Subject: Re: drill grinding

From: frank <[email-masked]>
Date: 27 Jun 1996 23:12:50 GMT

I've been working on a drill grinder gizmo.

I use a Jacobs 1/2" hand-tightening chuck from Northern Hydraulics, 
some 1/2" thick aluminum plate, two 1/2" oillite bushings from Home 
Depot, and a piece of 1/2 rod.  Total cost is low.

I've tried a few times, but have not yet been able to make
perfect or good-enough threading on the rod.  I get too much runout, 
but all my work has been by hand. I'll try again soon.

OTOH, I might just give up and buy a large, hard 1/2-Fine bolt and 
cut it so it fits.  This would also be cheap.

When I get it right, I'll post a few plans, as others have
requested.

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From: [email-masked] (G Merryweather)
Date: Thu, 27 Jun 1996 20:51:02 GMT

anyone got some good plans or ideas for a cheap drill grinder or
attachment - something in the order of 10's of dollars rather than
hundreds...
Geoff

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From: PPIERCE <[email-masked]>
Date: Thu, 27 Jun 1996 20:32:45 -0700

> attachment - something in the order of 10's of dollars rather than

Many folks sell a drill grinding attachment, Sears, General, Travers,
many others also.  Price runs about $15-20 I think...

They can be difficult to adjust properly.  Several magazin articles
have offered adjustment solutions.  Frank McLean, in "The Shop Wisdom
of Frank McLean" (Village Press), page 14, has a dandy.

Paul in AJ AZ
VILLAGE PRESS
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	HOME SHOP MACHINIST
	Also some Great Hardcover
	collections of reprints

http://members.aol.com/vpshop/index.html
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http://members.aol.com/vpshop/steambook.htm

1-800-447-7367

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From: [email-masked] (Scott Logan)
Date: 28 Jun 1996 11:38:46 GMT

> cut it so it fits.  This would also be cheap.

Why not get some 1/2-20 threaded rod?  This is readily available from
many sources, including Metal Buyers Mart, MSC, McMaster-Carr, etc.  

--
  ---------------------------------------------------
  From Scott Logan,
  http://ourworld.compuserve.com/homepages/LoganAct
  Reply to [email-masked]

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From: frank <[email-masked]>
Date: 28 Jun 1996 16:16:55 GMT

WRT "why not hard, find threaded rod"...

I thought the design was somewhat obvious from what I explained
earlier, but perhaps not.

The idea is to make a correctly-shaped U out of Al pieces, 
and put oillite bearings in the sides of the U.  Then slip
the bolt/rod through the bearings.  Threaded rod does not do
well as a bearing surface, but a hard bolt or partially
threaded rod would work well.  The chuck is then put on the 
bolt/rod and secured with a jamb nut.

This assembly has single-axis slide plus rotation -- nearly
exactly what is needed for a drill grinder.  Add a door hinge
to the bottom of the U and you have angle adjustment -- get
a plastic protractor from Kmart for a readout.

I have looked at and bought a few of the cheap sharpeners.  Most
are junk and are both too flexable and have too high friction
when rotating.  This results in imprecise cuts.  If I wanted 
imprecision, I'd sharpen drills by hand!