Adding a HF Jack to a H frame press

[LeeG]

A while back I picked up a real solid, US made 25 ton press for cheap from CL. After getting it home, I found that the hydraulic cylinder was bad. My local repair shop tried, but was unable to repair the old cylinder. I would like to use this existing frame and add to it a HF Air/Hydraulic jack.

Here is the frame as it exists, with what I think I need to add to it.

View media item 92180
The press is 35" wide. The uprights are 1/2" x 2", with a 1/4" plate spacer welded between. The top of the frame is two pieces of C channel (6 x 2 x 3/16 or so), with 1/4" plate welded between them 3" on either side of center (forming a box in the middle)

So I need a piece to attach the jack to the top, and a piece for the jack to set on that provides the downward pressure. There are existing tapped holes in the top channel where the old cylinder was mounted.

My initial guess is to make that top piece from 3/8" plate, about 12" x 6", so it spans the entire width of the channel. Have a hollow cylinder welded to the bottom to hold the piston on the jack.

For the bottom piece, it will have springs attaching it to the top piece (not shown. I figure a 2" piece of round bar welded to the plate that is on the bottom of the jack.

I see on the HF presses, this lower piece extends to the sides and forms a U shape around the outside. Is that the best way to keep this lower piece centered, or is there a better way?

I own a lathe and welder, and can get use of a milling machine if necessary. My main use for the press will be bending steel with my SWAG break kit, but I will use it to press bearings and such.

Any insight or advise is welcome.

Thank you

Lee

 

[MJD1]

If using a bottle jack, convert it for upside down operation. Either add a resivoir or dissasemble the jack and add on to where the oil pickup is at .

 

[slopdog]

I did mine like this /

 

[BD1]

Just duplicate what's on the harbor freight 12 or 20 ton press.

 

[whateg01]

I have never liked those presses with the crossmember that floats with the jack. I used a piece of rectangular tubing on the first press I built using a bottle jack. Put a hole through the middle and a piece of solid round stock through that. Then a plate that the jack pushed down on. That thing had very little play in it, so it was about as stable as a solid mounted cylinder. I think I got the idea from the little light weight A-frame presses. Something like this.

Dave

 

[rsanter]

If using a bottle jack, convert it for upside down operation. Either add a resivoir or dissasemble the jack and add on to where the oil pickup is at .

This is what I was going to say. On the web they’re are several people that have shown how to do the conversion

 

[whateg01]

This is what I was going to say. On the web they’re are several people that have shown how to do the conversion

I tried that with a jack I bought for that purpose. It could have been because the jack was from HF, but it wouldn't pickup, and it leaked around the nut when upside down.

Dave

 

[why worry]

I used a coleman propane cylinder for a remote reservoir on a HF 20 ton air/hydraulic jack. It sure is nice and stable bolted to the top. Upside down is the right way for this application.
Dave