Shortening Hydraulic Cylinders

[buffumjr]

I'm finally getting around to making an end loader for my Kubota L175. I bought a Ford 703 kit for it CHEEP, but it's WAY too big. I'm scrapping the frame, cutting down the arms and the bucket, but I have to shorten the 4 hydraulic cylinders. New cylinders range from $140 to $289 EACH. Need 4. This makes economic sense, to modify existing.

I watch the YouTube channels, "Cutting Edge Engineering Australia". and "abom79". With a BIG lathe, you can do ANYTHING to a hydraulic cylinder. My lathe is a South Bend 9 x 21. These cylinders are 38" long. Won't fit. Is there a way to shorten the tube and the shaft WITHOUT a lathe? Cutting would be easy, with a high speed grinder. It's lining things up for rewelding I worry about. Or should I not worry, and just do it?

 

[North Idaho Wolfman]

Cutting the tube section down is easy, its cutting the rod down that can get tricky.

Looks like you'll have to spend thousands on a new lathe to get it done properly.
Get someone with a bigger lathe to cut them down and rethread them.
Or just buy new cylinders.

 

[buffumjr]

Cutting the tube section down is easy, its cutting the rod down that can get tricky.

Looks like you'll have to spend thousands on a new lathe to get it done properly.
Get someone with a bigger lathe to cut them down and rethread them.
Or just buy new cylinders.

EEEEK! That sounds more like owning a boat or a full size airplane!

Wouldn't need to rethread. Cut the eye end to shorten the rod, then weld the rod back on. Cutting and welding the tube would also involve redrilling the extend port and threading for 1/4" pipe. The issues on both are tapering the contact zone for welding, and proper alignment.

Buying new anything is scary! "Run away! Run away!"

 

[North Idaho Wolfman]

Make sure you get the stroke right, or it will be POP and game over.

 

[Motion]

How much of the cylinder needs to be cut down? Is it possible to relocate the cylinder mounts to a lower part of the frame? If you cut the old ones down I'd suggest not cutting the cylinder end off but leave 1-2 inches to allow a square cut then remove the section needed and allow the second square cut, then tack 3 pieces of 1/2" square bar 4-6 inches long 120 degrees apart to act as an alignment, tack the cylinder remove the square bar and do a full weld. The welded area needs to back from where the piston rides. I wouldn't trust threading the cylinder I'd suggest welding a piece of 3/4" round rod by 1/2" long then drilling and tapping the boss. Good Luck

 

[Yooper]

Cradling both pieces in channel or angle iron will get the job done as far as alignment. I prefer the tig welding process but have done it with wire also. Without a big enough lathe you are pretty much stuck with shortening and rewelding the eye on. Make sure you taper the rod and eye and use multiple passes to weld out the joint.

 

[GreensvilleJay]

There's pleny of 'surplus centers' selling hydraulics search them for what you need. Obvious specs are PSI,bore, stroke, mtg configuration....... up here in Canada , I can get custion made cylinders made to MY spec pretty darn cheap.
Before cutting and shortening the cylinders, see if you can sell them. Use that money to buy 'proper' ones.
I never used a lathe to 'rework' a pair of cylinders 4 decades ago....when I didn't have any money but I had the time, only took an afternnoon.

 

[buffumjr]

Cradling both pieces in channel or angle iron will get the job done as far as alignment. I prefer the tig welding process but have done it with wire also. Without a big enough lathe you are pretty much stuck with shortening and rewelding the eye on. Make sure you taper the rod and eye and use multiple passes to weld out the joint.

Yeah, I had considered that. I just thought of using a fixture to hold the cylinder and the rod eye end to the 4 jaw chuck of the lathe. Drill a center, then cut the taper with the lathe. The taper doesn't have to be exact, or radical. Ten degrees would be fine. Saw Cutting Edge weld a small scrap block on an eye, and use that for the center, or I could hold the block in the chuck jaws.. I could do that, and grind it off after.

For used, Acme Industrial Surplus (where Wile E. Coyote shops!) sells 'em, but they're PROUD of them. It would be a shame to deprive them of the privilege of continuing to look at them . Also, no two are alike. Do you know of another outlet for used cylinders?

If I can't sell the 703, I probably can't sell the parts.

 

[Lil Foot]

Surplus Center

Warehouse distributor for many top name manufacturers. Parker Hydraulics, Hypro Pumps, Prince Hydraulics. Direct from the factory. Surplus equipment. We buy large quantities of manufacturer's surplus or excess stock.

www.surpluscenter.com