capstan spacing

[Allen Wright]

Fred,

Very interesting procedure you describe. Thanks!

Allen
On Thursday, August 5, 2004, at 11:06  PM, Fred Sturm wrote:

> --On Thursday, August 5, 2004 9:39 PM -0400 Wimblees@aol.com wrote:
>
>> In a message dated 8/5/2004 8:07:55 PM Central Standard Time,
>> awright440@cinci.rr.com writes:
>>
>> If keys are warped, is it possible to straighten them out, and if so
>> how?
>>
>>
>> I've been told to heat the key, and while the wood is warm, twist it 
>> in
>> the direction it needs to go, then take away the heat. (Just like 
>> bending
>> shanks.) I have tried to do this several times, but have never been 
>> able
>> to successfully do it.
>> Maybe someone else has a better idea.
>>
>> Wim
>
> 	Actually I do have what I think is a better process. Easier to show 
> than describe, but I'll try. I use a jig consisting of a length of 2 x 
> 4 with a small wooden block in the center. I clamp the key to the 
> block (and 2 x 4) using wooden handscrew clamp (could be done with a c 
> clamp and block just as well). The idea is to immobilize the key at 
> the balance hole, but support it out a ways on both sides to avoid 
> undue stress on that weak point. The balance hole portion of the key 
> should be centered on the block, and the hand screw or c clamp block 
> should straddle the balance hole.
> 	I then place a wedge of the proper height and angle between key and 2 
> x 4 toward the end of the key, engineered to make the key twist in the 
> direction I want it to go. Or, if all that is desired is a straight 
> bend, I place a square block similarly. The block or wedge should be 
> sized and/or shaped to allow the key to move in the desired direction 
> about twice the distance you want it to end up.
> 	Then I clamp the end of the key to the block or wedge, and apply 
> steam with a steamer (travel steam iron by preference, or a teakettle 
> spout. I find the pressurized steamer puts out too much pressure and 
> not enough wet and heat). Give it a good long shot of heat and wet. 
> Follow with a heat gun (mostly to dry it and speed up the setting of 
> the wood). Allow to cool and remove the clamp. Measure to see whether 
> you got the results you wanted (I forgot to mention measuring before 
> clamping, so you know where you were when you began).
> 	If necessary, reclamp, maybe with a shorter block or greater-angled 
> wedge and resteam. Or, if you went too far, it's usually very quick to 
> get back to where you were. I'll say that this procedure is usually 
> reliable, though sometimes I have needed to redo it. So I have learned 
> to aim at a little beyond where I really want to end up, figuring the 
> wood will tend to move maybe 1/3 the way back toward where it was.
> 	I should also note that I have had some rather disastrous results 
> with the method Wim described, trying to twist too hard (breaking the 
> key) and various bad experiences with cutting kerfs and inserting 
> wedges. Sometimes I succeeded, but more often had a mess to try to 
> rectify.
> 	I haven't used the method I described above enough to feel really 
> confident about its permanence, but results so far are encouraging. It 
> is, at any rate, the most controlled and controllable method I have 
> ever come up with or heard of.
> Regards,
> Fred Sturm
> University of New Mexico
>
>
>
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