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wierdscience
06-12-2010, 08:45 PM
We have this old W.A.Whitney angle iron shear at work,good machine,old parts now obsolete.It consists of a frame that holds a set of blades and a cylinder that holds a knife.It works on the same principal as a quillotine.

It had sat in storage for years before we got it and the cylinder rod had developed some rust pits,but the rod side of the piston is low pressure since it only retracts the knife.We have used it for years,but the rod seals finally went out and it started puking oil.Quick call to the MFG found no parts,not even seals.

Normally I would simply order up a section of chrome rod and machine a new one.This one I couldn't,the end of the rod that holds the knife on is hardened and larger than the rod diameter.Grinding and re-chroming was out as well since I was quoted $550 and six weeks lead time.

My solution was to buy a section of chromed OD tubing and make a sleeve.Tube is 3.00" OD and 2.460 ID.Of course they didn't put a center in the end of the rod,so that was the first operation.

http://img.photobucket.com/albums/0903/wierdscience/DSCF0002-5.jpg

Centered up and the sleeve material-

http://img.photobucket.com/albums/0903/wierdscience/DSCF0003-4.jpg

wierdscience
06-12-2010, 08:46 PM
The rod was machined to 2.460 and given a .001" taper over it's length with a mic and a few passes of emery paper.Once that was finished it was removed from the lathe,coated with Loctite 271 and slipped together on the arbor press.

The turned rod -
http://img.photobucket.com/albums/0903/wierdscience/DSCF0004-3.jpg

Once in place the sleeve was faced .001-.0015" proud of the rod end so the piston would bear up on the sleeve.

Now all that's left is to pack the piston and gland,then re-install.

http://img.photobucket.com/albums/0903/wierdscience/DSCF0005-4.jpg

Allen Hunt
06-12-2010, 10:58 PM
Neat trick! Thanks for posting!

Allen Hunt

torker
06-12-2010, 11:06 PM
Nice work as usual D!!!
I likey that trick of using and .001 taper!!!
Never woulda thunk that myself.

Carld
06-12-2010, 11:09 PM
Why the taper on the pin and what was the fit of sleeve to the pin? I have a guess about why.

wierdscience
06-12-2010, 11:23 PM
Neat trick! Thanks for posting!

Allen Hunt

Your welcome and welcome to the forum Allen!


Carl,I wanted the sleeve to just slip on so it would land about half the way home before it met any resistance.Luckily the tube ID measured within .0002" of round at each end.With the 271 in there I had to be quick,I just barely got it pushed home before it grabbed.

Carld
06-12-2010, 11:52 PM
I figured that was what you were going for. Nice job.

motorworks
06-13-2010, 12:01 AM
Great Job :)
eddie

Mcgyver
06-13-2010, 12:10 AM
with the taper strategy, any resulting OD difference between the two ends of the sleeve....I mean half is a press fit and half not?? ....or was the whole thing turned afterward

wierdscience
06-13-2010, 12:52 AM
with the taper strategy, any resulting OD difference between the two ends of the sleeve....I mean half is a press fit and half not?? ....or was the whole thing turned afterward

I get 3.0002 on the tight end and 2.999 on the small end,so not to bad,the rod gland bore is 3.005" so we're good.

Couldn't turn the OD though,it's chromed.

Carld
06-13-2010, 11:09 AM
The way I figure it with the slight taper and the locktite filling the void and the sleeve clamped by the yoke, nut or whatever he's good to go.

wierdscience
06-13-2010, 09:10 PM
Sealing shouldn't be any problem,at 18 tons I calculate the pressure at 1275psi.on the working side of the piston.This will see pressure on the rod side which is less than 200psi.8" worth of expanded Loctite should do it.

The piston screws directly on the threaded end so that will seal as well