Hydraulic press modifications

I have the 20 ton harbor freight press which I upgraded to a compressor driven hydraulic press.

Is there a way to get a faster stroke speed on the press? I want something that can be used like a fly press. Something fast and that I can control the squeeze pressure in some way. Any ideas how could do this without just buying an old fashioned fly press?

 

Some presses do have a handwheel and screw to quickly take up the slack mounted on the end of the ram. If you machine an ACME thread with two starts, you can machine a smaller size profile which would be easier on the lathe and also move twice as fast, like a 5 TPI two start thread with a 10 TPI profile. Other than that, maybe a few sleeves of different length with a socket that securely fits on the end of the ram made from round steel bar. You could embed a ball detent or magnet to keep it in place.

 

Well what i want to do with it is basically make a mold and use the press to slam/bend a piece of metal into the mold. I want to make an iron gate and need to make about 800 identical pieces. So I'm trying to figure out how to quickly get a couple tons of force to crunch the metal into the mold quickly. Something that can let me make a part every few seconds. A fly press would be great but they are 800 to 1200$ I'm wondering if there are any hydraulic options that can do something similar.

 

A modified log splitter maybe?

 

Isn't there a hydraulic cylinder that moves fast i could swap out my cylinder for? Or a hydraulic pump that could do it faster?

 

Short of finding a complete pump and cylinder at the scrap metal dealers, there's no quick solution apart from doing it properly/expensively. Any other solution involving something like a long stroke pneumatic cylinder driving a smaller hydraulic cylinder just ends up more complex/expensive. You got any hydraulic shops in your area?, sometimes it's possible to get secondhand pumps and a large broken cylinder to cut down and repair for the press.

 

Switch gears and think about a simple drop hammer?
I couldn't find a diagram of what I'm thinking about but something along the lines of motorizing and automating this:

 

Thats genius!

I could easily make something like that. I wonder how much weight I'd need to make into a hammer to apply about a ton of force onto the part. And how tiring it would be haha. Might start to hurt after 800 parts...

 

I'd love to make my own fly press. If I had a cad file of the thread and part that it slides through I could take it to a local machine shop and have them cut me a steel part on their cnc machine.. But I haven't been able to find a cad file and I don't have the skills yet to make a file of one.

I think I could fairly easily weld some heavy steel into a good frame for it. Or maybe cast an iron frame.

Apparently the thread has too much of an angle to it to machine on most lathes. They can't be geared up high enough to cut threads with such an angle so there are many forum posts out there of people complaining about not being able to make one.

 

Awesome. I will need to do some research and see what it requires. I think its close to 45 degrees and 3 tpi. But I'll do some reading and get back to you.

I wonder if I could 3d print it and cast it out of iron? Or would iron shatter when used like that? Maybe steel is better...

 

What are the parts you're making?

 

Rocco made a great suggestion with the log splitter. It seems like the whole machine is ready made for what you need. Just rent one for a weekend. Swap out the ram splitter for one half of your bending die. Clamp the other half to the anvil. Fire it up and press away.

Denis

 

Might be worth building a log splitter then haha. Those are pricey too!

Well looking at the info on fly press screws it seems they are multi-thread screws. With minimum of 2 independent threads but some have up to 4 threads. This is what let's them take the force of the blow, not lock up at the end of the stroke and travel so far per stroke. Probably a 4 thread is what I'd want with a 2 inch diameter thread and I think the thread pitch is about 40 degrees. I'll have to nail down exact numbers but thats what I've been able to dig up.

Also, seems like the screw needs to be made from some kind of shock resistant steel or it will shatter. So probably casting it is not an option.

 

Haha yeah. Not too many hefty friends. Mostly skinny nerdy types