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Gallery, Projects and General => How do I?? => Topic started by: John Rudd on July 28, 2010, 07:53:08 AM

Title: chuck backplate
Post by: John Rudd on July 28, 2010, 07:53:08 AM

Ok, calling on the collective knowledge of machinists...

I can obtain a blank backplate for a lathe chuck. It requires the centre drilling and tapping M40*4 for the lathe spindle and shoulder machining to take a chuck...

What is the correct procedure for drilling/tapping/machining?

Do I drill out the centre first, then machine the shoulder with the backplate attached to the spindle?

How is the backplate initially held when performing the operations required to make it fit?

How would you do it?

Your advice muchly appreciated

Title: Re: chuck backplate
Post by: kwackers on July 28, 2010, 08:33:32 AM

Set it up best I can in 4 jaw or faceplate.

Face, drill, tap to fit the lathe nose (without removing from chuck or faceplate).

Fit to lathe and machine to fit chuck.

Title: Re: chuck backplate
Post by: Davo J on July 28, 2010, 12:12:26 PM

If you are going to cut the tread on the lathe you can un screw the chuck holding the facplate turn the hole lot around to try it on the spindle without up setting the set up. Then if needed you can remount the chuck and take a bit more off.

Dave

Title: Re: chuck backplate
Post by: John Rudd on July 28, 2010, 02:03:33 PM

Gents,

Thanks for the help so far....My first hurdle is to obtain some backplate blanks... :D

What should be used as a datum for centring the blank either on a f/plate or 4 jaw? Should I just go for a centre mark in the centre of the boss? I guess there isnt much else to clock from...

Title: Re: chuck backplate
Post by: 75Plus on July 28, 2010, 04:46:53 PM

John,

Not sure what size lathe the back plate is for but broken tread mills are a source for cast iron fly wheels. I bought a 2 hp tread mill motor and it came with a 7 kg flywheel made from fine grained CI. The center hole is a great starting point.

Joe

Title: Re: chuck backplate
Post by: Davo J on July 29, 2010, 08:42:57 AM

Weight lifting weights only have a 25mm hole in them. It is hit and miss weather you get a good one but there cheap at markets and yard sales to try on.

Dave

Title: Re: chuck backplate
Post by: Bernd on July 29, 2010, 09:29:13 AM

Quote from: 75Plus on July 28, 2010, 04:46:53 PM

John,

Not sure what size lathe the back plate is for but broken tread mills are a source for cast iron fly wheels. I bought a 2 hp tread mill motor and it came with a 7 kg flywheel made from fine grained CI. The center hole is a great starting point.

Joe

Joe

Hey, never thought about that. Great idea. I'll have to try it.

Bernd