Thread: Muffin-top transmission, 40 ways to stuff a pen up

grrrr, grrrr, what else can go wrong, etc. etc. etc.

On a positive note, at least there was no blood spilt

Had a request for a bullet pen from an uncle-in-law, so tried to actually get hold of a bullet (the projectile bit) to use instead of a nib from a kit.
Despite a couple of firearms places promising to deliver, they never came through, and we're going to crash at UIL's place on the way to Qld in a couple of days, so it had to get done soonest.

I put a blob of JB Weld on the end of the tube, then turned it down to fit inside the casing (using heat-shrink tube just seems a bit Mickey Mouse to me), and carefully drilled the (deactivated) primer out to get a neat fit at the other end of the tube.

I also decided to fit a clip, and found that left-over clip from the mace-pen would work.

So far, so good. Glued the tubes into the casing, and into the blank. Cut end off another casing to use as end cap, and filed a notch in it for the cap. Went to bed.

Day 2:
Pressed in nib, then went to press in the transmission. With about 1.5 mm to go, the transmission tube started to collapse and fold over itself, looking like a slumped muffin top
Of course, the part which is in the tube is hanging on for grim life, and won't pull out
Short break to make some pen disassembly tools from a bit of brass rod from a toilet float, and a carriage bolt. Disassemble pen, look down tube - nice and clean. Hmmm...
Luckily, I have one trans from another kit, so here goes assembly attempt 2.
Same thing! This time I caught it just as the trans started to deform, so I was still feeling that this pen would happen.

Out with the verniers, and check the tube interior diameter vs. the other tubes on hand. Start wondering if the close fit in the casing is preventing a small required amount of stretch in the tube ???
I decided to turn the trans down a smidgen, and try again. Of course, take a smidgen off the radius = 2xsmidgen off the diameter, so now it goes in easier than usual, but looks like it will hang in there.

Now to the blank. Dammit! The tube is about 2mm proud of the casing, so why didn't I shove the tube that far into the blank instead of lining the tube up with the blank edge???

Whilst experimenting/thinking about this problem, I discovered that the trans was NOT secure enough, so I decided to superglue it in. But the glue was enough to make it too hard to press in with hands, and went off before I got to the clamp! Dammit !!!

Thinking I was pretty on top of this disassembly business, I whacked out the nib, this time sitting the casing holder on top of the vice jaws (instead of holding it between the jaws) and managed to badly scar the nib in two places as it came free. Dammittt!!!!

Rat through bag of bits, and, yes! one spare nib. Acetone, soldering iron, plus bigger hammer got the transmission out. Again! This time, I thought I'd see if the remaining glue would make the difference in tightness, so I carefully pressed in THE WRONG TRANSMISSION - the muffin-topped one.
Which, of course, went in beautifully, and stopped at just the right spot.
But wouldn't turn

Back to the blank, turned down to size, made mount for the clip, filed and filed and filed to get a nice fit. Each break, I had a fiddle with the muffin top, and after a while it began to behave again.

Several minor occasions for cussing later, it's all together, and looking like a pen

And, as I type this, I realise that with all the frustration, I only put one coat of CA on the blank !!!

So a) I WON'T post this on FaceBook, where UIL will see it,
and
b) I hope he likes it

Cheers,
Andrew