Re: Gauging interest in a run of reproduction knob tips
Don't get me wrong, I'd love to get good reproductions. The tact-switch caps are better than bare levers, but I only put them on because cracked falling-off bats MAKE ME CRAZY.
From: David Wise
Sent: Wednesday, December 02, 2020 10:36 AM
Subject: Re: [TekScopes] Gauging interest in a run of reproduction knob tips
The Tek lever knob tips are P/N 366-0215-xx. They're widely used, e.g. Type 453 and 547 scopes and 1A1, 1A2, 1A4, and 1A5 plugins.
For what it's worth, I replace broken ones with the cylindrical tact-switch cap made by E-Switch, part number 1RDGR, $0.18 each at Mouser.
Description is "Switch Bezels / Switch Caps RND DARK GRAY CAP". It doesn't have the feel of the original but it works and it stays in place.
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of thespin via groups.io <email@example.com>
Sent: Wednesday, December 02, 2020 9:27 AM
Subject: [TekScopes] Gauging interest in a run of reproduction knob tips
I've noticed that a lot of the lever knob tips have cracked due to the combination of being made of bakelite and the internal stresses of the leaf spring. I'd like to do a short run of replacement knobs. I've tried several different 3D printing processes and haven't been totally happy with any of them. In particular, FDM tends to have pronounced layer lines, and small enough nozzles require extremely high melt flow rates restricting the choice of materials and thus colors. I also have an SLA printer, but these resins result in parts that last a few months before cracking due to UV exposure. Thus, urethane casting and injection molding are seemingly the best options. MJF or SLS may be ok but I'm not a huge fan of the texture.
If you'd be interested, I'd appreciate a response to the following survey.