IBM Spring Specifications

[jevvix]

Trying to find precise IBM M/F spring specifications for a project. I searched high and low and couldn't find them and last resort would be measure them myself but why reinvent the wheel if the information is already out there somewhere?    As much information as possible would be amazing: OD, ID, Material Thickness (diameter), Free Length, Max Compressed Length, Pitch, Rate (lb/in), Number of Coils, etc.

[fohat.digs]

I can't answer your question, but the springs are different.

[jevvix]

Yep, I'd be looking for the specs on both F and M springs.

[fanpeople]

You could try asking Unicomp. I wonder if they make them or just purchase from a supplier and if they are a standardised size (for example a commonly used in other applications spring type). Then again they may think you were trying to reverse engineer and produce a variant of bucking spring.

I think this question has been asked before with no joy.

https://geekhack.org/index.php?topic=19900.0

[Melvang]

Also, just to note, the springs in question are "capped" and not "ground".

What this means is that the ends are not put to a grinder/sander to make a dead flat end.  There is just 3 or 4 wraps that are completely tight against each coil.

[jevvix]

You could try asking Unicomp. I wonder if they make them or just purchase from a supplier and if they are a standardised size (for example a commonly used in other applications spring type). Then again they may think you were trying to reverse engineer and produce a variant of bucking spring.

I think this question has been asked before with no joy.

https://geekhack.org/index.php?topic=19900.0

Good idea. I actually sent them an email last night about the material and they did confirm they use completely original IBM spec (some sort of generic spring steel I'm sure). I'll send a follow-up email to them now and see if they'll tell me either way.

[jevvix]

Also, just to note, the springs in question are "capped" and not "ground".

What this means is that the ends are not put to a grinder/sander to make a dead flat end.  There is just 3 or 4 wraps that are completely tight against each coil.

Correct. That would be another measurement I would need. If I can't get the specifics from Unicomp I may send a few springs away to get them measured. My hand measurements (despite using precise tools) probably wouldn't be precise enough

[dorkvader]

I can measure them with my calipers. I have M and F springs sitting around. I won't be able to test spring rate though.

[Melvang]

If you find a source for a company that makes springs, please let me know.  I have an idea that I would like to see come to life, but have no idea for companies to ask about this thing.  All of the spring manufacturers either want to do way more than I think would sell or they don't have tooling for that small of stock.

[jevvix]

I can measure them with my calipers. I have M and F springs sitting around. I won't be able to test spring rate though.

That would be highly appreciated thank you. I will do the same and compare.

[jevvix]

If you find a source for a company that makes springs, please let me know.  I have an idea that I would like to see come to life, but have no idea for companies to ask about this thing.  All of the spring manufacturers either want to do way more than I think would sell or they don't have tooling for that small of stock.

Your idea is likely the same as mine. What sort of minimum orders were they requiring? I could easily see ordering 10k-30k of these in a group buy scenario.

[jacobolus]

I think I put all my extra M flippies/springs in the Deskthority surprise box a couple months ago (or I might still have a couple), but I’d be happy to measure the physical dimensions of an F spring.

[jacobolus]

I have an idea that I would like to see come to life, but have no idea for companies to ask about this thing.

What’s your idea?

I really want to figure out a few specs of springs to use on Alps/Omron/SMK/Matias/etc. switches (all pretty close in size requirements) and then try to order some group buys, maybe through MassDrop (which would dramatically simplify payment processing and distribution). I don’t think finding a spring manufacturer is impossibly difficult, but I haven’t done an extensive search.

[Melvang]

I have an idea that I would like to see come to life, but have no idea for companies to ask about this thing.

What’s your idea?

I really want to figure out a few specs of springs to use on Alps/Omron/SMK/Matias/etc. switches (all pretty close in size requirements) and then try to order some group buys, maybe through MassDrop (which would dramatically simplify payment processing and distribution). I don’t think finding a spring manufacturer is impossibly difficult, but I haven’t done an extensive search.

My idea would be springs for Cherry that actuate right around a red but bottom out heavier than a clear, thinking in the range of a gray.  This sort of spring would have almost zero preload so another advantage would be that the stem would be sitting in the sides of the bottom half of the switch housing before the top half comes on to make switch assembly slightly easier. 

I would not be opposed to a non linear spring rate either.

[jevvix]

I think I put all my extra M flippies/springs in the Deskthority surprise box a couple months ago (or I might still have a couple), but I’d be happy to measure the physical dimensions of an F spring.

Fantastic! Thank you.

[jevvix]

You could try asking Unicomp. I wonder if they make them or just purchase from a supplier and if they are a standardised size (for example a commonly used in other applications spring type).

Thank you for the suggestion again. Good news: they replied and YES the M springs are a standard size spring, however, the CS rep did not have any further information on them. Really surprising I got a reply on a Saturday morning great support

[Touch_It]

That's pretty cool that they would divulge any info being I'm sure it could potentially hurt business for them.  However I'd be more interested in replicating f springs/hammers as they haven't been made in 20+ years and I feel that 20 cents a pop from unicomp is a pretty fair deal.

[rowdy]

If they are a standard size spring, you'd wonder what Unicomp order when they are gearing up to make a new batch of keyboards.

[Snowdog993]

Someone clicks a ball-point pen, there ya go!  I bet that's how the idea came on to begin with.  I'm sure they used some ball-point pen manufacturer in the beginning.  Makes sense to me.  Maybe this helps with your research.

[jevvix]

Well, the success was short lived. When I asked what model/part name I got completely shut down. Apparently their springs which, "have not changed in many, many years" changed over the weekend and are no longer standard but now: "Our spring design and specifications are proprietary. Thanks for your interest in Unicomp keyboards."

Anyone still willing to take spring measurements for me?  )

[jevvix]

double

[Snowdog993]

Did you call the W.B. Jones company in Wilder, Ky? 
http://www.springsfast.com/pdf/Full%20Line%20Catalog%20Aug27%202013.pdf
They may provide you with the information you need.  Maybe even sending them a spring for them to duplicate.  Hope that helps you.

[jevvix]

Did you call the W.B. Jones company in Wilder, Ky? 
http://www.springsfast.com/pdf/Full%20Line%20Catalog%20Aug27%202013.pdf
They may provide you with the information you need.  Maybe even sending them a spring for them to duplicate.  Hope that helps you.

Yep that sounds like a plan. Especially if it's a standard size they should be able to match it up real fast. Unfortunately, I don't have a spare M and F spring sitting around unless I gut one of my complete boards.

Anyone have a few they'd donate? 

[fanpeople]

I just measured a model M spring with some callipers and got...

18.65mm (0.734in)  long
2.75mm (0.108in)    girth

If someone else does this and gets the same results than it should be relatively accurate.

I could send you a Model M spring but I am in Australia so it would probably take time/be a waste of money. But if someone from US does not materialise I would be happy to send one free of charge.

[fanpeople]

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[ezrahilyer]

I just measured a model M spring with some callipers and got...

18.65mm (0.734in)  long
2.75mm (0.108in)    girth

If someone else does this and gets the same results than it should be relatively accurate.

I could send you a Model M spring but I am in Australia so it would probably take time/be a waste of money. But if someone from US does not materialise I would be happy to send one free of charge.

I would be happy to send a few free of charge, I am in the US.
I actually have 2 distinct different kinds of model M spring (one heavier and one lighter)
Pm me your address and I can zip a few off to you.

[jevvix]

I just measured a model M spring with some callipers and got...

18.65mm (0.734in)  long
2.75mm (0.108in)    girth

If someone else does this and gets the same results than it should be relatively accurate.

I could send you a Model M spring but I am in Australia so it would probably take time/be a waste of money. But if someone from US does not materialise I would be happy to send one free of charge.

I would be happy to send a few free of charge, I am in the US.
I actually have 2 distinct different kinds of model M spring (one heavier and one lighter)
Pm me your address and I can zip a few off to you.

Thanks both of you! I just got off the phone with a spring manufacturer and from what it sounds like my idea is definitely something that could happen (will be posting an interest check in a few days hopefully). They said I could send them springs so I'd gladly take you up on the Model M springs. PM incoming.

I would like to send them both a Model M and Model F spring. Don't suppose anyone has a couple of Model F springs sitting around they could send my way?

edit: Possibly a few of each as I may send them to a few manufacturers.

[jacobolus]

That’s not sufficient info to replicate a spring. You also need to measure the wire gauge and count the number of "active" spring coils.

[Melvang]

That’s not sufficient info to replicate a spring. You also need to measure the wire gauge and count the number of "active" spring coils.

Another piece of info that is needed is the actual spring material and temper can have an impact but I am not sure how much at these sizes.

Though if you can send them springs any reputable shop should be able to get all the measurements needed to accurately replicate them.

[jevvix]

That’s not sufficient info to replicate a spring. You also need to measure the wire gauge and count the number of "active" spring coils.

Another piece of info that is needed is the actual spring material and temper can have an impact but I am not sure how much at these sizes.

Though if you can send them springs any reputable shop should be able to get all the measurements needed to accurately replicate them.

Yeah. They said I can send them any spring they'll either:
a.) find an exact standard size spring and get me a part # for it,
b.) find the closest standard size spring,
c.) or get measurements for a custom spring clone.

Even if it's a custom spring size it may not be the end of my idea. The rough quote they gave me for custom tooling could actually work and be affordable in a group buy quantity (10k-30k springs) which was my plan from the start. I'll most likely wait until I hear back from them regarding pricing before I post an interest check. Thanks again to everyone for your help and input.

[Touch_It]

This sounds very promising.  I would be interested in F springs if the price is good.  Hopefully this is a standard size spring but I doubt it.

[jacobolus]

It would be awesome if someone could get a vendor to send like 10 slightly different springs to test (differing length & stiffness). Personally, I think the Model M would be substantially improved with its peak force reduced by about 5–10 grams–force. (I also wish it would buckle slightly earlier in the stroke, but I’m not sure that can be fixed through spring changes.

[jevvix]

@Touch_It There would obviously be less demand for F springs but either way these could be really affordable. I won't know until I send them out and get a quote. I'm still trying to find some Model F springs to send them. Anyone want to donate a few? If it comes to it I may just temporarily gut my 3178 for them (thing is an abomination imo anyway  )

@jacobolus The issue with changing the spring specifications is that it may mess with the 'buckling spring' mechanics and cause undesired side effects. I feel like a lighter spring could cause loss of key registration or less tactile feeling. Although maybe if its just slightly lighter (3g-5g?) it could be a noticeable improvement and not mess with any of the mechanics. No idea though. It is something I planned to look at and ask the manufacturer about. Stay tuned!

[Touch_It]

@jevvix I'm preparing to restore my 4704.  If all goes well I may have a couple spare springs.  I'm hoping this weekend but I guess time will tell.

Also if you have a ****ty 3178 is there any chance the solenoid would be for sale? lol.  I still need/want one.

[jacobolus]

@jacobolus The issue with changing the spring specifications is that it may mess with the 'buckling spring' mechanics and cause undesired side effects.

That’s why “it would be awesome if someone could get a vendor to send like 10 slightly different springs to test”. Obviously a spring that caused the mechanism to stop working would be right out. I don’t personally have a strong concept about the constraints on a buckling spring to make sure that it works properly... so it would be nice to test empirically.

[jevvix]

Still looking to source a few IBM Model F springs if anyone has any.

[orihalcon]

I am away from my stock of spare parts, but I definitely have a few model M and F springs I can send you free of charge.  Could be a few weeks or so though before I actually can get to them though.

I may have a bunch of new model M Unicomp spring/hammer sets from those 64 new Unicomp boards that are said to have issues. Definitely If it turns out that they are not fixable...  What sort of prices were you thinking potentially on the third party ones you'd make?  I was thinking of doing $22 shipped to the USA for a set of 122 spring/hammers from the Unicomps.

On another note, anyone come up with a good way to swap model M springs without taking the board completely apart? I'm not a fan of needle nose pliers, so I've come up with some other ideas.  Haven't tried it yet, parts are on the way, but just was wondering if there is already a fast and easy way to do this already in existence.

[SpAmRaY]

I am away from my stock of spare parts, but I definitely have a few model M and F springs I can send you free of charge.  Could be a few weeks or so though before I actually can get to them though.

I may have a bunch of new model M Unicomp spring/hammer sets from those 64 new Unicomp boards that are said to have issues. Definitely If it turns out that they are not fixable...  What sort of prices were you thinking potentially on the third party ones you'd make?  I was thinking of doing $22 shipped to the USA for a set of 122 spring/hammers from the Unicomps.

On another note, anyone come up with a good way to swap model M springs without taking the board completely apart? I'm not a fan of needle nose pliers, so I've come up with some other ideas.  Haven't tried it yet, parts are on the way, but just was wondering if there is already a fast and easy way to do this already in existence.

Isn't there some sort of chopstick trick?

[jevvix]

I am away from my stock of spare parts, but I definitely have a few model M and F springs I can send you free of charge.  Could be a few weeks or so though before I actually can get to them though.

I may have a bunch of new model M Unicomp spring/hammer sets from those 64 new Unicomp boards that are said to have issues. Definitely If it turns out that they are not fixable...  What sort of prices were you thinking potentially on the third party ones you'd make?  I was thinking of doing $22 shipped to the USA for a set of 122 spring/hammers from the Unicomps.

On another note, anyone come up with a good way to swap model M springs without taking the board completely apart? I'm not a fan of needle nose pliers, so I've come up with some other ideas.  Haven't tried it yet, parts are on the way, but just was wondering if there is already a fast and easy way to do this already in existence.

Awesome. Please let me know when you're back with your stock of spare parts as I'll likely take you up on at least the F springs.

I have no idea on the exact pricing. The rough price they gave me of a large bulk scenario (group buy) and if the springs are a standard size should easily beat $22/122. For non standard spring sizes the custom tooling and post processing is mostly labor and material cost. I'm waiting to get the M springs from ezrahilyer and then will get those out to the manufacturer for a quote. Not sure on their turn around time, maybe a few weeks max? If the price is reasonable I will immediately post an Interest Check and, if enough interest, start collecting orders shortly after