Arbor press modification w/ratchet

[dangod]

I picked up a #3 lever type Famco arbor press. I'm thinking of having a 3/4" square hole machined into the end of the pinion (after shortening the pinion to remove the lever arm hole), to accept a 3/4" ratchet.

I understand this arbor press exerts 3 tonnes, so, how much would I loose with this ratchet setup ? Assuming it's not able to meet the 3 tonne capacity, how quickly would a quality ratchet head break using this setup ? From what I can see, a SnapOn head would break at 250psi - so, how much does 250psi work out to when it's applied to the arbor press/ram head ? 1 ton ? 1.5 tonnes at the ram head ?

Forgive me if this seems like a foolish question - it's my first arbor press and I'm having a hard time getting my head around the math (tonnes/leverage/psi combination)

 

[Roberts210]

Why do you want to do this? Are parts missing?

Famco still makes the compound ratcheting arm for these I believe. But when I restored the one below, they wanted so much $$ for it I ended up making something. But the compound ratcheting arm increases the amount of pressure you can bring to the job. Mine is just a straight ratchet job.

Here's a picture of what I had to make.

Here it is completed.

 

[dangod]

Why do you want to do this? Are parts missing?

Famco still makes the compound ratcheting arm for these I believe. But when I restored the one below, they wanted so much $$ for it I ended up making something. But the compound ratcheting arm increases the amount of pressure you can bring to the job. Mine is just a straight ratchet job.

I want to do this for the same reason why you modified yours, because I can. No, parts are not missing - as per my post above, it's a lever type arbor press, not a ratcheting type. The only thing missing is the 3/4" hole I'm thinking about. If you can answer the question I asked in my previous post, I'd really appreciate it. Thanks for posting your pictures, it's not really what I had in mind though.

 

[Roberts210]

I understand this arbor press exerts 3 tonnes, so, how much would I loose with this ratchet setup ? Assuming it's not able to meet the 3 tonne capacity, how quickly would a quality ratchet head break using this setup ? From what I can see, a SnapOn head would break at 250psi - so, how much does 250psi work out to when it's applied to the arbor press/ram head ? 1 ton ? 1.5 tonnes at the ram head ?

Can you post a picture of what you have?

Assuming the Snap On head would break at 250 psi... what does that mean? Is there a torque value the Snap On would break at? The torque value might be easier to plug into the equation than a psi value... pounds per square inch WHERE?

And I didn't modify mine because I could, I did it out of necessity. Here's a picture when I first dragged it home. It was missing any kind of levering mechanism as well as a pawl and the brake. Probably missing some other things I have forgotten about.

 

[rsanter]

What is the length of the exsisting rod verses the length of the ratchet you will be using?
If the lever is the same length then you should loose nothing.
Will the 3/4 ratchet hold up, I would be shocked if it did not

Bob

 

[454ragtop]

If it were me, instead of shortening the shaft/gear why not make a sleeve that fits over it with a hole to pin it to the shaft thru the original handle hole with a plate welded on with the 3/4" square hole in it. Then it could always be returned to original, and a lot easier to make a thru hole with a square than a blind one.

 

[tool_scrounge]

If it were me, instead of shortening the shaft/gear why not make a sleeve that fits over it with a hole to pin it to the shaft thru the original handle hole with a plate welded on with the 3/4" square hole in it. Then it could always be returned to original, and a lot easier to make a thru hole with a square than a blind one.

I was going to do this with a modified deep socket. Most of the work is done and the material is pretty tough.

 

[tool_scrounge]

Or use a ratcheting pipe threading ratchet wrench....

https://www.garagejournal.com/forum/showpost.php?p=2958175&postcount=47

 

[Air21]

I think I saw in Home Shop Machinist where a guy used his torque wrench the same way for a repeatable assembly pressure, I forget what for.