Draw bar and collets

[westsailpat]

All this stuff I bought from McMaster Carr , the stud is a semi hardened mill tooling bolt . I don't know what grade it is but I think a little harder than grade 8 , the key here is no stretch for a solid feel . The nut is also mill tooling and has a captive rotating washer . The use of the nut is a throw back from the days I was operating large Cincinnati horizontals , you stuck the holder in the spindle gave it a little tap then you threaded in the draw bar and then did the final tighten up with the nut . For my little 6" this was over kill but then I (got) had to buy a cool little wrench . The spacer is 12L14 , In all my years as a machinist I never ran into a job that required this wonderful materiel . It really lends it's self to my machine as it is supper free machining and yet is tough enough for this application .
The brass hand wheel again was total over kill (you don't even really need one with this set up) . The collets are #2 Morse , this whole set up is really not a good way to go . For one thing the collet sticks out past the spindle nose by about 3/8 and obviously you do not have through hole capability . The one thing you have over a ER set up is less over hang . Optimum is the original Atlas set up with the spindle nose cap and draw tube . Anyhow here is is , hope you like it .
IMG_0030 by mark westi, on Flickr
IMG_0033 by mark westi, on Flickr

 

[mikey]

Came out really nice, Mark! Love it when a project is practical and comes out looking good, too.

About the only thing that turns better than 12L14 is that stainless rod they use in printers. Wish I knew what that stuff was so I could buy in larger sizes - turns like butter. You don't happen to know what it is, do you?

 

[westsailpat]

Hey Mike thanks for the nod , years ago I was asked to produce parts in Stainless Steel . It was a fairly complicated part compared to the price I was selling it for , to my customer . The part was a muzzle brake (recoil arrester) the Co. was a semi custom hunting rifle seller , they did not produce the rifles . Anyhow I was asked to select the materiel , I did some research and found that 416 SS was incredibly free machining and it was cheap . So I started making and they were paying , one problem that stuff was magnetic . I don't know if that's the stuff you are talking about , but it machined like butter .
My favorite SS is 303 , problem with it is in a marine environment it will rust plus it is not strong like 316 L . Hope that helps .

 

[mikey]

Thanks, Mark. No, it isn't 416. I have some 416 and this printer rod cuts nicer than any other metal I've used and it doesn't rust. Must be some kind of alien stainless steel and nobody knows what it is or where to get it. Would be nice to have some in a bigger size than you can get from a printer.