When Conditions Become Pressing!!

[carrdo]

HI All,

I think that only I could do it this way. When conditions become pressing! All of the following for only one operation.

How to turn a standard bench arbor press into something else.

Anyway, the story. I purchased this used bench arbor press some decades ago now and slowly have been transforming it into my go to tool for things it was never designed to do. It seems that this is a situation which repeats itself over and over again.

This press came with a few non standard features which I guess had been added by the previous owner(s). Chief among these was the ram, which had been modified to accept a precision 5/8" diameter reamed centre hole in the pressing end which would allow one to insert various other tools and a drilled and threaded base which would allow one to attach numerous fixtures to the base of the press. This turned out to be extremely useful in my case.

I added some additional modifications of my own namely I drilled and reamed a new access hole in the side of the ram as seen in photos 665 and 667. In certain high pressure broaching situations, the broach head steady as seen in photo 669, despite being tapered at one end would lock itself in the centre hole in the ram so I needed to be able to insert a non metallic drift to mechanically free the broach assembly after use.

The broach seen in photo 669 is a 1/8" square DuMont. These small broaches are obscenely expensive and quite delicate so you need to do everything humanly possible to align the broach straight and square to the work and prevent any off centre or sideways slippage/bending when broaching.

What is to follow is what I do to achieve the above and it approaches the insane.

To be continued.

 

[Ironman]

What I have found is that I push the broach an inch and then lift up and the broach will move over if it's needed. repeat til done. If you keep sinking it the side stress of an uneven table can cost you.

 

[DavidR8]

Good idea, well executed

 

[jcdammeyer]

HI All,

I think that only I could do it this way. When conditions become pressing! All of the following for only one operation.

How to turn a standard bench arbor press into something else.

Anyway, the story. I purchased this used bench arbor press some decades ago now and slowly have been transforming it into my go to tool for things it was never designed to do. It seems that this is a situation which repeats itself over and over again.

This press came with a few non standard features which I guess had been added by the previous owner(s). Chief among these was the ram, which had been modified to accept a precision 5/8" diameter reamed centre hole in the pressing end which would allow one to insert various other tools and a drilled and threaded base which would allow one to attach numerous fixtures to the base of the press. This turned out to be extremely useful in my case.

I added some additional modifications of my own namely I drilled and reamed a new access hole in the side of the ram as seen in photos 665 and 667. In certain high pressure broaching situations, the broach head steady as seen in photo 669, despite being tapered at one end would lock itself in the centre hole in the ram so I needed to be able to insert a non metallic drift to mechanically free the broach assembly after use.

The broach seen in photo 669 is a 1/8" square DuMont. These small broaches are obscenely expensive and quite delicate so you need to do everything humanly possible to align the broach straight and square to the work and prevent any off centre or sideways slippage/bending when broaching.

What is to follow is what I do to achieve the above and it approaches the insane.

To be continued.

Wow! You're doing a lot of what is on my list for my 3 Ton. That project (#42) was also going to add a small XY motion assembly to hold sheet metal so I could punch holes for metal boxes. One of my ELS units would have the software modified to read a list of positions and prompt the operator to both insert a new tool and/or pull on the handle.

Looking forward to more on your project.

 

[DPittman]

and a drilled and threaded base which would allow one to attach numerous fixtures to the base of the press. This turned out to be extremely useful in my case.

Seems like a good idea...what do you attach to the base?

 

[carrdo]

Hi All,

I agree with Ironman that, whenever possible, I would broach the way he has done it and I have done it this way in the past also but there are situations where one has to present the broach to the work in a certain geometric orientation or the shape of the work does not allow for "free" broaching and in such cases both the work and the broach have to be fixtured to the ying-yang. This was the case here as you are soon going to see.

 

[carrdo]

Hi All,

To continue,

For the part holding fixture which was used in this case, the first operation was to set the first part of the fixture dead square to the front face of the arbor press ram. The photos show how this was done and the progressive additions to the fixture to produce a complete part holding unit. All of the locating slots were made a push fit. I like to use a very sharp, but undersized, square cornered end mill for such operations as one can remove the majority of the material first and then shave down each side wall to get whatever slot fit one desires. This way, the slots will also be truly parallel, straight and square (and not tapered depthwise) vs what one will get if you try and produce a slot with a new end mill in one or two passes.

 

[carrdo]

Hi All,

The next operation was to precisely align the broach square to the front face of the ram. To accomplish this I machined a stout squared angle piece with a central slot which precisely fit the top end square on the broach (photos 675, 676). This was then set against the ground extended horizontal plate attached to the front face of the arbor press ram as seen in photos 677 and 678.

 

[carrdo]

Hi All,

To finally finish this off. The full locating fixture in photo 679. Everything shown was needed to ensure total alignment and that NOTHING moved. All of the above just for one operation.

PS: I have over 80 pages of machining instructions for the making of these couplers which includes a detailed description, with photos, of every setup used and machining step taken, the production of all of the special fixtures, templates and special tools used but I won't bore you with all of that.