Doug Fattic 

Andy, If I remember right you made a very nice tool to help keep number punches straight when creating a serial number. I'd love to see some pictures again if possible?

unterhausen

While we are waiting for Andy, Blondiehacks made one at about the same time.

zandoval 

If durability is not an issue you could print one out of PLA...



https://www.thingiverse.com/thing:5200545

unterhausen

I always forget to look on thingiverse. Of course, I took my 3d printer apart and haven't put it back together yet, as is my custom.

Andrew R Stewart 

I made two versions, one for a BB shell and the other for s steerer. The steerer version is based on a 1 1/8" steerer and the reducing sleeve, to 1", has a cutout for the stamp to go through. With my stamp set the forming of the head bulged out the stamp's end a bit so i sometimes need to slightly grind off that to let the stamp slide through the slot. That slot was cut specifically for the stamps, your stamps might need a different slot size. Both are cut from 3/4" thick Al (old jig plate).

These stamp holders work very well. One can really smack away with no fear of a thumb strike What i wanted was a holder that could be secured in place about the shell or steerer and held one stamp at a time. Andy (who wasted a day chasing sink fixture parts only to find out our sink is metric and the supply lines available are SAE)

unterhausen

Andy, do you have pictures of the results?

Andrew R Stewart 

Possibly somewhere, but I have a love/hate relationship with serial numbers. I use to punch really big numbers on a filed flat spot. Now i use a smaller size and don't worry as much about paint fill in, but stamp the steerer too... With these holders the horizontal line is well held. The space between the numbers is set by the user, for better or not. Andy

Doug Fattic 

Thanks Andy, for finding and posting pictures of your serial number punch tools! They are clever! Well done! Also thanks for posting about the other methods. I seldom put serial numbers on the frames I made. My punch set came from Johnny Berry's collection of tools from Manchester I took home 1975 after my time in England learning how to build frames. So they might even be pre-WWII.

JohnDThompson 

"Because chamfered edges are what separates us from the animals!" 😸

Andrew R Stewart 

Today as I started to assemble my "new" grovel bike (like a gravel one but slower) bike I took these shots of the stamped numbers. The steerer turned out nicely. The BB had a double strike that was a hammer bounce. Next time I might shim the stamp in the slot a bit to reduce the wandering. BTW I'll post a more complete thread on this frame later. Andy

smontanaro 

Reviving a sort of old thread. I will quite possibly only ever build the one frame I constructed in Doug's class (though I'd like to try my hand at more), but I'm still a bit enamored of the idea of punching a serial number into the bb shell just for the heck of it. Not having the machining skills or equipment that many here have, my ideas tend to try reusing scrap parts in my parts bin. To that end, here's where I'm currently at. I'm not going to wreck a perfectly good crank arm for this experiment, but pretend I cut it at the black line, then screwed on a piece of sheet steel or aluminum which extends over the shell. Drill and file a hole match the dimensions of the punch set I don't yet have and Bob's yer uncle. No doubt the registration won't be perfect, but this is a hobbyist-built handbuilt frame, so perfection might be a bit too much.




The parts consist of a British fixed cup, one set of cheap bearings, a spindle and bolt, and something to take up the space between the crank arm stub and the cup (in this case, some sort of old Schwinn cruiser headset part I found in the bin). I think it should work well enough for my modest needs.

Andrew R Stewart 

The only frustration I see in use is the crankarm/fixture being able to spin about the shell. Why not just use a block of something that is C clamped to the shell (bb removed) with the "then screwed on a piece of sheet steel or aluminum which extends over the shell." part. Most number punches are square in section, so any location hole really wants to also be squarish. A good job for hand files and hacksaw. Andy

smontanaro 

The crank bolt isn't tightened too much, but enough that the crank doesn't spin freely. I could snug it down a bit more when punching to reduce the odds of a bounce. In addition, as just a history, I'm not terribly concerned with perfection.

As for square holes, I think I can do a decent enough job with a drill and files.