Off Center

[jerry_stanek]

Check you X steppers I had an problem where one came unplugged and was giving me the same look

[MogulTx]

What control box do you have? Is it the computer style box, with the old drivers? ( This would lead to further questions- that basically would be designed to get you to figure out if you had blown a Zeiner diode (spelling?) This will make your stepper motors run poorly and or not at all. It can happen from static discharge or electrical spikes in your service, etc.

To see if one of the motors is affected, pull your x axis motors and set them to run on a LOOONG jog so you can check them and see if they both turn steadily and turn without making any noise. Then reinstall, carefully seating them deeply into the rack and do "air cuts" and listen for noise. Run only one axis at a time so you can isolate the issue. It is likely an X axis motor, because if the Y was dead, you would get nothing for movement in the Y... with one dead X motor, you can still get X axis motion from the other motor- but it will look awful.

And before you mess with any of that: Have you, with power on, pushed and pulled on your y carriage? At both ends? To see if you have any slop in them? This is a way to examine your wear of and seating of the pinion gears for your X motors. If they are not properly seated into the rack, they could have significant slop and that will cause you to have wonky cuts. You can do the same with your router/spindle carriage to see that it is seated well.

[MogulTx]

If it is a diode, and you are not running a fourth axis, you can steal the one from that part of the board and replace the one that is bad. Then order a number of them on ebay for $5. It will ship out of Hong Kong or something- and take 8-10 days- but it will be the best $5 you have spent in a long while.

Then install the new diode into your fourth axis portion of the board when you have a slow day and the inclination to open it up again... ( or when you want to use your indexer!)

[pappybaynes]

What control box do you have? Is it the computer style box, with the old drivers? ( This would lead to further questions- that basically would be designed to get you to figure out if you had blown a Zeiner diode (spelling?) This will make your stepper motors run poorly and or not at all. It can happen from static discharge or electrical spikes in your service, etc.

To see if one of the motors is affected, pull your x axis motors and set them to run on a LOOONG jog so you can check them and see if they both turn steadily and turn without making any noise. Then reinstall, carefully seating them deeply into the rack and do "air cuts" and listen for noise. Run only one axis at a time so you can isolate the issue. It is likely an X axis motor, because if the Y was dead, you would get nothing for movement in the Y... with one dead X motor, you can still get X axis motion from the other motor- but it will look awful.

And before you mess with any of that: Have you, with power on, pushed and pulled on your y carriage? At both ends? To see if you have any slop in them? This is a way to examine your wear of and seating of the pinion gears for your X motors. If they are not properly seated into the rack, they could have significant slop and that will cause you to have wonky cuts. You can do the same with your router/spindle carriage to see that it is seated well.

Yes, I have the computer style control box...so is this diode easy to change? Is it obvious what it looks like etc? I don't believe there is significant slop...I did a test cut tonight after I reinstalled SB3 and it was much better, but it is still obvious that something is not right...

[MogulTx]

Dick,

One thing: The gantry should be ROCK SOLID. With the power on, you should not be able to budge the gantry. If you can, you may have loose pinions ( still) or you may need new ones- but they do not fail suddenly! SO it should not be that they suddenly wore out. There MAY still be loose grub screws. I BELIEVE there are two screws per pinion gear. Make sure both are TIGHT TIGHT TIGHT.

DIODES: They are easy to replace. But I do not have that style board anymore. I sold my older machine and have upgraded twice since then. So, let me describe it in general so you can get the lay of the land.

Before we do that: did you take the motors off the machine and run them to try to figure out if one of them is glitchy? Did either of them sound rough? If so, that is the one you want to focus on. If they did NOT sound rough- you should probably be suspecting the grub screws on those pinions...

once pinions are ruled out: If you look at the board, near the plug in that goes to the X motors, you will see a moderately sized diode (black cylinder with bands on it- I don't recall the colors of bands on it, but those are a marking that tell the observer the characteristics of that particular diode.) But it should stand out to you. And if you send me a photo of that section of the board I can point it out to you.

Then all you do is unsolder the one from the 4th axis and the one from the suspect motor and solder the unused one into your board. And you are done. Replace the board. Hook up your connections. Do a test run. If she functions like a champ, order diodes. If she is still rough- you may have repaced the diode to the wrong position. With how well the machine is cutting, I would say that it would be nearly impossible that you would have a partial fault in both X circuits.

Send me a PM if you need more from me. I read here most days, but every day and not throughout the day.

Best of luck to you.

Monty

[pappybaynes]

Monty,
Have not checked the motors yet...just did the SB3 control software...work a day job and did not have time for all last night...will do so this evening and keep you posted. Appreciated the input from you and everyone else on the forum.
Dick

[MogulTx]

Dick

I know that "lost" feeling when the machine is not operating the way you want it to, and you don't know how to get it back to proper function. SB Support is excellent. If you can take some time and get them on the phone with you, they may have a specific set of tests that lead quickly to the proper conclusion. We operators are saavy, but not like those people.

And one note on the pinions and grub screws. "tight" is a relative term. I would say that once you have the allen wrench into the grub screw, you will want to exert a fair amount of force. And you have to be cautious that you are fully engaged so you don't risk rounding out the hex recess or the wrench. I realized that I wrote "tight tight tight" and thought... "he might attempt to over tighten. At least give him a little cautionary words..." So- there it is. You don't want to add to your concerns!

Best Regards,

Monty

[pappybaynes]

I powered up and attempted to move each side of the carriage - the left side +Y did not budge, the right -Y moved maybe a half an inch+- in each direction (didn’t measure it, but it was decided moving). I pull that motor, checked the set screws (they were tight) and reinstalled it making sure I had a good seat on the rack. Tightened it back up and tested again while powered up - same results. It showed signs of wear on the inside of the pinion - not even across the entire surface. So I guess I need to replace it - does ShopBot have these??? How much are they...should I replace both sides?? Thank you everyone and tech support...I so love the forum!
Dick

[bleeth]

Dick: If it's moving that much when you are "powered up" than that motor is not on. To verify un-plug the other motor and then power up and see if the gantry moves (push very slowly). If it does than there is your issue. This could be a lot of things from a loose connection to a blown driver.
Start by carefully checking all connections for that motor.

Yes:SB does have new pinions and you should never do just one.

[pappybaynes]

Dave,
wouldn't the SB3 screen indicate that the motor was not connected??