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Axis won't move continuous
« on: December 24, 2010, 01:47:38 PM »
I'm new to the whole CNC world so that probably explains it all.

I'm finishing up a cnc machine and and have everything up and working but when I give a simple g-code command the stepper motors just move a few revolutions, stop, then a few more revolutions, and so on. the table moves to the desired location just not in a smooth motion. And only when you run any type of program.

When using the jog function they move fine and when homing they run fine. I'm not loosing steps, it's just not continuous movement.

Tried running something through sheetcam and still the same problem.

Example: g0y5

Starting at 0,0.The Y motor should move to 5 and stop and it does, but the motor will stop/start 19 times in the process.
If you slow the speed down it's more than that. Looks like it pauses about every second.

It's running old XP computer running mach 3 to a gecko 540 and Keling motors.

What setting am I missing or should be looking at? Hopefully that is all it is.

Thanks

Offline Hood

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Re: Axis won't move continuous
« Reply #1 on: December 24, 2010, 01:58:29 PM »
Cant think of anything that could cause that problem but if you attach your xml I will have a look and see if anything is set wrong.
Hood
Re: Axis won't move continuous
« Reply #2 on: December 24, 2010, 05:48:35 PM »
Here you go. I've tried a lot of different things but nothing seems to help.

Thanks

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Re: Axis won't move continuous
« Reply #3 on: December 24, 2010, 06:02:24 PM »
Looks ok and seems to work fine in simulation. There are a few weird numbers in Ports and pins such as you have pin 23 for the E-Stop and also a few in the Outputs that are not real pins. You also have limits set for X and Y to same inputs but that could be correct if you have NC switches in series. You also have an A axis and no Z but none of these should really cause any issues.

The file you sent was actually the backup xml so there is a possibility that things have changed so if you can attach the actual xml, it is located in the mainMach3 folder and not in the xml backup folder.

Have a look on the Diagnostics page and see if the Frequency is sitting steady and near to 25,000 also what is the Time in Int?
Hood
Re: Axis won't move continuous
« Reply #4 on: December 24, 2010, 07:30:37 PM »
Not sure how I screwed up the pin numbers. Write everything down and and still screw it up ::)

I do have limit switches in series(N.C.) that is why they are on the same pin. They work properly, just need to add some more switches. I was thinking that I could set the home switches to stop movement but  I need to add a limit on that end also.

I'm not close to the machine but I did look at the frequency before I left the shop and it was staying over 25k and the Time in Int was bouncing between +11 and +15.

In simulation it works fine. When running an actual cycle, you can watch the feed rate go up and down. So, I think it is something the computer is telling it and not with the drive or motors. Is it possible that it could be a computer problem? Processor speed? Amount of ram? Just throwing out all the options.

Sorry about sending the backup and not the actual XML. I thought the backup was what you were looking for. It will be Sunday before I can get the actual XML file.

I'm thinking about loading the 540 file from the Gecko site and see if that changes things.

Any other thoughts?
 

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Re: Axis won't move continuous
« Reply #5 on: December 24, 2010, 07:37:06 PM »
You can use the Home switch as a limit if you want, just assign the limit to the same pin as the home.

Close Mach and run the drivertest.exe and see if the line looks smooth.

Would however think that if it was a bad pulse you would be loosing position.

Might be worth doing the optimisation steps detailed in the text file on the downloads page, especially if your computer is close to the min specs for Mach and also if its loaded with other programmes.
Hood
Re: Axis won't move continuous
« Reply #6 on: December 24, 2010, 07:52:04 PM »
I'll be honest, I looked at the requirements and saw that it had to be a 32 bit windows and stopped there, never saw the rest. Its an old PC I had sitting around running an 02 version of windows XP and have no idea the specs on it. I cleaned all the other programs off but will have to check the speed and ram. So its a good chance it doesn't have the processor speed or the ram.  I'll check on Sunday (possibly Monday) and let you know.

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Re: Axis won't move continuous
« Reply #7 on: December 24, 2010, 07:56:01 PM »
1Gig is the min recommended so if its newer than 7 or so years old then it should be fine, especially if it originally came with XP.

Often computers get crammed with junk in the registry even if you uninstall programmes so I always do a clean install when using a computer for Mach and then never install any programmes except Mach.
Hood
Re: Axis won't move continuous
« Reply #8 on: December 27, 2010, 08:35:23 PM »
Well, I feel like an idiot!

Thanks for your help, the computer was the problem. I thought that since it came originally with XP that it would have be able to run the program. Unfortunately I think this was the first XP built and had nowhere close to the required ram or processor speed. Put a different computer on it today and most of my problems went away.

The only problem I have now is the external e-stop. It operates the 540 fine. I originally had it on the wrong pin, changed it to pin 15 and it causes a problem with mach. For some reason it mach thinks it is activated when its not. On the diagnostic page, the e-stop doesn't light up when activate or inactive. I'll mess with it some more tomorrow and let you know what I find. Any suggestions?

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Re: Axis won't move continuous
« Reply #9 on: December 27, 2010, 08:40:21 PM »
Have you set pin 15 as the E-Stop pin in Mach? (config menu then Ports and Pins then Inputs)

Hood