Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: haydms on December 21, 2006, 10:07:57 PM
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Hello all,
I’m new to Mach3 and stepper motors and I have run into what I think is a small problem so I’m hoping you can help me. I have checked the forum before I posted to make sure I wasn’t repeating anyone’s problems My set up is as follows mach3 version 2.0.017 and its licensed, Xylotex 4 axis stepper board running the 425oz steppers (2 in master/slave on X /A and a normal Y and Z configuration. The power supply is also from Xylotex The pc is running XP professional SP2 its an older machine but its only running mach3. The machine itself is immaterial at the moment as this happens without lead screws connected.
Now the problem I can run at any speed I want in jog (within reason) however in MDI or program mode the axis moves about an inch then steps irregular and sometimes stalls. If the lead screws are connected at a slow speed then the distance traveled is correct so the set up of the pitch is correct with the irregular stepper movement even (if I go above 10ipm the motor seems to stall).
I’m thinking one of three things the power supply doesn’t have the correct current available however the use of jog speeds unto 31 ipm seems to negate that. It could be dropped pulses from the interface I placed a second parallel port in and experienced the same thing. Or last it could be my pc.
I have ordered a break out box from mini i/o products to possibly eliminate the parallel port issues that should be here soon.
The other thing I have noticed is that in lazy cam if I use line numbering the program has double line numbers every 40 lines or so (ie N120 N125 X22.56 Y 12.0) it only requires a re-edit but I wondered if any one else had encountered it, also if I import a DFX i lose part of the Acad or TurboCAD drawing if I import as a HPGL from the same program its fine.
Any help or direction you can give me would be appreciated. Just so you know I’m not a total CNC idiot I have worked for a CNC controls manufacturer for 20 years and know CNC’s and servo drives quite well but not steppers as we / I have never use them.
This is purely for a home router project and for hobby use. Thanks in advance
Mark Haydock
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You need to check sherline mode in under the ports and pins settings that should fix the problem that you are having
Thanks
Brian
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Is the machine put together? Until you home the axis you jogging will not be at full speed. I believe there is a setting someplace to set a homed condition.
When you are going into MDI or running a program you are using a different feedrate than the default jog speed. Doing a g0 move will move at the max speed you have set in tuning. try using a g1 move and slowly increase the feedrate untill it stalls out on you, then back off your max velicity in the motor tuning dialog.
You also may need to modify your acceleration times. You may be accelerating too fast.
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Thank you for your quick responses
Brian the sherline mode was unchecked so I checked it and restarted the program I didn’t see much of an effect (except the stepper seemed to pulse constantly from the start of the MDI x1 g0 move)
Macona X and Y are together although I have the lead screws uncoupled at the moment the home position is set via Mach3 and the tuning is now down to 6 ipm with a slow acceleration/deceleration with no change I even went as far as 2 ipm and the steps are more pronounced. It seems to acel/decel fine this problem is actually in the move
Thanks once again
Mark Haydock
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you should be running better then that... what do you have for axis settings?
Steps per unit?
Vel
and Accel
What mode are you running in? 25KHz?
thanks
Brian
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Hi Brian,
I’m running 28800 steps on a 5/16-18 Y screw the board is set up as *8 pulses (when connected) and velocity of 4.0002 with an acceleration of 3.57 all units in inches. This gives me the right distance traveled on the DRO and the machine. I tried both 25k and 35k on the Hz. Also when i say stepping it does about 1/3 of a turn on the motor but its not a consistant 1/3.
I’m just at a loss the X axis has a 9 tpi lead screw however if not connected what difference should it make? It wouldn’t on a servo so my knowledge goes out the window ….
Thanks once again for the help I don’t think it’s a Mack setup issue but I could be wrong (like usual according to my wife).
Mark Haydock
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I take it you are running microtepping drives? If you can turn off the microstep and lower your steps per unit.
You did restart mach between changing freqs right?
How fast is your computer? Processor? Mhz? Ram?
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Thanks for the help,
I found the issue today i happend to be bad performance settings in my windows configuration. I can now run full part programs and MDI without issue at approximately 31 ipm with no irregular steps.
Mark Haydock
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Great, you should be cutting parts in no time :)
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Could you say which Windows setting was off? Having the same problem...
Thanks,
Spark
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Spark,
All I actually did was went to Control panel then System under the Advanced tab go to Performance settings ten Visual E effects select custom de-check everything then select the Advanced tab make sure Programs are set in the Processor scheduling and Memory usage I also doubled my virtual memory then hit OK and shut down the system. Upon reboot I went back to the Visual Effects and made the let windows choose what’s best for my computer hit OK and then reboot.
I restarted Mach3 referenced and entered a MDI move it worked ok then I just increased speed until vibration’s occurred its now 31ipm X, 25ipm Y and 10ipm on Z they can all run at 31ipm however its not practical in the application I am using my machine for at the moment.
My Pc is an old 1.2 Pentium with only 256meg ram hence the reason I thought about the pc as a possible problem
I hope this helps if not let me know
Regards,
Mark
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Tun off everything under MSconfig/startup as well. There coudl be a program that is getting loaded that is the problem. Also you need to look for power settings on your computer. Laptops change the CPU speed to save battery life and that is Not so good for mach3 as it needs to have everything running at the right time (speed)
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Thanks all. will try these.
Spark