Blanks Tight On Mandrel, Help! (Long)

[Ryan F]

testing my signature.


Ryan Flaherty
http://home.kc.rr.com/myworkshop/Workshop.html
BT3000 is just a toy. Isn't it?

[Ken Massingale]

Blanks Tight On Mandrel, Help! (Long)

I now have a real problem getting the blanks on/off the mandrel. This started last week, I was then using a machinists vice on the drill press to hold the blanks. The holes, not always exactly in the center were always straight. I did not then have a barrel trimmer, I used a jig on the BT to cut the blanks square and flush to the tube. I was using a Jet MT2 mandrel, to make slimline, 7mm, pens. Not every blank pair was tight, but several.

Christmas came, I was apparently a good boy. I got a Woodcraft centering jig, barrel trimmer, Woodcraft mandrel, etc. The blanks are now drilled much more consistantly centered holes, and still straight through the blank.
I use the barrel trimmer (I cut the blanks 2 1/4" long to have plenty to trim) running it in/out of the tube to clean it good. Now using the new mandrel, in case the old one was warped.

I still have the problem. I know when it's tight going on, I will have real trouble getting the slick finished blank off, ruining the nice finish.

What can I be overlooking, doing wrong?

Thanks for any ideas,
ken

[kwgeorge]

Without seeing one up close I will have to guess based on my own experiences. Taking for granted that all the brass tubes are the same interior diameter we must believe the issue to be external. The only thing that is added is the glue used to secure the tube to the blank. So the first thing to do is examine the assembled tubes to make sure all the excess glue has been removed. The barrel trimmer is a smaller diameter than the mandrel shaft so it will not clean all the glue out of the tubes for you. The other possibility is glue on the mandrel shaft but you mentioned they were hard to get on so I believe we have glue inside the tubes. Even still I like to clean the mandrel shaft regularly with some 600 grit paper. If you find that you are having issues with the tubes either by excess glue or manufacture problems with the tubes a good and handy tool is a .22 Pistol cleaning kit with a brass wire brush. Inserted into the tube and rotated while pushing will help clean out the tubes and solve your problem I believe.

[mudder]

Ken,

Did you get any CA in the tube? I like to seal the ends with CA after I trim then to reduce blowouts and if I get a dribble of CA in the tube I have problems. The barrel trimmer does little to remedy this but I have found that a letter drill size "D" which is .246 diameter is just the ticket. maybe you should try one to see if it helps you.


Mudder

[Whaler]

I, like the others, have found that CA in the tubes is the problem if they don't slip onto the mandrel. The drill bit and .22 cal brush are both good suggestions for cleaning the tubes, I use the brush.

[Scottydont]

I have that probelm occasionally even after using a barrel trimmer. I too you a brass brush designed for a 22 cal. I usually don't have any problems after that. I do rub candle wax on the end of the mandrel just to help it slide on those difficult ones.

[Ken Massingale]

Thanks to everyone for the helpful responses.
The problem is resolved. I was doing a combination of getting CA into the tubes, and occassionally being too aggresive with the barrel trimmer, causing a burr. I now clean the wooden insertion tool between inserting tubes and use the .22 cal. brass brush before using the blanks. No more sticky blanks.
Thanks again to all.
Ken