View Full Version : Shopbot sounds Like a train

11-02-2002, 07:36 PM
All of sudden My shopbot sound like a train..
Its start Chugging and not moving smooth almost intermittant.. Could this be caused by a timing problem between the PC and the Controller.
As I was having some timing problems but now that seems to be OK.. ( I wonder if I acendently set something wrong..)
I disconected all the motors from the track and realined everything but still does it.
Has anyone had this problem.
Any Help would be appricated.

11-02-2002, 07:38 PM
Forgot to mention..
I also seemed to lost my Ramping up and down it just starts hard and quits Hard...

11-03-2002, 12:46 AM
has your shopbot gone unsquare in the process? does one side seem to be moving more than the other? if so make sure you dont have a bad connection where the wires that go to the stepper motors are. we had that happen. ran very badly. if you have a bad connection the sync of the motors will cause a rough travel on the long x axis of the bot. measure from the carriage to the end of the table on both sides to see if they are same distance if not look for a bad connection. probaly not the answer but a good start.

11-03-2002, 01:26 AM
Would also start by checking all wire/cable connections, including ground wires. . . .

11-03-2002, 02:02 AM
What were you doing immediately before the train came into the station?

Did your software settings get changed?
Did the machine get hung up on a piece of material and get thrown out of alignment?
Are all guide wheels riding their steel properly?
Is the set screw that holds the gear in place on each stepper motor fully tight?

Does the machine think one of your Zero positions is way different than where you think it is? It may be trying to move to Zero and it's already crashing into your stops.

If nothing is blocking the track or the guide wheels, and your motor wires are all connected properly at the motors and at the control box, check your speed settings and your ramp settings and make sure they are within an acceptable range for your particular machine.

On my machine (PRT 96) a ramp speed of about 60% of the cutting speed works for me.

11-03-2002, 05:12 AM
In addition to what Mayo said:

Is your computer running another program in the background? Linking to a network? Screen Saving? What does a fresh reboot do?

Do all the axes run rough? If you changed settings inadvertantly, would you have done it on all three?

When you dropped the motors out of the gear racks, was everything smoothly movable by hand? Did the motors turn smoothly (in the air) when running a program?

Is the roughness only present when running any other shop equipment, or the router itself?

PS. Our trains generally sound BETTER than our SB - it is GOOD when it runs like a train! But we do have electric trains . . . .

11-03-2002, 05:29 AM
Sorry I wasn't complete on my prob and what I have done so far...
It is doing it on all 3 axis so its not a table out of square Plus I did check that first thing.
Yes the motors do the same thing when not connected to the track.
I checked the rollers when I lowered the motor and everything is smooth.(Just a tap and it rolled the full leanth)
I will check the grounding again.
I did install a ne firewall program on the machine but it was doing this before then..
It started after I had a PC timing problem.
(Burned out a Video Card).....
Oh I might have figured it writing this..(This didn't start till a few days later but it still could be the problem)
When the Video card fried it might have caused a problem with other parts of the Motherboard..
I will install a new MB tomarrow.. I happen to have a extra one here.. I will keep you all updated..
Thanks for making me retrace my steps.
It gets fustrating and you don't think striaght till people start asking.
Its amazing what you think of when start typing it down.

11-03-2002, 09:45 AM
sounds like a partially FRIED driver chip, I had one of these, but it only affected one access. Do you have the same speeds as before?

11-03-2002, 11:49 AM
I had a similar problem and it turned out to be the SB program in my laptop. I removed it and re-installed it and it solved my problem.

11-03-2002, 07:45 PM
Im going to try reinstalling programs first before rebuilding the PC.. The speeds seem to be the same and its on all axis so unless the SB driver board fried I think its in the pc side we will find out on Monday...

11-04-2002, 06:50 PM
I thank everyone for the comments..Sometimes the simplest things are the answers...
Reload the program.. That worked... I still have the timing problem But I think that is with the Computer. Sometimes it will time and other times it won't....
I would run the prog from DOS.. But WinME dosn't let you reboot into DOS. So i can't find out if thats the problem or not..
Guess one day Ill reload the pc with Win98 like the rest of my Machines...
Thanks again

11-05-2002, 05:50 AM
Glad you solved it. This (http://www.talkshopbot.com/forum/messages/32/979.html) thread may help you in the future.

11-05-2002, 06:24 AM

If you have a floppy drive, you can use a DOS boot disk instead of running ME.

11-05-2002, 09:55 AM
. . . . if your BIOS looks at the floppy drive first during boot-up.

11-05-2002, 10:43 AM

Of course that's right - I should'nt take things like that for granted.

Most BIOS will let you disable floppy access on bootup, but it's usually enabled by default, and the drive is not used unless there's a disk in it.

10-02-2003, 11:43 PM
I might be in the wrong area but I will throw this out there and hope for some help. Our prt 96 is
very clunky or jerky along the x axis . This
causes a vibration which in turn leaves a poor
finish on any part we cut . It looks like a chatter or ridges. The machine is square and level , when the motors are disconected it glides very smoothly. I have tried various speeds and new sharp carbide cutters with the same results. I just had the router( porter cable) serviced and replaced the bearings and brushes. I almost think that the stepper motors are either worn out. Does that or can that happen ? Can there be excesive backlash ? The stepper motor set screws are tight and the rack is clean .

I have installed the latest Sb software sb239sx and ran the load46.exe program. Could this problem be computer hardware.
I think I have covered most of what I can think of.

Thanks for listening

10-03-2003, 10:22 AM
Check your unit values are correct [VU]If you have just upgraded the software I would bet your unit values don't match your steppers

10-03-2003, 11:17 AM
Can't see how wrong unit values will cause this?

I would disconnect (or swap) some motors to see if the problem can be isolated. There are two x-motors and one y-motor that can be fiddled with to see if the problem moves around. Be careful of the one x-motor that runs "backwards" - best to drop one of the x-motors out of the rack if you start fiddling with connectors. And start in the middle of the table somewhere . . . . . . . .

10-04-2003, 11:12 AM
Iíve had my PR48 for almost two years but have only put about 12 or so hours of use on it. This is due to my day job that keeps me away from home for 18 days out of the month. But coincidence or not Iíve experienced the same chattering symptoms and rough cuts as jdh. I too have micro managed the setup of the machine but as well experience this problem only in the X axis and then again only during a move not a jog. So I also could use some advice. Please e-mail me with a phone number and we can chat on my dime.

10-07-2003, 10:35 PM
Another possibility is that the sprockets on the stepper motors are being held too tightly against the track. Try loosening the turnbuckle a little. Also check to see that the sprocket sits squarely in the track - if the motor is not 90 degrees square to the track, the sprocket teeth will be contacting the track on an angle and that may make noise.