Subject: Re: RADIUS TURNING TOOL QESTION

From: [email-masked] (Dennis Wodtli)
Date: 28 Apr 1996 18:57:22 GMT

>Using this method, you can use gage blocks to set outsed radii, or 
rotate it
>and use verniers to set inside radii.
>Paul

Paul,

Thanks for the reply,  I now see how to do this.  The cresent shaped tool 
holder that pivots is held in place on a short stub shaft made of 3/8" 
drill rod.   I will make a 4" long shaft from 3/8" drill rod and insert 
it in place of the stub shaft.  Moving the cutting bit so it touches the 
drill rod will set it to cut a .1875" (.375/2) convex radius.   Once a 
known radius is set the tool bit can be moved to the desired radius.   
Milling a flat to the center of the 4" shaft would make it setable with 
calipers or gage blocks.  Also, a sleeve could be slipped over the 4" 
shaft to set the tool bit to the diameter of the sleeve.

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From: [email-masked] (Peter Drumm)
Date: 29 Apr 1996 00:46:30 GMT

In message <[email-masked]> - [email-masked]
(Dennis Wodtli)28 Apr 1996 00:05:59 GMT writes:
->
->I'm building a radius turning tool for my lathe and would like to know 
->how to set the radius of the tool bit.   This tool is a yoke with a 
->cresent shaped tool holder that is on a shaft with a handle you turn to 
->cut the radius.   It is a copy of the kind advertised in the catalogs for 
->about $500.
->
->Seems like some kind of jig to set the tool bit to zero radius would help.
->  Then move the tool bit to the radius you want by using the tailstock or 
->a lead screw handwheel.  Or is there a better way?
->
->Thanks in advance for any replies.

Couldn't you use a center in the tailstock to do -both-? First, close in on
the center til it just touches for a full sweep of the bit, (as far as
allowable anyway) Then, back off the tool until you measure the radius you
want from the point of the center to the tip of the tool.

[email-masked]
Using Warp/Neologic News/IAK
Wausau, WI. 44d 58m 00s N x 89d 36m 45s W
All opinions are my own, even if they are wrong!

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From: PAUL <[email-masked]>
Date: Sun, 28 Apr 96 10:28:14 -0500

Dennis Wodtli <[email-masked]> writes:
 
>Seems like some kind of jig to set the tool bit to zero radius would help.
 
You will need to index the pivot point on which the yoke is turning. You
needent worry about the angle upon which this measurement is made. I suggest
somehow "indexing" on a small length of shaft hanging below and above the yoke
in the cutting area, using
a "v" block shaped length of material, with a flat spot of metalin the center
area, milled out to the centerline of the pivot rods. I'll try a drawing....
(  )_______-------_______)<add v block here & other end. Dots in center is
milled area.
 
Using this method, you can use gage blocks to set outsed radii, or rotate it
and use verniers to set inside radii.
Paul

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From: [email-masked] (Dennis Wodtli)
Date: 28 Apr 1996 00:05:59 GMT

I'm building a radius turning tool for my lathe and would like to know 
how to set the radius of the tool bit.   This tool is a yoke with a 
cresent shaped tool holder that is on a shaft with a handle you turn to 
cut the radius.   It is a copy of the kind advertised in the catalogs for 
about $500.

Seems like some kind of jig to set the tool bit to zero radius would help.
  Then move the tool bit to the radius you want by using the tailstock or 
a lead screw handwheel.  Or is there a better way?

Thanks in advance for any replies.

-
DENNIS WODTLI  [email-masked]  Portland, OR, USA

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From: [email-masked] (Paul Pierce)
Date: 30 Apr 1996 03:54:58 GMT

Dennis:
I see you have a reply.  Great.

In one of the Village Press books there was an article on making a radius 
turning tool.  Therein the author described a method of setting the 
desired radius.  I will look it up for you.

-
  PAUL PIERCE in AJ AZ
  [email-masked]
  NRA Endowment Member

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From: [email-masked] (Dennis Wodtli)
Date: 3 May 1996 04:22:18 GMT

>All opinions are my own, even if they are wrong!

That sounds like a good idea; I will try that when it is finished.  
Should work for small radius.  Would be dificult for large radius because 
the tool bit must be short so it will clear the frame.  The short tool 
bit cannot be extended to the center of rotation without falling out.

The radius turning tool is an interesting tool with many challenges.  
This one has a set screw with a ball in it for a lower bearing.  I've 
just discovered that there is .020" clearance between the tool holder and 
the frame.  By adjusting the set screw, you raise or lower the cutting 
tool height by .010"
Cool.

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