how do you machine this notch out?

[replicapro]

<img src="http://www.replicaprops.com/notch.jpg"/img>

[Al_The_Man]

My guess would be wire EDM or use a Broach.
Al

[CNCadmin]

You can broach it.

[Ken_Shea]

Well if you do not have a EDM or a broach in your basement I have drilled the slot with a 1/32 undersize and then file the corners in, this works if not a great deal of precision is needed, but if you are careful it can be that to.

BTW, if the large center bore is already there then the drill wont get it but taking your time you can file it. You could plunge mill the slot and then file.


Ken

[Rekd]

Originally Posted by CNCadmin You can broach it.

Heh, we used to broach alum keyways on a fadal with a hand ground broach. Talk about beating your spindle head to a pulp....

[Ken_Shea]

LOL Rekd, another useful tool those precision spindles make is a great quick arbor press

[buscht]

If you have the room, you might be able to drill the inside corners first to remove the radii and then mill out.

Or simply add an overcut in the corners as shown. The dia of the overcut is slightly larger than your bit.

[Rekd]

Originally Posted by Ken_Shea LOL Rekd, another useful tool those precision spindles make is a great quick arbor press

Ken, that's another great trick I did with the Fadals. (Haven't had the heart to do it to meh Haas' yet.. )

[Ken_Shea]

Good idea Buscht, I will try and remember that.

replicapro, let us know how you ended up doint it.

Rekd I will admit that in a rush having done that on my old import bridgeport style mill where the precision beraings are not all that precision even when new, but it wont happen on my Haas for sure. Hey, on a CNC you could get a running start using rapids for those really tough press fits

[HuFlungDung]

In the olden days, I occassionally cut a keyway with a HSS square bit held in a boring bar in the lathe toolpost. I would "rack it by hand". Predrilling or roughing with an endmill helps a lot prior to doing this.

But for small work, broaches and a large arbor press will serve well, if you want to make the investment in the arbor press. It takes a so called "5-ton" arbor press to give you much usable depth for the work and the broach to fit beneath the ram.

[Rekd]

Originally Posted by Ken_Shea ... Hey, on a CNC you could get a running start using rapids for those really tough press fits

[Klox]

Hu to the rescue!!!LOL!!!!
I have done it like Hu described! It was to recut the undercuts on the commutator of my car's starter motor.
It's very effective, a little time consuming however......

Klox