Issue with Axes Skipping (X and Y

[BrandanS]

Hey Guys,

We've just setup our ShopBot and turned it on. I am having issues with a grinding sound while moving (jogging) manual with "K" command. This skipping action seems to take place anywhere along the travel; could occur at anytime, seemingly at random. The same issue is quite noticeable when the gantry is decelerating along the X and Y. I do not have this issue long the Z.

Any ideas of what to check?

Thanks,

Brandan

[gc3]

http://www.shopbottools.com/searchresults.htm?cx=007058511302222020632%3Alxjqz ewj5j0&cof=FORID%3A11%3BNB%3A1&ie=UTF-8&q=AXIS+GRINDING&sa=Search&siteurl=www.shopbottools.com%2F&ref=www.google.com.mx%2F&ss=4999j2320575j13

[srwtlc]

Give us a little more machine info. PRS Standard or Alpha? Control software version? How fast are you jogging it at? Does it roll freely with the motors off (pinions disengaged). If it's a standard, too high of jog speed and or a PC that can't keep up with data flow will loose steps.

[BrandanS]

Thanks Scott,

It's a PRSalpha running ShopBot control Version 3.8.14 Control Box Firmware running 216. The machine runs freely with pinions disengaged and also runs freely if doing large motion commands (ie. J2, 50.000,50.000) without issue running at 30 ips. I've slowed the manual jog rate with success. Seemingly, it only occurs when using manual 'keyboard' control at a jog higher rate. Should this be a concern? What are you guys using for this value?

Thanks,

Brandan

[srwtlc]

Since it's an Alpha, your jog speed with the keypad is limited to 14ips. I generally have my default jog speed set at 20ips. Although it can do 30ips, it's not good for the gearboxes to run at that speed on a long term basis.

If you command a move like MX,4 and then open UD, what is your packet_et.

[BrandanS]

If I run an MX 4 Packet_ET is 4.6ms, If I run a keyboard motion, packet_ET is 41.5ms

[srwtlc]

The 4.6 is good, if not oddly too good (if that can be). I don't know that a move with the keypad tests the packet_et, but if it does, that value is way high. Make sure you're not plugged into a USB 3.0 port (ports with a blue tab inside). Try using a different USB port. Laptop or PC? What is it with a 10" move (that's always been kind of my base test, but the UD diagnostics notes pdf used 4) That pdf can be found in 'C:\Program Files (x86)\ShopBot\ShopBot 3\Help'

[BrandanS]

Hey Scott,

Thanks so much for spending sometime with me. I can see you are very active throughout the forums :D. I seem to get varying results for packet_ET. After an MX 4 yesterday, UD returned 4.1 ms. This morning running another returned a value of 18.9ms which I think is coming near to a 'good' value. Running an MX 10 from origin returns 19.2ms:

"
Windows OS = 2, 6.01 Resolution = 1680 X 1050
Total Memory = 4,079,448,064 PRT P-type = 1
Starting Memory = 1,998,409,728
Available Memory 1,602,596,864
maxFileLines = 10000000 maxStack = 300000( 200000)
586 1006829574

Control Box Firmware Version = 216
IniVersion = 8.14
Port Number = 4 Speed = 5: 0
Starting Command Line -
User Value (via Registry) -
Last User Command (via Registry) -
Status Byte (in Registry) - 0
Sound = 0 ScreenSaver = 0

Size - 48 60 6
CBtype - 16167 BoardVer - 008 CardVer - 210 RouterType - S

uC Masks - 0-0-63-63

Supply VDC = 5.00 [5.00 to 5.00] Controller Temp = 36.3
Last Stack Size 0 1
Last Steps Transmitted 24828
Last Steps Confirmed 24828
Data Over-Runs 0
Buffer Underflow Last Stack 0 Buffer Underflow Total 0

Controller Loc -
24828 0 9315 0 0 0 44942

q_Freq- 311.8(hz) Static_ET 2.7(ms) Packet_ET- 19.2(ms;good<20)
"

Thanks again for your time and help,

Brandan

[BrandanS]

So I've played a little more with the manual control, at manual motions >10 jog speed, will consistently have a 'grind' down on the deceleration. I don't think this normal. Again I only experience this using the manual 'keyboard' control. Is there a ramp or "s-curve" setting I should look at.
I am lucky enough to have an electrician looking in to grounding the machine for me, but in the meantime I'd like to fix this. Is it possible that it's related to poor ground?

Thanks,

Brandan

[srwtlc]

Couple other things I'd try would be to do a reset with UR to load the defaults for your model of machine and try again. If you have access to another computer of proper specs, install SB3 on that one and give it a try and see if it runs differently. Could be a USB controller issue with your PC. Ground issues shouldn't cause this when you're not cutting and running a dust collector that could cause static build up, but....

You might want to give SBHQ a call and see what they have to say on the situation.

[BrandanS]

Thanks again Scott,

I have tried loading defaults via UR with no improvement. The strange thing is this issue is intermittent and only when using the keyboard control to move. Sometimes, there is no issue at all with the keyboard control and then 30 minutes later I'm back to the grinding sound at the end of a deceleration. Reset the control doesn't seem to improve either.

I will see if I can get use of another PC. I have read in another thread where you were helping troubleshoot something similar. Using USBView.exe, I have found that no matter what port I plug into, I am always using "Intel USB 3.0 eXtensible Host controller", perhaps this is the root cause? Trying another machine should eliminate this variable. I'll contact SB and see what they have to say about it. Any thoughts on the USB Controller?

Thanks,

Brandan

[srwtlc]

The 3.0 controller could well be the issue. It looks like you have another controller above that one that is not 3.0. Have you tried every port on the PC? 3.0 ports have blue tabs inside them, stay away from those. If that's all you have, you could put in a High-Speed usb 2.0 card (if it's a desktop PC). If it's a laptop, then you're probably limited to only 4 ports or so.

Again, if it's a desktop PC, maybe try a different keyboard since it only happens in keypad mode.

[BrandanS]

Hey Scott,

I had a chance to try out another PC with slower USB (~1.1) with success. Being as the issue is intermittent, I still want to do more testing... Something like a 95% failure rate for 'grinding' while in manual motion with the old PC vs the "I can't seem to get it to fail" percentage with the newer PC, things are looking up. We are ordering a USB 2.0 card for the PC I was originally using in hopes that I can get the intended controller functional. I'll post back when the dust has settled. I am lucky enough to have an IT guy supporting me so it's been at least headache free trial process.

Cheers and thanks again for the help thus far!

Brandan

[jerry_stanek]

Tell your IT guy to think backward as older slower computers seem to work better than the newest fastest ones for controlling the Bot.

[srwtlc]

How many USB ports are on the back of your PC? They shouldn't all be 3.0 ports. According to your USBview, there looks to be a lot of them. If you plug the USB cable into the various ports one at a time and once Windows makes it's connection tone, go to File/Refresh in USBview to see where it has moved to. You preferably want it on an 'Enhanced controller', but at least off the 3.0 one.