IBM Model M Screw, Nut and Bolt Mod

Samdoses

23 May 2019, 21:33

Do we have to remove all the springs and membranes or can we screw it from the outside

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fohat
Elder Messenger

24 May 2019, 00:03

If you just add screws to broken rivet shaft locations, that is a "screw mod" which is an order of magnitude easier.

Many people prefer this, including pseudo-professional refurbishers, but personally I want to take it completely apart so that I can clean all the parts including the membrane sandwich layers.

Samdoses

26 May 2019, 14:00

Is there a way to screw mod it without taking apart the barrel plate by just drilling the back and screwing it.

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fohat
Elder Messenger

26 May 2019, 15:59

That is exactly what it is. The term should probably be "screw repair" because you are not modifying anything.

Samdoses

26 May 2019, 16:02

I meant to say if we could half screw mod it

ebonarm

24 Jul 2020, 09:45

Hi all, I have done the bolt mod and everything went fine (tip: Aliexpress for bolts, washers and nuts amounted to around 10€)

Anyway, my question is, that now I have the following problem: the key 's' sometimes keeps registering as pressed even though the buckling spring returns the keycap. So bassically the mechanical part works just as intended but the key keeps registering.
Example, I press it once and it continues to print infinitely, or until I press it again.

Anyone has any suggestions?

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Jesseg

24 Jul 2020, 09:50

ebonarm wrote:
24 Jul 2020, 09:45
Hi all, I have done the bolt mod and everything went fine (tip: Aliexpress for bolts, washers and nuts amounted to around 10€)

Anyway, my question is, that now I have the following problem: the key 's' sometimes keeps registering as pressed even though the buckling spring returns the keycap. So bassically the mechanical part works just as intended but the key keeps registering.
Example, I press it once and it continues to print infinitely, or until I press it again.

Anyone has any suggestions?
I had a similar problem after I bolt modded my M122. I was able to fix it by taking it all apart again ( I know, annoying) and just lightly cleaning and re-adjusting/positioning the membranes a little, this seemed to work in my case.

ebonarm

24 Jul 2020, 09:52

Jesseg wrote:
24 Jul 2020, 09:50
ebonarm wrote:
24 Jul 2020, 09:45
Hi all, I have done the bolt mod and everything went fine (tip: Aliexpress for bolts, washers and nuts amounted to around 10€)

Anyway, my question is, that now I have the following problem: the key 's' sometimes keeps registering as pressed even though the buckling spring returns the keycap. So bassically the mechanical part works just as intended but the key keeps registering.
Example, I press it once and it continues to print infinitely, or until I press it again.

Anyone has any suggestions?
I had a similar problem after I bolt modded my M122. I was able to fix it by taking it all apart again ( I know, annoying) and just lightly cleaning and re-adjusting/positioning the membranes a little, this seemed to work in my case.
Ok, thank you for the tip, I guess It is inevitable. I was really hoping I wouldn't have to open it up again anytime soon :D
What did you use to clean the membrane? Did you clean it?

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Jesseg

24 Jul 2020, 09:56

I think I literally just used a lens wipe, just anything that won't leave any dust, mine was pretty clean anyway so I'm not sure it even did anything but it stopped playing up after that so go figure.. haha

ebonarm

24 Jul 2020, 09:57

Jesseg wrote:
24 Jul 2020, 09:56
I think I literally just used a lens wipe, just anything that won't leave any dust, mine was pretty clean anyway so I'm not sure it even did anything but it stopped playing up after that so go figure.. haha
Thanks man, I will try it again today !

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fohat
Elder Messenger

24 Jul 2020, 14:47

As I often say, overtightening can be a problem.

Remember that you are replacing compliant plastic rods with steel screws, so all you need to do is keep everything in place and keep the plates the same distance apart. There is no need to put the plates into compression by cranking down hard on the screws, and, even worse, inconsistent tightening.

In my opinion, "barely finger tight" is plenty.

Niels007

31 Oct 2020, 14:20

I just got two clean Model M boards for 100 euro, one is already taken apart but the previous owner was out of brave pills to perform the bolt mod. I'm reading up on how best to do it and thanks to forums like these, I think I have a chance of doing it successfully. :-)

Thing 1
There seems to be very little space for bolt heads or nuts at the bottom, especially on the first row or two. I can imagine this can give some issues trying to force the modded assembly in the outer casing. I've seen the limited space thing mentioned a few times but not as often. What's peoples take on this?

Thing 2
Another thing I wonder. After scraping off the rivets, you're left with slightly protruding round bits. In most guides you see people cutting these off with side cutters or a knife. Wouldn't it make more sense to keep them? Seems to me they act a bit like a spacer for the mat and flexPCBs. Wouldn't this prevent some of the issues people have of over tightening the bolt/screws?

I can see an issue if you would use a countersunk screw in your screw mod, as only a flat head screw would work properly in this case, and that might protrude too much and hit the keyboard casing once you slide in the assembly. Still perhaps it would make sense to not fully trim those protruding bits straight away..

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fohat
Elder Messenger

01 Nov 2020, 02:37

Niels007 wrote:
31 Oct 2020, 14:20

There seems to be very little space for bolt heads or nuts at the bottom, especially on the first row or two.

After scraping off the rivets, you're left with slightly protruding round bits.
Without washers the there is just enough room for the M2s to fit. If yours are interfering, you can use a Dremel to make shallow depressions. After the first or 2nd row, start using washers.

I use a chisel tip Xacto knife and shave the tops of the "mesas" flat, then drill through them creating a cylindrical hole.

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anthonymak

01 Nov 2020, 07:05

use this.
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Niels007

01 Nov 2020, 15:40

I managed to find some nylon locknuts in M2 size, which I think will be more long term than regular nuts, but they're a bit taller. I ended up buying a whole bunch of screws (2.2 and 2.5mm diameter, 6mm and 8mm length, countersunk and normal heads) as well as m2 bolts and the mentioned M2 nylock nuts.

Do you have part numbers / link to those super flat head screws in the picture Anthony?

I'm probably also taking the second one apart to see what its like inside. The cables are a bit tired so when I'm going to have to pay international shipping from Unicomp for a few cables, might as well add some other parts if mine seem suspicious. Two traces on the ribbon cable seem repaired with some solder or conductive silver paint, so I feel I better play it safe and order that as well..

Up until about a month ago I spent $50 on keyboards in my life, now I'm a few hundred in... :-)

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anthonymak

03 Nov 2020, 07:29

here are some variety of super flat head m2 screws from aliexpress

https://www.aliexpress.com/wholesale?ca ... d+m2+screw

Niels007 wrote:
01 Nov 2020, 15:40
I managed to find some nylon locknuts in M2 size, which I think will be more long term than regular nuts, but they're a bit taller. I ended up buying a whole bunch of screws (2.2 and 2.5mm diameter, 6mm and 8mm length, countersunk and normal heads) as well as m2 bolts and the mentioned M2 nylock nuts.

Do you have part numbers / link to those super flat head screws in the picture Anthony?

I'm probably also taking the second one apart to see what its like inside. The cables are a bit tired so when I'm going to have to pay international shipping from Unicomp for a few cables, might as well add some other parts if mine seem suspicious. Two traces on the ribbon cable seem repaired with some solder or conductive silver paint, so I feel I better play it safe and order that as well..

Up until about a month ago I spent $50 on keyboards in my life, now I'm a few hundred in... :-)

Erisie

15 Nov 2020, 04:09

A friend of mine recently bolt-modded my old Model M. The old barrel frame was broken, so we ordered a new one from Unicomp. Some keys on the ZXC row (X, B and sometimes N) are registering two keypresses from time to time.

What's causing this behaviour? Overtight bolts? Faulty membrane? Broken hammer springs? I also replaced the controller board for a new one from Unicomp, so that might be a potential issue as well.

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zrrion

15 Nov 2020, 06:38

that sounds like an issue with bolts being too tight

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anthonymak

15 Nov 2020, 10:05

looks like its faulty trace but I also come across a water damaged model m with its rubber layer swelled and causes the same problem.

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