Cylinder bench

[Mike L]

I’ve been on a run of rebuilding cylinders requiring 3500-5000 ft lbs on the nut. The local shop always takes several days to get one done. I need to build a cylinder bench. I’ve got a welder that I work with who will be doing the work. Does anyone on here have one? I’m thinking that it needs to be 16-20’ long. I’d like it to be able to catch the oil coming out of the barrel and have a drain plug to empty the basin. It will be powered by an electric over hydraulic pump. Beyond that I am looking for ideas and tips.

 

[pittsburgh cat man]

The older cat bench worked very well it was all fabricated look at this https://www.hawthornecat.com/wp-content/uploads/2022/12/Hydraulic-Cylinder-Repair-Stand.pdf

 

[John C.]

All the dealers that I worked for had one. The two easiest to use were built in house. The bench was built in two halves, one was bolted to the floor and the other would slide back and forth. There were two feet on the sliding half that were held down by channels on the floor. There was a top half of the bench and a lower half. The lower half had a cylinder that was operated by an electrically driven hydraulic pump. As I recall it was just a generic Commercial gear pump. The pump and motor were mounted on a reservoir next to the bench. There was a pan mounted above the cylinder that was angled down some and had a bit of a V bent into it to catch oil and from there it dropped into a pan mounted below the cylinder. The working part of the bench was the upper halves. The cylinder barrel boss would mount between two short arms that were bored to accept slugs. The slugs had different sized rounds that fit the bores of each type cylinder. There was a board mounted on the wall next to the bench that had about thirty or more different pairs of slugs. The moveable end of the bench also had two short arms with the same bores to fit the slugs. I forgot that the lower part of the moveable bench had a moveable boss to fit the working cylinder. It was mounted on a long piece of square tubing which had drill pin holes at certain points along its length. As I recall the working cylinder would extend about six feet and then the rod end unpinned and retracted. The extension piece would be slid to the retracted cylinder eye and repined and the working cylinder extended again. As I recall we could do around a forty foot total length of cylinder on those benches.
To work the retaining nuts the barrel would be removed from the sliding end and the rod installed in the stationary side. The sliding end was on a turn table and there was a special one or two inch diameter cylinder that would pin to a stationary arm and then to the turn table. There were hoses from a control valve on the bench to work that cylinder. There was a special set of V blocks that worked like a bearing splitter and they in turn attached to the turn table. Everything was tightened up and then the force was applied. There was a pressure gauge that was calibrated in torque instead of PSI to tell the amount of force being applied. You didn't need to buy huge sockets or crazy multipliers and it didn't take any special training to work those benches. A newby just watched a cylinder being done once and then they could do it on their own. I'm not near those units anymore but if I see another one, I'll get pictures.

 

[Truck Shop]

Johns description along with pcm's diagram is much like one in a shop in Dayton not far
from here, hydraulics only repair shop. Who knows how many cylinders have been through
that bench, one very busy shop.

 

[materthegreater]

I don't know anything about cylinder benches, but I snapped a quick picture of one at a hydraulic shop I was at recently. Not a good picture but maybe it'll help somehow.

 

[Welder Dave]

Can probably get some good ideas looking at websites for cylinder bench manufacturers. A shop near me apparently has the largest cylinder bench in N. America. They do a lot cylinders for the oilsands. I forget but I think their big cylinder bench was capable ot 125,000 ft./lbs. It was some insane number!

 

[MFM Truck&Equipment]

I was planning on copying this bench. Im going with a smaller bench like this so I can bring the bench to the jobsite.

 

[Mr. Wrench]

I was planning on copying this bench. Im going with a smaller bench like this so I can bring the bench to the jobsite.

The only one that I have ever used was like that one. It was shop built. Simple design and would not cost alot to build. You could add more things to it like, a drain pan, a way to pull the cylinder apart, and an overhead hoist.

 

[pumkinhead]

mms just started selling an import bench that looks fairly decent for the price https://www.mm-source.com/products/e4670c5b-80a2-45a5-bc2c-210236fd4eaf

someday I'll get around to building a bench and probably do something like this

https://www.reddit.com/r/Hydraulics/comments/1kxoc96

 

[crane operator]

I was always going to build one out of a big I beam, but I just don't have room to store it. IF I would clean up the shop, I would probably have room for one.

You got room inside, or just going to do it outdoors?

 

[Zewnten]

Do you want it to be portable at all? My very redneck version was 2 C channels welded in parallel with a table that slid outside the C channel to hold the barrel and a pipe vise for the rod end fo stabilizing. Tightening or loosen the nut I used a pulling portapower attachment to pull on custom wrenches cut from 1/2 AR plate about 2ft long. Crane operators idea is probably simpler if you don't need the odd ball wrenches.

 

[Mike L]

It will be indoors. my biggest customer has 2 shops and we’ll put it in one of them. I appreciate the input from all of you guys. My initial idea was to use an old delimber boom which is probably 4”x6” tubing 1/4” wall. V it out to about 12” wide and build sliding brackets to hold the rod. Then build something fairly universal to break the nut. Our local shop has a very large hex cut into a plate with some bolts to adjust to the size of the nut with a cylinder to rotate it. how would I turn psi to torque specifications?

 

[John C.]

I've used square inches of the cylinder piston times the pressure being applied to get linear force. Then add in the length of the lever that the cylinder attaches to for turning the nut.

 

[Zewnten]

I bought a hydraulic press gauge that had pounds and psi. It was set up for a particular size of cylinder. Then same as john I kept my wrench lengths the same so all I had to do was hit a specific psi or

 

[SVS]

If you are using the spine of the machine to anchor parts and torque nuts and glands on and off it needs to be a tube or an imitation of one.

Big square tubing or widely separated and braced channels. A lone I beam will twist into a spiral.

I’ve considered various ways to use a fork lift mast to build a cylinder bench that could pull and push cylinders apart or together.

 

[Diesel Dave]

The torque applied at the cylinder rod nut is accurate only when the work cylinder (pull or push) is at 90 degrees.to the lever (wrench). With the same hydraulic pressure at the work cylinder, when the work cylinder is at 25 degrees from vertical the torque is reduced by approx 10% and at 40 degrees from vertical the torque is reduced by approx 25%.