Need 4000kgf and only got 10cm room....how?

Hello,

I have have sort of an engineering styled puzzle that i thought i would throw at you guys :-)

I have almost no room between my milling machines spindle and the ceiling in my shop. But i need to somehow put around 4000kgf on the toolchanger to change tool in the spindle. The pneumatic cylinder that came with the spindle is something like 40-50cm long, but ideally it should be no more than 10cm...

I've looked at "pancake styled" pneumatic cylinders, but i cant find any that can push that hard. I've looked at hydralic cylinders, but the whole hydralic system is rather complex and expensive... i thought about turning the pneumatic cylinder up-side down or sideways and use some sort of lever, but i cant seem to find any good solutions...

So... are anyone out there having a good and simple idea how i could add 4000kgf to the spindle and only take up around 10cm?

/Thomas

If possible, I would raise the ceiling in that area.

But maybe connect an air cylinder to a screw or cam and rotate the screw with an arm connected to the air cylinder. That way, the cylinder would be mounted horizontally.

Hi Thomas what "throw" or action length do you need? Is this outside the 100mm mechanism height? Peter

Quote:

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Originally Posted by Jim Dawson

If possible, I would raise the ceiling in that area.

But maybe connect an air cylinder to a screw or cam and rotate the screw with an arm connected to the air cylinder. That way, the cylinder would be mounted horizontally.

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Can't raise the ceiling....or rather, i've realy done that...there is no more to give, and i'm still 20-30cm short....

I've been looking at making a sort of cam, but the amount of force worries me a bit. First of all there is a ring which pushes down on the pressurering on the spindle, this ring needs to be hold in place, which is done by the cylinder in the original setup. So i need to keep this in place somehow...with 4000kgf on the end of it :-/

I've attached some pictures of the testassembly i have at the moment...and where the pressure ring is that needs 4000kgf to push it about 10mm to disengage the tool...

Attachment 460300Attachment 460302

Quote:

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Originally Posted by peteeng

Hi Thomas what "throw" or action length do you need? Is this outside the 100mm mechanism height? Peter

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I need about 10mm of engagement with the pressurering on the spindle and a little bit of air between the stationary and rotating parts... the original cylinder has 13mm stroke:
Attachment 460306

Quote:

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Originally Posted by badhabit

I've been looking at making a sort of cam, but the amount of force worries me a bit. First of all there is a ring which pushes down on the pressurering on the spindle, this ring needs to be hold in place, which is done by the cylinder in the original setup. So i need to keep this in place somehow...with 4000kgf on the end of it :-/

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Forgot to mention the second issue: Most of the rollers etc i can find for a cam-based solution is nowhere near strong enough to handle these kinds of loads and still have a reasonable size...

Maybe think about automotive clutch release arm and bearing system. Maybe for a heavy truck? They have about the correct amount of movement.

Quote:

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Originally Posted by Jim Dawson

Maybe think about automotive clutch release arm and bearing system. Maybe for a heavy truck? They have about the correct amount of movement.

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That is actually a quite good idea... i will look into how these work!

I've been searching all over for a large pancake-styled air cylinder, can it really be that they do not exist in like Ø300mm?

/Thomas

Looking at your picture, there is a lot of room below the CTS rotary union. I think it is no problem to remove all of the original hardware and build a release mechanism below the CTS. This would eliminate about 600 mm of height. Also look at heavy truck air brake actuators, that and a clutch release type device would work well.

you could try an air spring. https://www.mcmaster.com/9539K48 this will actuate 3991kgf at 100PSI air pressure and is only 2.6 (6.6cm) inches when not actuated.