Model M Advice

[raoulduke-esq]

Recently picked up a square badge. Opened it up for cleaning and to diagnose why the bottom row was so sad. I have a cracked barrel plate (horizontal crack running most of the length of the space between the Q row and the A row. Only about 5 of the rivets are still intact on the whole board.

Do I:

1 - plastic weld the crack and do a screw mod

2 - buy a new 101-key barrel plate from Unicomp and do a screw mod on it

3 - get a Class 2 repair from Unicomp. Will they preserve the sticker on my plate and use my original gorgeous thick treated plate?

4 - something else entirely

[Weezer]

I mean I'm a cheap ass but when had the same issue with my model m and I just screwed it back together with about 5 screws. I wouldn't bother with a class 2 repair since I think the new barrel plate is cheaper right?

The duct tape fix would be the way I'd suggest going.

[Bjerrk]

I'd go for option 1 or 2. Which to choose depends on your level of perfectionism.
I'd wager that the keyboard would feel perfectly fine after a proper screw mod, crack or no crack. (It'll obviously feel better on crack. but again, your choice)

[kbdfr]

Oh no, not another thread about a cracked model M…

On the other hand, it's a blessing that precisely because it is sooooo common, there are replacement parts.
So I think your best option is option 2.
Unless, of course, Unicomp stuff is no better quality than IBM

[fohat]

1 - plastic weld the crack and do a screw mod

2 - buy a new 101-key barrel plate from Unicomp and do a screw mod on it

Either of these can yield a good result. Unicomp would "repair" it by opening it up and replacing everything inside.

[raoulduke-esq]

Oh no, not another thread about a cracked model M…

Yeah - found a lot of complaints when I searched the forum for this but not a lot of suggestions. Bolt and/or screw mods are fairly covered, but not cracks (except complaints).

I'm just not ready to ascend to Tipro and MX yet

One of these was the first keyboard I used that wasn't part of an Apple II series and it was life changing.

[raoulduke-esq]

Unicomp would "repair" it by opening it up and replacing everything inside.

Thanks for the warning! I'll be avoiding the Unicomp repair like it's an invitation to send my child to Neverland Ranch for the summer...

[E TwentyNine]

If the crack is that bad it's possible the rest of the plate is just as fragile. You might try plastic welding or similar, or just doing a mod with the plate as is - with everything buttoned up it might be fine.

Beyond that a new plate from Unicomp is the best option.

[raoulduke-esq]

If the crack is that bad it's possible the rest of the plate is just as fragile.

I think you're on to something there. The crack itself doesn't go all the way edge to edge yet, but it looks as though there are a few others that dream of being cracks when they grow up... Kind of leaning toward replacement at this point.

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[E TwentyNine]

If you bought a plate from unicomp I think they come with the rivet "spikes" as they would be on the factory line.

So, if you had the right tool, you could clamp barrel plate/membranes/pad/backplate sandwich assembly together and do the rivet mushroom melt yourself. No screws at all.

I *think* there was an instance of someone trying that here or on GH.

[raoulduke-esq]

Barrel plate completely snapped in half while removing it, so there's that... This keyboard uses wire stabs for the numpad. Does the Unicomp barrel plate support wired stabs or do I need to replace these keys to work with barrel stabs?

[Weezer]

Yeah youll have to replace them or remove the little tabs which are glued on and glue them onto the new barrelplate

Honestly though, it doesn't need to be a whole piece. Just think of it as two screw mods and align the pieces up when you screw it together. It should work just fine

[Sheepless]

If you bought a plate from unicomp I think they come with the rivet "spikes" as they would be on the factory line.

So, if you had the right tool, you could clamp barrel plate/membranes/pad/backplate sandwich assembly together and do the rivet mushroom melt yourself. No screws at all.

I *think* there was an instance of someone trying that here or on GH.

Personally, I'm not sure I'd bother trying that. I have a Unicomp from 2011 which has seen little use (because of screwy boot-mode behaviour), and it already has some broken rivets. Though maybe they've improved the quality since then.

[Bjerrk]

No, agreed. Screw rivets.
(Badam tssss)

[fohat]

Barrel plate completely snapped in half while removing it

keyboard uses wire stabs for the numpad.

Airplane glue (old style as used for sniffing) works on these, or epoxy. They don't serve a structural function so holding them in place with the screws is fine.

Going to barrel inserts is easy and convenient, although you will have to buy a few parts.

[raoulduke-esq]

The duct tape fix would be the way I'd suggest going...

...Just think of it as two screw mods and align the pieces up when you screw it together. It should work just fine

I'd wager that the keyboard would feel perfectly fine after a proper screw mod, crack or no crack. (It'll obviously feel better on crack. but again, your choice)

Airplane glue (old style as used for sniffing) works on these, or epoxy.

Really appreciate everyone's suggestions and information. It was very helpful to know that Unicomp would just stick a new sandwich in my case (don't want) and that the new barrel plates would require janky stuff or replacement of my beautiful wire stab keys with janky Unicomp keys.

I was particularly inspired by these quotes above to try to do this as cheaply as I possibly could. I decided to use the 1/16" drill and M2 flat head screws I already had rather than buying a 1.5mm drill bit and M2.2 screws. I had a box with M2 x 4, 5, 6mm which turned out really convenient. I used the 4mm in the very bottom row of holes, 5mm above that, and 6mm in the middle, which helped me to grab the barrel plate despite the depth of the plate curve. I figured the rounding error of difference between these and the ones referenced in the forum wouldn't make a difference and I was right.

The old blanket was in good shape so I decided to use it. Needed some painter's tape around the edges of the plate to hold the blanket snug while I got everything lined up. This was easy enough to remove even after everything was reassembled. I had to do the bottom section a couple of times because I'd knock a flipper out of alignment or forget that some of the holes don't need flippers because that's where wire-stab keys go. Eventually I got the bottom to be ok.

The top half of the barrel plate was slightly challenging because the break was right on the thin section with the most curvature. Eventually it ended up not quite perfect but close enough. I used my handy dandy Model M opener to push it down into place and then went over the crack a couple time with Testors sniffing glue and a tiny paint brush. I did the same on the section where a crack was forming to reinforce for the future.

I tightened the screws just to finger tightness and that seemed to be fine because all the keys worked just fine and feel perfectly even on the first try. One thing I discovered in this process that was that each flipper had a unique number on the top right side of it. Don't know why and I can't recall hearing about this before.

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Again, thanks for all the help for a cheap restore!

Filthy old Silver Badge: $104 including tax/shipping
Restoration materials: $3 for sniffing glue (plenty left over to get high with)
5.5mm slim driver: $7
Parts/tools on hand: sunk cost; no new expense

Total: $114 and I'm very happy with that!

[fohat]

I had to do the bottom section a couple of times because I'd knock a flipper out of alignment or forget that some of the holes don't need flippers because that's where wire-stab keys go.

I have done this dozens of times, but it is still rare that I get an M/F back together on the first go. It can take half a dozen.

[Bjerrk]

I had to do the bottom section a couple of times because I'd knock a flipper out of alignment or forget that some of the holes don't need flippers because that's where wire-stab keys go.

I have done this dozens of times, but it is still rare that I get an M/F back together on the first go. It can take half a dozen.

I got it on the first go when doing my first screw mod (although getting the flimsy membranes aligned was tricky ... ). The trick was taking a bunch of pictures when disassembling the thing, so I could just refer to those when reassembling.

[Weezer]

Awesome results! Glad it worked out for you.

[fohat]

oops, duplicate post

[fohat]

because I'd knock a flipper out of alignment

get an M/F back together

taking a bunch of pictures when disassembling the thing, so I could just refer to those when reassembling.

You do learn about holes and springs soon enough. My problem is keeping hundreds of parts that weigh less than a gram each in their seats while you are jostling them all about for several minutes.

[Bjerrk]

You do learn about holes and springs soon enough. My problem is keeping hundreds of parts that weigh less than a gram each in their seats while you are jostling them all about for several minutes.

That's a hassle too, but I found that leaving the barrel place absolutely still almost eliminates that problem. Having it supported on both sides, raised off the table. I got that trick from Madhias:

[E TwentyNine]

That's a hassle too, but I found that leaving the barrel place absolutely still almost eliminates that problem. Having it supported on both sides, raised off the table. I got that trick from Madhias:

...and Madhias probably got that trick from fohat. He's shown several frames he has for working with different barrel plates.

[Bjerrk]

That's a hassle too, but I found that leaving the barrel place absolutely still almost eliminates that problem. Having it supported on both sides, raised off the table. I got that trick from Madhias:

...and Madhias probably got that trick from fohat. He's shown several frames he has for working with different barrel plates.

The circle is complete, then. In any case, it solved the problem for me.

[raoulduke-esq]

I did something sort of like this using a couple of tall board game boxes (Yahtzee and Telling Lies) and it was helpful indeed. The struggle came when I had to reach under to push up on the barrel plate to bring it closer to the top of the arch of the back plate. I'm not as dexterous as I once was... Oh hell I've always been kind of clumsy. I'd either hit my finger on a spring and knock the flipper loose or I'd bump the whole thing and knock a bunch loose. I was able to struggle through, though. Can't imagine doing this without the boxes!

[clickykeyboards]

Another variation on a theme.

1-2-3 steel blocks (16 oz, .45kg/each) work well to elevate the internal model M keyboard assembly.

The small steel blocks are dense and heavy enough to keep the frame parallel and flat to the workbench and to prohibit excessive moving during mechanical drilling and reassembly.

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