Converting an inverted hydraulic press into a light-duty forging press

[Frosty]

Ayup, that looks like I'm thinking. I'd weld spacers into the posts at intervals just because. You could bolt everything together and it'd work fine. I'd weld the posts but the rest can safely be bolted. Just take a look at shop presses, some have 50 ton jacks, fast ones have air over hydraulic cylinders. The horizontal members are much longer too so there's a lot more leverage than you're dealing with.

Anyway, this concept sketch is what I was thinking of. Details will of course depend on . . . 

Frosty The Lucky.

[bubba682]

That'll work make sure you do at least 3 passes all the way around the i beam if you go stick use 1/8 rods 7018 and no undercut on the welds i'd be around 130 amps depending on machine remember your to hot if your gettin alot of splatter .

[JHCC]

5 minutes ago, Frosty said:

Ayup, that looks like I'm thinking.

Which: (1) or (2)?

[JHCC]

Lots of work cutting away the unnecessary substructure, leaving the mounts for the motor and hydraulic pump.

Before:

And after:

I think I was right not to trust these welds under tension:

Cutting off the cylinder supports yielded two ~27” pieces of 4” channel, which will doubtless come in handy. 

[JHCC]

So, this is what I’m thinking. 6” wide C-channel for the uprights; 1/2” x 4” plate as the core of the bridge, the center guide of the moving die holder, and the inner faces of the bridge and the die holder; and 4” wide C-channel on either side of the bridge core and the center guide. The bridge will bolt to the uprights, so that the die holder can be removed if necessary. The 4” channel will have some vertical gussets at each end (serving as guides on the moving die holder and possibly bolting to the flanges of the 6” channel for extra rigidity on the bridge) and in the middle as support under the dies. 

I made a mistake in the drawing: the base plates of the dies are shown as 6” wide. They should be 4”, so that they can be turned 90 degrees. 

[Frosty]

10 hours ago, JHCC said:

Which: (1) or (2)?

I missed sketch #2.

Number one all the way. 

I'd prefer something wider than 4" for the bridge but it'd be okay.

The dies you show in sketch 1 could be holders for interchangeable dies. Being under compression two 3/8" screws in each die plate are plenty. The dies for my 50lb. LG are welded to plates with 3/8" holes that match tapped 3/8" holes in the dovetails. I think by now most of the guys in the club with power hammers set up closely enough can interchange dies.

If you make the die plates square you can put 4 holes in each and rotate them as well. This is a good idea on a H frame press, you'll be able to use dies both ways. Good thinking.

I don't see your vertical gussets in the sketch, how about a detail sketch. 

I need to give this sketch some more thought. 

Frosty The Lucky.

 

[JHCC]

I’ve seen a number of presses (both on IFI and elsewhere) where the dies simply slide into a holder and are held in place with a simple catch. That’s the plan here. 

[JHCC]

Peppie has some interesting die holders in his most recent comment on his “Pressing forward” thread:

 

[JHCC]

8 hours ago, Frosty said:

I don't see your vertical gussets in the sketch, how about a detail sketch. 

Here you go:

Note that this has two gussets under the dies rather than the one in the earlier drawing, for greater strength. Another option would be a section of vertical C-channel trimmed to fit and welded in place inside the horizontal channel. 

8 hours ago, Frosty said:

I'd prefer something wider than 4" for the bridge but it'd be okay.

This is sketched with 4” C-channel, because that’s what I have on hand (from the old cylinder supports I cut off yesterday). I might go with 6”, depending on what length of drops I get for the uprights

[Frosty]

I noticed Peppies slide in die holders, a set screw or pin retainer aught to secure them nicely.

4" C channel posts will work well enough, all the forces are centered and the frame is under tension. 

I was referring to the bar bridging between the posts. The moving die doesn't need to be as heavy it isn't going to flex like the top will. The moving die has the hyd. ram centered on the die so there isn't an appreciable bending moment it only slides in the guides. 

The anvil die however is mounted on a bar bridging between the posts and WILL be under a strong bending moment. This is what I'd like to see wider than 4", 6" is good, 8" is better.

The stiffeners you propose on the bottom die will help but the second plate across the vertical one isn't necessary. It won't hurt but you can get a better effect by making those stiffeners proper gussets. Gussets are typically triangular to direct forces. If you were to make 4 truncated triangles with the clipped end welded into the ram connection and the wider ends spreading half way to the edges of the die plate it will prevent twisting and bending of the guide plate.

What you propose will help though, it's not a bad plan.

Frosty The Lucky.

[JHCC]

1 hour ago, Frosty said:

 

I noticed Peppies slide in die holders, a set screw or pin retainer aught to secure them nicely.

 

One thing I’ve seen (e.g., in one of Walter Sorrells’s videos) is a little swiveling tab whose own weight holds it shut. 

1 hour ago, Frosty said:

The anvil die however is mounted on a bar bridging between the posts and WILL be under a strong bending moment. This is what I'd like to see wider than 4", 6" is good, 8" is better.

I can always weld this chunk of 5-1/2” x 8” I-beam onto the top of the bridge if necessary:

1 hour ago, Frosty said:

4" C channel posts will work well enough, all the forces are centered and the frame is under tension. 

Interesting. If 4" is good for the posts, that would certainly help the materials budget, assuming that they have some in the drop bin -- that really is the deciding factor for what I use. I assume that adding some gussets to the joint between the uprights and the table will help strengthen it against those tensile forces; one of my biggest concerns is the hydraulic force ripping those joints apart.

[Frosty]

If you weld that piece of I beam/wide flange to the tops of the posts you might as weld the bridge in too, you won't be able to remove it. That piece of structural steel is just lack of confidence overkill.

Check the drop bins for a piece of 1/2" x 6" for the bridge and pick up a few feet of 1/2" x 1 1/2" strap stock for stiffeners and gussets. Making the bridge member stiff and rigid is easy, and it won't look like something Jethro Bodine invented. (Beverly Hillbillies reference for you youngsters)

I guess I'll have to start taking pictures of graph paper sketches, emailing them to myself and reducing file size to post here. Dude, you are really starting to rub my lazy nature the wrong way. 

A verbal description of stiffening the bridge member. Cut four pieces of 1/2" x 1 1/2" strap stock long enough to back the hard mounted die plate and extend to the upper corner where the bridge member meets the post. 

With these stiffeners welded in place the bridge can NOT be bent upwards without upsetting all 4 stiffeners. Nor can it twist without upsetting two stiffeners and stretching the other two. The stiffeners do not need to be welded to the posts unless you want to weld the bridge member. I'd weld it, the dies are interchangeable anyway and 25 tons isn't enough to bend 1/2" x 6" probably not even 4" the hard way. Especially not with proper stiffeners.

Do something ELSE with that piece of wide flange (I beam it's not) it doesn't do ANYTHING for the press but look hokey. 

About worrying about the welds. Consider the tensile strength of properly run 7018, you can look it up, it's considerably stronger than mild steel. your C channel appears to be 4" web x 1 1/2" flanges and it doesn't make a lot of difference how thick. Say it's 1/4" thick for the purposes of discussion right now. 

A competent welder say Tom WILL get 100 % penetration from one side. The bead length will be 4" for the web and 3" for the flanges. 7" x 1/4" x 45-50 k lbs tensile mild steel. The welds on each C channel post will have 1 3/4 sq in of steel. for approx 17k - 87 k lbs tensile strength the weld beads themselves will be considerably stronger. Let's go with a conservative number for safety's sake. 17k x 4 post members = about 315,000 lbs tensile strength. That's the tensile strength of the mild steel C channel if it's 1/4" thick. call it a conservative 150 tons to pull it apart. 

Feel a little better John? While I relinquished them decades ago I held a welding cert for pipe and structural among a couple others and had papers saying I was a trained, qualified fabricator. Tom and I won't let you build a dangerous press. Honest. 

Frosty The Lucky.

 

[JHCC]

2 hours ago, Frosty said:

A verbal description of stiffening the bridge member. Cut four pieces of 1/2" x 1 1/2" strap stock long enough to back the hard mounted die plate and extend to the upper corner where the bridge member meets the post. 

Like this?

This assumes a vertical web on the bridge of 1/2" x 6" and a horizontal plate on the bottom of 1/2" x 4", making an upside-down "T". That horizontal plate can be welded to the flanges of the channels that make up the corner posts. I'd need to resize the die plates down to 4" square, but I don't think that's an issue.

2 hours ago, Frosty said:

Check the drop bins for a piece of 1/2" x 6" for the bridg

I haven't seen stuff of that dimension in the bin, but I do have a 11" x 28" chunk of 1/2" plate that I can cut down.

2 hours ago, Frosty said:

pick up a few feet of 1/2" x 1 1/2" strap stock for stiffeners and gussets

I've already got a 43" piece that I got a few months ago.

2 hours ago, Frosty said:

The stiffeners do not need to be welded to the posts unless you want to weld the bridge member. I'd weld it

I guess I should make the moving die holder and insert it before I weld up the outer frame. There's no way I'm going to be able to install that after the bridge gets welded to the posts.

[JHCC]

By the way, the two pieces of 4" C-channel I took out yesterday are not enough to make all four corner posts. Might come in handy for the bridge or the moving die holder, though.

[Frosty]

That's the idea but spread the bottom of the V to the width of the die or the point might become a stress riser over time.

Seeing as the bottom die moves you and is under centered compressive forces you can make the die holder a saddle that bolts to the guide plate so you can disassemble it if you wished to remove it. Yeah, that's kind of fancy but doable without lessening anything else.

I didn't think you had enough C channel in the unit. That's okay though it'll give you a chance to find wider.  Look at it this way, it's more rigid and even if it's only 1/4" thick 4 posts 1" wider increase the tensile strength by about 45,000lbs. More rigid is more beneficial but don't sweat it, 4"channel is okay. 

Frosty The Lucky.

 

[JHCC]

41 minutes ago, Frosty said:

you can make the die holder a saddle that bolts to the guide plate so you can disassemble it if you wished to remove it.

Hmm...I like that idea. I have some 3" x 3" angle iron (1/4" thick) that would be good for that. A couple of gussets would help, too.

I'm also thinking that I could cut off the upper part of the old pulling stem (leaving the cylindrical part welded on top of the nut; see photo below), notch the center guide to go around the nut and cylinder, and then weld the whole thing in place. That would give a nice solid connection between the hydraulic cylinder and the guide, and we already know that the existing weld is plenty strong (after all, it was resisting the entire pulling force of the cylinder in its original configuration.

Having a removable saddle also eliminates another issue: being able to install the tie rods through their holes in the top. With this setup, I can put the guide in place, screw the rod on from below, install the tie rods, tighten the lock nut on the rod, and finish by attaching the saddle.

[Frosty]

Turn the angle iron flange out and weld it to the die mount plate and bolt it through the guide plate should work nicely. 

You don't want to notch the guide plate that deeply, welding on the sides of the nut is likely to bigger the threads and it's a compression joint so it doesn't need such a heavy weld. 

Frosty The Lucky.

[JHCC]

I could just notch around the cylinder and leave the nut alone. 

And here’s a cross-section with the saddle:

[Frosty]

Those look  pretty workable, might see what Tom thinks. He might have better ideas.

Frosty The Lucky.

[JHCC]

Good news! I stopped by the steelyard on my way home and found some 5” x 6.7 lb C-channel already cut to length!

On the one hand, they’re a mite shorter than originally conceived (and thus will require a bit of redesign), but each already has one end cut perfectly square!

Time for more sketching. 

[Frosty]

Nice score John! How much is a mite shorter than planned? We can make an inch not matter without trouble. 2-3 inches will take a little fabbing but not a deal killer.

Frosty The Lucky.

[JHCC]

I had originally planned to make the corner posts 23” tall. These pieces range from 20-1/2” to 21”, so they still overlap the central web of the bridge by ~3”. 

I’m now planning to make that central web 6” high and reinforce it on either side with 4” C-channel (possibly with diagonal stiffeners, as shown). 

[Frosty]

You've lost me John. What do you mean by  "central web" of the bridge? 

Frosty The Lucky.

[JHCC]

The 1/2” x 6” x 20” plate that forms the core of the bridge. 

[Frosty]

Got you. Web has a specific meaning regarding structural shapes, we don't apply it to a fabricated thingy. Well I didn't.

The horizontal bar you have sketched in on the bridge member between the posts can be eliminated, it no longer reinforces the bridge against deflecting upwards. It's too close to the center to have any significant effect.

Rather extend the 4 stiffeners angling from the tip die to the far corner of the bridge member. This will make the entire bridge member very rigid and resistant to twisting. Just like the short versions but the wider bridge member and extended stiffeners will make it near bullet proof.

No need to turn it into a T or I shaped structure, the plate and stiffeners are more than good overkill.

Frosty The Lucky.