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Round vs square arbor press rams

Just a Sparky

Hot Rolled
Joined
May 2, 2020
Location
Minnesota
Just a little bit of curiosity going on here. I've got an old 3 ton Greenerd arbor press with a round ram in it. Most other press manufacturers use square rams.

Are there any particular reasons that come to mind which might make one design preferable to the other? Did the engineers just shrug their shoulders and say; "Eh, let's make it round!" ?

Mind you Greenerd has been using the round ram design since the 1890's. Is it just a habitual thing that has stuck around with them to this day?

:scratchchin:
 
It certainly seems like it's easier from a design and manufacturing standpoint to make a square ram press than a round ram style. A simple square 'rack' and a simple square hole for said rack versus a lot of fiddling to cast and machine a round hole and cut a rack on the back of a round bar. These are merely non-professional observations.

Stuart
 
Probably 6 of one, half dozen of the other. Making a square hole vs a round one - harder (do they use a broach?). Making a square ram vs a round one - easier (? but holding the round ram to cut teeth might be harder. Interesting question.
 
The teeth in the round rams are on the centerline of the ram, so the force is applied more directly downwards.

On the other hand, the square rams have gibs that can be adjusted to take up wear.

But the most important factor is: Which one is available locally for a decent price?
 
I have one of each. I bought a Dake 1 1/2B with a square ram. A friend of mine wanted to use it, so it’s never been home yet. Another friend gave me the main casting for a Sheldon #3. It was recovered from a pile of junk. No other parts were recovered. I made enough parts to make it a ratcheting press. I didn’t make the ratchet wheel nor the hand wheel. Hand wheel is off a Cincinnati mill that was scrapped. Ratchet was a rejected part the friend had laying around. Cut the teeth on ram with my shaper. No problem.
Sorry for sideways pic.
 

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The teeth in the round rams are on the centerline of the ram, so the force is applied more directly downwards.

On the other hand, the square rams have gibs that can be adjusted to take up wear.

But the most important factor is: Which one is available locally for a decent price?

I was going to make this comment (re: centerline) as well. But on an arbor press how much does that really matter? An arbor press is a rather crude (non-precision) tool.

And your comment about what's available at the right price is dead on.
 








 
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