Pneumatic Cylinder Draw Bar clamp/unclamp

[sparky]

Hi
I have a Denford ATC Star Mill (1994) and the draw bar cylinder clamp/unclamp stroke is only 4.5mm which is not enough to release the tool holder. It has got steadily worse, but I wouldn’t know what the stroke was initially.
The part number on the cylinder is Compair Climax L.11.B VB439-C. The threaded diameter is 48mm. (see attached photo).

I have another Star Mill (identical) and that cylinder has a stroke of 10mm which is fine. The part number stamped on that is VB489-C J-17T.

Would it still be possible to source this type of cylinder?
If not, is there a re-placement cylinder which could be used?

Any help appreciated.

Kind Regards

Mark

CompAir Climax Pneumatic Cylinder.jpg (348.91 KiB) Viewed 15151 times

[TDIPower]

As the distance has reduced over time could it be that the seal on the piston has failed or is leaking thus does not have the required force for the operation? Could you not just strip it and get a new seal? I'm not familiar with the system. Another thought is, if overtime moisture has been able to collect inside the cylinder it won't compress so could reduce the travel.

Pete

[Martin]

It may just need the oil topping up. If you unwind the top plate & pull out the piston the cylinder should be full to the top.

[sparky]

Thanks for the replies.

It was the oil that needed topping up and closer investigation revealed that the cylinder could do with re-placement seals.

In case anyone needs a replacement in the future, I did manage to locate a source and part number for a re-placement cylinder. (See attachment).

Many thanks again.

Regards
Mark

[TDIPower]

glad you got it sorted,

Pete