O/T Machine stuck in rapid..

[Brent Wilkerson]

We have a Supermax VMC with a Fanuc controller and since awhile the machine will just freak out. When the NC code calls for a feed movement it's like it's stuck in rapid mode. This really sucks when you rapid to above the part and then begins to feed and it rapids into the part instead. The only thing that clears it is cycling the power and it usually goes back to normal.

 

This does this randomly for no apparent reason.

 

Has anyone experienced this before? Or is it just fluff on in the controller.

 

TIA

[mold100]

I gonna go out on a limb and say I think something is not right

[Brent Wilkerson]

quote:

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I gonna go out on a limb and say I think something is not right.

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That's the answer I expected.

 

It so random we've chalked it up to just an oddity, but it happened again.

[Surface]

Brent, it is amazing how many of these "oddities" can atributed to poor ground in the electrical system or in the machine itself. Although it seems unlikely, I have seen some strange things atributed to electrical charge buid-up. It may not solve your problem, but at least it's a place to start.

[Rekd™]

Brent, it's a sign. You're running your parts too slow. Please increase the feedrates and the problem should go away. If not, check the grounding..

 

'Rekd

[KMI]

Hello,

 

We had a problem like that on one of our Takumi Seikis with a 18mc control. It would try to feed in rapid mode if you were in 100 rapid mode on the control panel. If you turn the switch to 75% everything worked out fine. It ended up being traced to a ladder problem. The techs came and fixed the ladder and no problem since. We checked everything else first but once we had a tech stand in front of the machine and watch it he finally believed me. It only took about 2 hours to sort out once they realized I wasnt nuts. Good luck.

 

Daryle

Kodiak Motorsports Inc

[Brent Wilkerson]

quote:

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Brent, it's a sign. You're running your parts too slow. Please increase the feedrates and the problem should go away.

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Well we tried doubling the spindle speed to match the feed which did increase our output.

 

I'll have someone check out the grounding of machine. This had just started in the last year or so, the machine about 3 or 4yrs old.

 

quote:

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It would try to feed in rapid mode if you were in 100 rapid mode on the control panel. If you turn the switch to 75% everything worked out fine.

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Did it always do this or sometimes?

 

quote:

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It ended up being traced to a ladder problem.

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Do you know what in the ladder logic was hosed up?

[Scott Bond]

Hi Brent Wilkerson

Is it possible that you ( or set-up guy) Hand edited in a G95 to drill, or bore a hole,,and then failed to put a G94 back in?

[Brent Wilkerson]

quote:

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...Hand edited in a G95 to drill, or bore a hole, and then failed to put a G94 back in?

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It happens on drill cycles, feed per minute / feed per rev., G1 moves, etc. We've broke drills, delta drills and mills. I'd say it's happen like 5 or 6 times.

 

Just sometime it's going to really mess something up bad.

[crazy^millman]

Ladder Logic is a bear unto itself. I woudl ask what does the Maker of the machien say about this problem. I would also be keeping a log book of all problem and just go bak to them and say I hate to go to extremes but unless you can help us come up with a solution we will.

 

Crazy Millman Teh the ground is a grounding rod 6 ft in the ground within 1 foot of the machien ground and it shoudl be a solid copper in rod 1/2" dia and solid copper wire from the ground block on the machine to the rod. Just for those of you who may not know the differecne between a ground ni the buliding and a grouding rod for a machine and every machien should have one. I would also ask that you have not high arc welders on the same breaker box as a CNC will do funky things also.

[JG]

I can't say I had this problem, however I had 1 out of 3 GE 1050hl controls skip one rough cut in a G73 pattern repeat cycle only SOMETIMES (usually when you really needed the part), it took 8 months to convince senile management.....oops...

sorry that was senior management that there was a problem. Turned out to be a revision on one of the logic chips was no good (the logic, not the chip). New chip, no problems again

[George_Gerhard]

Brent

I would ask to see your nc file. Check that the control has actually gone to G00. If not one suspect is the feedrate overide switch, the feed may be going to max feedrate not G00. I have replaced many of these wafer switches for such problems

 

rgds

George

[Müřlıń®]

+1 on feedrate pot.

 

Grounding also +1.

 

Dont put air compressors or welders on the same circut either, since spikes can cause bad results.

 

Since rebooting cures it I would also look at the boards.

 

It only happen in the z? I'm not sure how your control is made but you can swap out boards with diffrent axis on some controls and troubleshoot them.

 

Note: This should only be done by qualified personel.

 

 

Murlin