plate for the servo, I had a chance to manually run the ball screw up and down. There was no binding at all. I know the small motor has a very weak detent torque. When the motor is energized it was very easy to manually turn the shaft. This is the only aspect that could possibly be the cause of the lost step problem. I have 1200 oz*in motors on the X and Y and never seem to have a problem.
The new servo is a 360 oz/in that I purchased from Jeff at homecnc.This motor has a maximum speed of 2150 RPM. Jeff has his servo on the X axis designed with a 2 to 1 ratio. I decided since speed was not a issue on the X. I went with a ratio of 3 to 1 just to play it safe. I got the timing pulleys from http://sdp-si.com/
A 6A25-020DF15 5mm (HTD) Pitch, 20 Teeth, Aluminum Alloy Timing Pulley
A 6A25-060NF1512 5mm (HTD) Pitch, 60 Teeth, Aluminum Alloy Timing Pulley
A 6R25M104150 5 mm HTD Pitch, 104 Teeth, 15 mm Wide, Neoprene Belt.
The next step is to do the wiring, these servos look to be more complex then steppers so I hope I can get thru the process with my new Gecko 320 intact.

Regards Barry

bgolash
03-18-2006, 01:47 PM
Hi
Just upgraded my spindle to one from the littlemachineshop. The timing pulleys I selected are setup more for my woodworking. The maximum speed of the spindle is 5000 rpms. For my test in steel I set the depth for .1 at a very slow feed of 4 ipm and cutter speed was 700 rpms. The cutter was cutting its full width at .5. I was happy with the results except for the fact that when I was almost done to my surprise the spindle slowed to a stop. It`s my guess that the grearup drive is loosing a great amount of torque due to the ratio change. So it seems I`ll have to purchase more timing pulleys for a gear down drive. At that speed of 700 rpms I could grab the spindle by hand and stop it. Even with the variable speed 1 hp baldor motor. I am optimistic that this machine can do some work with steel. During the cut there was no cutter vibration or chatter.

Regards Barry

Enraged
03-18-2006, 03:53 PM
read up on this thread, Mike has done some very good work modifying that spindle:
http://www.cnczone.com/forums/showthread.php?t=10695&page=1&pp=15

page 7 is where some of the good info is. what ratio are you using from motor:spindle? If you are running 1:1 or close to it, at 700rpm I doubt you are seeing the 1hp out of your motor.

keep up the posts, I really enjoy reading about your project :)

Netjams
03-19-2006, 07:45 AM
Very inspiring!

Thanks for sharing your top notch build with us.

ballscrewed
03-19-2006, 08:44 AM
just an illusion or do you have the larger pulley on the motor and the smaller one on the spindle? If so that is why you are having torque issues. You should have the pulleys reversed for a steel cutting app. to give greater torque at slower speed rates.
Aaron

bgolash
03-20-2006, 11:59 AM
Hi
Its no illusion with the pulley arraignment. This is all a experiment . I just got the new spindle and the machines main
function is for woodworking. As a result the drive is a gearup to 5000 rpms. The steel test was just a experiment
to see what the limitations of this DIY machine would be. I was aware when the spindle stopped it was a gearing
problem. Down the road I plan to retrofit a 2 groove step pulley for a gearup and down drive. It would be so much
more convenient then changing taperlock sheaves for metal to wood.
The 5000 rpm for the wood is considered slow but I`ve had good results machining cherry, mahogany and birdseye maple.
I did a 3D sample of a violin top in mahogany and one in birdseye maple and I was very happy with the surface finish.
When I can I purchase the bits in a 4 flute version . For the violin I used a carbide cutter that was only a two flute cove bit but
was surprised with the surface finish. I recently did a brass limit switch stop which was a bit overkill for the machine
and it did a decent job milling the surface. I`ll admit I had to do some filing to cleanup the surface after the milling. This problem
with surface finish was traced back to the machine table. A unsupported 3/4 thick piece of MDF just isn`t up to the job when it
comes to machining metal.

bgolash
04-29-2006, 09:30 PM
Hello
Here`s a detail note. I changed the Z axis to a servo to eliminate lost steps. It seemed to be a great solution until I started running the machine in a 3D cut at 70 ipms. The servo I have has a 3/16 shaft and the setscrew is very small.I did not create a flat spot on the shaft and as I ran the machine at higher speeds the needed torque was greater then the pressure I had on the setscrew. The pulley slipped. I`ll take a guess and conclude that as the speed increases for a stepper or a servo the torque needed to move the axis increases also. This increase is higher then you might think. So, instead of taking a shortcut save yourself problems and create a flat spot or pin the shaft. It seems with this DIY stuff you can never can take shortcuts.

Barry

bgolash
05-30-2006, 07:38 PM
Hi

I decided to upgrade my ball screw assembly on the Y axis to a anti-backlash design. I was getting a total backlash of .005. I could push and pull on the z axis and feel the movement.
In the original design I had cannibalized a ball screw which happened to have a custom mounting bracket. For this upgrade I again took parts from another spare ball screw and used the ball nut housing. I then machined a piece of aluminum to a sliding fit. This would then slide onto the ball nut housing. The other end of the aluminum part was bored and tapped to a 15/16-16 which was the size of the second Nook ball nut thread. Just assembled the parts today and now I have .002 backlash. If time permits I`ll spend some time to get it closer but may tend to be conservative on how much I preload to minimize the backlash. I`ll take a guess that too much pressure on the ball bearings could cause problems. I`m wondering if anyone at the zone had a method to adjust the ball screw to a safe level.

bgolash
02-01-2007, 09:14 AM
Hi

Just finished my relief carving. The results were good. It was a bit slow
to machine, 5 1/2 hours at 50 ipms. The wood was cherry with 3 coats
of Tung oil.

Barry

joecnc2006
02-01-2007, 02:52 PM
Hi

Just finished my relief carving. The results were good. It was a bit slow
to machine, 5 1/2 hours at 50 ipms. The wood was cherry with 3 coats
of Tung oil.

Barry

What was the software steps you used to get the relief you wanted?

Joe

bgolash
02-01-2007, 05:17 PM
Hi

I`m not certain I understand the question. I had a person that uses Artcam to design the 3D relief. I then used a .005 stepover. I might have used a larger stepover but I was concerned the surface might be too rough. This project was for me so as a result I used a stepover I had used in the past. .005 stepover provided great results.

Barry

mxtras
02-01-2007, 05:57 PM
Very nice work!

Glad to see you are still plugging along.

Scott

bgolash
01-18-2008, 09:35 AM
Hi

Just finished turning and installing a new motor pulley for my machine. I had a gear up drive using timing belts. This allowed speeds that worked fine for my woodworking. I tried a bit of steel machining but reducing the speed via the DC speed controller lowered the torque so much you could nearly stop the spindle by hand. By having a two step pulley I have a great amount of torque for the metalworking . The high speed is 4700 and the low speed goes up to 1500 rpms. The spindle pulley was purchased from the LittleMachineShop.

Barry

bgolash
10-16-2008, 02:46 PM
Hi

I finally got around to milling my machine frame. Prior to machining I made up four leg levers and attached them to the machine.
I also added cross braces to the machine frame and epoxied them in place. I noticed that heavy down pressures which are typical of drilling really deflected the old table design.
Before I machined the frame I first used a master level to get the table as close to level as possible. It takes alot of time. Those levels are just so sensitive.

bgolash
10-16-2008, 03:04 PM
Hi
I forgot to add a pic of the new 1 1/2 thick MDF table. Its attached with
fifteen bolts direct into the machine frame. Before attaching the top I finsihed
the bottom and edges with polyurethane. I will add a spoiler board on top of
the 1 1/2 MDF. I just got a piece of 3/4 MDF.

calgrdnr
10-16-2008, 04:04 PM
Looks very nice and stout ...

bgolash
10-28-2009, 10:18 AM
I`m attempting to make a new cast iron and aluminum work surface for my DIY CNC milling machine. The current table was just a piece of 1 1/2 MDF. I got prices on a piece of cast iron and it would make your head spin. As a result, I had two pieces of .875 thick cast iron available in house. It would have been better to use one piece 12.5 x 35. Even so I ended up rabbeting the short edges of the cast plate and placing three screws along the joint.Aluminum stripes were then placed under the plate to make the plate 1.533 thick overall. This will match the thickness of the MDF after I machine away .033 form the cast iron surface
The aluminum pieces were pinned and screwed to the underside of the cast plate. I then dissembled the complete project then used west system epoxy to glue all the parts together. The next step will be to bolt down the plate and mill the surface of the cast iron table.

Regards Barry

bgolash
11-05-2009, 07:50 PM
Hi

Over the weekend I managed to drill 12 bolts holes in the cast iron plate and secured it to the machine frame. I then surfaced the plate by taking a roughing pass of .014. Today I did a finish pass on the cast plate. Total time was 5 hrs and 58 minutes. I used a 3/8 diameter carbide end mill, 4 flute at a spindle speed of 300 rpm and 4 ipm. I ran a dial indicator over the plate and see a deviation of .003. I had no idea what to expect regarding surface flatness but I`m very happy with the results.

PS... Special thanks goes out to widgitmaster for his recommendations for speeds and feeds for cast iron!

You tube video of the machining: YouTube- DiyRouterMillingCast Iron

bgolash
11-06-2009, 10:29 AM
Just recently I added and surfaced a cast iron work surface to my diy mill. I`m ready to add some bolt holes to act as a hold down system. Not certain what to use for spacing between holes. I am thinking about making the holes to allow them to be tapped for 3/8-16. Using a smaller size then 1/2 -13 to minimize weakening the plate. The plate size is 12.5 x 35.
It was my thought to have two rows of holes with 2 inch spacing. This hole pattern would run the long dimension of the plate. On the opposite side I`d have a mirror image of the hole pattern. I`m hoping the pros here can help out. I`d hate to screwup and make a mess out of the plate by using a unusable spacing.

CNCfun&games
12-04-2009, 04:16 PM
Beautiful rock solid design!!!
With the addition of the cast iron table you can machine any material.

The layout you now have cries out for a 2 axis trunnion table.
It appears you have the resources & experience to build one so...Go for it!

Then get one of those 2.2kw Water cooled spindles and you have a world beater.

Congratulations...W. Smith

Benonymous
12-07-2009, 09:46 PM
I have to congratulate you on a really superb machine! Isn't it amazing what something like cast iron can cost new! If you saw it in a scrap yard you could get it for a few dollars but don't try to buy it new :eek: I'm planning a steel framed machine and if it turns out even half as good as yours I'll be happy!

CNCfun&games
12-18-2009, 12:17 PM
Barry,

Took the time to read your thread start to finish this AM.
I'm glad I did.....A remarkable journey.....I learned a lot.

Thanks!
W. Smith, Mission Viejo, CA

bgolash
12-19-2009, 07:18 PM
Hi CNCFun&Games

Thanks for the positive comments on my build. I feel especially flattered by your comments. Considering the impressive results you have showcased at the zone.

Thanks and have a great holiday season.

bgolash
12-19-2009, 07:27 PM
Hi Benonymous

This build keeps moving forward with endless modifications to the original
design. Thanks for taking the time to view my build. Good luck with your
project. If you have any questions don`t hesitate to email. I`d be happy to
help.

Regards barry

coop2005
01-26-2010, 10:12 PM
Hi
I am finshing up my own router table and your machine seems as tho it has a similarly heavy gantry. I also have a long leadscrew drive on the gantry and i was wondering about your steppers driving that axis. I seem to have a lot of trouble with acclerations, even tho they are set low i seem to be getting lots of scary vibrations and noise with the small intricate movements. What microstepping/accel/velocity/etc settings did you find the best.

golash
01-31-2010, 11:52 AM
Hi
I converted from 1200 oz in steppers a few years ago to servos. I had some of the same problems you mentioned when using steppers. Its also possible your problem may be due to noise issues. EMI can cause strange sounds and results. Even with my servos sometimes I have lost position.
Also, using a power supply that is not high enough in voltage can make for a lack of power in the system. In your case I`d try the same G code project and
try different accelerations and also try running the code slower... ipm. See how slow you need to go to produce consistent results. Some code with complex movements must be run slower then usual to be safe.

RomanLini
01-31-2010, 08:50 PM
This is a great thread, thanks for posting it and taking the time to add all the pictures etc.

It's nice to see a good solid home build and even nicer to see all the changes and improvements over the years. :)