Modded Unicomp SSK from Ultra Classic, Is it possible?

[khirin]

Not long ago, I got a dead Unicomp Ultra Classic for parts and spare. It turns out that its controller went bad, no lights, no response at all when plugged into a computer. I'm thinking that it will be nice to have a thinner-bezel SSK, all out of its parts, but couldn't find any previous references. 

I know that a chopped SSK from a full IBM Model M is quite manageable. But with this Unicomp, has it been done before?

Update 12/13/2016

I just did it. It's a good experience, testing, debugging, cutting, painting, etc. It's my first time doing most of the work, so I made many mistakes and had to do things over, again and again. Thanks for all GH good information and suggestions. It works great now. 

[samwisekoi]

I tried, but was never able to accomplish the feat.  So, probably?  The problem is what to do with the extra membrane.

Actually, I think someone has done it.  Dorkvader, perhaps?

 - Ron | samwisekoi
(Auto-typed by my GH36 Matrix Keypad.)

[kalrand]

Didn't phosphorglow have some ssk membranes printed up a while back?

[mike52787]

Pretty sure you can just fold the extra membranes under the board into the bottom of the case, just make sure that the membranes arent making contact to avoid unwanted key presses on the numpad.

[thokir]

Simply cut the membranes and reroute them with conductive silver or copper tape with conductive adhesive.
I actually did some modded foils with conductive silver, it's quite easy.

[supamesican]

Unicomp still uses the same membrane don't they? So yeah totally doable if it works on a classic M. Let us know if you do get it working, sounds so cool.

[thokir]

The membrane layers might be slightly different, but as the layout is still the same, worst case would be that you need to reroute some wires from the membrane to the controller, or use a teensy controller (I'd recommend using a teensy at all, more possibilitys for the layout).

But I see no reason why they should have changed the membranes, the old ones are working great, all model Ms have basically the same membrane layout, so imho they would've done a big mistake with taking a new membrane layout.

[dorkvader]

I restored a rusted "barn find" SSK with a new membrane from a 104. I was able to cut the non-conductive center section off and put tape over one of the sheets to prevent contact, it was easily small enough to roll up under the case. I recommend it over conductive pastes for reliability reasons.

I used a NIB 104 membrane from unicomp on the original SSK controller. I also recently used a 104 membrane from an affirmative (unicomp) model M on a 1390120 that I'm fixing up. Membranes shouldn't be an issue.

now if it's the unicomp controller that sits on the extreme right of the membrane and makes physical contact there, then you can relocate it but I would be worry about maintaining contact pressure with the membrane rolled over like that.

I agree with thokir, you can just cut the wires on the controller and wire up a teensy to it. It's what I'm doing on mine and it's saving a lot of hassle in the long run.

[kalrand]

Is there a part source for the connector piece that was on the old IBM controllers that held the membrane? Before Unicomp went to "push it tight against the board"?

[khirin]

...
now if it's the unicomp controller that sits on the extreme right of the membrane and makes physical contact there, then you can relocate it but I would be worry about maintaining contact pressure with the membrane rolled over like that.

I agree with thokir, you can just cut the wires on the controller and wire up a teensy to it. It's what I'm doing on mine and it's saving a lot of hassle in the long run.

The IBM Model M controller is in the midsection while the Unicomp's really sits on the extreme far right of the membranes over the numpad and make pressured contacts with them (the top and bottom membrane). Folding this part over the back of the curved steel plate in a tight space is very difficult because of the Ultra Classic's thin bezel. 

Since my controller is dead anyway, I tried this approach with a teensy but it turned out that I ended up destroying many tiny traces especially at the plate's edge where the membranes folded.

So, I decided to cut the membranes.  I am now trying to find all the 16 columns and 8 rows contact points and then wire them up the teensy.

[XMIT]

Silver paste is your friend. I've used this in the past to repair traces on Model M membranes. Something like this:
http://www.ebay.com/itm/281871336599

[khirin]

Silver paste is your friend. I've used this in the past to repair traces on Model M membranes. Something like this:
http://www.ebay.com/itm/281871336599

Thanks XMIT. I wish I had the silver paste and made my life easier. I ordered it on ebay and it will take 3 weeks to come my country (Thailand). So, I went ahead and used only the copper tape. It's ok now (see my update above), and I learn to properly use the copper tape along the way too.

[supamesican]

Dude that is awesome... I almost want to get a new unicomp and do this now. Maybe next Christmas

[Tangtawan]

Nice one kub p'nop

[fohat.digs]

The IBM Model M controller is in the midsection while the Unicomp's really sits on the extreme far right of the membranes over the numpad and make pressured contacts with them (the top and bottom membrane). Folding this part over the back of the curved steel plate in a tight space is very difficult

Always my problem.

But the big question is: What kind of glue did you use? I have done this twice and never found anything strong enough.

[khirin]

...

But the big question is: What kind of glue did you use? I have done this twice and never found anything strong enough.

No, I did not use any glue. Regardless of whether the copper tape is double or single-side conductive (with or without conductive adhesive),  the trick is to fold the end of the copper tape, just 0.5cm, on itself. The exposed copper is now on both sides and can touch the membrane circuit. Then you may use scotch tape or clear stationery tape, or another piece of the copper tape to secure this connection. Lightly stab (needling) the connection with the tip of the multimeter probe helps as well. This makes sure that conductivity is as good as it can be. If I had conductive paint at hand, I would use it as a glue too.

[fohat.digs]

No, I did not use any glue.

I was asking about the case. That is the difficult bit. Mine have never been rigid and sturdy enough.

[losing_ctrl]

Wow, looks good Khirin! Great job!

[khirin]

I was asking about the case. That is the difficult bit. Mine have never been rigid and sturdy enough.

Oops, sorry.

For the case, I used the 2-ton clear epoxy glue A+B, Alteco brand, and put some more of it on the inside seams of the case.  I think it's sturdy enough.

[rowdy]

That's absolutely fantastic!

I've often wondered about doing something like that, but don't have anywhere near the skillset required.