Author Topic: Arbor press accessories?  (Read 17622 times)

Offline Tinkering_Guy

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Arbor press accessories?
« on: September 18, 2010, 03:52:54 PM »
I have a 1/2-ton arbor press from Harbor Freight that I would like to use to punch holes in several layers of leather.  The punch and punch plate I can make, no problem -- but what sort of fittings are there (or do I need to make) for the business end of the press ram?

I haven't been able to find any discussions/descriptions online for adding chucks or what-all to press rams, so any pointers will be very welcome!

Thanks!
Tinkering_Guy
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Offline John Stevenson

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Re: Arbor press accessories?
« Reply #1 on: September 18, 2010, 05:00:55 PM »
Is there a hole in the base of the ram? often you can locate punches by short dowels with a screw in from the side.

John S.
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Offline Lew_Merrick_PE

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Re: Arbor press accessories?
« Reply #2 on: September 19, 2010, 01:23:15 PM »
Tinker,

I am not familiar with the Harbor Freight press in particular, but I have worked with a number of the Chinese presses in general.  They are a far cry from the Wilton presses of my youth!  All three of the Chinese presses I have worked with needed be set-up and have the spindle hole rebored to be (A) parallel to the direction of motion and (B) sized to take a close-fit pin.  What I am saying here is that, in my experience, the arbor hole is neither straight nor round in Chinese presses.  It's no big deal to fix, but until you do, you are fighting a losing battle.  Two of the three Chinese presses also needed to have the face of the arbor milled to make them square and flat -- another thing to consider.

My preference (not universally shared by any means) is to make an arbor-end anvil/holder for any tooling I intend to mount on the end of the arbor.  I go so far as to keep a sacrificial end in my ram so that the arbor itself is not munged when something slips (much easier to replace than the rack-geared arbor).  Toolsets (such as, say, a crimping formset) are set up so that I can slip in a (or pair) of dowel pin(s) to line up my tooling on the baseplate.  (I also have several "inserts" for my baseplate that allow me to bolt down tooling bases accurately.)  These are all things that will be specific to your arbor press, but they are simple to design and build once you have thought them through.

Offline Tinkering_Guy

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Re: Arbor press accessories?
« Reply #3 on: September 19, 2010, 02:53:11 PM »
No, both ends of the ram are unpierced, and in fact rather roughly cut as steel fresh from the bandsaw.  I'm not sure what the material is, but I'll probably want to square it and finish it before adding anything.

Thanks!
Tinkering_Guy
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Offline Tinkering_Guy

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Re: Arbor press accessories?
« Reply #4 on: September 19, 2010, 03:02:50 PM »
My preference (not universally shared by any means) is to make an arbor-end anvil/holder for any tooling I intend to mount on the end of the arbor.

I don't suppose you have a photograph of this device, do you?

Considering that the ram is about 27cm long and 3cm wide and deep, drilling a spindle hole will take some thought; my mill doesn't traverse that high, and my lathe's spindle is too narrow.  Maybe a 4-jaw chuck, a thick disc with a 3cm square centre hole, and a steady-rest that can handle the disc..
Tinkering_Guy
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Offline DMIOM

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Re: Arbor press accessories?
« Reply #5 on: September 19, 2010, 03:55:53 PM »
.....Considering that the ram is about 27cm long and 3cm wide and deep, drilling a spindle hole will take some thought; my mill doesn't traverse that high, and my lathe's spindle is too narrow.  Maybe a 4-jaw chuck, a thick disc with a 3cm square centre hole, and a steady-rest that can handle the disc..

Can you tilt the head on your mill and use it as a horizontal borer?

If you have to do it on the lathe, maybe it would be safer to spin the drill bit and keep the ram clamped to the cross-slide?

If you can't find any other way, maybe you could make a quick jig. Take a block you can fit in the mill and drill it through. Then pop it on the end of the ram and use a few clamps to clamp it to a 'splint' of angle iron or similar? With that, you could drill it on a drill press, or even just hold the ram with jig on top in the bench vice and if the jig is good, drill it freehand.

And ... if you can't find any way you're happy to drill in to the end, leave the ram as is. Make a block with a pocket in it big enough to take the end of the ram tightly and deep enough to ensure it stays co-axial with the ram, and drill the end of that block as your holder.  Then you can have one or more of these as almost Q/C tool holders for the press - you can have a grub-screw or a pip-pin or similar to stop the block dropping off when you raise the ram (or if you want the block to be permanent, dowel it to the ram).

In fact when I needed a temporary bigger foot at the bottom of the ram, I took a block of scrap the size of the pressure pad I need and squared it up. The block was bigger in X and Y than the ram (a couple of inches square IIRC) and a couple of inches tall. I then reduced it in X and Y so it had a square column above a wider base - leaving about a half-inch thick base and the remainder milled down to the same dimensions as the ram with a height of about an inch and a half. I then took a couple of say 3 inch long pieces of angle, drilled through the angle and the foot's column and secured them, then slipped it up over the bottom of the ram and fasted it with a couple of toolmakers clamps.

Dave
« Last Edit: September 19, 2010, 04:15:47 PM by DMIOM »

Offline Lew_Merrick_PE

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Re: Arbor press accessories?
« Reply #6 on: September 20, 2010, 11:37:53 AM »
I don't suppose you have a photograph of this device, do you?

Not that I know of.  My press is in storage (my shop fits really nicely in 2500 sq ft and I have it crammed into 880 sq ft these days) making taking pictures rather difficult.  I could post a drawing set in the file upload area (though that is unlikely to happen before the weekend).  ???

Quote
Considering that the ram is about 27cm long and 3cm wide and deep, drilling a spindle hole will take some thought; my mill doesn't traverse that high, and my lathe's spindle is too narrow.  Maybe a 4-jaw chuck, a thick disc with a 3cm square centre hole, and a steady-rest that can handle the disc..

Two thoughts: (1) Do you know anybody with a horizontal milling machine?  That would be the easiest way to get it done.  (2) Can you use your lathe like a horizontal milling machine?  That would be mounting cutters/drill chuck in the spindle and mounting the arbor on the cross-slide -- which certainly will require some support packing and clamp set-up.

The arbor press I normally work with is (as I recall) a 25 ton press.  The arbor for it is 4 inches square (i.e. about 10 cm square) and about 30 inches long.  That's what I "see" when I think "arbor press."

Offline tony ennis

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Re: Arbor press accessories?
« Reply #7 on: September 20, 2010, 12:19:42 PM »
If you're just punching leather, make a socket out of plywood that fits over the end of the ram.  Screw a piece of steel to the bottom of the plywood.  Attach your punch to the steel plate.

The normal way is to fabricate a cylindrical tool holder that fits your punch.  Then bore a hole in the end of the ram that accepts the tool holder.  Finally, tap a hole in the ram for a set screw.