Thursday, April 26, 2012

WORKING the Hydraulic Press

['Mark Green' ,21 April 2012 - 02:56 PM' - Don Fogg's Blade Forum]

I hope all is well with you. Jesus told me you were setting up a log splitter press for bloom compaction.
I was just wondering if you have that going yet, and how it is working?

This is an edit of the reply I sent to Mark, as I expect some of the rest of you will be interested as well.

My purpose for building a hydraulic press was to allow me to work up a huge pile of iron blooms (from a decade of smelting!). I currently have a 50 lb home built air hammer, but the dies are only 1 1/2 x 4. Not near big enough to work a bloom on.

I had taken a lot of images while I was working up the hydraulic press. My intent was to put together an e-book (pamphlet) on the topic. Never got past the information collecting - at least for this year!

That being said, I did write some pieces seen earlier on this blog :

http://warehamforgeb...ulic-press.html

http://warehamforgeb...-continues.html

http://warehamforgeb...ulic-press.html


The overview is this:
I took a look at a couple of presses others had built. Both in person and via various web sites.
I'm not the 'machine' guy - but my friend David Robertson certainly is. Hydraulics represents a level of complexity (and potential disaster) that I was uncomfortable with.
I had looked at several layouts - single or double cylinder, cylinder on top or bottom, C or H frame.

Anyway, I had already bought a used hydraulic pump and electric combination, from a guy I do trust. Question was 'how much and how fast'. A long session at a local shop did not answer that. I considered buying some valves, hoses and a high pressure gauge to test this. Was going to cost me at least $100 for those parts - even more if I bought long enough lengths to incorporate into a functional press later.

David and I went back to his local TSC to get those parts. As we walked back to the parts section, we passed through a display of log splitters. The manager spotted us and asked 'Are you thinking about one of those? If so, have I got a deal for you..."
Turned out the Champion 30 ton was going on sale for 1/3 off starting the next day. That put the cost of a *pre-engineered* system (with self contained power) at only $1300. The unit was already designed to work in the horizontal position.

David went off to do the math. The cost of purchasing all the components (2 hp electric, cylinder, pump, valves, hoses) was going to be at least as much. I would have to build a frame in either case, the difference being that if I scratch built, that frame would need to be considerably heavier (enough to manage the full 30 ton thrust). The alternative was simply holding the existing machine up off the floor to working height.
Most importantly, I would not be *changing* any of the actual working machine.

The final design moves the gas engine from its original mount to the opposite side of the machine (to allow the operating controls of that to be accessable to the front side. This did require adding an extra 24 inch piece to two of the hoses, only one a high pressure line. I did this via a T mount, which allowed me to mount a high pressure gauge - which turns out to be very handy in opperation.

The biggest problem I had with the conversion was venting the exhaust from the gas engine.

In operation the actual pump and cylinder are very quiet. You do *not* get that shriek that Jesus's machine produces. Balance that against the noise coming from the 5 HP gas engine.
Given my shop layout, I could in fact add another 6 feet of hose to all the lines, and just mount the engine outside the shop altogether. I did not want to do that at first, as I was concerned about slowing the action time of the cylinder.

In use the machine is wonderful.
The ram moves 'about as fast as you would want' - with 2 inches clearance on any given piece of metal, to full compression (at 3000 psi on the gauge) takes about 5 seconds. Fast enough to preserve the heat, slow enough that you can stop it if things start to go off.
I can compress a piece of 1/2 thick by 2 inch down to 3/4 thick in a single shot. The maximum compression under the full 2 inch width of the rectangular block die is effectively down to about 3/8 thick. The full plate die I made up is roughly 5 x 7 inches (used for compacting blooms, or using smaller handled dies or tools).

The fiddliest part of the conversion was setting up a replacement ram head. I just replaced the existing log splitting head, which had a step diagonal to it. I had to figure out how to make for easily switching top dies. You can see the solution in the blog postings. This proved most certainly worth the extra trouble. With the slot and single pin system I worked up, I can swap a top die out in about 5 seconds.

If there is any major disadvantage (other than the noise) it is that the press has a C shaped frame. The maximum depth is about 6 inches, only a problem if I was to attempt working with plate.

With EVERYTHING included, my total cost to get the machine up and running was $2100 (CDN).
That included the block steel to make three dies , a large flat plate, a rectangular compression head and a heavy cutting head.

Images:
First is a view of the completed log splitter to hydraulic press conversion
Second are some of the test pieces worked up on my first session. The rectangular bar is 1/2 x 2 mild steel. All the compressions are single strokes.

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