Deformed tubes

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PMisiaszek

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Oct 22, 2005
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Venice, FL and St Mikes, MD
In my never-ending research into ways to screw up a perfectly good pen, I've run into a new one. I'm in Florida for the winter and don't have access to my shop. I'm using the minimum number of tools to prepare my blanks. I do have a borrowed drill-press, but it only has a 2" quill, so drilling is a two step process. Drilling and gluing in the tubes seems to be going fine. Because I can't drill straight through the blank, I check to make sure the tube fits in the blank, and clean out the hole with a file if the tube binds. Then, because I don't have the corded hand-drill I usually use, I trim the barrels with a barrel trimmer using the same drill-press. Although that seems to go OK, when I am done with the gluing and trimming, the blanks no longer slide onto the mandrel. The two pens I prepped yesterday required considerable filing to get them on the mandrel, so today when I assembled them, I had to glue in the findings. So, what's happening? When I drill in two stages, could it be that the hole isn't straight and the tubes are somehow deforming because of that? Or, am I generating enough heat in the barrel-trimming to somehow deform the tubes?
 
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JimGo

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Jan 24, 2005
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The process you're using now is almost exactly what I do, so I'm not sure why you're having trouble. What kind of glue are you using? Is it possible that the glue has gotten into the tube, and that's why you're having to file the inside of the tube?

Also, if you're putting them directly on the mandrel, it sounds like you're doing slimlines. If so, there's some variation between mandrels, and occasionally with the tubes in different slimline kits. Your mandrel may have expanded from the heat, or the batch of tubes you got in your kits may be slightly under-sized, which would make them stick on the mandrel.

Just some thoughts. Of course, I've been wrong before. Granted, it was 1988, but it does happen.
 

Dario

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Apr 14, 2005
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Is there a possibility that the tubes were bent to begin with?

Next time...test the tubes first (inset them in the mandrel) before you glue them in.
 

mrcook4570

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It doesn't sound like a bent tube. It sounds more like a consequence of (over)trimming on the drill press. The force of the drill press combined with the spinning trimmer head will cause the brass tube to "roll over" on the ends. Chamfer the tube afterwards and it should work fine. I use a deburring tool for reloading, but a file or even an exacto knife will work. Chaferring the tube will also allow the components to start to seat with less force, thereby reducing stress on the turned blank.
 

alamocdc

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I trim using my drill press and have had this happen if I get too agressive or "kiss" the tube a bit too hard. What happens is you end up slightly folding the tube to the inside thus reducing the ID. Reaming afterward should help. If you have to do a lot, then you are using too much force while trimming.

Sorry, Stan, I guess I missed your reply. [B)] Didn't mean to repeat it.
 

guts

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Fairchance Pa. USA.
i'm not a very experienced turner in any aspect but i never trim the barrels with a drill press,i only use a hand held cordless drill for that part,you might have to hang on pretty tight but it works for me.
 

Spike

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Nov 19, 2005
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Archdale, NC, USA.
I had the same excat problem. I figured that the shaft on my trimer was bent and deforming the tube. then also the problem of the drill press not be excatly square with the table messed up the tube. i now only use the hand verison. takes a little longer but I do not have to swap between drill bit and trimmer on drill press.
i get more of a "feel" with the hand one.
 
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