Old ShopBot...anyone still running one?

[3Dsigns]

I have an old PRT/PRS 4x8 ShopBot table which I upgraded to the new controller board. With the old board, whether hitting the spacebar, clicking the stop button, or a remote stop button, the machine would stop immediately. A little alert/notification prompt would come up giving you the option of "quit" or "resume". Clicking on "quit" would allow you to abort the file, then give the MH command and send the tool back to zero. Click "resume" and it would resume the loop it was on. My question: Did yours stop immediately(with the old board)? Because it does not stop on a dime with the new board. I have been told that they never stopped immediately and I call baloney on that: Also told that you couldn't resume the job either and I call baloney on that too. Mine always did. What say you? Thanks

 

[Gene@mpls]

https://www.talkshopbot.com/forum/forum.php not very active anymore but your best bet.

 

[JBurton]

Did yours stop immediately(with the old board)? Because it does not stop on a dime with the new board. I have been told that they never stopped immediately and I call baloney on that: Also told that you couldn't resume the job either and I call baloney on that too. Mine always did. What say you? Thanks

Haven't owned a shopbot, but you really don't want something like a CNC stopping on a dime. You'd rather it decelerate as fast as possible to zero, so you don't jump a tooth on the rack or overload the drivers. The old one may have, but I could see the new one adding a ramp down in speed instead of cutting the current. The E stop should cut the current and stop it in it's tracks, but again, this could be detrimental, and it should not allow you to resume without rehoming the machine.
Did you mess with any acceleration or speed settings when installing the board? Are you sure it's not just a perception thing? Like if the old board you could stop while going 60ipm and it appeared to be instantaneous, but the new board lets you go 200ipm and now you can tell it's not stopping on a dime?

 

[fixtureman]

Mine with the 4g board stopped pretty quik maybe not on a dime but it didn't move more than a 64 th of an inch. I now have the Centroid Acorn controller on it and that stops about the same.

 

[3Dsigns]

Haven't owned a shopbot, but you really don't want something like a CNC stopping on a dime. You'd rather it decelerate as fast as possible to zero, so you don't jump a tooth on the rack or overload the drivers. The old one may have, but I could see the new one adding a ramp down in speed instead of cutting the current. The E stop should cut the current and stop it in it's tracks, but again, this could be detrimental, and it should not allow you to resume without rehoming the machine.
Did you mess with any acceleration or speed settings when installing the board? Are you sure it's not just a perception thing? Like if the old board you could stop while going 60ipm and it appeared to be instantaneous, but the new board lets you go 200ipm and now you can tell it's not stopping on a dime?

No, it stopped immediately. Now it moves between 2 and up to 7 inches or so before stopping; long enough to keep damaging whatever might going wrong at the time. I run most of my toolpaths no more than 100 ipm. Most of them slower. I've never had a problem with skipping steps while stopping it. The only times I've ever had that happen was like if the cutter became restricted by something in the toolpath. Now I wish I had gone with the Acorn.

 

[fixtureman]

Did you upgrade your software I had some trouble with one of the upgrades. Call Shopbot and ask them about it they are very nice to talk to and will support their machines. I had one that I was the 3rd owner and they just had me regester it and they provided support for it as they knew what machine I had

 

[JBurton]

I don't know anything about shopbot's actual control software, but it sounds like an acceleration issue. When you start a cut, how long does it take to reach full speed? Is it a slow ramp, or does the machine go like a bat out of hell? I'm thinking it takes as long to reach top speed as it does to come to a stop...

 

[fuzzy_cam]

We're probably running the same ShopBot. Call or email ShopBot support - they're pretty good help even on the older machines.

Ours will not stop on a dime but it does stop in place pretty darn quick. All original control board, just replaced the gecko drivers several times over the years. Running ShopBot 4 still.

 

[fixtureman]

If you have gecko drives they are pretty hardy. Gecko will repair or replace them you just have to get a RMA number from them and send them in. I had 8 repaired and all it cost me was shipping