Z-Zero instability

[dlcw]

I have had my Buddy 32 up and running for about a month now and have been attempting to practice carving some of the samples that came with the tool. I've been trying to plow through this problem, have had no luck and am out of ideas.

I am trying to carve one of the 3D models from Vector Art and I noticed that, even when using the same toolpath files each time I get different Z-axis results each time I try to carve the same model.

Run #1 3/4" MDF using a Z-Zero to the top of the material surface and I got a perfect carving.

Run #2 3/4" pine (checked thickness with calipers against the MDF) and the model was promptly carved all the way through the pine and into my spoiler board.

Run #3 Another piece of 3/4" pine and the carving process stopped half way through with an error about a comma missing in the toolpath file.

Run #4 Another piece of 3/4" pine and the machine proceeded to carve the model only about 1/2 the depth it was supposed to be carved.

All of these carving attempts were done on the same day using the exact same toolpath files. The spoiler board is brand new and has gone through the surfacing process. The spoiler board is held to the aluminum plate using all of the ShopBot provided screw holes. Each attempt, the Z-Zero is reset to the material surface. I use the exact same hold down technique on each attempt.

Can anyone give me some ideas what might be going on with this? File corruption, communications corruption between the control computer and the ShopBot, problem with Z-axis?

Thank you,

Don
Newport, WA
www.diamondlakewoodworks.com (http://www.diamondlakewoodworks.com)

[Brady Watson]

Don,
What are you running for a router? A Porter Cable, Bosch, Spindle? Make sure that your tool is not slipping in the collet & if using a spindle, make sure that the collet is twist-locked into the nut before threading it onto the shaft.

-B

[dlcw]

Brady,

Thank you for the reply. I use a PC router. I have checked the collet and there has been no slipping. I make sure the collet is good and tight before starting the process.

Don

[myxpykalix]

Do you know whether or not when the fle was created if the Zzero point is the top of the material or the bed of the machine?

Although I am no expert at reading the code maybe those who can might be able to look at it and tell you if the code is calling for it to make those plunges way deep. If so then the problem is in the code, if not then you have a mechanical issue.
Maybe someone here could look at his sbp file and advise him?
I would also advise you to remake your toolpath files, rename them so you know which is which and try cutting it. If you have some type of wordpad reader and can open them up side by side to see where they differ.

[dlcw]

Jack.
Thank you for the reply. When I open the model in Partworks3D I set the Zzero to the top of the material. Then I create the toolpath file and save it. The only other changes I make the the model is to set the model carving depth to .45" and the material thickness to .625" and set the X,Y zero to the center of the model. I mark diagonal crosshairs on the work piece to find the exact center.

I have tried to rebuild the file twice already and it is still doing the same things. I will try your suggestion of opening the files to look at them and see if there are differences. I know the finishing pass toolpath file is about 93,000 lines of code so I won't be able to compare line-for-line.... :-)

Thank you,

Don

[gerryv]

Are there any other "botters in your immediate area?

[dlcw]

I don't know any botters myself. Is there a way the the ShopBot folks can provide that kind of information? My zip is 99156.

[khalid]

is there any suspected ghost in ur workshop?

I think you are loosing steps at Z-axis motor...try to reduce the IPM and dop and then try it again....
Hope this will solve the problem.

[sawdust535]

Are you re-zeroing your z-axis to the top of the material (with a contact plate and the z-zero routine) each time you change or re-install a bit. This may sound too obvious, but just a thought.

[mikeacg]

Don,

I would get up with ShopBot on this problem. If the tool path file was corrupted, it would at least be repeatable. This is certainly erratic from your descriptions so it can't be the file. You make no mention of any distortion on the X or Y movements so your Z must be the source. I haven't had my machine much longer than you but I have never experienced anything like that though I did have a problem with my Z setting file because I installed the software in my F Drive (which has more space than my C drive) and the program had a hard time finding it. I reinstalled the software and that cleared it up. Worth a try...

Mike

[dana_swift]

Don- is your Buddy an alpha or standard? It is important to know, as the machines act significantly different from each other.

Also.. for those of you looking to glimpse into the SBP files to see if zero is on top or bottom.. its easy to tell. If all the Z entries on the move commands are negative, the zero point must be on the top. If all the Z entries on the move commands are positive, the Z0 must be on the bottom. Its as simple as that.

It doesn't take being a rocket scientist, though it probably doesn't hurt anything!

D

[beacon14]

Dana, well, almost. In the second case only the move commands that do not go all the way through the material will be positive.

Backing up a step, is the machine properly grounded? It sounds like you are losing steps or getting spurious moves in the Z axis. Grounding issues cause many of these types of non-repeatable gremlins.

[khalid]

yes i agree with David.. check ur Z-axis wirings.. are the connections tight?.. are the wires are far away from any electricity source/cables?..
Also try to run the controller software without running any thing (Net/multemidia etc) on computer...usually they too interfere..

[dlcw]

I would like to thank everyone for their very great feedback and ideas on helping me with the ShopBot problem I've been having.

I don't know what has happened but I we had a power outage yesterday so everything was shut down for an hour or so. Today when I turned everything back on and started attempting to carve again, I've gotten three perfect carvings in a row with no problems. I don't know if the ShopBot had a brain-fart and needed to be turned off and restarted or what, but things seem to be very consistent now.

I guess going forward, I need to shut off everything at the end of each day to make sure the ShopBot restores its brains on a daily basis. Live and learn.

Again, thank you everyone for helping me with this problem. This is a fantastic form made up of fantastic people willing to give of themselves to help out fellow "botters". How cool :-)

Don Thomson
Diamond Lake Custom Woodworks, LLC
www.diamondlakewoodworks.com (http://www.diamondlakewoodworks.com)

[myxpykalix]

One thing I learned when i had a problem that wouldn't go away I figured out to shut the computer down, shut down the control box and then go and shut down the circuit breaker. The reason for that is that I believe the control box has a module that keeps relevant info in memory like your Zzero point and stuff and so if you have bad info in your memoery you have to clear it out by a total shutdown.

[khalid]

jack i don't think so... IMHO u may have some trojan/viruses in ur computer, that steadly taking the memory of ur computer and getting ur processors busy...

Just run through a goood spyware and virus program through all hard disk of ur computer...also defragment the drives once in a month..

When u run the controller software, avoid to start/run any other software on ur computer...this may include screen savers, multimedia players etc