A different type of Model M Bolt Mod

[bettablue]

I realize this post will be somewhat long, but I have a question to pose and a request. 

Over the last few years I have come to truly appreciate this group and all you have to offer.  Even though I'm not as active within the group any longer, I do troll.  You would be surprised at the things one can learn just by reading a few threads. 

I also belong to a Vintage Computer Forums as well.  Depending on what computer issues I run into, I'll either head over hear, or if I suspect a more computer related issue, I'll go to the VCF.  Between the two, I have learned more in the way people use and abuse their keyboards at any given day, someone throws a keyboard though the computer monitor about once every 5 minutes.  Lets get back to why I'm here.  When it came time to troubleshoot my Model M keyboard, one of the members of the vintage Computer Forums suggested a different kind of attachment method for holding all of the layers of the keyboard together. 

Rather than go through all of the motions of tracking down the hardware, sharpen chisels, buy all of the nuts and bolts, drill all of the holes...  You get the idea.  This user actually suggested that we take all of the plastic rivets that have already been broken and replace them with # 20 self tapping screws. Of course, he recommends that pilot holes still be drilled.  The screws would be started from the underside of the metal plate and run up into the upper plastic layer.  This would be opposite of most bolt jobs in which the bolts are run from the top of the plastic down with a nut that is tightened next to the metal plate. 

I had wondered about that myself.  Other then to replace a bent or broken spring or foot, there is virtually no reason for the keyboard to be dis-assembled.  So attaching the internal layers in this manner makes a lot of sense to me. It is just as solid as a regular nut and bolt job too.  Because after replacing just the broken rivets, the user would then perform the same routine on the rest.  Remove the rivet, drill a pilot hole, and drive the screw.  This method is also very easy on the clock as performing a full bolt job can take several hours. 

The only thing I would change to his version is that I would leave 4 nuts and bolts in the corners.  Call it Toms Mod, or whatever you will, but my hybrid installation of using the majority of attachment would be done by the screws, but we still have four bolts to assist in reassembling the keyboard.  My method takes anywhere from 1/3 to 1/2 the time required for a complete bolt job.  Plus, in many locales, the proper nuts and bolts are quite expensive. A friend of mine paid over $25.00 on just the nuts and bolts.  In particular, Las Vegas is a dead zone for doing any kind of work on Vintage computer equipment.  So the parts we need are quite high.  However, #20 self tapping screws seem to be everywhere ans are quite inexpensive.  Most are proper stainless steel. 

So far, I haven't tested this theory, but I am expecting a "new" IBM Model M keyboard to replace my original since the controller went out.  The board with the BAD controller has already been bolt modded.  This was one reason I purchased that particular keyboard when I did.  That saved me a lot of time.  Yes, I was given a fantastic deal.  Too bad I couldn't find another deal like that.  I have need for one more Model M to work with my vintage IBM 5170 PC AT which was manufactured in 1987. 

I would like your input regarding Toms Mod.  And also, If someone here has a Model M controller and a couple of springs to replace the couple that I bent tonight because of my own stupidity.  (I didn't support the keyboard properly while working on cleaning the contact points.)  I ended up bending 2 of these delicate springs. So, Again, if you have the parts, or a parts keyboard to donate,  I need to repair my IBM Model M keyboard and put it back to work  lets chat.  Please send me a PM so we can discuss what you have available,  And if you would like a copy of my plans for Toms Mod, we can discuss that too. 

Thank you very much. 

[fohat.digs]

Having done at least half a dozen bolt mods, I don't think it is too bad time-wise. And bolts with washers and nuts are certainly more secure than self-tapping screws into plastic (how many in-outs will that survive?).

McMaster-Carr will deliver nuts, washers, and bolts for 2 bolt mods to your doorstep for under $15 (they come in 100s).

I also really like being able to adjust the tension of the bolts very carefully.

But yes, drilling the holes is very tricky and tedious.

My last concern would be all the tiny plastic shavings that could get in between the layers (I am especially worried about that in a Model F bolt mod, but that is totally different) and keep things from moving and touching properly. One of the nice things about a bolt mod is that you can clean the whole thing very well throughout.

[bettablue]

I see where you you would have concerns.  But once a board has been bolt modded, how often will the board need to be opened? Seriously, there are no moving parts, and other than replacing a spring on the rare occasion that a use bends one, there would never be any reason to undo the entire assembly. 

As far as stability is concerned though, I would think that one would be a solid as the other. 

On the off chance that my new replacement needs a bolt mod, what would you charge to do one?  I am definitely disabled, and for me, its like the one armed man trying to tie a bow know in a piece of rope.  I could probably do the job, but it would take me quite a while to complete.  That's why, I am looking at the self tapping screw as an option.  There would be a lot less for me to try to hold onto. 

[rknize]

If you look at the bolt mod article in the Wiki, you'll find a link to Sandy's original article upon which the process is based.  He used self tapping screws in some areas.  There is no reason why you couldn't do that for all.  One thing he machine screws gives you is alignment pegs for reassembly.  Sandy used a combination.

[bettablue]

Thanks for reminding me of Sandy's bolt mod.  I was actually thinking of doing mine with only 4 machine screws with nuts to act as you say, as studs in the corners.  Still, I would be curious to know how the stability of the plastic is affected by the different stresses.  The differences being one type of compression, by using the nut and bolt, vs, a sideways compression combined with torsion and compression of self tapping screws.  Eventually, something will show.  And I suspect that the plastic will get more and more brittle by the use of self tapping screws vs. the nut and bolt method. 

[fohat.digs]

I have used self-tapping screws a few times on the front row, because of the ridge that interferes where the nut should go.

Part of my irritation was that they were so much more expensive - 10 self-tappers cost more than 100 bolts of similar size.

It would make more sense to only put screws where the plastic rivets have broken off.

The nuts and bolts provide a lot of flexibility in tensioning. I have taken them apart as many as 3 times, initially, correct some tiny irregularity each time, but that just proves that I am stupid or careless (or a perfectionist).

[bettablue]

Ah, now this is information, I was looking for. Apart from the expense... The flexibility to slightly adjust the tensioning and layers is one thing I had not thought about. 

Thanks fohat...

[fohat.digs]

Oh yes, the tensionsing makes a big difference, in my opinion (and of course this is all my opinion, and you know what they say about opinions .... )

My method is to cut, drill, etc, and then run all the screws through the front of the plastic plate. Then I stack all the layers (number them in the corner with a Sharpie when you take them apart) and wiggle the metal back plate on (inevitably I will have to back out a couple of them, then run them in with a hand screwdriver after the layers are together). Now the bolts are sticking out of the metal by a millimeter or 2. Use a hand screwdriver to get a little more.

This whole procedure is what you avoid when you put self-tapping screws into a complete panel. And, along these lines, forget chisels and buy chisel tips for your Exacto knife.

Anyway, I put a washer on each, then a nut. I tighten these nuts with the 4mm socket (also hard to find, many sets only go down to 5mm) held in my fingers. I find this to be PLENTY tight.

For whatever reasons, more torque (eg putting the socket on the handle and using that extra leverage) makes the board feel worse. I think that you are stressing the barrel plate (IBM uses another terminology that I can never remember) because it was originally just those plastic studs melted over, so there was really little or no stress at all!

So if you do use self-tapping screws, I recommend washers and not tightening them any more than "just barely snug" or less.

[rknize]

Cranking down on the screws will also deform the rubber mat.  The original melted plastic rivets had little if any tension against the layers.  It's mostly to force the otherwise flat barrel frame to the curvature of the plate.

[bettablue]

I am definitely upset with Unicomp right now!  I ordered a new controller for my IBM Model M keyboard.  I don't know what they sent me, but it certainly isn't the controller I need.  The problem with dealing with Unicomp is that they're only open 9-5 M-F Central time.  So now I have to wait another week at least to get another controller.  That sucks!  I even gave them the model and part numbers...  Today I submitted another ticket to have them send out the correct part.  The only thing I got right so far is the springs.  I only needed one, but I ordered 5 any way. 

What really sucks is that I haven't been able to speak with an actual person for over 3 weeks!  I can't get them to call me, so I'm at a loss. 

I wonder.   Do they not want my business?

[fohat.digs]

Lexington, KY, is on Eastern Time, but I don't know their hours.

It is frustrating to conduct business without being able to speak with a human being. It is interesting that 2 people speaking orally, even via telephone, can resolve something in seconds that would be difficult to accomplish in hours via writing. 

Unless you are attached to the insides of your keyboard, their "all new internals for $30" is probably a great deal. If your board really has been bolt-modded by Sandy's method, it is probably worth hanging onto.

I am not you, of course, but if it was me, I would buy a cheap used 1391401 on ebay and trade controllers. I have never had a problem with an IBM controller, in probably at least a dozen Model Ms that have passed through my hands, while there have been at leas a couple of problems with later ones.

Good luck. Once you get it resolved you should have many years of good service ahead.

[bettablue]

Personally, I would love to buy a cheap board, and yeah, that would be a great solution.  Right now I am just so pissed, frustrated and angry because this was the third thing I have ordered this week alone that wasn't right!   Trust me, if I scream through the Internet, I would! 

However, your idea might be what I want...  I have a couple in my wishlist, but I want to see what Unicomp does. 

[fohat.digs]

As I understand it, you have a complete working Greenock 42H and a 1391401 that needs a controller and one spring.

One option is to use the 42H until you get the 1391401 working, and then sell the 42H to defray some or most of the repair costs. Used Model Ms have been selling surprisingly high lately, I would imagine that you could get at least $35 + shipping for it.

As long as you can wait a few extra hours/days/weeks you will come out OK.

I have had a Model F-122 project that has been frustrating me for a couple of months, and I finally got it resolved today. My irritation is fading rapidly, but I was not out of a top-shelf keyboard in the meantime.

[bettablue]

The real sad part about this whole affair is still one of my physical abilities.  As far as knowing what to do, I'm all over it.  But post polio is a real issue all it's own.  I was not having a good day yesterday.  Not good at all.  And, it started with me working on my Model M.  I got it all broken down, undid all of the nuts, and replaced the spring with one of the new ones I bought, but then as I was putting it back together, I noticed that I had inadvertantly moved one of the rockers.  So, I had to undo the 3 nuts I had gotten back in place.  I fixed the rocker and spring, and commenced with reassembling again when I noticed that I had screwed up ANOTHER spring! 

This was precisely why I was, and am still willing to ship my keyboard to someone who can complete the repairs!  Whenever I get into anything like this, my hands shake so badly, it's almost impossible to hold even small screw drivers properly. 

So, now I'm back to square one!  I still don't have the correct controller, and I still have a bent spring.  This time, it's one of the function keys I bent.  Unlike most people, I actually use most of the keys on my keyboard.  It comes from working with vintage computersall day long.  You learn to use whatever function keys, or keyboard shortcuts to do simple tasks. 

Any way, I'm back to the same question.  Is there someone willing to help me out here? 

Either that, or I'm also interested in purchasing another gray label 1391401 before 1990.  I know there are other gray labels after 1989, but I personally have this thing for the earliest part number 1391401.  However, I'll accept any gray label 1391401 as long as it's been bolt modded.  If we can keep the cost reasonable, I can even offer the working one built in 2004 in trade.  In the end, I hope to have one Model M for my primary computer, and one for my tweener; a 1990 Gateway mini tower I use to bring programs over from my Windows 7 computer to my IBM 5150 dual floppy computer. 

So, any takers? 

[fohat.digs]

I have sent you several PMs.

Email me at fohat.digs@gmail.com

[bettablue]

Today, I'm sending my bolt modded 1987 Model M  to Unicomp.  They have offered to do a complete refurb on the board for only $10.00 in lieu of sending back the controller I bougt from them  For that price, I couldn't refuse.  The nice thing is that I was finally able to get through to someone.  Any way, Unicomp also promised to do whatever they could to keep the bolt mod in place even as they replace the membrane layers between the black spring towers and the steel back plate. 

So when I get it back, this keyboard will have all new springs, new membrane layers, and still have the stiffness and feel of the bolt mod! 

So far, thanks Unicomp!