X/Y Motors Stalling

[jdervin]

My X/Y motors suddenly developed a case of stalling (or something else that makes a very ugly grinding sound). I think it has something to do with the jog speed. I dropped it to 4ips and the problem went away. Similarly, there were no issues when running at the move speed. I have a PRS Standard and have been jogging it at 6ips for quite some time now without problem (until yesterday), so I'm not completely sure that reducing the speed is the solution. Besides, I'd really like to continue jogging at that speed if at all possible.

Of course this happend at the end of the day on a Friday, so I'll have to wait 'til Monday to call ShopBot. In the meantime, can anyone offer some insight based on this video?

http://www.youtube.com/watch?v=xoWKC5_1DGA

FYI, I'm using the arrow keys to control the movement of the 'Bot in the video and found the problem to be 100% repeatable.

[bleeth]

John:

You are losing steps. Is it possible that there was something that "jarred" the gantry and it is now out of square and the x is not properly aligned on the y rails now? It only takes a little bit of out of alignment to have enough affect to reduce the top speed of jogging. The large amount of mass being moved by the standard motors requires very perfect alignment.

[ken_rychlik]

I agree with Dave. Loosing steps.

Drop the motors and move it around by hand and see where it is binding.

After you get it adjusted to run free by hand, then put the motors back on and you should be fine.

[jimmya]

Try this, turn off your limit switches and then do the same thing you did in your short clip. I think it is like my machine, I got one limit switch engaging for some reason. Use the VN command to get to the settings.

[ed_lang]

I don't think it is an X axis binding since it also showed the same problem when moving the Y axis.

What updates have happened to the computer?

Run a speed test-

Ed

[bill.young]

I have no troubleshooting suggestions (though I think Ed may be on the right track...that something's distracting your computer), but just wanted to make sure that you knew that there's someone from support on call 7 days a week. On the weekends they may not be in the ShopBot office so might not answer the phone, but they monitor the phone calls and tech support emails and will get back to you ASAP.

If you need to get up and running quickly it's the quickest way to get a problem resolved...they know the right questions to ask to narrow it down.

[jdervin]

Thanks all for the tips and suggestions.

Bill,
Thanks for the correction about SB support. I've just been going through tech support with a couple of other companies in the M-F/9-5 model and made an assumption. Now I know better.

++++++++++++++++

Well, today everything decided to work fine, however, my computer first booted to a blue screen of death and on reboot, to one of those start normally or safe mode option screens. Fact is, I've been having problems with conflicting drivers since I first installed the RPM tool last summer -- but that's another saga, which is chronicled in the following threads:

http://www.talkshopbot.com/forum/showthread.php?t=5497
http://www.talkshopbot.com/forum/showthread.php?t=11671

For now, I've decided that my problems are with the computer and likely USB or driver conflict related. Despite this decision, I've looked into several of the suggestions posted above. Here is what I did along with the results:

**Since the problem was occuring on the X and Y axis, and since it's been running quite well lately, without anything more jarring than a lost comm problem earlier in the week, I decided not to drop the motors for now. If the problem persists, I will look into this theory again.

**Using a Widget Works pen plotting tool, I marked the three corners of a Pythagorean 3-4-5 triangle and then measured the hypotenuse with a tape measure (the most accurate method I could think of, but certainly allows room for a margin of error) and it looked quite precise.

**I've tested both of the limit switches and they appear to be working fine.

**Updates: there have been a few of those "yellow shield" Windows updates in the past week, and I've udated the control software from 3.6.24 to 3.6.28 a couple of days ago. Other than that, things have remained pretty much status quo for awhile now.

**I ran the speed test ten times in succession (knowing that it would show problematic results based on previous experience). The range was 65.7-66.7 with an average of 66.6 (hmmm. ya think there's anything symbolic about that result?) On my to-do list is adding a USB 2.0 pci card as suggested to me in a previous thread. I've tried once, but apparently ordered the wrong size pci card and it didn't fit my computer.

**My RAM is 3.21 Gb, so I don't think there's an issue with it.

For now, the bottom line is that everything is working again. I've certainly got computer issues to resolve, but hopefully, there's nothing wrong with the 'Bot itself. Thanks again for all the help.

[jerry_stanek]

Download a copy of memtest an burn a cd run it and check your ram to see if there are any problems. Some times just one little sector of ram is bad and that will cause things not to work right.

[kevin]

John

Its your speed I had the same thing .I got rid of the hub thinking a direct line was better wrong I had scores of 67 with made all kinds of sounds that you think its mecchanical. Now with the hub i get 77 the machine is smoth also i disable antivirus when running the shpobot its senestive .

Also go in search type msconfig GET RID OF ALL BACKGROUND PROGRAMS LIKE ADOBE UPDATE.If I'am not clear you can find on line how to do it .Also a lap top runs the shopbot slow even with 4 gig of ram I tried both

[bleeth]

A comm speed of 66 is too low for PRS. Now that we know you are square and generally well adjusted it is clear that that is the issue. It needs to be over 75. When I rebuilt my PRT to PRS gantry and rails I had the same issue and the hub and high speed adapter fixed it. Got them in from Amazon or Tiger Direct for a total of like 50 bucks and have run smooth since with jog at 8ips.