[FMF] - Free Model F - DT Workshop project & (real) Group buy

User avatar
idollar
i$

01 Jan 2025, 03:01

Introduction to the FMF: project concept and call for community support

Note: this post will be updated. As such it shall be considered work in progress. A change log is shown at the end.
Last change 2025.01.01 (yyyy.mm.dd)

Dears,

This could turn into the most beautiful project in the keyboard community. It is all in your (our) hands.

The purpose of this post is to start the process of creating a free model f keyboard. Free as the FSF understands freedom. Users have the freedom to run, edit, contribute to, and share the software (and in this case the hardware). Thus, free software (and hardware) is a matter of liberty, not price. Free to use and modify, with the only condition that any improvement or evolution shall be made available to the community also.

To be 100% clear:
  • I do not plan to create any company (at least keyboard related)
  • I do not plan to raise any profit from the project
  • The only goal behind the FSF project is to create a free source of information allowing anyone to run their projects, whatever the nature of these be.
  • I have named this a DT project but it is actually an open-to-anyone project as the ultimate goal is the information and the knowledge
I am aware that this may sound weard to some people. But you should be used to altruism as is the main source of the components of the Model F Labs LLC products.


My favorite layout is the SSK (which can be extended easily to have a number-pad). I would suggest to start with this one, but this may be discussed if the community has a different preference. Lets see.

Thanks to the community, most of the elements required to build a Model F keyboard are available.
My intention to call for support in separated threads in the workshop section to progress the different components.
Please note that components have different priority. This is indicated before the component title between brackets, being 0 the highest priority.
  • (0) Controller - Already available
  • (0) Capacitive Flippers - In the process of being created. Two options a) Ordering from China - contacts ongoing b) 3D-print under investigation
  • (0+) Springs - To be designed options tested and progressed
  • (0+) Barrels - In the process of being created. Two options a) Ordering from China - contacts ongoing b) 3D-print under investigation
  • (0+) Miscellaneous - For completeness only (e.g. screws, washers ... etc). Mainly a list of COTs components to ensure completness.
  • (1) PCB - Already available - updates may be required - refer to "case/s" later
  • (1) Top and Bottom Plates - To be designed and progressed
  • (1) Foam - It does not seem to be a real challenge as it has been done before. - not a big task
  • (2) Key inserts - In the process of being created. Two options a) Ordering from China - contacts ongoing b) 3D-print under investigation - not a big task
  • (2) Stabilizers - To be designed and progressed - not a big task
  • (2) spacebar tabs - To be designed and progressed - not a big task
  • (2) Case/s - To be designed and progressed. Different cases could be created to support different layouts. Includes feet.
  • (3) Solenoid controller - Already available
  • (3) Solenoid - Commercial options available to be investigated - not a big task
  • (4) USB cable - Available in the market
  • (4) OLED display - Available in the market - concept has show working
  • (4) LEDs plate - To be check if needed. It could be integrated in the case of replaced by OLED
  • (4) Keycaps - To be addressed

The result you be a set of components that could be assembled in a final woking keyboard (acquired as a kit or as a keyboard) or used in any side projects (e.g. flippers and springs alone would be useful in FSS and FEXT).

I have called this new project the "Free Model F" as it will be based on the following concepts:
  • All components will be open source.
  • Costs shall be transparent.
  • The components will be made available for individual purchasing. The source to procure will be made public
  • Logistics shall be made public. For instance, if a mold for some[url=https://www.deskthority.net/viewtopic.php?f=7&t=29412 plastic parts are required the project shall guarantee public access
  • In case that economies of scale are required, GB could be organised in different areas
This should be a team effort for which I call for support.
I can think on the following roles and needs:
  • Coordination effort. Mainly focus on ensuring arriving to system (keyboard) integration.
  • Per-component book-captain. This person shall focus on a) specification b) design and documentation c) prototype manufacturing c) testing d) logistics
  • Testing team
  • Others roles will be added here.
Please reply to this post in case that you are interested in supporting any of the above.

Finally any comment is welcome. This should NOT be my personal project but DT's project.
I plan to edit this initial post with your suggestions.

Looking forward to your contributions in this new endeavor!

Thanks

i$

--- change log (yyyy.mm.dd) ---
Spoiler:

2025.01.01 - initial version
2025.01.01 - priorities for different components shall be added - https://www.deskthority.net/viewtopic.p ... 25#p521925
Last edited by idollar on 03 Jan 2025, 00:17, edited 36 times in total.

User avatar
idollar
i$

01 Jan 2025, 03:06

Executive progress report and work allocation
  • (0) Controller - Initially i$ - calling for volunteers.
  • (0) Capacitive Flippers - Initially i$ - calling for volunteers.
  • (0+) Springs - Initially i$ - calling for volunteers.
  • (0+) Barrels - Initially i$ - calling for volunteers.
  • (0+) Miscellaneous - Initially i$ - calling for volunteers.
  • (1) PCB - Initially i$ - calling for volunteers.
  • (1) Top and Bottom Plates - Initially i$ - calling for volunteers.
  • (1) Foam - Initially i$ - calling for volunteers.
  • (2) Key inserts - Initially i$ - calling for volunteers.
  • (2) Stabilizers - Initially i$ - calling for volunteers.
  • (2) spacebar tabs - Initially i$ - calling for volunteers.
  • (2) Case/s - Initially i$ - calling for volunteers.
  • (3) Solenoid controller - Initially i$ - calling for volunteers.
  • (3) Solenoid - Initially i$ - calling for volunteers.
  • (4) USB cable - Initially i$ - calling for volunteers.
  • (4) OLED display - Initially i$ - calling for volunteers.
  • (4) LEDs plate - Initially i$ - calling for volunteers.
  • (4) Keycaps - Initially i$ - calling for volunteers.
Last edited by idollar on 02 Jan 2025, 15:39, edited 19 times in total.

User avatar
idollar
i$

01 Jan 2025, 03:06

Reserved - Looking forward to your contributions in this new endeavor!
Last edited by idollar on 01 Jan 2025, 13:52, edited 4 times in total.

User avatar
idollar
i$

01 Jan 2025, 03:07

Reserved - Looking forward to your contributions in this new endeavor!
Last edited by idollar on 01 Jan 2025, 03:49, edited 2 times in total.

User avatar
idollar
i$

01 Jan 2025, 03:13

Reserved - Looking forward to your contributions in this new endeavor!
Last edited by idollar on 01 Jan 2025, 03:49, edited 2 times in total.

User avatar
idollar
i$

01 Jan 2025, 03:14

Reserved - Looking forward to your contributions in this new endeavor!

User avatar
idollar
i$

01 Jan 2025, 04:10

Reserved - Looking forward to your contributions in this new endeavor!

User avatar
idollar
i$

01 Jan 2025, 12:53

FYI ... massive update of the introduction of the component threads in the workshop section is ongoing.
You may want to read the introductions again once the update is done

The update is completed.

User avatar
idollar
i$

01 Jan 2025, 13:57

Please, consider supporting this project.
Otherwise, I will have to progress each component :)

This is NOT my project, it is a DT project. Feel free also to propose helping in the organisation.

BTW: All the best for 2025 ! Is there a better way to start the new year like this ? :D

i$

User avatar
idollar
i$

05 Jan 2025, 11:05

I believe the consolidated findings from this project should be documented in a centralized location. Searching through the forum is not convenient, and information tends to get lost.

Does anyone have suggestions for a tool we could use?
We could use the wiki, but to be honest, if the main goal of this site ultimately leans toward sales and marketing for companies, I’m not sure the wiki would be my first choice

Hak Foo

06 Jan 2025, 05:25

Probably terrible idea: One of the things that makes the Model F hard to deal with on a hobbyist basis is the curved aspects-- a curved PCB, the curved sandwich plate, a case to accomodate the curve, getting all the tolerances right, dealing with foam to pack it all together. Without fancy tools, that means going to a pro manufacturer, high MOQs and startup costs, and iteration is very expensive.

I wonder if it might be possible to design individual barrel-spring-flipper assemblies in plastic "cages" that could snap into slots in a flat PCB. Think of a unit looking like one of these individual-switch module keychains (https://www.ebay.com/itm/282392918945) but with the bottom plexi removed and some little hooks added to engage the PCB.

That would make it more or less possible to design "flat" buckling spring designs that fit into essentially the same cases as common MX hobbyist projects. If you could say "dig out an old G81-3000 from the scrap pile, remove the PCB, and drop in the FMF PCB", that could make the product hundreds of dollars more accessible. Or, of course, you could have deluxe, more custom cases fabbed, but it wouldn't be anywhere near the same level of required it would be with a curved assembly.

Further riffs on the hook idea:

* Instead of a simple hook, maybe use a split circular prong-- the sort where it can be pinched slightly to fit through the hole, then spreads out to prevent back out. Think of the mount on non-screw-in MX plate mount stabilizers. The idea is to give the PCB shop the simple requirement "drill a 2mm hole" rather than the somewhat harder "drill a neat rectangular slot 1.5mm x 4mm for a hook"

* Four hooks, maybe positioned at slightly off positions on each side, would engage from all sides, but avoid having to put two drill holes right next to each other. For example

Code: Select all

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I fully expect this to have wild implementation problems I haven't thought of yet, but I wanted to share.

User avatar
DMA

06 Jan 2025, 07:39

Hak Foo wrote: 06 Jan 2025, 05:25 Probably terrible idea:
Not quite! It's not even that hard to make flippers a bit smaller - but doing that will change the sound (not feel) of the keys.
Hak Foo wrote: 06 Jan 2025, 05:25a curved PCB
Curved PCB isn't actually needed - original IBM ones are curved simply because they were sandwiched between plates for 30+ years. "PCB-curving machine" was invented because somebody didn't understand shit about how IBM keyboards were made.
Hak Foo wrote: 06 Jan 2025, 05:25getting all the tolerances right
Those are pretty wide tolerances, actually.
Hak Foo wrote: 06 Jan 2025, 05:25I wonder if it might be possible to design individual barrel-spring-flipper assemblies in plastic "cages" that could snap into slots in a flat PCB.
That _is_ possible, but there's a problem: 87 keys x 65 grams is 5655 grams of force, 104 keys is 6760 grams. FR4 will buckle significantly - most noticeably between "G" and "H". So the plate needs to be steel. 1.5mm steel, to be exact - because plate-mount stabilizers expect 1.5mm plate thickness. (yes, keys will need to be MX or something else designed for a flat plate - IBM keys on a flat plate will form 19x21mm grid, see wcass's beautifully machined flat model F).
Iteration cost for laser-cut 304 steel is about $100 at ponoko (about $30/plate at 100 copies last time I checked).
Hak Foo wrote: 06 Jan 2025, 05:25If you could say "dig out an old G81-3000 from the scrap pile, remove the PCB, and drop in the FMF PCB", that could make the product hundreds of dollars more accessible.
Actually, the case can be just two plates, like download/file.php?id=78222

Re: hooks - I remember that most antique keyboards have a steel plate. That plate can hold the modules down, and holes just need to position the module horizontally on the PCB.
Something will need to hold that 6 kg of constant force down, no way around that.

Anyway - I'm currently finishing a fume hood for my resin printer, and can run some experiments along with viewtopic.php?f=7&t=28101 I bought that printer for.

ChairmanMeow

27 Jan 2025, 07:01

Hak Foo wrote: 06 Jan 2025, 05:25 I wonder if it might be possible to design individual barrel-spring-flipper assemblies in plastic "cages" that could snap into slots in a flat PCB. Think of a unit looking like one of these individual-switch module keychains (https://www.ebay.com/itm/282392918945) but with the bottom plexi removed and some little hooks added to engage the PCB.
I've thought about this a good amount, too, but more in the context of creating a single-key unit compatible with the common MX keyboards and PCBs. It could be possible to take one of those single-unit switches you linked, add a small piece of PCB underneath, and hold the assembly together with fasteners. Some pins exiting the assembly could be used for sensing the change in capacitance. A very crude drawing is attached.
Image

The original patent also mentions other ways of sensing actuation could be taken, some of which may be better suited for use with common PCBs (optical?)
Image

I'm sure this is much more complex than it looks, but like Hak Foo, I think it could be convenient to have access to buckling spring switches in a more modular form, even if they are substantially fatter than standard MX switches. It should also be relatively easy to prototype because one could use existing flippers, keys, and barrels.

User avatar
idollar
i$

27 Jan 2025, 11:46

A very interesting discussion :)

User avatar
DMA

29 Jan 2025, 06:52

@ChairmanMeow yeah, I just given up on properly setting up my resin printer, and will work around what I've got instead. So I should be able to produce some physical items to test them real soon.

However.

Model F flipper is 16.7x16.8mm. It's a moving part, so it needs at least 18x18mm free space to operate in. (ok, the actual flipper is 15.2mm wide, so 18x17mm). Where you propose to put the fasteners, considering that standard key spacing is 19.05x19.05mm?

I'll try to print something that should fit into 14x14mm MX hole and not violate the 19x19mm space (although ideally all of it should fit 14x14mm footprint - stabilizer wires won't fit otherwise) and check how it affects feel (and possibly sound - I'm pretty sure the sound will change, but I don't care about sound, it's all about the key feel for me).

"more modular form" for PCB is irrelevant nowadays: PCBs are really, REALLY cheap (and 87 13x13mm PCBs are probably 20 times more expensive than 5 keyboard-sized PCBs). You probably think that you can use existing controller - but no, it won't work with capacitive sensing. Same goes for existing PCB - it has probably corroded in a couple inconspicous places already, and even if it didn't - most of those PCBs were really shitty, and at least couple of tracks will be lifted while trying to desolder the switches.

Using ohmic contacts will require a metal flipper, accompanied by at least one spring on the PCB, to work.
Inductive - just say no. As an author of the only modern inductive sensor (which reads MagValve switches) I can confidently say that inductive switches are forgotten for a good reason - and that reason is requirement to catch very fast (50ns) very weak (50mV) pulses.
Piezo is an interesting idea, but it will also require catching very short pulses (plus vibrations of a key will cause pulses in adjacent keys (because vibrations do travel fast and far. Yes, per-key PCBs will solve that problem - but see above on cost)
Optical is probably practical, but requires either N LEDs or a per-row (LED + custom light pipe) + N photodiodes/photoresistors.
In any case, it won't be a hotswap replacement to any other switch - except for piezo and ohmic, the switches will require more than two pins, and everything except ohmic will require a different controller.

So, PCB will definitely need to be replaced anyway. What else do we have in G81-3000 that's worth saving?

ChairmanMeow

29 Jan 2025, 23:48

Using model F flippers/barrels would only be the proof of concept model for what I was thinking of. Since manufacturing would have to be done anyway, I thought the "final product," if it ever came to that, would just use smaller versions of model F flippers/barrels with potentially slightly different shape, allowing clearance for fasteners within the appropriate area. My electronics knowledge is slim, but I don't know of a reason why smaller flippers wouldn't also work as a switch.
Given your info about PCBs, it seems this idea would be better as a switch with an open bottom that bolts onto a large PCB (or attaches with some compliant mechanism) instead of a unit containing a small PCB.

User avatar
dcopellino

30 Jan 2025, 16:57

idollar wrote: 27 Jan 2025, 11:46 A very interesting discussion :)
truly an inspiring discussion. the suggestions proposed immediately reminded me of the Brother bucking springs, which have the same feeling as the IBM originals with a slightly more acute sound (pinging). for the rest they are modular and have a snap-fit system on the pcb and the back plate very similar to the one depicted by DMA. Furthermore, they are smaller than their model m counterparts with which they share the membrane actuation technology (not capacitive). A much more savvy eye than mine would not have trouble recognizing a better overall construction quality on the part of the japanese ibm cousins. Who knows... maybe one could imagine a capacitive flipper inside a modular barrel like the one adopted in Japan. See the wiki and follow the article links, on this wiki web page.

Edit: if the wiki page doesn't load, try to Google it or go here otherwise:
https://ex4.sakura.ne.jp/kb/tech_bucklingspring_e.htm

User avatar
DMA

31 Jan 2025, 03:32

> https://ex4.sakura.ne.jp/kb/tech_bucklingspring_e.htm

Wow. That guy.. That guy has a PHENOMENALLY SHARP SAW!

And similarly sharp observation skills - for example he is pointing out that it's a slanted base that nudges the spring to buckle that particular way, not "having springs positioned to 12 o'clock" bullshit I keep hearing elsewhere.

I notice that brother switch is somewhat shorter - so the spring must be shorter too.
Re: "not capacitive" - yeah, model M is also not capacitive, but the Unicomp I've bought 10 years ago (which is still the only keyboard I haven't got at Goodwill) failed in 2 years of use because of the membrane: G and H started to register keypress intermittently - they clicked OK, so the mechanism was OK, just not the membrane.
Also, wcass tried to find anybody who would produce those mylar membranes - guess what, the cost was like $500 per unit for 10 units. PCBs are cheaper nowadays.. I mean, it could be that it would be $50 per unit for 100 units - but PCB would be probably $5, can't beat that.

..now I just need to find that brother typewriter with bucking springs.. It's a really intriguing thing, especially the flipper holder. Plus their springs seem to be shorter - another problem with buckling spring as a module is that original barrel is almost 18mm high.

Does anyone here actually have one of those keyboards in their collection? The photos in that link are too small to be useful, and I'm definitly not paying $300 + shipping from Japan for one of those just to take some measurements :(

User avatar
dcopellino

31 Jan 2025, 12:13

DMA wrote: 31 Jan 2025, 03:32 Does anyone here actually have one of those keyboards in their collection? The photos in that link are too small to be useful, and I'm definitly not paying $300 + shipping from Japan for one of those just to take some measurements :(
Hi DMA, I got one of this in my collection, even though no caliper available, sorry. Let me know if I may be of some help, otherwise. In the meantime have a look to these very big and hi res pics.

https://www.flickr.com/photos/triplehaa ... 617851639/

User avatar
DMA

01 Feb 2025, 07:08

dcopellino wrote: 31 Jan 2025, 12:13In the meantime have a look to these very big and hi res pics.

https://www.flickr.com/photos/triplehaa ... 617851639/
Thanks for pointing me to this link. I might be able to access that particular keyboard.

User avatar
DMA

03 Feb 2025, 21:18

TIL "Alps buckling spring" is a thing: https://www.paulbramhall.uk/bits-n-bobs ... -keyboard/
Shorter spring is a benefit - I was able to shorten the barrel to 15mm in height, but cherry MX switch is 11.6mm high, and I'm kinda worried about stabilizers not working with that extra 3.4mm.

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