Double twist type transmission question

[pmpartain]

On the last several pens that I have assembled, I am having problems with the transmission properly seating into the finial. I've had the problem with the perfect fit and the cigar. The finial doesn't grip the transmission enough to unscrew the pen and change the ink cartridge. You can easily pull the two halves apart. I can see two possible fixes. Use CA to give a little stick, or shorten the top tube to allow the finial to press farther onto the transmission. I tried the CA and promptly ruined a cigar pen. Froze up the transmission solid. I'm not excited about trying that again, so I thought I'd ask if anyone else has experienced similar problems.

Thanks as always

 

[cdcarter]

Get out your caliper and check the precise length of the upper body (with the finial off) on each pen, AFTER milling. Let us know what it is, and some of the guys may be able to better advise you.

It is critical on both, esp. Perfect Fit. My guess is you're cutting the blanks too short in the milling. But get the numbers and I'm certain you'll have your answer.

 

[pmpartain]

I'm not at home right now to measure, but I can tell you that the length is not longer than the tube that comes with the kit. May be ten to twenty thousandths short at most from squaring the blanks.

 

[Randy_]

When I change the ink cartridge in my cigar pen, I always pull off the top of the pen and remove the transmission with my fingers. I'm not sure the top/finial is designed to fit the transmission tightly enough to unscrew the transmission, itself. You may be asking the pen to do something it isn't supposed to do??

 

[cdcarter]

You are right, Randy. I was thinking Perfect Fit since I've been turning more of those lately.

 

[pmpartain]

Well problem solved then! Some of the ones that I have made will unscrew the transmission with the top of the pen. I just thought they were made to do that. Maybe not.

Thanks much.