Pneumatic Cylinder Draw Bar clamp/unclamp

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sparky
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Joined: Sat 06 Dec , 2014 12:05 pm

Pneumatic Cylinder Draw Bar clamp/unclamp

Post by sparky » Tue 03 Apr , 2018 15:15 pm

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
CompAir Climax Pneumatic Cylinder.jpg (348.91 KiB) Viewed 8477 times

TDIPower
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Re: Pneumatic Cylinder Draw Bar clamp/unclamp

Post by TDIPower » Tue 03 Apr , 2018 23:34 pm

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
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Re: Pneumatic Cylinder Draw Bar clamp/unclamp

Post by Martin » Wed 04 Apr , 2018 9:33 am

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
Posts: 19
Joined: Sat 06 Dec , 2014 12:05 pm

Re: Pneumatic Cylinder Draw Bar clamp/unclamp

Post by sparky » Wed 04 Apr , 2018 18:50 pm

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
Attachments
lse clamping.pdf
(316.16 KiB) Downloaded 930 times

TDIPower
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Posts: 613
Joined: Tue 29 Apr , 2014 18:38 pm
Hardware/Software: Starturn 5 (sort of running, I will get this done!)
Lathe cam designer V1.11
Quickturn 2D Design
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Microrouter Pro NS V5 (microstep)
VR2 and VR5
Boxford VMC260
Techsoft 2d Design tools V1 > V2
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Re: Pneumatic Cylinder Draw Bar clamp/unclamp

Post by TDIPower » Wed 04 Apr , 2018 22:39 pm

glad you got it sorted,

Pete

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