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Gallery, Projects and General => How do I?? => Topic started by: John Hill on March 21, 2010, 06:12:39 PM

Title: How do a drill a hole?
Post by: John Hill on March 21, 2010, 06:12:39 PM

I want to drill a hole accurately in the end of a shaft so that I can clamp a tool in the manner of a collet.

This is a simple job to fit a centre drill to a Morse taper blank but every attempt so far has come out crooked. :doh:

Here is a sketch, of course the male bit has a saw cut so that it can compress somewhat as it is screwed into the shaft.

(http://farm5.static.flickr.com/4013/4452420816_1f04099cb0_o.jpg)

I drilled the hole with the two bits screwed together and mounted in the lathe spindle taper.

Title: Re: How do a drill a hole?
Post by: Bernd on March 21, 2010, 08:22:26 PM

Quote from: John Hill on March 21, 2010, 06:12:39 PM

I drilled the hole with the two bits screwed together and mounted in the lathe spindle taper.

Did you cut the slot before you drilled the hole?

Bernd

Title: Re: How do a drill a hole?
Post by: John Hill on March 21, 2010, 08:26:31 PM

No, drilled then cut.

Title: Re: How do a drill a hole?
Post by: No1_sonuk on March 21, 2010, 08:34:16 PM

How many cuts?

Could it be that the hole is accurately concentric, but that the grip isn't.

Title: Re: How do a drill a hole?
Post by: John Hill on March 21, 2010, 09:41:53 PM

I have only one cut in the 'collet'.

Title: Re: How do a drill a hole?
Post by: sbwhart on March 22, 2010, 02:21:27 AM

Try putting the cut part way through, or two cut part way through from opposite ends 90 deg to each other.

Hope this helps

Stew

Title: Re: How do a drill a hole?
Post by: John Hill on March 22, 2010, 02:23:49 AM

Thanks for all the comments and advice guys!  I am home now and just about to go down and try to check if the thread is true to the spindle axis.  The main part of this tool is stainless and I had a hard time cutting the internal thread.