Zero shift in the middle of cutting

[wonderpilot]

I have been having intermitent problems withe Zero change using the shark and VCarve or Aspire. I've been using VCarve 5.0 and then 6.0 for about 18 months. I recently upgraded to Aspire and love the programing and ease of use.
Recently I was cutting the free download from Vectric Magazine rack. While doing the main panel the cutter would stop half way up a line and I would watch as the program showed continuing. Then on the next down pass it would start back down only then the zero had been moved. All I could do is move the cutter back to actual zero and rerun the program. (I had already ran one of the panels and it had done a beautiful job, so it wasn't the program.
Chyecked here for help and then did all the suggested fixes. screws tight, shaft not moving without the motor. removed the coupling and reseated. would have loved for it to be any of these positive breakages. Using the jog, it ran all over the table (SharkPro) without even a hickup! Finally I took out the SD card and changed it with another 2g camera card. This stopped the problem for now. This was in the Y axis.
I posted this on the VCarve forum also.
Has anyone experianced this. any ideas. I'm spooked now and just can't walk away while running.
I have the old control box. Was the change for any problem?
when you see your 1/8" carbide snap off, it really ruins your day. any help or suggestions would be appreciated.
P.S. I also cleaned all rods and screws and put on fresh teflon spray.
Thanks for any help,
Rob

[hbutch8]

I had that problem when trying to run in very high Humidity. we are experiencing the same at work . the fix was to run a big fan throwing alot of air into electrical panel. Same with shark, turned control on side in front of big fan , no more problems

[wonderpilot]

Thanks for the tip, will give it a try. I'll put a fan directly on the boxes.
wonderpilot

[Barbarossa]

it looks simmilar on my Xaxis.after a while reset the zero point to te right side or also sometime to the left. in the the postpocessor isn't a fan. my first immpresion is also an overheating of the controllerbox. how can i install a fan on it?
it's on the board a 12volt interface?
thanks for your advice Stephan

[rungemach]

I'm not sure what the newest controllers are using, but my older shark pro uses a xylotex driver board. This is the generation of sharks that used Mach3 through a parallel port of a pc. The newer units may be using the NCpod controller to eliminate the need for Mach3, and still be using the xylotex driver board to run the steppers from the signals generated by the NCpod. I know that the Xylotex driver boards need good amounts of fresh air blowing across the heat sinks, and if the devices get too hot they may just stop working till they cool a little, then they will work gain.. The controller would not know this had happened, and just keep sending step and direction pulses to the driver (as there is no encoder loop to tell the front end of the system that a motor is no longer in "sync" with where it should be). So your symptoms seem to fit that mode of failure.

When you stop and then jog, etc, you are not working the motors like constant cutting does, and the devices get the chance to cool down a little.. So the time you take checking something else, lets the unit cool and it then works fine, so you can think what you did solved the problem, when it just let the drivers cool down.

Temp related problems are perplexing in that they are usually not repeatable unless you go to great pains to start at a known temperature and repeat the exact same process to let the heat build up. once the machine is at normal temp, it will take less time to get it to over-temp conditions.

My electrical enclosure has a fan inside the case blowing outside air directly on the heat sinks , and two other fans blowing air out of the case. It came that way, I did not have to add them. The power supply is external to the driver case and does not add it's heat to the situation.

The current controllers may benefit from more air exchange. If anyone with a newer model has opened their controller box, it would be helpful to know what is in there and how the cooling is arranged.

Hope this helps.

Bob

[REG]

The current controllers may benefit from more air exchange. If anyone with a newer model has opened their controller box, it would be helpful to know what is in there and how the cooling is arranged.



Bob

Newer controllers have smaller electronics but larger heatsinks. no fan. No troubles with mine although I did have a problem running a file from Cut3d.
It would go on some errant run. From all other posts I figured my SD card was failing. Popped in new SD card and had the same problem. I did all kind of other stuff to no avail. I finally ran the project again in Cut3d starting from a clean project. Built the file and saved. Ran it on the Shark and it worked perfectly. Point being that if one is experiencing axis errors, it is worth trying to build the file from scratch versus a file that has half a dozen revisions - at least with Cut3d. I never had an issue with V-Carve.

Bobby

[Barbarossa]

I had instaled now a strong Fan with an external 12 V Powersupply on the Postprocesor (38m2 per minute)
The Shark run's since then wihtout errors.

Thanks for your advice
Stephan

[rungemach]

Just curious to know how the newer units are moving the heat away from the electronics.

Is the case closed or ventilated?
if there are no fans, do the heat sinks mount against the enclosure to move the heat to the outside?
if so, cooling the outside surface where the heat sinks are will help keep the output devices cool,
but will not help move out any heat that is inside the enclosure.
any heat build up will heat all the other components that normally do not generate much heat themselves.

from past experience, electronics in a warm enclosure can start behaving erratically, particularly microprocessors etc..

with some jobs generating long constant run times, it may be helpful to move some clean air through the enclosure.
If I had a newer machine I would just stick a thermocouple in the case and see how hot it gets in there and how quickly.
my electronics take air from outside the cabinet that the shark is in, to avoid getting a buildup of dust coating the components after a long time.

Bobby, it would be curious to see if your old file consistently misbehaves followed by a successful run with the newly rebuilt file.
and will the old file misbehave on another shark?

That could help sort out how much difference the file rebuild makes.

Thanks

bob

[REG]

Just curious to know how the newer units are moving the heat away from the electronics.

Is the case closed or ventilated?
if there are no fans, do the heat sinks mount against the enclosure to move the heat to the outside?
if so, cooling the outside surface where the heat sinks are will help keep the output devices cool,
but will not help move out any heat that is inside the enclosure.
any heat build up will heat all the other components that normally do not generate much heat themselves.

from past experience, electronics in a warm enclosure can start behaving erratically, particularly microprocessors etc..

with some jobs generating long constant run times, it may be helpful to move some clean air through the enclosure.
If I had a newer machine I would just stick a thermocouple in the case and see how hot it gets in there and how quickly.
my electronics take air from outside the cabinet that the shark is in, to avoid getting a buildup of dust coating the components after a long time.

Bobby, it would be curious to see if your old file consistently misbehaves followed by a successful run with the newly rebuilt file.
and will the old file misbehave on another shark?

That could help sort out how much difference the file rebuild makes.

Thanks

bob

Bob, it is vented. Not overly so but it does have some breathing slots. I think improvements in electronics help them run cooler and this may be the case with new Sharks. Sort of like what flat screen televisions did compared to tube type I never notice it running hot that much and I typically run my Shark in an unconditioned space.

I never had anymore issues with files so I firmly believe it was a file build in Cut3d. In my opinion I believe the software of Cut3d doesn't build pp as well as VCarve or Aspire (which probably why they cost more).

Next time I have my controller open I will take some snap shots of it.

Bobby