Help: Grinding noise & position loss

[rcnewcomb]

I'm working with Shopbot on this but we still don't have a resolution. Perhaps people on the board can offer suggestions.

Background:
- Shopbot PRT Alpha 48 & indexer mfg. in July, 2005
- Windows ME on a 1.7Ghz processor with 256MB running latest Shopbot software. No network connection. I do not have easy access to another computer to try a replacement.
- Porter Cable router
- Shop is metal clad wooden building in a rural area and NOT near high voltage power lines or RF transmitters
- Cables are run neatly: not coiled and are well seperated.

Symptoms:
We've had occasional communication loss issues since the beginning. Switched to the Quatech USB/serial interface. Still had occasional communication losses.

Beginning 1/10 motors began randomly making a grinding noise and the machine would either lose position (gantry traveled farther than shown on the screen) or would do random reversals in Y and/or Y. This occurred while surfacing the sacrifice board with practically no load on the router bit.

Problem also occurred during air cutting with the router not powered on.

Replaced the control board with one sent out by Shopbot. Have not had the random reversals but still will randomly make the grinding noise and lose position. The limit switches do not stop the machine when it is making the grinding noise but they do work otherwise. I can still use them to XY home the Shopbot.

We have tried running without the limit switches, Z-zero plate or indexer motor hooked up. Still malfunctioned.

One of the relays is very slow to close after hitting reset. Shopbot is sending a replacement but they didn't believe a defective relay would manifest this behavior.

There is another Shopbot PRT in our town that the owner may allow me to use in his off hours so at least I can finish a critical job -- but I'd rather use my on system.

[jay]

Randall, sorry to hear about your problem. I wish I had a solution, I/we all feel for you. Just sending this note so you know there are other botters out here that hope the problem is resolved quickly.
Jay

[paco]

Symptoms:
We've had occasional communication loss issues since the beginning. Switched to the Quatech USB/serial interface. Still had occasional communication losses.

Have you tried additionnal grounding wires to avoid erratic grounding continuity from the Z to the control box (assuming it's well grounded)? Have you checked the complete (Z to box) grounding while the tool is moving (run aside it with the "multimeter"!)?

Have you tried grounding the USB to serial adapter connection as shown by another forum user/Botter (soory I can remember where I've picked that on the forum)... here...


10978.jpg

Do you have the latest SB3 3.4.16 installed?... I guess (hope) so... that fixes most of my similar problems...

Beginning 1/10 motors began randomly making a grinding noise and the machine would either lose position (gantry traveled farther than shown on the screen) or would do random reversals in Y and/or Y. This occurred while surfacing the sacrifice board with practically no load on the router bit.

Problem also occurred during air cutting with the router not powered on.

Is this with the CR command?... I've reported an issue (to Ted) about the tool randomly doing a jerky stop and go while surfacing with CR... I think (hope) they are looking at it... I now use another routine to surface the spoilboard.

1.7 Ghz is almost the minimum since about 3.4.?... I have 1.3 Mhz and I cannot move faster than say 11"/sec. (rather than full 12"/sec.) 256 Mo of RAM is not enought if you ask me; you probably hate to use the previewer don't you?! I've recently upgrade to 640 and it did make a difference (I had 384 before). Just watch the CPU usage along with the RAM too on the Task Manager (CTRL+ALT+DEL ONLY ONCE before launching SB3) while the tool MOVE (Jogs use less ressources than moves)...

I'd bet on communication issue...

One of the relays is very slow to close after hitting reset. Shopbot is sending a replacement but they didn't believe a defective relay would manifest this behavior.

What is slow?! ..click or ....................click?!... or better yet, 2 minutes later... click?

Have you double checked your port setting about the Quatech?... you should be set full capacity transfer in both SB3 setting (VI; 4) and the Device Manager (port setting; 460.8).

[rcnewcomb]

Thanks for the suggestions and support.

I'll try checking grounding continuity on the Z.

I can try another ground to the USB, though I do have a ground from the control box to the computer case that should perform a similar function.

Running 3.4.16

Bizarre behavior was primarily during M3 commands. I use part wizard to surface particular areas of my spoil board and use area clear. I experienced the failure during all 3 patterns: primarily X moves, primarily Y moves, and combination (outside moving inward)

Regarding memory and processor, I'm not running WinXP which requires more horsepower and memory.

[snip]
What is slow?! ..click or ....................click?!... or better yet, 2 minutes later... click?
[snip]

Slow is between 6 seconds and two minutes. Sometimes as many as 5 additional pushes of the reset button are required before the second relay closes.

I'll recheck Quatech settings in the morning.

[Brady Watson]

Randall,
I have encountered a similar problem with Alpha machines. Two areas to look come to mind:

1) Are you running dust collection? If so, make absolutely sure that you have the dust foot grounded to the machine, or ideally run a piece of copper wire through the entire hose, making sure that it is connected to metal at the end.

2) Software running on the computer in the background. This one is a bit trickier, but I have had the X car fall off of the tracks due to miscommunication as a result of software running on the PC competing with the pulse stream sent out by the control software. Make absolutely certain that there is no software looking for an internet connection. Use the Windows Task Manager to see what is running & disable the following (or uninstall): Windows Update, Quicktime, Any type of virus scanning software, disable screensaver, turn off power management so that the computer is in 'Always On' configuration. I don't know exactly what came pre-loaded on your computer, but uninstalling programs that are not necessary to run the ShopBot is a good idea.

Your problem is most likely software/computer configuration related from the symptoms that you describe.

-Brady

[paco]

I think A-L-O-T will agree, making a throughout cleaning OR a SUPER clean intall of ONLY the necessary programs is a benefit to your control PC. You could have a look on the MSconfig too; I have disable some services on remaining running programs.

[gerald_d]

Trying a different PC first will probably tell you if you need to rinse your current PC.

[marshawk]

Hi Randall,

I would try installing the ShopBot Dos software and run your programs. This will generally bypass the windows background schemes. You have to make sure that screen savers, power saving routines, etc... are all shut off.

Using Dos will give you a better idea of whether the problem is caused by the computer or the controller.

I have serious issues with Windows ME and run Win 98se instead.

Software notwithstanding, the problem that you are having sounds more like a controller problem than anything else. As everyone else has said, grounding the hell out of your machine is necessary and required. If problems still exist, take a look at internal wiring to ensure that everything is plugged in where it should be. Even check to make sure that pins and plugs in connectors are not bent or crushed.

Then, check all of the cables and make sure that some internal wires are not broken. I had a problem once where one cable was at a "choke point" and through constant bending, broke one of the internal wires and would make intermittent contact. The wire looked normal when I conducted a continuity check, but when I began flexing the wire at the "choke point" I found the break.

The symptoms I had are exactly the same as yours.

Besides broken wires, check all of the connectors to ensure that the wires are firmly seated.

My $0.02.

Cheers!

Chip

[gerald_d]

"Sometimes as many as 5 additional pushes of the reset button are required before the second relay closes." I don't have an Alpha, so I don't know if this is a hardware button or not......if hardware, does the button make/break correctly? (something like dirty contacts buzzing away?....)

[rcnewcomb]

Received and installed the replacement contactor for the one that was slow. The new one closes quickly.

I defragmented my C drive.
We grounded the USB as Paco indicated.
Added grounding on the Z axis
Added grounding to dust collection system
I ensured that the Port was at the maximum baud rate
I used MSCONFIG to disable any spurious code getting loaded.
I have checked grounding continuity on the Z while it was moving
I have checked screensaver and and power management settings -- all are off

Recurring symptoms are one or more of the following:
a) the 'Bot will just freeze like in a communcation loss but not yellow dialog box
b) the 'Bot will lose communcation and the yellow dialog box appears
c) low growl or grinding noise. The 'bot loses position but keeps running unless it hits a mechanical stop or loses communication. It will respond to the 'S' key. If you resume the grinding noise goes away (at least for a while). Grinding noise occurs during X and/or Y movements

Tomorrow I can try booting in DOS mode.
I suppose my next choice is to buy a new computer but I'm reluctant to shell out the money if it won't fix the problem.

For the real hard-core in the group I'm posting my problem.log file below:
'ShopBot Configuration Version 3.4.16 --- 01-16-2006 17:21:47
' Copyright 1997-2005 ShopBot Tools, Inc. All Rights Reserved.
VK,
VD, 1, 5, 0, 0, 2, 1, 0, .5, 0, 1, 1
VU, 1273.2395, 1273.2395, 1273.2395, 1388.8889, .05, , , .25, 13.8889, 4, 4, 4, 4, 1
VA, 41.5751, 12.5342, .9990, 1.0001, 1.0080, -209.0801, -79.9493, .0000, 359.9997, 359.9997, 359.9997
SA
SO, 4,-1
VS, 4.0, 2.0, 0.2, 240, 3.5, 4, 3, 1440
VR, .4, .4, .4, .4, .4, .4, .4, .4, .4, .4, 100, .15, 65
SW, 2
VL, -1, 49, -1, 49, -2, 8.0, -3.0, 8.0, 0, -500, 500
VP, 6, 48, 48, 6, 0, 1, 0, 1, 1
VC, 0.25, , , 3, 0, 10, 1.00
VB, .1, 4.25, .4, .3, , 0,
VI, 2, 0, 0, 0, X, Y, Z, A, 4, B
VN, 0, 0, 0
FS, C:\My Documents\CutFiles\Syverson, *.sbp, c:\SbParts\Custom
UN, SbEdit.exe
SM

ShopBot Diagnostic Information Version : 3.4. 16
----------------------------------------------------------------------- 1
Windows OS = 1, 4.9 Resolution = 1024 X 768
Total Memory = 267,661,312
Starting Memory = 171,511,808
Available Memory 134,934,528
maxFileLines = 1000000 maxStack = 75000( 50000)
586 655375

Control Box Firmware Version = 130 SerNum.
Port Number - 2 Speed - 4: 460800
Starting Command Line -
Sound = 1 SCreenSaver = 0

Last Stack Size 24 1
Last Steps Transmitted 617257
Last Steps Confirmed 615642
Data Over-Runs 2
Fixed Over-Runs 0

'Recorded Commands ----------------------------
MZ, 1
FP, Plane_075_14x43V3.sbp, 1, 1, 1, 1, 1, -0.00, 0, 0, 1, 1
'Recorded Commands ----------------------------