Mismatched connections

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pinscar

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Aug 12, 2008
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charleston, sc
Here is the second of two real basic questions in two separate threads so others with the same question but unwilling to admit they need help. I find that when I turn things down to the final diameter, after sanding and finishing etc. and the blank diameter matches the bushing diameter; it is still off by a couple of thousands of an inch. Enough, I can catch the edge with a fingernail. I want to have an even smooth connection and would like to do better. I have taken to making this edge somewhat "rounded" rather than "square", but see this as a sloppy way to make up for poor technique.

Any thoughts or ideas?
 
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leehljp

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Feb 6, 2005
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Tunica, Mississippi,
It is a matter of experience and determination to get it as near perfect as you can.

First thing to do (and reading between the lines, you may be doing this) is: always measure the fittings with a caliper, mark the fitting sizes down and then turn, sand and finish to that size.

Next, begin to measure the fittings of the pen on two or three sides. You might begin to note that not all fittings (especially CBs) are not always perfectly round.

The point behind all of this is to suggest using the calipers on everything, all the time for sizing and checking for round. With experience, the fit you search for - will come.

AS a side note, I do round the edges just a tad on ones where the CB or other fitting is off by .001 or .002 in roundness.
 
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wizical

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Jun 14, 2007
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Los Angeles, ca, USA.
I have learned that using a mandrel when making your pens is that it never spins true and there is always going to be a little bit of wobble. So you have to do the best job you can in making a smooth transition from wood to metal. good luck to you
 

Randy_

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Nov 29, 2004
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Dallas suburb, Texas, USA.
I agree with Hank. If you want a good fit, you need to have a caliper and measure everything. Hardware in kits will vary from lot to lot so you can't depend upon bushings and bushings aren't always accurate right out of the package. And even if they were, as they get some use they wear down so they won't be right later.

Given the vagaries of sanding and finishing, it will be pretty tough to get a perfect fit until you have loads of experience so easing the sharp edge on the blank just the very littlest bit is a legitimate technique to help out with the transition from wood to hardware.
 
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ldb2000

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Sep 11, 2007
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Laurence Harbor, NJ, USA.
As Hank said , Calipers are the best way to be sure that you are turning everything to the right sizes . If you don't have a caliper , you really should get one , they aren't very expensive and have many uses in penturning , like checking bushing sizes , checking tube sizes and any time you need a precise measurement .
Another technique to help make a better fitting pen is to turn between centers . Almost all mandrels have a certain amount of run out , which will make your pen barrels out of round to begin with and most commercial bushings also have a certain amount of run out as well , when you put both of these factors together you get an out of round pen that even if you measure your edges with a caliper will not always match all the way around . Dead centers are very inexpensive and much more precise and will then leave the bushing as the only problem factor deal with , which will make for a much better fitting pen .
 
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