Tips for replacing tenon on pre-molds

[Ocelot55]

Okay, I have read some very helpful posts on using delrin tenons so I decided to give it a whirl. I've found some bits that create the appropriate sized hole in vulcanite and briar, bought some epoxy and all the needed bits. I tried to replace a tenon on a pre-form vulcanite stem yesterday. It worked well save one caveat: I'm having hell keeping the stem straight up and down. I'm using a drill press. I wondered if any of you have some tips on making this easier. Right now I'm using a drill press vise but it's a pain to make sure the stem is straight up and down befor I face it and drill the hole for the delrin. I imagine using rod stock would be easier but I have TONS of pre-molds. Any tricks would help.

[SchmidtN]

Not pre-molds, but I have a pretty bad habit of dropping acrylic stems while working on them and breaking off the tenon. I use a cordless hand drill clapped down and holding the stem in my hand, slowly drill out the hole for the delrin tenon. As long as I go slow the drill bit finds the air hole and keeps itself centered. Probably not the safest option, but just be careful and go slow.

[DMI]

Find a drill bit which gives a snug fit in the airway and push it in firmly.
Mount the drill bit in the chuck and lower the stem into the clamp, carefully align and clamp.
The stem should be 'square' to the drill bit.

You may find that you need different drills for vulcanite, acrylic and wood.

David.

[Ocelot55]

Find a drill bit which gives a snug fit in the airway and push it in firmly.
Mount the drill bit in the chuck and lower the stem into the clamp, carefully align and clamp.
The stem should be 'square' to the drill bit.

Great idea. I would have never thought of that. Thanks.

[DMI]

If you get some long series taper bits you can open the airway all the way to the bit and get a more accurate alignment.

David