[highcountrywnc]

I bought the 4848 kit and electronics kit(NEMA 23 320oz-in 3/8 shaft motors, cables, g540, 48v pwr supply) from crp(Great guys by the way!) I have worked every evening and weekend for a month, much to my wife's dismay. Im still not convinced she didn't have a boy friend during that month.:tired:

At any rate I have take every precaution that I am aware of to set this machine up correctly, but now I am losing steps on what I assume is the y axis.
I say Y axis because on this sign the machine keeps drifting to the right. I did not see this in the few simple test pieces, but this is a super complex piece and when i say losing steps, I mean big time!

I will let the machine run on board and now in air and after roughly 5 min i stop the program and return to zero and its out to the right nearly a quarter of an inch.I have checked the driver program and get a smooth line with a dot here and there off of it. I have backed the velocity down to 100 ipm acceleration to 10in/sec step pulse is at 1 dir pulse is 1, and steps per is 1736. I have limit/home switches on x+, X home, Y+, Y home, A home, and Z Home. Machine seems to zero fine seemed to run fine till this piece. I am completely new to cnc but highly technical and a quick study.I used the cables from CRP that are shielded so I would not think the cable would be the issue but hey if I knew I would not be asking for help. I have read and watched enough you tube videos that I probably could have gotten a pilots licence in that amount of time. Please give me any advice(well good advice)that you may have to what could be my problem.

Thanks in advance,
Jonathan

[cbr929]

Had the same problem, drove me mad until i found the solution.
Your problem looks to be on the X axis and not on the Y since your drift is on the right assuming you are looking the machine from the front.
If that's correct then the problem might be the single X axis stepper motor being defect and loosing steps on its own.
Best way to test it easy is to swap it with the one on the Z axis and do an air job to see if it returns to zero accurately.
Hope that helps.

George

[ahren]

Jonathan,

The issue could be related to a number of things:

1) Loose set screws on rack and pinion drives -- I'd check the pulleys on your motors to make sure these haven't vibrated loose. We recommend putting loctite on these screws.
2) PC related issue. If you are running with the parallel port (rather than a Smoothstepper or another separate motion controller), I'd suggest turning off any services (virus scanners, etc) that could interrupt Mach 3. Or purchase a Smoothstepper -- we steer everyone we can towards these units, as they save a ton of frustration caused by Windows and flaky parallel ports.
3) G540 related issue. The G540 runs hot, and without auxiliary cooling can experience issues with lost or intermittent steps. Additionally, I'd suggest moving the "step pulse" and "dir pulse" up to 10 to see if this helps. A number of G540's require longer than normal pulses in order to respond reliably. While this was theoretically being addressed by the manufacturer, we still see a number of drives that experience this issue, and benefit from increases in pulse length.

As always, feel free to call us to discuss and we can come up with a strategy to help you get past this problem.

Ahren
CNCRouterParts

[ger21]

step pulse is at 1 dir pulse is 1

For a G540, I believe the minimum pulse width required is 2ms. Try setting it to 3-4.

[highcountrywnc]

I assumed the y because standing in front of the machine, the stepover cuts start drifting to the right, x goes front to back y goes left to right and z goes up and down am I wrong about this?

[highcountrywnc]

Jonathan,

The issue could be related to a number of things:

1) Loose set screws on rack and pinion drives -- I'd check the pulleys on your motors to make sure these haven't vibrated loose. We recommend putting loctite on these screws.
2) PC related issue. If you are running with the parallel port (rather than a Smoothstepper or another separate motion controller), I'd suggest turning off any services (virus scanners, etc) that could interrupt Mach 3. Or purchase a Smoothstepper -- we steer everyone we can towards these units, as they save a ton of frustration caused by Windows and flaky parallel ports.
3) G540 related issue. The G540 runs hot, and without auxiliary cooling can experience issues with lost or intermittent steps. Additionally, I'd suggest moving the "step pulse" and "dir pulse" up to 10 to see if this helps. A number of G540's require longer than normal pulses in order to respond reliably. While this was theoretically being addressed by the manufacturer, we still see a number of drives that experience this issue, and benefit from increases in pulse length.

As always, feel free to call us to discuss and we can come up with a strategy to help you get past this problem.

Ahren
CNCRouterParts

Ahren thanks so much for you diligent attitude and getting the parts to me despite the postal service. I did use loctite, but will check them again I may decide to get smooth steper if I cannot get this remedied. I do have a clean install of windows nothing but mach3 installed. I have two huge fans on the enclosure with dust gaurds (120 mm) one intake and one exhaust. I will chang step and dir pulse.

Thanks again you are a great guy to deal with!

[highcountrywnc]

For a G540, I believe the minimum pulse width required is 2ms. Try setting it to 3-4.

Will do and let you guys know what happened. Thanks Gerry and everyone else who are willing to help.

[cbr929]

I assumed the y because standing in front of the machine, the stepover cuts start drifting to the right, x goes front to back y goes left to right and z goes up and down am I wrong about this?

Nope nothing wrong, just different orientation, still same concept as mine, the left to right movement has a single steper instead of back to front that has two, if any of the suggested solutions won't work just flip the the Z and Y step motors, no need to do anything else, are you using nema 23 or 34?

George

[highcountrywnc]

Gerry,Ahren and George
This is the axis orientation my table has:
Attachment 294836
periods are an example of where bit lands when go back to zero is hit in mach3(bold period is where zero is set before starting cut file.
I------------------------I
I
I
I picture
I . .
I_______________I
front of table

I would assume this is losing steps on y when i pull bit back to zero(left) it gives a deficit reading on y axis in mach3

I was hoping that one of these would resolve the problem, but they did not. Ahren i have a 120 mm intake and 120 mm exhaust fan(with dust covers in the 24"x8" enclosure.

Here is a list of the changes I made with exact same results as before:
-changed step and dir to 10
-changed step and dir to 4
-took all motors off and checked set screws replied lock tite(just in case one let go) everything looked good tight belts no slippage on pulleys/gears.
-took the motor from y and switched with z.

I ran some of the very simple vcarve files(in the air) I started with and the machine was within .01 of the point i set to zero after the file ran, that is why i did not see it until i ran this much more detailed larger file. It seems that the more steps that are ran the more it loses, I guess this is typical when losing steps.

I am Bumfuzzled...

[highcountrywnc]

Nope nothing wrong, just different orientation, still same concept as mine, the left to right movement has a single steper instead of back to front that has two, if any of the suggested solutions won't work just flip the the Z and Y step motors, no need to do anything else, are you using nema 23 or 34?

George

Nema 23

[cbr929]

Yeah but you are only loosing steps on the Y axis not on the X.

[highcountrywnc]

Yeah but you are only loosing steps on the Y axis not on the X.

Yep that is what has me puzzled, everything on the machine seems to be in order. I can't wrap my head around what would cause only that axis/motor to lose steps.

[MobiusConcepts]

How is the bearing on the drive spindle? When you take the drive assembly off, but with the motor (power off)/belt attached, can you spin the motor/belt by hand easily? When you remove the belt is there any play in the bearing? I just had a problem with my Y axis where the bearing was on it's way out and I had a heck of a time finding the problem until the bearing failed completely and stalled out the motor.

[ahren]

My suspicion is that this is electronics or PC related -- the spindles on this machine are brand new. Given that it is only one axis, it would be worth swapping the Y and Z axes drivers, and changing the ports and pins in Mach 3. If the problem moves to your Z axis, it's a sign that one of the drivers in your G540 is having an issue (potentially needing longer pulses, or some other issue).

Best regards,

Ahren
CNCRouterParts