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Servo taig help needed
« on: January 10, 2008, 06:20:07 AM »
Ok, here is my situation; I purchased a used Taig mini mill that was converted to CNC by Super-tech.com.  It is a servo system that has gecko drivers but used the old Supercam software to control it.  By old I mean it took a windows98 box to control it. 
The Supercam software was ok, but it is really dated and it had problems if I tried taking any g-code into it crashed the mill and I can forget about doing 3d surfacing. 

My machine is similar to this http://www.super-tech.com/root/grp.asp?p1=PN_TAIG-3000-LBGS-C.

I got hold of a different computer and installed Mach3 but am having some problems setting it up. 

Old system:
Pentium 2 desktop
Win 98
Running original Supercam
Jogged accurately but difficult to get g-code into it.


New system:
P4  -  1.2ghz  desktop
Win XP
Running mach3
Can take G-code no problem.
Will accurately jog on X and Z  but not Y axis.

I was able to get the XML file from Dennis at Super-tech and it only needed a little adjustment for my particular machine.  Dennis and the file hes sent have been a big help.

My problem is that the Y-axis  is not tracking properly.  It is spinning normal one second then continues to spin but not turn the screw.  When running a program it tracks but it is not consistent one pass a one inch line will be 1”, then 5/8”, and then ¾”.
I checked the cable with a multimeter and it is reading 5v on several pins.  So, I’m not sure if it is a glitch there.

When I hooked it back up to the old win98 box and old software, it still runs fine.

Please help.  I have spent several days trying to get this working and I will have no time when school starts back up next week.

I just don’t know what to try next.

Thanks Omega_sam

Offline Hood

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Re: Servo taig help needed
« Reply #1 on: January 10, 2008, 06:30:07 AM »
It sounds like your motor is needing tuned, try lowering the acceleration a bit.
Hood
Re: Servo taig help needed
« Reply #2 on: January 10, 2008, 12:29:18 PM »
Thanks for the reply hood. 

so everyone is on the same page:
 The Servos that came with the system are DYNETIC SYSTEMS  model 230188A

Settings are at 16000 steps with Accel at 2.5,  Steps at 4 and Dir at 4

Most of this is going off of the XML file that I got.

I'll play with the acceleration a bit and see what happens.

Any other advice welcome. Omega_Sam
Re: Servo taig help needed
« Reply #3 on: January 10, 2008, 02:14:54 PM »
Mach3 motor settings are at 16000 steps with Max speed at 90 ipm, Accel at 2.5,  Steps at 4 and Dir at 4. 

Tried a range of Acceleration from 0.5 to 6.0  with no luck.

Also tried changing the signal to 35,000 since the CPU is over 1ghz.

No luck on either front.

Offline Chip

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Re: Servo taig help needed
« Reply #4 on: January 10, 2008, 03:57:52 PM »
Hi, Omega_Sam

If this is what's happening, "It is spinning normal one second then continues to spin but not turn the screw."

Probably a lose "set screw" in the Y axis drive train, Are you sure it's servos and not steppers. ?

What's the PN on the Gecko's

If it's steppers, Then reduce your Velocity in motor tuning.

Hope this Helps, Chip.
Re: Servo taig help needed
« Reply #5 on: January 10, 2008, 04:28:39 PM »
Ok  looks like  the original motor setup has pin out for “step”  and “direction” but in the Motor Tuning dialog there are fields for “step pulse” (milliseconds) and a redundant “Dir #” for the direction pin?
  I think I’m gonna be sick.
Re: Servo taig help needed
« Reply #6 on: January 12, 2008, 02:52:16 PM »
They are G320 dc servo drivers, at least I think that is correct.

I've been beating my head against a wall trying to sort this out.  I hooked it back to the original control system, the win98 box, and it started acting like it the y-Azis was slipping.   When drawing a square it doesn't come back to the same position, it looks like a flag on a pole.
After Turing to adjust the motors the x axis stated sounding like it had gravel inside it. 

I got the feeling that I had a hardware failure (cable, contoll er, or motor), both systems were having problems with the Y-axis.

As a last ditch effort I tried calling Dennis  at Super_tech one more time, and got brushed off. 

I decided to just start from scratch with a fresh copy of the XML file.  The motors sound awful unless the "step pulse" is set to 4.

now I can get it to draw a square, and I got it to follow a pocketing toolpath but it still cant handle polyline to cut consistently.

Thanks.  Omega_Sam

Offline Chip

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Re: Servo taig help needed
« Reply #7 on: January 12, 2008, 03:29:50 PM »
Hi, Omega_Sam

What size nails are you driving into the wall, OUCH ! ! !. Been there Before.

Have you tried both EX Stop and CV mode's in General Config, Reduced Acceleration a little more, So many short line segments can be a pain.

What kernel speed are you using in Ports & pins first page, Try 35 or 45 k-speed, You'll need to re-start Mach and Re-Tune.

Thanks, Chip
Re: Servo taig help needed
« Reply #8 on: January 12, 2008, 04:24:48 PM »
Hi chip and thanks again for all advice,

I also changed to the demo of Mach3  v3.01,   I had been running v2.62.  I am waiting to pay until I can get it runnning.

Mach3 motor settings are at 16000 steps with Max speed at 90 ipm, Accel at 2.5,  Step pulse at 4 and Dir at 4.   What does the "Dir" box mean in in the motor tuning page?  Does that match the Dir pin in general setup?

Never even saw the EX or CV modes, so not sure.

I was told that the step pulese should be at 1 Milisecond, but the motors sound horible with current config. 

Currently i'm set up at the recomended 25K but I am running a P4 1.3 ghz processor so I should up it.

What is a good method for Re-tuning?    I'd like to try and keep it simple and systematic.

I ran the port diagnostic tool and it seems pretty clean signal wise,  mostly steady fuzzy line.   I have a new parallel port card on the way as well.

Offline Chip

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Re: Servo taig help needed
« Reply #9 on: January 12, 2008, 05:41:23 PM »
Hi, Omega_Sam

If your in demo mode 25 k speed is all that's available, So no re-tuning for faster k speed.

Did you get any setup info for Vel and Accl from the Mfg. ?

With your Max speed at 90 ipm (thought you sead it was 4 earlier), Accel at 2.5, Set your Acceleration up to 20 or higher and see if that helps.

The F settings in your G-code G1, 2, 3, moves will override your Acceleration setting, If your servos don't lose position and fault with G0 moves is really the

only speed limiting factor.

Step pulse at 4 and Dir at 4, (Both of these are the time Mach gives your control to see the pulse's it's sending out.

You can find the Ex-CV mode in Config, General Config setup box/page, CV mode blends/Looks Ahead for faster smother cut's.

Sent you a PM, Top left near your user Info.

Give it a Try, Chip
« Last Edit: January 12, 2008, 05:52:30 PM by afn09556 »