Shop built vertical milling head spindle question

DiscoDan

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I would like to make my own vertical head for my P&W 3C horizontal. I am generally following what a guy on YouTube did but he used a Morse taper for his spindle and I want to use R8 due to wider availability of tooling. I haven't been able to find anything on what the shape of the spindle should be to receive the R8 collet. Does anyone know what the shape should be?
 
I would like to make my own vertical head for my P&W 3C horizontal. I am generally following what a guy on YouTube did but he used a Morse taper for his spindle and I want to use R8 due to wider availability of tooling. I haven't been able to find anything on what the shape of the spindle should be to receive the R8 collet. Does anyone know what the shape should be?
Bridgeport never posted the specs for R8 collets after bringing them to market. There are a few sets of specs listed on the web here and there, but they seem to all be aftermarket measurements of R8 tooling built by various manufacturers. They do not all have the same dimensions listed, in fact there can be considerable variance in commercial R8 collets. If you make a spindle to hold R8 collets, find a high quality collet in new condition and make your spindle fit it, not too tight...
 
Dimensions for R8 tapers are in Machinery's.

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if you're making the spindle from scratch, why not make it an ER32 or 40 set up? No need for a drawbar, collets aren't all that expensive and if you make more of your tooling with a straight shank (boring head, face mill etc) you won't even need to change the collet. You might even be able to adapt an off the shelf straight shank ER collet chuck as the spindle.
 
I would like to make my own vertical head for my P&W 3C horizontal.
I want to use R8 due to wider availability of tooling.
I haven't been able to find anything on what the shape of the spindle should be to receive the R8 collet.

I'm new to the forum, But I've been thinking about converting a old 20" Walker Turner drill press into a small benchtop mill/drill set-up.
In my case I'm thinking it may be possible to buy just the inner R8-spindle shaft part# P0705011-6 for a Grizzly G0705 Mill/Drill, Then machine the shaft and/or the ID of the Walker Turner's quill to get a standard bearing to fit.

Doug
 
Doug, you'd need to find out if the spline pattern and size of the Grizzly spindle fit the spindle pulley of the WT and how much meat on the spindle you'll have to remove to fit the WT quill bearings. To be honest, even after that you'll have to source an XY table and you'd still be left with a very flexy "mill" that also doesn't have a fine down feed on the quill. You'd be better off putting that $200 or so towards a second hand mill - there should come up fairly frequently in your area. Even a small HF bench mill would be better.

Trust me, I lived with a WT900 drill press as my only "mill" for a couple of years. It sort of did the job but it was a slow tedious nightmare to use that destroyed cutters and was in the process of destroying it's spindle bearings. I was VERY glad to get a "proper" mill.
 
Doug, you'd need to find out if the spline pattern and size of the Grizzly spindle fit the spindle pulley of the WT

Yeah it would be somewhat of a "hope it fits" / trial & error project, Pretty much just an idea for now.

To be honest, even after that you'll have to source an XY table

That seems to be one of the main problems, Most of the XY tables available on-line seem way to flimsy!

Trust me, I lived with a WT900 drill press as my only "mill" for a couple of years.

Yeah I've been there, done that!

Doug
 
Another holder to look at, in the NMTB, 30, and the various variants. For the spindle end, it is only one angle to worry about, and they are nice and short, so you do not need much room to change them.
 
that would be quite the project you would need to get it trammed and the bearings i would hate to imagine what those would cost I saw a headstock for a hardinge dv-59 on ebay those are good bearing plus it has a 5c spindle.
 
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