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geekhack Community => Keyboards => Topic started by: Hypersphere on Mon, 22 September 2014, 16:50:13

Title: IBM Model F Plate Tectonics?
Post by: Hypersphere on Mon, 22 September 2014, 16:50:13
I have recently received two IBM Model F keyboards, an AT and a F-107, that seem to be victims of "plate tectonics". That is, the inner plates seem to have shifted relative to the outer case, so that the keys on the far right side of each key grouping are jammed up against the case and cannot be pressed down without rubbing against the case. I have not yet dismantled the boards to start refurbishing them.

Is this going to be a problem, or will this sort itself out when I take the boards apart and reassemble them?

Depending upon the condition of the inner plates, I might end up separating the plates, sanding and repainting them, replacing the foam layer, etc.

Thanks.
Title: Re: IBM Model F Plate Tectonics?
Post by: dgreekstallion on Mon, 22 September 2014, 16:53:05
I'm pretty sure moving plates will end up being a bad thing. All I know is when I opened up my F-122, I immediately knew there was some witchcraft involved to keep all the plates aligned properly during post-repair reassembly...
Title: Re: IBM Model F Plate Tectonics?
Post by: E TwentyNine on Mon, 22 September 2014, 17:13:30
If you have the keys on the far right hitting the case, you should have extra space on the left side. 

There's some leeway when mounting the assembly inside the case.   You can slide it over a little when reassembling the board.
Title: Re: IBM Model F Plate Tectonics?
Post by: snoopy on Mon, 22 September 2014, 17:17:07
doesn't sound like a big problem.

Open it and post some pics. :)
Title: Re: IBM Model F Plate Tectonics?
Post by: fohat.digs on Tue, 23 September 2014, 08:08:56

post some pics


You can't get us interested and then leave us hanging.
Title: Re: IBM Model F Plate Tectonics?
Post by: dorkvader on Tue, 23 September 2014, 12:25:51
I have recently received two IBM Model F keyboards, an AT and a F-107, that seem to be victims of "plate tectonics". That is, the inner plates seem to have shifted relative to the outer case, so that the keys on the far right side of each key grouping are jammed up against the case and cannot be pressed down without rubbing against the case. I have not yet dismantled the boards to start refurbishing them.

Is this going to be a problem, or will this sort itself out when I take the boards apart and reassemble them?

Depending upon the condition of the inner plates, I might end up separating the plates, sanding and repainting them, replacing the foam layer, etc.

Thanks.

on the 107, the plate is held in place relative to the case with 4 screws that go through the bottom case through the plate and into the top case. you don't even have to remove them: just loosen them up and shift the plate over. I had to do this on mine and it was no big deal.

AT is a little different. I will have to check to be sure, as the case is harder to open what with the tabs and all that, but I think you can do the same.
Title: Re: IBM Model F Plate Tectonics?
Post by: Parak on Tue, 23 September 2014, 12:31:49
Yeah, there's always some leeway as to the location of the plates with respect to the case. Adjust as needed - I've had to do this for ATs, 4704 boards, etc.. often in ATs for example you get the effect of getting even spacing on the left Fblock but then the numpad will have a larger than normal gap on the left side of it. Slight OCD as I'm typing on said board currently...

Also happens in beam springs.

No idea why they varied like that. Maybe differences in molding/casting..
Title: Re: IBM Model F Plate Tectonics?
Post by: dorkvader on Tue, 23 September 2014, 12:52:47
No idea why they varied like that. Maybe differences in molding/casting..

always easier (read: cheaper) to have looser tolerances and a way to deal with them so it'll still fit than to have tighter tolerances.

one of the springs in my 107 was all bent at the end, and wouldn't buckle properly. I just installed it upside down on the pivot plate and it works great now.
Title: Re: IBM Model F Plate Tectonics?
Post by: Hypersphere on Tue, 23 September 2014, 17:54:26
Apologies for the lack of pics. I am terrible at photography. I need to get a proper camera and lighting setup.

I appreciate the encouraging words and tips. I think the 107 is probably going to be okay after loosening the screws on the bottom of the case, centering the plate assembly, and retightening the screws. Likewise for the AT, although this might require a bit more fiddling. I look forward to getting back to this, but my day job is demanding all my time and effort at present.
Title: Re: IBM Model F Plate Tectonics?
Post by: The_Beast on Tue, 23 September 2014, 18:01:41
I had the same with my 107. I just pushed to two parts of the case apart and it seemed to alleviate the problem for the most part.
Title: Re: IBM Model F Plate Tectonics?
Post by: dorkvader on Tue, 23 September 2014, 23:52:00
I forgot to say, but the old (you can tell because they are yellowed) relegendable keytops are often a bit wider, which can cause them to rub when they shouldn't.

Not sure what you guys are after, complete disassembly pictures of the 107 have been available for quite some time. One reason I didn't take them when I changed the layout on mine the other day when I got it. If no proper pictures existed, you can believe I'd have taken some with my phone and posted them ASAP.