Bullet pen twist problem

[bcoyne]

I have a request for some bullet pens using 30-06 casing and antler tops. Using 7 m Slimeline pen kit. I had to cut the lower inserts longer to make up for the extra length of the 30-06 casing length. Nib matches up very nice.

Problem is that I have to insert the twist mechanism further into the tube insert, well beyound the normal range. When I insert the pen and attempt to twist it to write, it is extremely hard or will not even turn. I know that the twist mechanism is binding on the inside of the tube insert. I have tried oil to loosen it and failed.

Has anyone had this problem? Solutions?

Big Thanks
Bob

 

[ed4copies]

Do you want to fix the one you have, or find a way to avoid in the design?

Why couldn't you use the normal lower tube? I do.
Maybe a pic to see where your design is different?

 

[KenV]

It must be a "slimeline" problem -- I have had some of that kind of parts kits too -- too much "gunk" perhaps --

Design wise, the regular tubes will work easily unless one is soldering the tubes at the primer hole, in which case solder and trim and it works -- The '06 is a bit longer than the 308 (near perfect length) but not a lot longer.

 

[bcoyne]

I have included a photo.

Top casing you can see how much further I have inserted twist mechanism.

lower casing shows how much shorter standard slim line tubes are.

I did glue in the extra longer tubes into the top casing.
Maybe my design has a flaw in it.

I am open to design changes. Anything to make it work.

Thanks
Bob

 

[GregHight]

I use an 8 mill PENCIL tube first inside the casing that runs the length inside the casing then insert the 7 mm tube in nib end. Makes for a perfect fit when you slide the 7mm tube from the top, into the bottom. As long as you have about .25 inches of top tube going into casing, you should be ok.

 

[Sylvanite]

Once you glue the tube in at the case head, it has no give and the transmission will fit more snugly. I haven't had the exact symptom you're experiencing from that - the usual failure mode is the transmission crumples during insertion. My current process includes reaming out the tube with a 1/4" drill bit about 1/4" deep. That allows the transmission to slip into the tube past the case web (the solid part) before press-fitting.

Another possible failure is that you aren't letting the glue offgas long enough before you press in the transmission. I had a stretch when I was rushing the assembly - and wound up with several failures due to glue fumes settling in the transmission. That gave me the same problem: stuck or hard-to-turn transmission. I now wait overnight after gluing before pressing in the transmission.

Oh, and be sure to check the transmission before you insert it. Sometimes you just get a bad one in the kit.

You could try to disassemble the pen, although you might have difficulty knocking out the transmission without destroying it.

I hope that helps,
Eric

 

[THarvey]

I use an 8 mill PENCIL tube first inside the casing that runs the length inside the casing then insert the 7 mm tube in nib end. Makes for a perfect fit when you slide the 7mm tube from the top, into the bottom. As long as you have about .25 inches of top tube going into casing, you should be ok.

I like Greg's suggestion. I will have to try that.

Currently I use 10" long 7mm tubes and cut to length. I wrap the lower end of the tube with a couple rounds of painters tape, to enlarge the tube to the size of the neck. (I use painters tape because it is pourus enough to soak up CA and harden in place.) I used a small wire brush to rough up the inside of the neck section of the casing. Since I cut the tube to length, the tube and cartridge are the same.

The transmission does need to be pressed further into the tube. If the iside of the tube is clean, that should not cause a problem.

From you last post, it sounds like you have two sections of tube in the cartridge. If these two pieces of tube do not line up absolutely perfect, the transmission or the ink cartridge will bind.

 

[GregHight]

Am I the only one that uses the 8mm pencil tube inside the cartridge pens?

 

[bitshird]

Am I the only one that uses the 8mm pencil tube inside the cartridge pens?

I use 8mm Americana tubes, transmissions and just turn down the adapter to fit, the worst part is getting the finial to fit right, since it drives the transmission,