Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Hairball on May 02, 2006, 07:29:02 PM

Title: Missing Steps
Post by: Hairball on May 02, 2006, 07:29:02 PM
Help,
Is it common for a stepper motor(new) to miss steps only in one direction during the jog mode? (6 IPM, Continous or Incremental, but only in one direction. I have been all over the tuning , ports and pins,  and nothing seems to make any difference. I plugged it into another axis controller that runs an identical stepper motor without missing steps and it still does it. I took it off of the machine and ran it on the bench and it still does it. Will it miss steps when i run a program? anybody ever have this problem?
 ???
Thanks
Title: Re: Missing Steps
Post by: Brian Barker on May 02, 2006, 08:07:54 PM
Put in a pulse width of 5us that could help it...
Title: Re: Missing Steps
Post by: Hairball on May 03, 2006, 02:21:53 PM
Pulse width makes no difference. Still missing steps. I tried to cut a 3 inch circle and it progressively gets cumulative errror in x and y.
Any other ideas?

Thanks
Title: Re: Missing Steps
Post by: Brian Barker on May 03, 2006, 02:43:33 PM
What are the drives?
Title: Re: Missing Steps
Post by: Hairball on May 03, 2006, 04:31:29 PM
Hi thanks for helping,

The driver systems are a Dan Mauch built and tested box with geckos and power supply built in. It was pretty much plug and play.
The stepper motors are 460 in/oz from Camtronics also (Dan Mauch). It seems that x and y are both missing steps only in one direction? Should I try Mach 2?

Danny Nelson
Title: Re: Missing Steps
Post by: Brian Barker on May 03, 2006, 09:08:17 PM
Try putting in a prechange of 5 us as well... What are you running for a breakout board?
Title: Re: Missing Steps
Post by: Hairball on May 04, 2006, 05:14:55 PM
Changing Prechange number(Mach 3 calls it Dir Pulse) does not make a difference. I emailed Camtronics to find out about the breakout board and have not heard from them yet?
Here is something I have noted. It does not matter if you reverse the motor in the Home/Limits box, the motors always miss steps when they go the same rotational direction (i.e. Clockwise)?

Respond if you want to and I will let you know what Camtronics says. If I don't hear from them I'll open the box and see if I can Identify the breakout board if that will help.

Thanks 
 Danny
Title: Re: Missing Steps
Post by: Brian Barker on May 04, 2006, 06:59:52 PM
What is the voltage coming out of the P port? I BET you have a 3.5V system...
Title: Re: Missing Steps
Post by: Hairball on May 04, 2006, 08:24:36 PM
The Camtronics box has a +5volts plug in in the back and they supplied a USB cable that adapted from USB to the plug.
I measured from USB cable to PC Case(ground) and got 5 volts. I will take the Camtronics case apart and try to identify its
components.   Danny ???
Title: Re: Missing Steps
Post by: Hairball on May 07, 2006, 09:19:54 AM
Hi Brian,
I think you are onto the problem...

I was able to troubleshoot over the phone with Dan Mauch (nice guy!) and we think we may have it solved. After going thru some tuning stuff in Mach2, he had me check voltages coming out of the PC (Brand new 2.2 ghz Emachine from Best Buy) thru the DB 25 cable. Hooking up meter to pin 3 (controls x axis) and pin 18(common). Going in the direction that it did not miss steps the meter read 3.2 volts.(Still too low) In the direction when it missed steps the meter read .1 volts! Dan is sending me device to amplify the DB 25 output next week. I will let you know if this solves my problem.

Thanks for listening...Danny
Title: Re: Missing Steps
Post by: Brian Barker on May 07, 2006, 12:32:49 PM
Good, Glad to hear that you are getting the problem fixed!
Title: Re: Missing Steps
Post by: christopherwoods on May 10, 2006, 04:09:29 PM
Hello,  Mind if I piggieback on your thread?  I am having the same problem with Mach3.  I am a newbie to the whole CNC scene.  I got a used K2 about 6 months ago.  It came with DOS CNCZEUS.  I bought the Mach licensce a couple months ago.  So I am up and running perfectly with Mach2.  The problem that I have with Mach3 is that after running it for about 5 minutes it starts loosing steps and gets progressively worse until there is little movement at all from the axises.  Return it to Zero and it is way off.  I bought new Nema motors thinking that that was the the problem but had the same results until I switched to Mach2.  I'll go through some of the above suggestions and see if changing the pulse with helps out in my situation.  But Danny, if you have solved your issue, I'd like to hear about the results.  Thanks.
Title: Re: Missing Steps
Post by: Hairball on May 10, 2006, 05:56:39 PM
Hi Chris,
The company that supplied my control unit(three 452 in/oz motors, three gecko drivers, power supply,cables, etc.(Camtronics) is sending me a parallel port booster.  Maybe I'll get it before the weekend. As soon as I get it I will install and let you know if it fixes it.

Danny
Title: Re: Missing Steps
Post by: christopherwoods on May 10, 2006, 11:38:13 PM
Danny,  That would be cool if yoiu could let me know your results.  Did you try running Mach2 and if so did you have any problems with it or is it just a Mach3 problem?
Title: Re: Missing Steps
Post by: Hairball on May 11, 2006, 10:06:23 AM
To see my machine go here... Over there I'm "sprintfan"
http://www.cnczone.com/gallery/showgallery.php/cat/505
Title: Re: Missing Steps
Post by: Hairball on May 17, 2006, 12:13:29 PM
The Parallel port booster Camtromics sent me fixed all of my problems! Just got done cutting a circular pocket with islands that needed to be concentric and to size and they were perfect! What out for new computers.They are dropping the output voltages
down to 3.5 volts. Thanks Brian for helping. ;D
Title: Re: Missing Steps
Post by: christopherwoods on May 17, 2006, 03:04:33 PM
Danny,  Thats great to hear that you have fixed your problems.  You'll probably be busy cutting stuff for several days now.   I checked out your pictures on CNC zone and the machine looks great!  I'd like to see some things that you make on it as well,  What are you planning to make with it?   -----  Did you ever try running Mach2?  I suspect that my problems are software based because I run just fine in Mach2 but in Mach3 it takes about 5 minutes of running a program before it starts loosing steps and then get progressively worse.  I haven't had time yet to play with any adjustments in the perameters.  I like the layout of Mach3 better but since Mach2 works good....  I am so busy using the machine that I am just using Mach2 for now.  Maybe I can play with Mach3 this weekend. 
Title: Re: Missing Steps
Post by: Brian Barker on May 17, 2006, 10:07:11 PM
If there is anything that I can do to help :)  I am here
Title: Re: Missing Steps
Post by: christopherwoods on May 18, 2006, 01:53:30 AM
Brian,  Thanks!  and I will probably be asking you some questions soon.  I'll be doing some experimenting with the settings that you mentioned above this weekend.  But for now, is it logical to think that since everything runs well in Mach2 that my problems in Mach3 are caused by some wrong setting?  -----  I actually have 30 minutes to spare right now,  I'm going to go see what I can figure out.
Title: Re: Missing Steps
Post by: christopherwoods on May 18, 2006, 02:28:12 AM
Brian,  you are talking about the step pules and dir pulse in the motor tuning settings right?  Mine were both set to zero and I changed them both to 5.  I am running a test now.  Also my machine has Nema stepper motors,  Since I can set the maximum travel rate, is there a danger of over running them and burning them out?  I have them set to:  Steps per 10000 / In's per 80 / accel 5 / and now both pulses at 5.
Title: Re: Missing Steps
Post by: christopherwoods on May 18, 2006, 03:30:29 AM
I ran twice through a pattern that takes about 20 minutes to cut.  No problems this time.  It used to start loosing steps about 10 minutes in and get progressively worse.  But after the changes, its all good.  Cool!  Now I can use Mach3  Thanks!!!
Title: Re: Missing Steps
Post by: Brian Barker on May 18, 2006, 07:12:15 AM
Very Good! No you can't do anything to hurt a stepper  ;D Other than taking a hammer to it I think you are safe

Happy cutting
Title: Re: Missing Steps
Post by: BobsShop on June 22, 2006, 09:48:16 AM
Art, Brian, Someone!!!

I have read every post about missing steps in the "Y" axis and applied all of the fixes i could understand.  When configuring motors the "Y" AXIS runs fine (no skips).  I have changed motors from one drive to other to see if it was the motor - no difference.  Changed out cables - no help. 

I have shut velocity and acceleration down to minimums or set to maximums and still get skips.  Changing to Sherline mode did not help.

I even pulled the lead screw our of the "Y" axis to determine if it was screwed up or blocked.  Looks okay.  Like I said - "Y" works fine when in the motor tuning mode.

I have determined in MIDI when I type in same distances for "X" and "Y" ex: G0x4 y4 - Y4 "Y" does not skip steps.  If I type in different  distances - ex: G0x4 y2 - "y" skips steps.  It isn't compensating for the differences.  The machine coordinates are wrong for "y" after the exercise.

Any suggestions will be appreciated.

Thanks

Bob

Title: Re: Missing Steps
Post by: Brian Barker on June 22, 2006, 01:52:23 PM
Could you pleae run a driver test and tell me what you see?
Title: Re: Missing Steps
Post by: BobsShop on June 22, 2006, 06:15:34 PM
Brian, ran a driver test and here is what I recorded (Mach3 not running)

Interrupt Used 00
Pulse per sec. 23517

APIC Present - Green Box

CPU Speed - 3067

APIC Timing - 5642

Shortest time 36,157 (I think)

Longest time 48, 700

Line variations basically flat with occ. 1/8" spike

With Mach3 Running:

Interrupt Used 00

Pulse per sec. 25812

APIC Present - Green Box

CPU Speed - 3067

APIC Timing - 5642

Shortest time 32,950

Longest time 32,950

No activity Line

No other programs are running when I am running Mach3.

Thanks for looking

Bob ???
Title: Re: Missing Steps
Post by: zealous on June 22, 2006, 07:23:53 PM
I was wondering if buying the:

"Campbell Designs" "Breakout Board Plus
for Mach2 and Mach3"
would solve the voltage problem caused by new computers and what other advantages there are to having it or if it helps with allot of problems people are having?
Title: Re: Missing Steps
Post by: Brian Barker on June 22, 2006, 07:29:09 PM
Bob's board will fix the problem of a low voltage printerport :)


I think you should look into the optimization and see if there is something in there that is making the spikes..

Thank you
Brian