Tachometer Clip-on Bezel

[wkearney99]

Painting 3D printed plastic is indeed a chore, even more so when you're doing a small surface area that's going to be right in your line of sight.

Getting it printed with as few layer line artifacts as possible is tedious, especially with curved surface. Variable line height helps, but can GREATLY increase printing time, likewise using ironing effects.

Once that's tackled then there's the steps of getting primer/paint to stick to it enough to hide the base material without drips or looking too thick.

This is where injection molded plastic from very polished molds often provides superior results. But with significant mold and injection hardware costs. I marvel at how cheaply some shops seem to be able to crank this stuff out for.

[Bob Z]

Maybe the file can be provided to a shop that can make them that way? I have no clue of who it could be but Tom is a perfectionist so if he is satisfied with how they come up I cannot disagree!

[Tom]

These are done on a Formlabs Form 3 resin printer with layers under 2 thousandths of an inch -- the same basic machine is used by dentists to make crowns. There are no visible layer lines like you get on FDM (squirted plastic) printers, and the resin can be sanded as smooth as desired. And yes, I do the sports chrono and mode dial pieces too. All of them press on and hold without adhesives and without removing any factory parts. That's only possible because of the precision with which the Formlab prints. I don't know enough about injection molding to say whether that would be possible, but the thin walls and need for precision down to the thousandths would make me think it would be tough to mass produce in this design. That's probably why they use tape to hold the Ali-express version on

[wkearney99]

ah, right, resin certainly has advantages over FDM. The Formlabs is a nice unit.