How much air does a Hardinge AHC or DSMA need?

I am setting up two AHC and one DSMA. In the worst case, how many CFM of air will these three machines use? All three will run Lipe 125 pneumatic bar feeders. My parts are 1" long, need to be hit with six tools. Cycle time per part should be 50 seconds.

In the past, someone mentioned 7 CFM for an AHC that is running strong. Is this close?

If so, I will need at least a 25 CFM compressor???

Any examples of single machines air use would even be helpful.

Thanks,

Dan Miller

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I don't know but on my Hardinge CHNC (very first early version) the Vari-grip collet closer bleeds vast amounts of air by design just to operate. The more grip pressure, the more air has to bleed.

It's just a horrible design so I disconnected it and I'm not using CNC with the collet closer. I run my operation at my home and that air would eat me out of house and shop.

I wish I knew of a replacement, that just used air on opening and closing and not in between...

Not sure on CFM but our DSMA needs 70-90 PSI to operate correctly. Less the turret won't index and the collet closer is delayed. More and the turret will index so hard you'll swear it's going to fly off! And the Versa-Valve is always bleeding. Shop compressor runs A LOT when that machine is in opperation.

Thank you guys for both your replys.

I have a 5HP 4 cylinder compressor that creates about 25cfm. My need is to run both the AHC and the DSM-A. The two machines do indeed have Varigrip collet closers.

If the Varigrips are in ( average ) used condition, think my compressor will keep up? How large were the compressor that you mentioned that had to work hard to keep up?

I have read that Varigrips can be rebuilt. I do have two extra VG's that I am about to crack open to see what they look like inside. Both the spare VG's came from AHC machines that were parted out. I have read that there may be a hard chrome application, to the main tube, that could then be ground to help seal the closer?

Any words on that repair having any success?

I have also read the Hardinge wants BIG bucks ( $3,000 ) to rebuild a VG .......... which is not an option for my low buck shop. I will take my chances doing my own work or buying more used VG's and testing them out to see if they are indeed better than those on hand.

The DSM-A or AHC can be had for $1,000 used nowdays. I would rather tackle buying and moving a whole VG equipt machine, to see if it is in good shape, rather than pay Hardinge that kind of money.

Thanks,

Dan Miller

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You autta have air-o-plenty with that compressor for your machines Dan.

I just think the Vari-grip is a horrible design due to the air bleed. The cost may have not been an issue back in the early 80's and big shops, but no way for my pocket book.

My Hardinge only needs air to lube the ball screws and ways. 70-90 psi and no leakage bleed needed. I disabled the turret and use it in a gang tool configuration. Works OK for my needs.

I'm going to sell mine (varigrip) eventually. I don't use it now.

I've been searching for other brands of air activated collet closers that can be controlled via CNC, but as yet have not spoke with any dealers on the subject.

Surely, there has to be an affordable closer retrofit that doesn't leak air to operate.

Frankly, for that matter I don't think the Vari-grip needs to bleed air to operate. I think may be just a poor design excuse for Hardinge at the time.

Hardinge needed a volume of air to run various systems. Some need much more air to operate at the same time. For instance, the collet closer only needs a starting pressure of 20 psi then progresses from there depending on how much grip you need.

The turret, cut off parting systems needed much more. So they use the bleed valve control to the Vari-grip.

This is all total speculation on my part. I haven't found anyone who knows exactly how and why this old Hardinge system is set up like it is. Hopefully someone here does and would like to explain it.

I think a dedicated voltage/CNC controlled air switch system could be made for the Vari-grip that did not have to bleed air. The next question is how much does it cost to rebuild a vari-grip and keep one running? I've read in the past, quite a bit with expensive parts.

Are there other newer, more cost effective replacement options such as on this website?:

Collet Chucks and Collets -5C, 16C, 3J, B42, b60, BZI

Atlas? Royal?

These setups here are starting to make more sense to me:

AIR COLLET CLOSER

Dunham (sp?) makes a good 5c air collet set up.

I need to check into that Dunham.