Model M Bolt mod American measurements

[bettablue]

I hope I can get an answer for this before morning so I can stop at Fry's on my way home from work.  

I got my parts list ready to go for the bolt mod on my model M keyboard.  I was told that the 2mm x 8 x .4 pan head bolts and nuts were going to hard to find.  I checked our local Home Depot and Lowes and found nothing.  

However, I looked on the Fry's website and found that they carry a pretty good assortment of hardware in their stores.  The problem is that I don't know what the conversion is for the bolts I need.   I'm not worried about the nuts; I'll match those to the bolts once I have them.  

They have bolt sizes 2-56 x 1/4,  2-56 x 1/2,  4-40 x 1/2,  4-40 x 3/4,  6-32 x 1/4,  6-32 x 3/4,  8-32 x 1/4,  8-32 x 1/2,  8-32 x 1.0 and on and on.  

Does anybody know what exact size I need using this measuring system?

I know they are going to be pretty small.  At the very worst, I guess I could take a drill bit with me to match up the diameter, but I really need to know how long the bolts need to be.  (please use plain english,  I'm no dummy, but I am new to working on these conversions.)  

Again, Thanks everybody.

[theferenc]

2mm = 10/127 inches
8mm = 40/127 inches

Honestly, your best bet is to just order from McMaster-Carr. The links are in the bolt mod post. It's what I ended up having to do, but our Fry's didn't have the right size bolts.

I do seem to recall an "american style" version of the bolt mod, but can't seem to find it at the moment.

[bettablue]

Don't bother with Imperial bolts.  You won't be able to close the case.  See my mod post for details.

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Thanks.  I'm glad you mentioned that.  I was considering using the american equivelent.  I knew I read someting about the clearance.  I went to Ace Hardware today and found some 2mm X 8mm X 4.1 bolts and nuts.  Wow, they are expensive.  I ended up spending 27 cents each for the bolts and 20 cents each for the nuts.  To top it off, I had to go to three different stores to get enough to complete the bolt mod.  None of the stores in my area had enough in one place.  In fact, I cleaned out two of the stores' supply.  

At that price I did good to just get the 50 required to do it right.  15 at one store, 20 at another and finally another 10 at the third.  What a chore just getting the hardware.  $23.50 later, plus gas, and I finally have them all in one place.  I'll start taking my board apart tomorrow.   I had my wife get my KB-8923 out of our storage closet so I'll at least have something to use while I'm working on my M.  

I am a bit worried that I'll mess something up, but between your guide and the one written by jpc, along with "Sandy's Nut Bolt Mod American Style".  I'm hoping that everything goes the way it should.  I am very good at following instructions.  So, I should have enough information and guides to complete it properly.  

I'll let y'all know how it goes from the one armed bandit!  (hmmm, maybe I should change my profile name...   naaa!)

[theferenc]

It's really all about patience, and attention to detail.

You might have some issue cutting off the rivets, as I found 2 hands almost essential.

The only other place that it might be an issue is the actual drilling. For me, at least, I needed a second hand to balance the dremel to get everything lined up.

If I could offer a piece of advice though, after you remove the rivets, and take everything apart, you will be at the point where you will be prepping the barrel plate. I've found the easiest way to do this is not to sand the studs, but rather to use a box cutter or exacto knife to actually cut them off just above the level of the little half moons.

This makes them flat, and the lower studs also simplify reassembly. Hopefully that helps.

Oh, and for future reference, McMaster-Carr is your friend. About $10, shipped, for all of the parts, and enough for 2 boards. Takes a few days to get them, though.

I ordered enough for almost 4 boards (one was a bit larger), and it was only $14. If you are willing to wait on the parts, it's definitely worth while.

[Surly73]

Oh, and for future reference, McMaster-Carr is your friend. About $10, shipped, for all of the parts, and enough for 2 boards. Takes a few days to get them, though.

So, just like usual, I doubt there are any Canadian online stores that sell nuts and bolts in anything less than qty 1000s.  What do Canadian bolt modders do?  I haven't started scouring local hardware stores for the appropriate size yet but I am thinking of doing two model Ms with full bolt mod.  One for "practice" and one for keeps.

[theferenc]

Shipping on these would be fairly cheap, so if you need them, I could easily cross ship them.

Probably for a total less than the OP paid at local hardware stores.

[bettablue]

It's really all about patience, and attention to detail.

You might have some issue cutting off the rivets, as I found 2 hands almost essential.

The only other place that it might be an issue is the actual drilling. For me, at least, I needed a second hand to balance the dremel to get everything lined up.

If I could offer a piece of advice though, after you remove the rivets, and take everything apart, you will be at the point where you will be prepping the barrel plate. I've found the easiest way to do this is not to sand the studs, but rather to use a box cutter or exacto knife to actually cut them off just above the level of the little half moons.

This makes them flat, and the lower studs also simplify reassembly. Hopefully that helps.

Oh, and for future reference, McMaster-Carr is your friend. About $10, shipped, for all of the parts, and enough for 2 boards. Takes a few days to get them, though.

I ordered enough for almost 4 boards (one was a bit larger), and it was only $14. If you are willing to wait on the parts, it's definitely worth while.

Well, lesson leanned.  Too late for this time around though since I've already gone out and got all of the bolts.  If I have too much trouble I'll be enlisting the assistance of my wife, but I really hope I don't need to.  She's about as skilled with power tools as, well, I won't go there.  Besides, I'm kind of anal about doing things myself.   I really dont think I'll have too much trouble.  

I was planning on using my dremmel to kind of hollow out the rivet tops a tiny bit to help center the drill bit to keetp it from wandering.  As for the mushroom, the advice to use an Xacto knife to clean up the rifet tops seems like a good idea too.  

Either way, it looks like a I have a project that will take me a couple of hours.  

Thanks for all of the advice.  I really appreciate all you have given me.

[Surly73]

Shipping on these would be fairly cheap, so if you need them, I could easily cross ship them.

Probably for a total less than the OP paid at local hardware stores.

I might think about that....

After (far too much) wading through the M-C site I did determine that they ship to Canada but they use DHL.  I don't think DHL will be favourable in terms of brokerage etc... regardless of what M-C actually charges for shipping.

I'll see if I've got any affordable options for local sourcing and then make a call...

[bettablue]

So, the one armed man strikes again.  I was able to drill out all of the rivets with no problem.  So, I'm all set.   The board seems more solid and doesn't ping nearly as much as it was.  Thanks for all the help and support.  You would think that IBM would have thought about these rivets being the weak link in their design.