Messages

1

General Mach Discussion / Off the shelf servo controller for Mach3

« on: July 27, 2010, 02:54:17 AM »

I unfortunately have the Imserv Servo setup for Sherline machines. I very strongly recommend against anyone getting it if you have any desire for a stable machine that just works.

I have had servo faults with this system forever. Sometimes are better than others. It is getting worse. I have the servo's set for 20 IPM and 1.5 acceleration. They have worked at 40 and 4.5 and the servo fault rate seems to be about the same.

I have a huge amount of parts that I need to get finished by Friday. With this screwball Imserv crap, I'll never get them done, much less by Friday.

Does anyone know of a off the shelf controller system that:

a. works decently
b. works with Mach 3
c. does 4 axis
d. preferably will connect to the existing servos from Imserv. (NEMA-23 mounts)
e. If D is not practical, I'll take stepper motors, new servos, whatever I need to do.

I don't need to do anything fancy. The only movement commands I use are G01 and G00. No spindle control, no coolant, just the 4 axis is what I need controlled.

Any suggestions?

Thanks!

2

General Mach Discussion / Re: not stopping in correct position

« on: April 12, 2009, 12:31:15 PM »

Seems to have worked so far. If I have further problems, I'll post.

Thanks for the help

3

General Mach Discussion / Re: not stopping in correct position

« on: April 11, 2009, 06:23:44 PM »

Thanks for the replies.

My XML is attached.

4

General Mach Discussion / Re: not stopping in correct position

« on: April 11, 2009, 03:30:27 PM »

Hm, Ok I'm confused. (not hard to accomplish).

In inch mode, the resolution on each of the axis is .0001" on the main screen. I go to motor tuning, and each axis as 22,588 steps per unit, so there should be enough motor resolution to get within .0001-.0002"

I went into each of of the config drop down menus, and couldn't find anything labeled resolution. I also went to settings (alt 6) and didn't find anything.

Where do I find resolution and what should it be set at?

Thanks!

5

General Mach Discussion / not stopping in correct position

« on: April 10, 2009, 09:41:10 PM »

Hi guys. I'm running into a ongoing problem with R2.0.060.

In MDI mode, and also at the end of programs, Mach stops the machine at the wrong position. I don't know if it's happening within programs, it doesn't seem like it, but my stuff is small enough that it might not be noticed.

For example, the last move in a program might be G00 Z1. The machine will move to Z.978 (or whatever number) and stop, according to the display, and the position is pretty accurate on the machine itself. It doesn't happen with every program, but if it does happen with a program, it's very consistent. It happens everytime, and it always stops at .978.

In MDI mode, I'll be at x5.0 or something, and enter G00 X0, and Mach will stop at X.492 (or something). Enter the command again, and it doesn't move. Jog the machine in X, enter the command G00 X0 again, and it moves to X0 like it should.

It doesn't happen all the time, but certainly enough to be frustrating.

Any ideas?

Thanks!

6

General Mach Discussion / Re: external estop requested problems

« on: December 04, 2008, 05:37:30 PM »

Thanks Hood.

I don't have any limit switches on the machine.

The debounce interval was set to 0, so I set it to 1000 and am running it now, cutting air. I'll check in the morning to see if it went through the program.

There is also a index debouce, which is also currently set to 0. Could that have anything to do with the problem?

Neither of these terms mean a thing to me.

Thanks!
Scott

7

General Mach Discussion / external estop requested problems

« on: December 04, 2008, 02:56:24 PM »

I'm having a problem with Mach 3 at the moment.

Seemingly randomly, Mach3 will stop and need me to click the reset button. I get the message that an external e-stop was requested. I click reset, and cycle start and it starts going again. It doesn't loose position, but the next few lines of gcode are screwy, and I almost always violate and scrap out the part.

I have a 5 hour long 4 axis program that I am cutting on a Sherline mill the IMServices's controller and servos. I have run the program before with no problems, and Mach 3 doesn't stop at a consistent point in the program. So the problem is not the program.

I had this same problem a couple months ago, and it went away. Now it's back. Nothing changed that I am aware of. Same PC, controller, version of Mach, servos, etc.

Any suggestions on how to fix this? Is it possible to tell mach to ignore external estops entirely?

Thanks!
Scott

8

General Mach Discussion / Re: problem with getting detail

« on: August 29, 2008, 01:34:51 PM »

Think I figured out the problem. For some reason, I all of a sudden have huge backlash on the Z axis, like about .025 or so.

I'll never get another Sherline again. Can't say they are bad machines for the money, I've just had problem after problem with them. I buy a 3rd party add-on and the problem goes away.

Anyway, ordered a precision leadscrew Z axis from A2Z, hope to get it tomorrow and I can finish this stuff up this weekend.

9

General Mach Discussion / Re: problem with getting detail

« on: August 29, 2008, 12:20:33 PM »

I'm using a 15deg profile cutter with a .004" tip.

10

General Mach Discussion / problem with getting detail

« on: August 29, 2008, 10:51:42 AM »

I'm having real problems with my CNC setup right now. Not sure where the problem lies, or how to determine what it is.

I'm using mach3, have a sherline 4 axis mill, and the IMService's servo system (converted for use with Mach).

The attached simulation image is what the program should be cutting, as seen in Rhino3d with RhinoCam. The other image is what I am getting when I cut the wax.

All the detail in the feathers and such is gone. It's pretty flat. I cut 1 piece, looked great but decided I needed to reduce the stepover to reduce the size of the steps, and try changing cutting direction from across the X axis to along it.  I reprogramed the part and cut it. Next run was good, but I didn't go quite deep enough and it wasn't cleaning up the workpiece. Dropped my Z .02" and restarted. Ever since, I have not been able to get any detail.

I've rebooted the PC, reduced the velocity and acceleration on the Z axis by about 1/2, went back to a XML file that worked flawlessly (a copy is attached, the accel/velocity changes not included though), tried reprogramming again, reduced my feed to 3 IPM  (first piece was cut at 8 IPM), and nothing has changed the problem. I'm still getting almost no detail.

What's really wierd is that if you look at the simulation image and the wax, it looks like the step up from the flat cylinder to the wing is ok, but it cuts off almost all the feathers. The step up to the wing doesn't look to be as much as it should be, but it's consistently making that step and not making the step over the feathers.

I have cut quite a few 4 axis things before, without a problem. This is my first wax cutting job.

Any suggestions? I'm desperate to get this part out. Been playing with this for a week and am at my wits end.

Thanks