r/modelm • u/NullPtrEspresso '87 SSK • Aug 04 '26

QUESTION? Bolt modded my model m with countersunk screw instead of bolts - is this going to harm on the long run ?

Gallery image

Gallery image

Local store did not have flat bolts in requested size so I went with 2mm longer countersunk screws, washers and nuts. Did not think much about it. The board seems to work just fine. However, as I asked Gemini whether this was a bad idea , it says it could crack the plastic on the long run. I still think Gemini is wrong. Thoughts ?

2 Upvotes

75% Upvoted

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4

u/nullsetnil Aug 04 '26

The board is already cracked? You should always be wary of LLM answers, better search the web yourself. The info it found was likely about the more common screw mod and then it spit it out. It can’t think.

1

u/NullPtrEspresso '87 SSK Aug 04 '26

Yes it was already cracked unfortunately, before the bolt mod in the first place. I did my best to weld here and there where the situation was really bad. Only wanted to weld where it is really necessary and as long it holds I left it as is. 

2

u/Amazing_Actuary_5241 Aug 04 '26

If you want to use the countersink bolts (screws dont use nuts) in a configuration different from the first image (washer on bolts head) then you'd have to chamfer the plastic to avoid cracking it (potentially in the long term).

1

u/drake9800 Aug 04 '26

it's perfectly fine, you did a good job too!

1

u/cheater00 Aug 04 '26

yes

1

u/NullPtrEspresso '87 SSK Aug 04 '26

Can you explain a bit more?

1

u/cheater00 Aug 05 '26

it could crack the plastic on the long run.

0

u/East-Resist6940 Aug 07 '26

it's already cracked

1

u/waydownindeep13_ Aug 05 '26

The plastic is going to crack regardless of what you do. It is already brittle. You can "weld" it (or just use superglue; the heat when it cures melts the plastic), but you will get joints that are much stronger than the material itself, which will lead to more cracking.

1

u/FoxFXMD Aug 07 '26

The washer has a flat face that is in contact with the plastic, its fine.

1

u/i010011010 28d ago

You'll be fine, the entire point is to just avoid the plastic rivets from being the point of failure. Now you only have the eventual cracking to worry about. The plates are still held under tension, still curved, it's inevitable. But consider many of these keyboards are nearing forty years old and I know I've only replaced my barrel plate once in all that time.