(Model MF) Remodeling the Model M (aka.. the Mara)

[kmnov2017]

Injection molding is the way to go. The flipper plastic needs an additive (carbon) to make it capacitive.

I'm just going to order a complete keyboard and then disassemble. I will offer the designs up to Unicomp if they want them - if not, i will publish them as open. It would be best if folks could order an "F upgrade" directly from the manufacturer.

Finding a manufacturer that can make the flippers for a decent price may be a challenge. But who knows.

Btw unicomp has confirmed that the barrel frame, backplate and the SSK cases can be ordered from them in the future.

[SneakyRobb]

Ive been experimenting with making new flippers with 3d printing and resin. At first I thought it might be possible to produce just basic plastic and then coat it with conductive material. I think the carbon additive is the best way to go.

I've found that carbon content of the flipper gives a bit of graphite lubrication where it rotates about the "ears." You can even faintly draw with the flipper on paper like a H Pencil. This is leading me to conclude that a coating/metal tape on normal plastic while fully working, wont provide the full lubricated feel of the carbon filled flipper cleanly moving.

When you cut a model f flipper with scissors it doesn't even deform and cut like most plastic. It breaks and crumbles like a pencil lead. There must be quite a high carbon content. I am still experimenting though. It may still work with something like POM plastic then a coating.

[DMA]

^ you mean graphite additive.
I'm currently testing flipper material - charcoal doesn't work at all, graphite works above certain concentration, can't yet figure out the threshold.

Metal foil basically dominates everything.

[wcass]

I think "carbon black" is preferred over graphite. It is commonly used as a plastic additive for color and anti-static, but also for capacitive pens at higher concentrations. I did some research a while back, but the manufacturer should know how high they can go given a flipper size and thickness.

It is kind of a specialty thing, but maybe look into metal vapor deposition - like how some balloons are made.
https://en.wikipedia.org/wiki/Physical_vapor_deposition

[gianni]

Ellipse solved the problem by interviewing ex ibm employees who explained to him to route to follow and every detail about the material. I don't know if there's a chance that we can find someone who worked for IBM like he did. Or maybe just ask Ellipse??!?
He interviewed "a supervisor of Model F keyboard production at one of IBM’s factories in the 1980s".

[Rimrul]

I know Ellipse has worked up the following for the barrel and flipper in his F62/77 project:

• Barrel Material: ABS POLYLAC PA-757
• Flipper Material: Torayca ASHT-18A

Is this what you want to ask Ellipse about? He's injection molding the flippers from ABS with 18% Carbon fiber content.
He also ruled out electroplating the flippers, due to cost.

Also I got some advice from one potential supplier regarding the recommended plastic. ABS PA-757 is both smooth and strong according to this web site: http://www.chimeicorp.com/en-us/products/plastics/abs/

They recommend 18% carbon infused Torayca ASHT-18A plastic for the flippers instead of electroplating (electroplating appears to be much more expensive).

Barrel
Material: ABS POLYLAC PA-757

Flipper
Material: Torayca ASHT-18A

I can't quite find a good estimate for the cost of PVD appart from "it's quite cheap if you can afford to buy the expensive machines and keep them running at thousands of parts per hour for a couple of years", but I'll assume it's more expensive than electroplating for our expected quantities.

[DMA]

Gentlemen, may be we should not indulge in necrothreading and make a new thread and discuss there instead.

I keep subscription active for an eventuality that OP returns. I have obligations.

[SneakyRobb]

Gentlemen, may be we should not indulge in necrothreading and make a new thread and discuss there instead.

I keep subscription active for an eventuality that OP returns. I have obligations.

Was a new thread made? Should we make a thread called model F CAD files/experiments or something?

[kmnov2017]

I don't seen a reason why we don't continue the topic here. It's still very much relevant to the original intent of the project. If lot_lizard isn't coming back, we might as well try keep this project going...

[Hypersphere]

I don't seen a reason why we don't continue the topic here. It's still very much relevant to the original intent of the project. If lot_lizard isn't coming back, we might as well try keep this project going...

I agree!

[SneakyRobb]

I don't seen a reason why we don't continue the topic here. It's still very much relevant to the original intent of the project. If lot_lizard isn't coming back, we might as well try keep this project going...

Agree

[zrrion]

The benefit of starting a new thread is you can actually update the OP with the progress of the project, can't do that in someone else's thread

[SneakyRobb]

The benefit of starting a new thread is you can actually update the OP with the progress of the project, can't do that in someone else's thread

fair point

[Techno Trousers]

I will offer the designs up to Unicomp if they want them - if not, i will publish them as open. It would be best if folks could order an "F upgrade" directly from the manufacturer.

That would be amazing wcass! Let's hope they go for it.

[Hypersphere]

The benefit of starting a new thread is you can actually update the OP with the progress of the project, can't do that in someone else's thread

fair point

I would be okay either way. The important thing is that the project gets continued.

[Erisie]

I've been following this project for a while now and I thought this would be a good idea to give some new life on my existing Model M. I personally enjoy the standard IBM ISO configuration, but I thought it would be nice to have the same idea, except in an ortholinear layout, like this:


I made some modifications to i$'s/wcass's FEXT PCB layout with Adobe Illustrator, and this is the result (vector PDF files attached to this post):

Top traces:

Bottom traces:

Both:

I had to ground two unneeded row lines from i$'s design (since this would only need six) and add an additional column line. Also, I added some key spaces that I personally would not be using, but that someone else that moves forward with this idea can use in their keyboard.

Keep in mind that I don't know a damn thing about PCB design, so I'll be glad if you guys can provide any feedback on this idea: would this PCB (or something close to it) work on an Xwhatsit controller?

After the PCB design is complete, the list of things to do includes:

1. Buying and perforating an aluminum sheet to mount the barrels.
2. Fabricate the barrels: my idea is to buy a small bunch of XT ones and produce copies with casting resin.
3. Buy the spring hammers from Ellipse's Model F project (I considered casting copies of those, but the conductive plastic they're made of is an issue).
4. Buy blank keycaps from Unicomp.
5. Acquire an Xwhatsit controller, solder and program the keys.
6. Dye-sub the lettered keycaps.
7. (optional) Find four guys who might be interested in this specific PCB to share costs

Whatever the case, I would be doing this after the lockdown in my country is over, so there is some time before I do anything.

Thanks in advance.

[wcass]

Unfortunately, that is not going to work. There are actually too many things wrong for me to go into it. I'll try to explain how to do it right in a future post.

The idea behind this thread is to take an off-the-shelf M and make it an F by swapping out just membrane, flippers, and controller. Changing the key layout to ortholiniear would require that AND a new barrel frame and probably back plate.

[Erisie]

Unfortunately, that is not going to work. There are actually too many things wrong for me to go into it. I'll try to explain how to do it right in a future post.

I would greatly appreciate if you could provide that some additional information on the correct way of bringing this design to fruition, or even a proper PCB design. Again, I have zero knowledge on this subject matter, so I just went with trying to modify an existing design using Illustrator, rather than a proper software suite for circuit design like KiCad or AutoCAD, with which I am not familiar.

I've been trying to get ahold of any documentation as to how the Model F board works, with little success.

In any case, I do know of one person on Reddit who built an ortho capactive buckling spring keyboard.

The idea behind this thread is to take an off-the-shelf M and make it an F by swapping out just membrane, flippers, and controller. Changing the key layout to ortholiniear would require that AND a new barrel frame and probably back plate.

I am well aware of that. In my case, however, keeping my Model M's barrel frame isn't a good idea: I broke the bottom row after doing a bolt mod on it.

Thanks for your reply, anyway.

[gianni]

An ortholinear layout would surely work if you use the model f flippers and barrels. You need a new pcb, a new controller and a new curved plate. This would be a very big task for anyone. If I can suggest something, wait for this program to succeed and then adapt what you can use?!

If you broke the bottom row of your keyboard, a new plastic frame isn't that expensive, it should be around 30 usd from unicomp.

[Erisie]

An ortholinear layout would surely work if you use the model f flippers and barrels. You need a new pcb, a new controller and a new curved plate.

That has always been my plan.

This would be a very big task for anyone. If I can suggest something, wait for this program to succeed and then adapt what you can use?!

In a sense, that's what I tried to do by modifying i$'s PCB to make it ortholinear. I probably did an awful job at it, but I take it as a "proof of concept" for my layout project.

Doing that layout using MX switches would definitely be a lot easier, but I don't like the way they feel while typing compared to buckling springs.

If you broke the bottom row of your keyboard, a new plastic frame isn't that expensive, it should be around 30 usd from unicomp.

The cost of the frame itself from Unicomp isn't my issue ($20). It's shipping to my country ($60 to $100!). There's also the non-trivial risk of it breaking during transport.

[ppCircle]

In case someone is interested, this is how the flippers look on the Polish ICE (Model F AT clone)



It's probably easier and cheaper to get metal flippers made

[zrrion]

I would think that something like that, but with plastic studs for the pivot wouldn't bee too difficult to do, and would hopefully smoother than an all metal part.

[gianni]

An ortholinear layout would surely work if you use the model f flippers and barrels. You need a new pcb, a new controller and a new curved plate.

That has always been my plan.

This would be a very big task for anyone. If I can suggest something, wait for this program to succeed and then adapt what you can use?!

In a sense, that's what I tried to do by modifying i$'s PCB to make it ortholinear. I probably did an awful job at it, but I take it as a "proof of concept" for my layout project.

Doing that layout using MX switches would definitely be a lot easier, but I don't like the way they feel while typing compared to buckling springs.

If you broke the bottom row of your keyboard, a new plastic frame isn't that expensive, it should be around 30 usd from unicomp.

The cost of the frame itself from Unicomp isn't my issue ($20). It's shipping to my country ($60 to $100!). There's also the non-trivial risk of it breaking during transport.

I don't know how and why you think that you'll be able to succeed where other people have found big difficulties that make a project like this a really big task that involves engineering, programming, computer science, while requiring a lot of passion and dedication. And a good mood too, to deal with people that treat you like a clerk in an convenience store. The best that you can do is join this project, and when it will be successful, making all the possible layout variations will be the obvious next step.

Your project requires some extra steps when compared to this project. For example making a curved plate isn't as simple as it seems. People did it but it required a lot of effort, since the two plates need a different curvature radius in order to keep contact with the foam.

[SneakyRobb]

Hi,

This model is not optimal/may not work but its my progress so far. The dimensions do need to be edited. It is untested and may not exactly work/fit yet. So do not take this as a working model. It's just my current draft.

I think the nubs on the "ears" are not optimal and extend down too far.

I just got the resin printer for making beamspring parts so I'm not very good at it. I will try printing the flipper again. The first attempt didn't work at all. The resin... had some issues.

When I get more experience I will just add 20% graphite to the resin and see if that works.

Robb

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flipper untested.zip

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[SneakyRobb]

Hi,

Okay it needs refinement but I managed to make a new model f flipper in resin. Very exciting.

Dunno if work. Seems a bit wide. Regardless happy with results.

[gianni]

Fantastic accomplishment. In the next iterations someone could consider also silent "inserts" in order to make the rebound of the flipper more silent (in the upper part of the flipper).

[wcass]

Very little sound is generated by the flipper. Most comes from the spring smacking the inside of the barrel when it buckles - with secondary coming from vibration of the spring itself. Changing the spring will have the biggest impact on sound. I think Ellipse reported this too.

[gianni]

Very little sound is generated by the flipper. Most comes from the spring smacking the inside of the barrel when it buckles - with secondary coming from vibration of the spring itself. Changing the spring will have the biggest impact on sound. I think Ellipse reported this too.

Surely the spring makes its big part, let's say 60% of the noise, but the flipper makes some noise too.

Look at this thread
viewtopic.php?t=16550

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[Hypersphere]

@SneakyRobb: The shape of the flipper looks good. However, does it have capactitive properties? The model F flippers have either carbon black or short carbon fibers added to the plastic to impart electrical capacitance. Have you added either of these ingredients to your resin?

[zrrion]

I imagine you could adhere some foil to the flipper to make it capacitive without having to mess with custom plastic flavors