Losing Z zero location and strange loop in file

[georgew]

I've had this problem in the past with older software versions, but I just upgraded to latest v 3.5.5 and it still does it. I had cutter set to zero on the top of material and started a cut. I decided I wanted to go .030' deeper so I stopped the program, lowered the Z .030", re-zeroed the Z and started the program over. The cutter drove down through the material and the waste board. The Z setting had changed to 5.66". That has happend more than once. I can never catch it doing it until it's too late.

I have also had the strangest thing happen a couple of times since I upgraded. When a file has gotten to the end, and it should stop, it jumps to a line up in the file somewhere and starts over again from that point. The problem is that at the end of the file the Z is at 1" and the line it jumps to was at cutting depth of -.125". It went on a straight line from 1" to -.125" and cut into the material before it got to the end of the move. It ruined the material. Can't find anything in the file that would make it do that. It did it twice when I ran the file twice but jumped to different lines each time.

Any help is appreciated

[andre]

I found that ghost in the machine are usually caused by interference in electrical. The biggest for me was an un grounded dust collection hose. Check that first. and the second biggest would be a short in your proximity switches. call sb and have them walk you through a check list in your controll box.

[georgew]

thanks for your reply Andre, I'll add a couple of new ground locations to the machine. Shopbot support also said that might me the problem.

[georgew]

My machine is up to it again. It's jumping back into the file and runing the file from that point again. At the start of the file the first line is j2, 0.0, 0.0 It ran that line and started to move to the second line location when it reversed and joged back to 0,0. It then run the rest of the file in order until it got to the end. I wasn't there to stop it in time and it jumped about half way up into the file and started runing commands from that point. As it happened, the command it went to was at z, -.125 so it cut it's way through the material to that point ruining the piece.

I am suprised that no one else has had this problem. The guys at Shop bot have not heard of it before either. If there is anyone that has an idea of what might be going on I would appreciate any help.

George

[andre]

George my first guess is a short. Open your box and look for blinking lights on the lower circuit board. That is an indicator of a short. then start by unplugging the proximity switch plug from the board and run a file without the proximity switches and see what happens. Thase switches are only delicate wires that can tear easily if pulled. I shorted mine taking my z car off.

[rcnewcomb]

George, If you have another computer to swap out then try that. I'm suspicious of a bad memory module.

Give me a call if you want me to drop by and have a look.

[44henry]

George, did you ever find out what your problem was? This sounds like exactly what is happening to my machine currently. I just switched computers and ever since it has been acting up.

[georgew]

Alex

I started using a different ShopBot file type when I saved the file in V Carve, and that seems to have solved the problem. I have to go into the file and edit a bunch of junk out of the beginning and end for the file but it seems to be working. If you use V Carve give that a try.

[wayne_walker]

I am having a problem with my Z not lifting up to the safe Z height. At the end of the cut it is suppose to go up to .50" safe Z and it stutters up about .100". The noise is bad but it seems to be in only 1 area.

I have reloaded the firmware.
I have rebooted several times.
I have check to confirm a good ground. (not running the vac hold down - clamped fixture)
I have checked the WAGO plugs on the "Z" - reseated the wires and cleaned the plug ends.
I switched the plug from the "Y" to the "Z" and the "Z" to the "Y". I set the speeds to the speeds set with original wiring set up. The "Z" seems to run very smooth and the "Y" now stutters and makes bad noises. The noise is all of the time that the "Y" is in motion.
I did a search and it sounds like it is a driver... Please say it aint so!!!

I also have a line in the file that moves the bit off of the path about .50" and then it goes back to the path and continues to cut. I have run this file a 100+ times without this glitch.

I have a PR that was upgraded to a PRT and running a PC router. It has the rack and pinion.

Any Help is Appreciated!

Thanks

Wayne

[rb99]

Are there any other bugs like this that I should be aware of?

RB

[cnc_works]

Sounds to me like you might be losing steps on the way up, like there is too much resistance for the steppers to lift it up. Does your screen indicate that it lifted .5" while the fact is that it only lifted .1"?

Donn

[wayne_walker]

Richard,

I don't think this is a "bug", I think is probably the loose nut in front of the keyboard!

Donn,

The screen indicates .50". I also pushed down with a fair amount of force, on the router, while I ran it up. I ran up OK, and did not loose steps.

Since I switched the cables and the problem moved to the "Y", won't that indicate that it is upstream of the stepper motor? I also checked conductivity of the "Z" wire loom from Wago to Wago, with positive results.

I am already using the "A" alternate plug-in on the board. (crashed the carriage into the stops)

I have another board that I can switch out but I wanted to try and resolve the problem.

Thanks

Wayne

[wayne_walker]

It must of been a driver...

I changed to my other board and it runs fine!

Thanks for the help.

Wayne