[drogers]

Hello All

Ever so often the drawbar does not release the tool and then the drum starts rotating knock all my expensive tooling out as it rotates. Is this a spring problem and how hard is it to change? Has anyone else ever have this problem and what was the fix.

Thanks

[maver1ck]

There are prox switches in the spindle which, if adjusted properly, should not allow what you have described to happen. The three prox switches on the spindle are used to detect when the drawbar is clamped with a tool, clamped without a tool or fully unclamped (clear to proceed with tool change cycle). If yours is proceeding without the drawbar being fully released, the prox switch is either misadjusted, or something is not set properly, causing it to trigger prematurely.

Not knowing the history of your machine, there are various things that could cause it to not release fully, but the springs are unlikely. Has the spindle been rebuilt? I've had to fix several spindles that were someone reassembled improperly (usually the customer attempting to do it themselves). It could also be that the drawbar is releasing, but the knockout is not set properly (which could also happen if the spindle was not reassembled properly) resulting in the tool sticking in the taper.

[drogers]

I am going to clean the groove the ball drops into this morning as the tool holder releases from the spindle but the retention knob gets suck on the balls so the tool holder is dangling about an inch down from the taper.

I will get photos and codes if it happens again.

Thanks Maver1k

[maver1ck]

If the drawbar extends too far, it will hold the tool in the extended position as well as when retracted. Since the drawbar cylinder itself can not over stroke (unless someone replaced it with a different unit), it sounds like you have a problem with the spindle not being assembled correctly which needs to be corrected.

This would also explain why the limit switches are allowing the machine to continue the cycle with a tool still in the spindle.

[meckardt55]

So the big question is, did you have the spindle worked on prior to this problem?? If you look in the prints it may show the un-clamp piston travel and the tool knock out dimension. Did anyone work on the unclamp cylinder ??.