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geekhack Projects => Making Stuff Together! => DIY Discussions ARCHIVE => Topic started by: talis on Mon, 08 June 2009, 17:45:10
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I just finished re-assembling and testing my model M space saver, after replacing all of the rivets with screws. The action and sound are much better then before I started. And the whole process took about 2hrs from start finish. I figured I'd share what I did. I'm sort of limited by the 5 picture limit, but I have a few more pictures I may include in the comments later on if they are needed. I'm pretty sure that keyboard is now completely indestructible, and will likely survive for a long time.
Tools you will need :
(http://geekhack.org/attachment.php?attachmentid=2575&stc=1&d=1244499739)
1) 7/32 deep socket.
2) Dremmel tool (or power drill), you don't want to use a pin vice for this.
3) #43 drill bit.
4) #4-40 Tap and handle (this is a common size, and you can probably get away without the handle if you're careful).
5) Flat head screwdriver.
6) #4-40 1/4" pan head machine screws.
I won't go into the whole process of disassembling the case, or removing the PCB as there are a fair number of guides out there already on this (and you likely won't know that you're missing rivets unless you've taken it apart already and looked =P ).
The first step is to locate the broken rivet heads and drill them out. You need to be very careful of two things when doing this. The first is the drill needs to be perpendicular to the metal plate. If its not, the head of the machine screw won't sit flush to the plate. Secondly you need to drill down the exact center of the rivet. The rivet sits on a ridge molded into the front plate if you slip off this ridge while drilling thee things will occur. One is that there won't be much plastic for the screw to thread in to, and the pressure the screw exerts will be on the face plate, rather then the supporting ridge. Secondly you will likely damage the rubber membrane while tapping, and thirdly the drill shavings will be trapped inside the housing between the rubber membrane and the key membrane.
(http://geekhack.org/attachment.php?attachmentid=2578&stc=1&d=1244499785)
Extra plastic inside isn't such a big deal if you're planning on replacing all the rivets, but can cause problems if you're just repairing a few.
Next you need to tap out the hole. Make sure the tap is perpendicular to the plate as well.
(http://geekhack.org/attachment.php?attachmentid=2579&stc=1&d=1244499795)
Finally simply tighten the screw in. If you use 1/4" pan head machine screws, the front of the screw will sit almost perfectly level with the front of the plastic housing. The screws also don't seem to interfere at all with any of the housing, and the board sits in the housing exactly as it did with the plastic rivets.
(http://geekhack.org/attachment.php?attachmentid=2581&stc=1&d=1244499858)
You can see the screw heads between the keys if you are looking carefully. If you are really worried about them, you can paint them black, to better blend in to the plate.
Repeat again for all the rivets.
(http://geekhack.org/attachment.php?attachmentid=2582&stc=1&d=1244499866)
Ignore the few hex head machine screws, I ran out of pan head screws. They work fine in the middle area of the board, but would hit the housing in the front part. Ideally they would all be the same type of screw.
If you're doing a fair number of rivets (especially in the same area) be very careful when you are drilling and tapping that you don't put too much pressure on the front plate. If the back and front plate separate too far the rocker and spring can come unseated and not switch properly. If this happens, you will need to completely take the keyboard apart (which involves removing and replacing any of the remaining rivets. I mention this because it happened to me, I had only planned to replace the broken rivets, but ended up having to cut and replace all of the rivets.
I hope this helps.
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webwit, you are one insane dude.
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I take good care of my keyboards. Thankfully, I don't have a broken rivet problem. If I did, I would follow the OP's directions and fix it. Granted its the weakest link for the model m's but nothing is ever 100%.
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ooh. insects. Its whats for dinner. or dessert anyways.
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this mod looks great, much nicer than chiseling the plastic rivets off with a screwdriver first and then drilling the posts out later :)
*ahem* XD
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for the record, inserting here the link to "sandy's method" to fix the rivets (thanks to ripster mentioning it in another thread) so anyone looking to fix rivets will find both methods in this thread.
http://sandy55.fc2web.com/keyboard/repair_model_m.html
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The only problem with this method is that some of the plastic dust could get into the membrane. It will then work its way through with the vibrations of typing until you have a key that will not work.
It is a much better idea to take out the membrane sheets and drill the plastic away from them. This way you can be sure you wont let a stray fragment ruin all your hard work.
Otherwise this is the same as Sandy's method so cool! It works well.
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I think they're both pretty much equivalent. You could do either method to a few or all of the rivets. The big difference is, when you tap all you end up with on the key side is a few nice flush metal dots, with the other method you have screw heads, and pointy screw tips sticking up through to the key side.
You can drill out and use self tappers (as in sandy's method above) as well, but doing so can tend to balloon the plastic and possibly interfere with the rocker arms.
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I am just going on some tips that Sandy gave me.
I also found some hobby screws that do not make a bulge on the top side.
Its possible to do it without any marks on the top of the board.
I would worry about the dust as it dose come off in lots of tiny bits.
I would worry about the soldering iron and hot paper clip method too. If you touched the membrane with it you could ruing the board completely.
Its best to take the membrane out of the way to avoid any risks.
Webwits analogy is spot on and how I would feel about it :)
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Excellent writeup! In my mind, you've shifted this project from something I feared taking on into what looks to be a rather painless operation.
Is there any danger of the replacement screws rusting? If so, it might be worth the effort to seek out their stainless equivalents? That's probably overkill, but such is the M. Also, does anyone know the number of screws required off-hand?
Its best to take the membrane out of the way to avoid any risks.
Is the membrane difficult to remove?
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Beware the internet. Everything looks easy
I should have rephrased that; it looks to be a relatively painless operation. I mean there's no saw, no soldering, and no switch hoarding OR donor boards required. This mod is a break from standard geekhack mod protocols...except for the mandatory dremel of course.
Safer to put the Model M back in the box and admire it.
I'll have a couple of test subjects to live-and-learn on, I can almost hear them screaming now.
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Beware the internet. Everything looks easy......
Tell me about it. There's this fool on the Geekhack forums trying to perfect my facial grease method of lubing plastics. He should leave it to the pros...
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Is there any danger of the replacement screws rusting? If so, it might be worth the effort to seek out their stainless equivalents? That's probably overkill, but such is the M. Also, does anyone know the number of screws required off-hand?
Stainless steel screws are the only way to go =P. They cost about $2 for 50-60 at most hardware stores. You can even go the full hog and use Mill spec. (http://www.mcmaster.com/#91400a106/=2g7idd)
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Talis, a man that hangs around McMaster Carr is a true handyman.
McMaster Carr is a wonderful place. Alas they don't take international orders. With some major trouble i succeeded in getting some anti-vibration grommets, shoulder screws and metal epoxy from them.
The shoulder screws showed up being to long...
Does anyone knows a retailer that has and ships shoulder screws internationally?
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So...no worries about stainless screws? I rebuilt a few espresso grinders about six months ago using a smallish metric SS screws, which require frequent removal for cleaning, bad idea? I sold two of them on ebay, so I'm hoping their new owners aren't "screwed."
I find contrasting answers on google, what do the GH experts think?
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So...no worries about stainless screws? I rebuilt a few espresso grinders about six months ago using a smallish metric SS screws, which require frequent removal for cleaning, bad idea? I sold two of them on ebay, so I'm hoping their new owners aren't "screwed."
I find contrasting answers on google, what do the GH experts think?
Passivated stainless won't rust (almost 100% guarnateed). Non-passivated may or may not based on the environment. Inside a keyboard I wouldn't worry much about either =P.
The plate is standard steel anyways, and that will rust long before any form of stainless will.
The price difference between "cheap" and "best" here is so small that you may as well just use the best you can easily get.
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Thanks for the info; I knew they wouldn't rust, but I thought Ripster was suggesting that they are brittle.
The plate is standard steel anyways, and that will rust long before any form of stainless will.
For some reason I thought the inner steel plate was stainless. It seems futile to hassel with SS screws now.
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Thanks for the info; I knew they wouldn't rust, but I thought Ripster was suggesting that they are brittle.
Stainless is more brittle then standard steel, but in this case, we're talking about the difference between the rest of the keyboard being either a fine powder, or more like sand after experiencing enough force to sheer either.
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I've sheared quite a few stainless screws for example on outdoor furniture. Watch it though for metal to metal and when a sheared bolt means a real painful extraction, or death.
Rule of thumb is : The harder a screw is to extract, the more likely it is to sheer off =P.
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That's a nice grinder Ripster. I tried out/fixed up two Gaggia MDFs and a Rancilio Rocky, which are flat-burr grinders off a lesser quality than your mini. They were thoroughly disappointing. I've settled on the Nemox Lux, as I needed something to travel with, and it has conical burrs to boot. I actually wrote a review of it here (http://www.coffeegeek.com/reviews/grinders/iberital_grinder/sleepdance). Oh god, it just hit me that I'm a member at geekhack & coffeegeek...****, I'm a geek.
They are more breakable but it doesn't matter in this application. I've sheared quite a few stainless screws for example on outdoor furniture. Watch it though for metal to metal and when a sheared bolt means a real painful extraction, or death.
Noted, thanks.