Tips/Techniques Holding an R8 Arbour

[Susquatch]

Perhaps not worth posting, but took me a while to get this worked out so I thought I should share it.

If you ever have to work on an R8 Arbour, it might help to know that the bottom end of the R8 arbour is a beautiful slip fit into a 24mm 5C Collet. If you have a 5C collet chuck, chances are it runs pretty true. Certainly well enough to do any necessary. work on the business end. This is much better than mounting it into a 3 or 4 jaw chuck that might damage the rear register.



I plan to machine the face mill arbour above to look like the 40 holder below it so I can use it with the optical center I bought a while back.

The business end of an R8 Arbour typically also has a 60 degree center drilled into it. The one above does. The center can be held in a live center in the tailstock so you can work on the business end. It's a very solid setup that way.

I'm pretty sure it would fit just as well into an 24mm ER40 Collet too

 

[PeterT]

Do you mean facing work like in lathe setup, or holding in 5C indexer & doing some milling? Either way, I get how you are gripping it on the thread end register OD, but hopefully you are contemplating some kind of tail stock support, v-block, jack etc? Otherwise that is a lot of stick-out to be doing machining on the business end.

 

[Susquatch]

Do you mean facing work like in lathe setup, or holding in 5C indexer & doing some milling? Either way, I get how you are gripping it on the thread end register OD, but hopefully you are contemplating some kind of tail stock support,

In the lathe, not the mill. More than facing. Mostly turning. Gotta make the business end of the top R8 Arbour look like the business end of the 40Taper below it. I thought I described how to hold the stick out but as usual I failed. It will be mounted in a live center inserted into the business end of the R8 Arbour.

Normally I'd have taken a photo of the setup, but I have another project on the lathe right now.

 

[ChazzC]

Could also machine keyway / flats / whatever in the mill using a SpinIndexer with a ”foot stock” in the 60 degree center hole.

 

[PeterT]

Keep us posted on how it machines. I've always wondered to what extent arbors like those they are hardened, meaning the number & to what depth.

 

[1018Machine]

Handy to know Susquatch! Thanks for the tip!

 

[Susquatch]

Keep us posted on how it machines. I've always wondered to what extent arbors like those they are hardened, meaning the number & to what depth.

Will do. I'll prolly use HSS to cut it because of the interrupted cut at the dogs.