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geekhack Community => Keyboards => Topic started by: ezrahilyer on Sun, 19 October 2014, 01:02:33

Title: IBM Model M 70% Cut Down Boards Build & Customization
Post by: ezrahilyer on Sun, 19 October 2014, 01:02:33

I am building Model M 70% cut-down boards as a sort of beta test of the feasibility of the idea. I will be adding photos and my process.

I am cutting them down to 70%, so there will not be directional arrows, or scroll-lock, page up page down ect. I cut the boards right at the mold line where it almost looks like IBM designed them to be cut.

I have the contact sheets cut and the traces re-worked using 1/8" copper Foil Tape.
http://www.amazon.com/gp/product/B00EY44I42/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00EY44I42&linkCode=as2&tag=strapoet-20&linkId=HDGIVCROV3ECMT4V (http://www.amazon.com/gp/product/B00EY44I42/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B00EY44I42&linkCode=as2&tag=strapoet-20&linkId=HDGIVCROV3ECMT4V)

I have tested and re-tested the continuity of the traces, and it works really really well. I think this is much better than using that liquid circuit writer pen.

I will cut the steel barrel plates tomorrow on the band-saw, and then I can re-assemble them and start building the cases. ( I am making wooden cases for them)

I will start with 4 and see what I need to do to improve the process before I make some 60% boards.

-ezra

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: yasuo on Sun, 19 October 2014, 01:05:51

Like hbs :)
http://geekhack.org/index.php?topic=29483.0 (http://geekhack.org/index.php?topic=29483.0)

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: ezrahilyer on Sun, 19 October 2014, 01:33:42

Yes, exactly like that infact.. wow, right down to using copper instead of a circuit writer. I am readying the thread now.

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: ezrahilyer on Sun, 19 October 2014, 01:43:59

Quote from: yasuo on Sun, 19 October 2014, 01:05:51

Like hbs :)
http://geekhack.org/index.php?topic=29483.0 (http://geekhack.org/index.php?topic=29483.0)

i never thought about cutting and then gluing the case, I am keeping the function row on mine, but if I cut the case just right, i can put the pieces back together just like he did and make it look like it was made that way. that is such a cool mod.

I had read about people folding the membrane sheets, and using a liquid silver circuit pen, but looks like I am not the first to the party with the copper foil tape.
I was thinking a nice minimal wooden case, and an internal soarers, maybe It would be better to try and cut down the original case like his mod.

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: 0100010 on Sun, 19 October 2014, 08:28:34

Put Unix keys on it (with a front function number row) and go 60% :

(http://s28.postimg.org/hhp111hsd/BS62.jpg)

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: fohat.digs on Sun, 19 October 2014, 09:56:35

This is how I can make my faux-SSK work by dis attaching that stupid 42H controller.

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: ezrahilyer on Sun, 19 October 2014, 13:21:38

Quote from: 0100010 on Sun, 19 October 2014, 08:28:34

Put Unix keys on it (with a front function number row) and go 60% :

Show Image

(http://s28.postimg.org/hhp111hsd/BS62.jpg)

I do intend to go 60% in a future version, but for now I am just doing the 70% because I have to get the cases right. 

Lots of experimentation.

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: Vizir on Mon, 20 October 2014, 09:29:48

sweet! between Matt3O's cherry keycap mod and this, it'd be very close to my ideal keyboard. Keep us posted!

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: Oobly on Tue, 21 October 2014, 01:59:45

I'm also in the middle of a Model M chop using copper tape with conductive adhesive. It works fantastically well and can be soldered to. Going for 60% using a Teensy. Having some trouble with the firmware, though, since the one I chose drives the columns and senses rows and this causes a bit of problem with the 2KRO membranes... I cannot use right Shift and V,B,N or M together and since I use right Shift all the time I need to change the firmware.

I've been considering playing around with capacitive sensing and using aluminium tape on the hammers, copper tape on a closed cell foam layer with a coating of Shellac for the capacitive contacts and magnet wire to connect them to each other (minimal contact area to minimise parasitic and stray capacitances), but I'd like to get the basic board working as a "normal" Model M first.

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: ezrahilyer on Sat, 25 October 2014, 22:44:01

Quote from: Oobly on Tue, 21 October 2014, 01:59:45

I'm also in the middle of a Model M chop using copper tape with conductive adhesive. It works fantastically well and can be soldered to. Going for 60% using a Teensy. Having some trouble with the firmware, though, since the one I chose drives the columns and senses rows and this causes a bit of problem with the 2KRO membranes... I cannot use right Shift and V,B,N or M together and since I use right Shift all the time I need to change the firmware.

I've been considering playing around with capacitive sensing and using aluminium tape on the hammers, copper tape on a closed cell foam layer with a coating of Shellac for the capacitive contacts and magnet wire to connect them to each other (minimal contact area to minimise parasitic and stray capacitances), but I'd like to get the basic board working as a "normal" Model M first.

I thought about etching a board for the 60% ones with individual contacts on one side, with boss connections through to traces on the back with the controller. That way i could use some sort of 2 layer custom membrane without traces. i would still be able to sense each key, with only one contact. (think of it this way: conductive foil backed sheeting for the top layer directly under the hammers, then a regular non-conductive later with holes cut to add a separation layer, then a PCB with bare copper pads home-run back to the controller (after a few registers since there would be 80+ traces)

I have decided to focus on the 70% conversions right now, here are a few pictures showing where I am at now. I have the traces done with the conductive tape, and it does work great! I went ahead and left the membranes intact as far as output is concerned, so I am still going to use the M controller behind the teensy, but I see the advantage to just going with my own controller.

These are 2 of 4 I am making like this, I will be putting them into custom wooden cases. (or ateast 2 of them, I may try modding 2 back into cut down original cases)
If I get ambitious, I may do led backlighting as well...... decisions decisions....
(http://straypoetry.com/wp-content/uploads/2014/10/IMG_16422.jpg)


(http://straypoetry.com/wp-content/uploads/2014/10/IMG_1641.jpg)


(http://straypoetry.com/wp-content/uploads/2014/10/IMG_1640.jpg)

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: quantalume on Mon, 27 October 2014, 00:11:45

They look awesome!  Do you just have them bolted together temporarily, or is that the total number of bolts you intend to use?

Title: Re: IBM Model M 70% Cut Down Boards Build & Customization
Post by: ezrahilyer on Mon, 27 October 2014, 09:01:26

Quote from: quantalume on Mon, 27 October 2014, 00:11:45

They look awesome!  Do you just have them bolted together temporarily, or is that the total number of bolts you intend to use?

Good eye!

No, that is only temporary, I didn't want to put all those screws and washers on, only to have to tear it back apart if it didn't work the first time. (though it did)

Every rivet hole is drilled, and is now secured with the screw and washer that I always use.

I am hoping to have atleast one of them done tonight. (but I have told myself that before)