Low profile Beamspring project

User avatar
DMA

16 Nov 2019, 06:49

Hmm. Plastic actually not needed in this configuration - except for PCB protection. But if no plastic - some weight must be added to the bottom part, or all the beamspring fill's gone.

Would be fun to try different plate weights.

Heikkonen

16 Nov 2019, 10:39

Im honestly impressed by amount of work you have put into this project. This is what we all wanna see. Keep it up!

manisteinn

18 Nov 2019, 00:29

DMA wrote:
16 Nov 2019, 06:49
Hmm. Plastic actually not needed in this configuration - except for PCB protection. But if no plastic - some weight must be added to the bottom part, or all the beamspring fill's gone.

Would be fun to try different plate weights.
Are you referring to the capacitive flyplate or some other component?
I'm planning to try different materials/thicknesses for many parts :)
Heikkonen wrote:
16 Nov 2019, 10:39
Im honestly impressed by amount of work you have put into this project. This is what we all wanna see. Keep it up!
Thanks! I finally got started with the CNC router this weekend so there'll be a proper update soon.
If anyone knows of reasonably priced sources of 15mm thick PA6/POM (nylon/delrin) please let me know.

User avatar
DMA

18 Nov 2019, 17:44

Flyplate.

manisteinn

15 Dec 2019, 23:41

I've been focusing on other projects recently and there hasn't been much progress, but here's a quick update:

Image gallery

I've finally got SKCL/M springs lined up, there were some unexpected delays.

I CNC'd and assembled the mold mentioned in a previous post. Still haven't cast any housings with it. I also have plenty of dowel pins and stainless m2 screws on the way so I can eventually cast more than one at a time.
I also CNC'd a 2x2 plate/lid and 4x2 housing block (wood, just proof of concept). I'm not sure exactly what material the white plastic is, but there's several m2 of it around, great for experiments :)

Finally, I found a source for reasonably priced 16mm thick POM which I plan to try out for housings and lids.

User avatar
PlacaFromHell

27 Jun 2020, 00:30

Any update?

manisteinn

29 Jun 2020, 07:59

PlacaFromHell wrote:
27 Jun 2020, 00:30
Any update?
There's just been a little bit of progress, I took a break when covid was starting to spread and focused on other things. I'm slowly getting back to it though.

I've got a small POM block for a 2x2 switchtester, it's cut to size but I haven't milled it yet.
There's also been some nice cnc upgrades; software spindle control and lots of new endmills. I need to make some CAM adjustments.

Image

As I mentioned earlier I was planning to make a rigid stem for casting future caps, even before the stems ripped they'd bend:
Image

judging by the circular tooling marks I imagine the original mold construction was something like this:
Image

Seems like a good way to do my own molds, the circular cutout should be more precise and less prone to damage than a rectangular one.

I milled a 6mm D-shaft to turn/polish custom knobs a few years ago from a polished steel rod, pretty much the same. I'd definitely make some effort to improve the surface finish though :)
Image
(click for larger)



A bit of a tangent:
Ever wondered what even taller Beam/Selectric caps would look like? Well...

Image

Grey: Original mid row deepdish (F/J)
Red: Original top row
Black: Remington lock, shift, space

I picked up a Remington typewriter with some mechanical issues that headed for recycling, it looked very similar to Selectrics so I assumed it was a licensed clone with just a different (plastic) outer case. I figured I could use the keycaps and spare parts for my Selectric.

The different font I can understand, but I really didn't expect a several mm taller profile with weird rear cutouts to clear the row behind them. The internal keycap structure and tooling marks look identical to IBM caps, as do the mechanical typewriter internals. Seems like an incredibly unnecessary tooling investment, they must've really wanted that profile for whatever reason.

Gallery https://imgur.com/a/S2J0U1g



I also printed a 2.32 scale (to fit an o-ring I had) version of my original switch model a while ago, anyone who wants a desk toy could do the same using my models :)
Image
(click for larger)

I thought I'd add a stencil sheet to my next PCB order with both original and larger spring sizes for a functional big beam switch. I printed a few PETG springs in various thicknesses and while they did work they weren't great.

I'd also like to have a go at making custom coil springs, like so
Coincidentally a "new" lathe with a proper gearbox just showed up, no more disassembly required for changing thread pitch/feed rate :)
It also has T-slots on the cross-slide, useful for mounting custom fixtures and such.

User avatar
ayehavgunne

01 Jul 2020, 07:01

This is exciting!

Look out ModelFKeyboards.com
Here comes BeamSpringKeyboards.com

manisteinn

02 Jul 2020, 07:02

ayehavgunne wrote:
01 Jul 2020, 07:01
This is exciting!

Look out ModelFKeyboards.com
Here comes BeamSpringKeyboards.com
Interestingly that domain redirects to modelfkeyboards.com, Ellipse's next project perhaps? :)

Just in case you're unaware there's another thread related to DIY reproduction of the original switch and a commercial project with a different mechanism and sensing method.

To be clear I doubt I'll ever offer assembled switches (or keyboards for that matter), there'll always be some DIY involved.
I suppose the effort would be comparable to spring swapping/lubing with some extra steps.

I also spend time on this F65 project and a bunch of personal ones, I don't really have an ETA for this.
DIY/experimentation is very much encouraged which is why I share all design files. :)

Post Reply

Return to “Workshop”