7mm twist help -

[RustySocket]

So I made a real nice Slimline comfort pen but am having a small issue.

The upper barrel is loose on the twist transmission and slips when trying to extend or retract the cross cartridge. It feels snug when slipping it on but id like to stiffen up the endpoints so that it works more reliably.

Im sure one of you experts will have an idea how to tighten the interference fit of the upper barrel without damaging the transmission

appreciate the help

Scott

 

[BCBULLDOG78]

So I made a real nice Slimline comfort pen but am having a small issue.

The upper barrel is loose on the twist transmission and slips when trying to extend or retract the cross cartridge. It feels snug when slipping it on but id like to stiffen up the endpoints so that it works more reliably.

Im sure one of you experts will have an idea how to tighten the interference fit of the upper barrel without damaging the transmission

appreciate the help

Scott

Not an expert by any means but 2 suggestions that I have used from personal experience:

1) If you have a dis-assembly set or transfer punches: remove the transmission and try a different transmission. There are often slight differences in the diameter that will allow a different 7mm transmission to work where that one slips; or

2) it is not as clean of a fix but a very small piece of scotch tape around or partially wrapped around the top section of the transmission will fill the gap between the transmission and the tube and allow it to engage.

 

[Edgar]

A couple of variations on Bill's suggestions...

Before disassembling that pen, check another transmission or two with the upper barrel to see if it is a problem with that tranny. If it is, then disassemble & replace it with one that has a better fit.

If the tube is loose with any transmission, the tape trick is one possible solution. Another possibility is to wipe a little CA glue on the inside of the tube with a Q-tip. Be sure to let it dry & cure completely before trying it on the transmission.

 

[campzeke]

Thanks for the tips! That may be just what the Dr. ordered for a teachers pen I am having the same problem with.

 

[Sylvanite]

Check out http://www.penturners.org/forum/f14/how-do-i-fix-loose-slimline-94963/#post1375071.

I hope that helps,
Eric

 

[RustySocket]

Thanks guys, the transmission was undersized and replaced with one that functioned properly.

Thanks edohmann, I don't always think clear and test fit several before pressing another into place and to dcbulldog78 for the tape idea. Had this been a personal user that would have been fine, but looking for a proper fix in this case was warranted.

In the future I will be checking this and making adjustments to the tube prior to gluing.

I do always try to search for ansers but don't know all the terminology or have trouble describing in words what the problem is. I appreciate everyones help.

 

[chartle]

Yea I just give a bit of a squeeze. Per the post above.