HELP SHOPBOT DRIVING INTO TABLE

[David Mackey (Unregistered Guest)]

Recently our shopbot has been driving directly down into the table. I would check the toolpaths in shopbot editor but they looked fine. Then we resave the toolpath and It works fine. It just seems to randomly drive the bits into the table. RIght through the wood as if it was never there. The zero was fine it kept correct coordinates. We can't figure out what's wrong. Thanks in advance. David,
Northside High School

[gerald_d]

A common problem, unfortunately. You might find the Forum regulars being a little jaded in offering repeated help on this mysterious issue - maybe call ShopBot?

[ted]

Hi David,

If you haven't given us a call on this one yet, please do. We can probably help you resolve it pretty quickly.

In the meantime, if we were trying to diagnose the problem, we'd ask a few quick questions to help get a feel for the situation (I list these here mostly as examples for others of the kinds of info that it's good for us to know to help you solve problems):

- What type of ShopBot and what version of the software ?
- Did you look at the file in Preview Mode (and rotate it in 3d to inspect the plunges)?
- When you say it maintained it's zero location, do you mean that after the plunge happened, and you made an MZ 0 move, that the tool correctly positioned itself at 0.
- We'd also want to take a quick look at your part file as well as the file: problem.log from the C:\Program Files\ShopBot\ShopBot 3 folder. (You could send them to me now at: ted@shopbottools.com (mailto:ted@shopbottools.com))

-Ted

[David Mackey (Unregistered Guest)]

The machine had the correct z measurement at all times. I checked the preview in 3d and inspected as always. We have a PRTalpha96. I'll send you the files soon. But it would help if you could answer it on the forum cause I don't believe our school district allows uploading from the server. Thanks

[ted]

Hi David,

When you say it has the correct Z measurement, I think what you are saying is that the correct value displays on the screen but that the tool is no longer at that location ?? (Please confirm that you do not mean it is correctly showing its unintended position ...)

I am guessing that when this happens, either before it happens or after, you get a message that there was a motor/driver fault and that the tool needs to be reset. What has probably happened is that there is a move in the file (typically a Z clearance move at the start or end of a move segment) that is pulling the Z axis up beyond its physical limit (the dust skirt might also be restricting the upward movement). When this happens, the motor/drive for the axis will try to correct its position and when it cannot, it will issue the driver failure message. Because of the inability of the motors to get the axis to the right location, the fault message is issued, indicating accurate Z location has been lost and that you will need to re-zero the axis.

This may not be the exact scenario that you are experiencing which is why I thought it would be useful to hear you describe it in more detail, but I believe it is probably this one or some variation on it. Again, if you give us a call, I think we will be able to help you get it right pretty quickly, particularly if you can be there at your computer and tool so that issues can be readily clarified.

As you may gather, I have a lot of confidence in these tools and want to make sure we get this one figured out. Please do make sure you are using the current software. I am not aware of any problem with maintaining Z position accurately or in carrying out any kind of move ... and of course if there were, we would want to quickly resolve it.

-Ted

[mikejohn]

Ted
When you do solve this 'over the phone' can someone come back to the Forum to update us on the solution?
Thanks
........................Mike

[gerald_d]

My response at the top of this thread was made because one could see that the Forum regulars don't reply to this issue anymore: 4 zone vac file troubles (http://www.talkshopbot.com/forum/messages/26/9177.html).

Some previous reports and discussions.....
Seeking utility/technique for "debugging" SB code (http://www.talkshopbot.com/forum/messages/31/1198.html)
CR command went doolalley today (http://www.talkshopbot.com/forum/messages/1843/3706.html#POST14297)
Leveling my bot (http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=7&post=13230#POST13230)
Phantom Problem (http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=26&post=8620#POST8620)
Z Axis Creep (http://www.talkshopbot.com/forum/messages/26/104.html)
Losing z zero (http://www.talkshopbot.com/forum/messages/26/1654.html)
Diving Z axis (http://www.talkshopbot.com/forum/messages/26/5828.html)
Z Axis Shifts — A LOT (http://www.talkshopbot.com/forum/messages/26/1258.html)
Z axis problem (http://www.talkshopbot.com/forum/messages/312/1790.html)

Mike, what was that theme song that you mentioned recently?

[David Mackey (Unregistered Guest)]

Hey guys an update...My teacher hasn't called yet cause hes "too busy" The machine has already destroyed about 100 bucks worth of materials. What is happenening is I'll make a toolpath in artcam. Everything looks great. then Ill get to the shopbot control software. I'll zero the axis's. Everything looks good then. No driver faults occur. THen I'll run the file. All of a sudden, the machine seems to hesitate and then drive down the z and x axis going straight throughg the material and into the table. It has happened many times and can't figure out the reason. We then have to slam on the emergency stop and pull teh bit out of the table. I would appreciate some help on the matter as I can't call myself. Thanks in advance David

[David Mackey (Unregistered Guest)]

P.S. I have all the latest software updates. We are using Artcam pro 7 and the new shopbot control software with a PRTalpha96.

[paco]

Hi David!

Would you post one of your problem file here and maybe your shopbot.ini file too?... I think this would help us help you...

[evan]

Sound like your refrencing the the tool off the table in Artcam but zeroing the tool off the top of the material...
been there done that.

Evan