Anybody Here Broach With an Arbor Press?

[Roberts210]

I restored an old Famco, ship's wheel arbor press, with a 28" ram, and I need to broach a 1/4" keyway in a pulley. Anybody done this before?

 

[Provincial]

What is the ton rating of the press. 1/4" in cast iron takes more pressure that one in die cast. You need to tell us the material you are working with.

You can make thin shims for the cutter so it is taking a smaller bite. The pressure is related to the number of teeth engaged with the work and also the depth of cut. The depth of cut is determined by the thickness of the shim(s) installed. The initial depth of cut is determined by the depth of slot in the guide bushing. The cutters on the broach are progressive, so the depth of each one is greater than the previous one.

You run the broach through with no shim to start, then add shims until you reach the desired depth for the keyway.

 

[Doug Arthurs]

lots of times

 

[MShaw]

Depth of cut is determined by the step up between the teeth. This cannot be altered. The shims are used as the broach cannot reach full depth in one pass. Using thinner shims just means you are using less of the broach length. Once the teeth engage with the work the depth of cut is the same.

 

[redragoon]

Did it this way in college to make keyed wheel hubs on an offroad buggy.

 

[Roberts210]

Sorry, it was late last night when I posted the thread.
It's not a pulley, it's a steel gear.

The Famco is an AC31R. I'm guessing it's rated at 3-4 tons.

 

[dutchgray]

That will do it easily, just be gentle and press the broach a little at the time to avoid any side loads breaking it. Put a catch bucket full of rags under it to catch the broach for when it drops out the bottom.
Use plenty of cutting fluid, the typical thick brown stuff for pipe threading will do.

 

[Roberts210]

Thanks Dutch.

 

[Bottlecapdigger]

Always have. What else would one use? I find the arbor press is the best way, then you can feel the broach cutting the key way. If it's not cutting you will know it. BCD.

 

[Oldtuleguy]

thats a cool arbor press!

 

[Roberts210]

Thanks. Sometime soon I'll post before and after pics, and tell the story. Gotta work today.

 

[Jawn]

Nice press!

I have done keyways (carefully) using a small hydraulic press. That's not ideal, so I am keeping an eye out for a good arbor press.

And yes, depth of cut is a fixed amount determined by the offset of each tooth. Shims do not affect that.

 

[Provincial]

Using thinner shims limits the number of teeth engaged with the work, which limits the force required. The force required is determined by the number of teeth engaged. By using thinner shims, fewer teeth are engaged, even though the depth of cut per tooth is the same.

Thus, you can limit the number of teeth cutting on the stroke to say, two out of ten, which will require much less force. The work is now done by the last few teeth on the broach, and the preceding teeth do no work.

 

[marinusdees]

Using thinner shims limits the number of teeth engaged with the work, which limits the force required. The force required is determined by the number of teeth engaged. By using thinner shims, fewer teeth are engaged, even though the depth of cut per tooth is the same.

Thus, you can limit the number of teeth cutting on the stroke to say, two out of ten, which will require much less force. The work is now done by the last few teeth on the broach, and the preceding teeth do no work.

Well said.