old typewriter/new keyboard? lol

[chimera15]

I bought this old manual here:


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280443118642&ssPageName=STRK:MEWNX:IT

I'm hoping it will be reasonably functional.

My idea is to turn it into a functioning keyboard for a computer, in total, not just taking the caps off or anything, although I may just do that as well.


My thoughts right now, are that I want to put a metal plate over the place where the key strikers would normally hit the paper.  That will be my negative contact. Then I'll wire each separate arm up, which I assume is a single piece of metal.  Thus I'll be able to wire each "switch" into a modern matrix, maybe finally the teensy controller, which I've been looking for a project to use on.

[chimera15]

There are a lot of unknowns about this of course.  I'm hoping that each striker will be electrically isolated, but this may not be the case...if every arm is metallically connected to the other in some way this idea of course won't work.

The keys themselves are worth $60, so I shouldn't be out any $ one way or another, plus it looks like a sweet little typewriter.

hee!






1947, coool.

Here's another one with much better pics... hmm

http://cgi.ebay.com/VINTAGE-REMINGTON-RAND-DELUXE-MODEL-5-TYPEWRITER-W-CASE_W0QQitemZ310191143969QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4838d53c21




It looks to me based on that photo that the strikers are fairly well isolated, and may be enamel covered so they wouldn't be electrically connected...might work.

[chimera15]

Hmm, I realized my idea of having a single metal plate for all the strikers probably won't work, since a matrix on a keyboard makes use of multiple negative contacts...hmm...

Still if I can find a way to make a striker into an individual switch my idea would still work..might take a bit of customization.  Hopefully not though.

[ak_nala]

There will be multiple linkages between the keys and the actual type heads, and all of them will be electrically linked as they are essentially bare metal. Worse, there will be at least two pivot points that are all either on the same shaft (the first) or all pinned to the same plate (the strikers themselves). All the pins are also metal, so essentially all the key levers and all the striker levers are electrically connected on manual typewriters.

It would take some heavy modification to make them individual electrical circuits.

Note that even if they were enameled (which they usually aren't), that isn't usually good enough, considering wear and tear, to isolate things when one is talking about moving surfaces that wear against each other. Enamel only works on things like coils where there are no moving parts.

Sorry to be the bearer of bad news.

[msiegel]

an optical or capacitive sensor *behind* each striker can tell you when it starts to lift.

assuming they impact in the order the keys are pressed, just buffer a key code when a striker lifts and wait until an impact is detected, then send the oldest buffered code, first-in first-out. this will provide n-key rollover.

assuming the strikers stay in order while in flight

there will also have to be a timeout in case no impact happens, and the buffer may need to be flushed, but that's an exception

[ak_nala]

Actually, a "non-strike" can happen quite easily, so this would have to be dealt with, preferably without having to flush the buffer. Good ideas, though.

Only other thing that comes to mind is installing microswitches to activate at the bottom stroke of each individual key lever and then wiring them to a controller in the same pattern as the controller's matrix. Not for the feint of heart.

[chimera15]

Actually, a "non-strike" can happen quite easily, so this would have to be dealt with, preferably without having to flush the buffer. Good ideas, though.

Only other thing that comes to mind is installing microswitches to activate at the bottom stroke of each individual key lever and then wiring them to a controller in the same pattern as the controller's matrix. Not for the feint of heart.

Yes, that was another idea I had, putting in a bunch of switches under the strikers...well I guess I'll see when I get it.

I realized the strikers will probably be connected in some way.  I also thought about possibly replacing whatever's connecting them, like if it's a rod, I might be able to replace it with plastic, or teflon or something like that...

[microsoft windows]

Maybe you could rig up some hall-effect thing with it.

[Mental Hobbit]

I realized the strikers will probably be connected in some way.  I also thought about possibly replacing whatever's connecting them, like if it's a rod, I might be able to replace it with plastic, or teflon or something like that...

I don't know this particular machine, but usually the common bearing for all strikers is one big block of cast iron. Certainly not something you could easily modify or replace.

[inornate]

My idea is using magnets and reed switch, but I don't sure that it'll work or not. Maybe the strength of magnet should be carefully adjusted.

[ak_nala]

My idea is using magnets and reed switch, but I don't sure that it'll work or not. Maybe the strength of magnet should be carefully adjusted.

Since almost everything is steel, magnets might be problematic. Not only do you run the risk of affecting the stroke or return of individual keys, but all that iron will do interesting things to the paths of the magnetic fields.

[msiegel]

this is lame, but... gut a modern optical mouse and mount its optical sensor in the platen. then do OCR on the incoming strikers.
:lol:

[chimera15]

this is lame, but... gut a modern optical mouse and mount its optical sensor in the platen. then do OCR on the incoming strikers.
:lol:

I have some, but I don't have 50 of em. lol I'm not sure 50 optical sensors would fit in there, and then I'd have to tie the motion to keystrokes with a custom driver or something?  Is there a driver that converts mouse motion into keystrokes?
Maybe autohotkey...?

I think I'd rather just mount some alps switches somewhere or something.  I have a set of blacks that if I use there won't make a difference if they feel horrible. lol

[msiegel]

but i wonder... if the strikers were all hitting a single trackpoint, could you tell which one was hitting it (by angle)?

[ak_nala]

I think ALPS switches will take up too much room. Something like microswitches/snap switches would have a smaller footprint.

Edit: You can get them with little rollers at the end of the activation lever that seem perfect for this application.

[chimera15]

I got it.  It basically works, it's not rusted or anything.  Some of the action isn't really smooth.  I'm really surprised at the travel each key press takes, and the force necessary to produce a stroke.  The ribbon really need replaced or reinked or something.  It doesn't appear to advance.

As far as continuity tests..it's as everyone said, everything appears to be electrically connected to everything else, so I'll have to really do some modification to isolate it.

I may end up just putting alps switches directly under the keyset.  so a keypress moves an arm, and hits a button.  I think that would be the easiest.

It's a really cute little typewriter.

[chimera15]

It seems to me that there are two ways I can go about this...

One is to make a platform underneath the keys, and put switches directly under each arm.  This would of course expose the switches.

The other way is to find a micro switch that will fit behind that wall in the middle of the photo, and line them up next to each other.  It would probably be a pretty easy modification to make this way, I might even be able to glue the switch right to that wall if it's small enough.  This will preserve the look so you wouldn't even be aware of the conversion.



At this point I think it's very possible to do that, the key will be to find the right switch.

[chimera15]

Pretty interesting.  Remington Rand, after being bought and merged with a bunch of other companies eventually became part of Unisys.


http://en.wikipedia.org/wiki/Remington_Rand

They also made guns and univac. lol

Wonder what kind of keyswitches...

http://cgi.ebay.com/Unisys-Keyboard-Model-PCK-101-KBD_W0QQitemZ220521153618QQcmdZViewItemQQptZPCA_Mice_Trackballs?hash=item335815c452

[chimera15]

Hmm, these would probably work...

http://cgi.ebay.com/Lot-of-20-Cherry-Microswitches-E33-10A-125-250-VAC-259_W0QQitemZ350278129248QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518e341660''

Or maybe these...

http://cgi.ebay.com/4-X-15A-Long-Lever-Microswitches-AC250V-Micro-Switches_W0QQitemZ230418084340QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a5fcf1f4

[chimera15]

Chimera, just making sure you've seen this mod.  I had posted in earlier in another thread.

Show Image

Boy, that's a lot of wires.

Link to Instructables Article.

A wow that's awesome!! Thanks.  It's interesting that I'm not the only one thinking this way, and that it's not completely ridiculous. lol

[chimera15]

It's interesting, he really kind of destroys the typewriter...since his is electric? It has a power supply? Ideally I'll just want to fit the switches in a place that they'd be able to be taken out if I want to at some later date.

[ak_nala]

Hmm, these would probably work...

http://cgi.ebay.com/Lot-of-20-Cherry-Microswitches-E33-10A-125-250-VAC-259_W0QQitemZ350278129248QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518e341660''

Or maybe these...

http://cgi.ebay.com/4-X-15A-Long-Lever-Microswitches-AC250V-Micro-Switches_W0QQitemZ230418084340QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a5fcf1f4

Or ones with rollers like these:

http://cgi.ebay.com/50-15A-Roller-Lever-MSW-Microswitch-Micro-Switch-AC250V_W0QQitemZ320468550537QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a9d6a0389#ht_2195wt_728

[ak_nala]

It's interesting, he really kind of destroys the typewriter...since his is electric? It has a power supply? Ideally I'll just want to fit the switches in a place that they'd be able to be taken out if I want to at some later date.

You shouldn't have the same kind of problems since yours is a manual. Should still be fully functional (and able to make "carbon" copies as you type on the screen, if you want).

The trick will be to mount the switches in such a way that you can adjust them for optimal actuation. This could be tricky enough that you wouldn't want to epoxy the switches in such a way that they can't be moved for calibration to get everything to work just right.

[ak_nala]

Also, it looks like most of these microswitches are running a little under 0.4" thick/wide.  

Problem is there's only 0.75" between keys (center-to-center) on a given row ("bank" in typewriterese), in the space of which three other levers pass (nominally 0.1875" center-to-center between levers) - so just not enough room to have all four needed switches in one row.

This means you will likely have to have at least two banks of switches, each at most only able to handle two of the four banks of keys. Depending on what switches you get, you might  even need one row of switches per row of keys - noting that they are over 1" long, so you would rapidly run out of real estate down there under the levers.

Edit:  It looks like, based on the measurements given in the three samples above, only the Cherry microswitches you found would allow an extra switch between the two adjacent ones of a given row (if their 3/8" measurement is correct and if your Remington has the full standard 3/4" center-to-center key separation). The others are all a fraction too big (one at 10mm the other at 9.8mm, where you would need 9.525mm or less).

[ak_nala]

They do make narrower switches (like those in the Instructibles article, but those don't seem to be available from given source ATM), so just look for ones as narrow as possible.

In order to fit them all in one row they would have to be at most 4.75mm (0.1875") thick/deep.

[ak_nala]

Looks like the Cherry DH series ultra-miniature are what you need:

http://www.cherrycorp.com/english/switches/submini/dh.htm

Cherry part #DH2CB1PA, only 2.69mm (0.106") deep. Unfortunately, Digi-Key pricing is a bit on the stiff side:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CH173-ND

Actuation force is listed at 50gf.

Ones without the lever (but 90gf actuation force - though real force would depend on leverage employed by typewriter levers - Cherry Part #DH2CB1AA) are available at slightly cheaper, but not by much:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CH172-ND

Seems the next size up on Cherry switches (eg, sub-miniature DB series) run 0.26" deep x 0.79" long, so would require two rows.

W/ levers and 55-60gf activation:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CH882-ND

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CH884-ND

No roller and 150gf activation, but a bit more reasonable:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=CH288-ND

[ak_nala]

Here is the Digi-Key catalog entry with all the dimensions, et al:

http://dkc3.digikey.com/PDF/US2010/P2253.pdf

Note that the DG series is also small enough to fit all on one row; however, they are PCB mounted w/ pin solder terminals, so much less versatile.

[ak_nala]

Looks like none of these are rated to last quite as long as MX switches. Cherry's site says min. of 10,000 at max rated load and a mechanical life of "up to" 15,000,000 operations for the DB series, while remaining mute on the smaller DH series, though the latter uses gold plated contacts on all variations.

[chimera15]

I bought 40 of these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350278129248&ssPageName=STRK:MEWNX:IT

Seemed to be the best price at .50 cents a switch.  Almost every other switch I could find was more around $1.  I really don't want to spend another $40 on this experiment.  As Ak said it's probably one of the few switches that will fit in the space as well.

I'll have to make my own levers.

The typewriter is working well.  I made a new ribbon for it out of a newer typewriter ribbon which used a cartridge.  I just cut the ribbon out of of it.  It was pretty easy, the wheels just have a little tab you lift up and you can put in whatever ribbon you want.

Anyway the typewriter is working almost perfectly, as far as I can tell right now, so pretty awesome.

I need to find the linkages that move the carriage assembly and see if there's a way I can disable that function easily, so if I end up succeeding in this I won't have to keep moving the carriage over every time I get to the end of a line.

Actually it has a thing where if you press the right arrow key, which seems to be like a primitive backspace, it seems to disable the carriage, so maybe I wouldn't even have to do that.

[msiegel]

I bought 40 of these

they're rated for 10A 250V

now you're playing with power! :lol:

[JBert]

I need to find the linkages that move the carriage assembly and see if there's a way I can disable that function easily, so if I end up succeeding in this I won't have to keep moving the carriage over every time I get to the end of a line.

What, you weren't going to use it to make a newline?

Anyway, my mom's old Olivetti typewriter had a little lock lever with a spring which would engage into a notch on the carriage when the carriage was centered. This way, the carriage would remain locked when you need to move the thing.

[ak_nala]

Yeah, every maker was different. Some had locking devices for transport, some didn't. Don't know off hand if the Remingtons of that vintage did or not, but be warned that some of these locking devices also lock the keys from being fully pressed or the type-bars from hitting the platten.

One thing you can do is to disengage the cable that connects the carriage to the mainspring. Should be a hook that hooks on somewhere on the carriage (move the carriage all the way to the right and look in the bed and you should see the round spring-driven wheel on the left and be able to follow the cable from there to where it hooks on the carriage). Just be careful to tie it off or hook it somewhere once you disengage or you might loose it into the wheel/mainspring (some are enclosed, some more exposed). Unhooking won't lock it, so you would have to do something else to stop it from moving when you tilt the typewriter, but it will stop it from advancing with each keystroke (except for the Backspace, which actually moves the carriage).

Action of a typewriter is a controlled release of the carriage with each keystroke so that the mainspring pulls the carriage and then the mechanism catches it at one space (much like a mechanical watch). The Tab key does it in a less controlled way, only stopping with a set Tab stop or a Margin stop.

[chimera15]

So I gave up on this conversion, but it looks like someone else had the same idea and is selling kits now...

It might breath new life into this idea:

http://www.etsy.com/listing/49720392/diy-usb-typewriter-conversion-kit

[chimera15]

This is the email he wrote me in response to my question.  This sounds really interesting.  It seems like it might have more applications than just this typewriter if it really works..

"I have a remington remette that looks a lot like your rand,  and it works great with that model.

As for how it works, there are no switches involved, except for two or three reed switches (a type of magnetic switch) used to detect return carriage and shift and other weird keys.  For the most part, the kit takes advantage of the fact that the keys are all electrically connected to the chassis of the typewriter, and so signals can be passed to the microcontroller through the chassis.  A sensor board sits underneath the keys on the typewriter's springloaded crossbar, and it has a bunch of metal contacts wrapped around said bar.  When a key comes down and whacks a contact, theres a way to figure out which key was hit by shooting a time-delayed signal through that contact, into the chassis, and then out to the microcontroller. See the "How it Works" section of usbtypewriter.com for details.  

I think there are a lot of people out there like you and me who have tried projects like this, and everyone has come up with their own very different solution.  But all the other projects I have seen use many many wires... since the USB Typewriter only uses about 9 wires in total, its very easy to install and is more rugged.  See the "Installation Instructions" section for a photo of a complete unit -- simple, right?.  I would suggest you give it a shot."

[chimera15]

bought a diy kit, sounds really cool.

[bettablue]

This entire thread is interesting in that IBM essentially went through the same process in developing the model F and model M keyboards.  The IBM Wiki by ch_123 located at http://geekhack.org/showwiki.php?title=IBM+Wiki explains the progression from typewriter to keyboard rather well.  I wonder though if using one of the old Selectric typewriters would make a decent keyboard.  The thing is, since it uses the electrical actuators, would that be a better typewriter for this kind of conversion?  Isn't that what IBM did?  Aren't the keys interchangable with IBM AT, F, or M keyboards?  Could I possibly use a model M controller board to somehow get it to connect to a computer?  Hmm.  

I wrote a lot of term papers on that old ugly assed puke green IBM Selectric so it would be a pretty neat project to have sitting on my desk.  Of course, I would repaint it if I did decide to undergo that conversion.  The IBM Selectric I had used the "golf ball" mechanism to type characters on paper.  It was actually Frankenseined together from 3 seperate units my father found on the side of the road.  We think they were bought through auction from the Clark County School District, Las Vegas, and thrown out because they didn't work.  In fact, none of them would even power on, so he spent an entire day taking them all apart to see how they were supposed to function, tracing wires, looking at the actuators and motor assemblies etc.  After that he took another day to swap parts back and forth between them untill he finally had one complete working typewriter.  My father was not an especially brillient individual, but he could figure out the mechanical end of things that still dumbfound me.  

I used that typewriter all the way from high school where it was used to type reports and term papers, and later when I went to college, I took it with me, where it was used extensively by me and several roomies all doing our homework, writing letters or in one case writing a book.  (No, not me, one of my roomies wrote a book during college and actually got it published)  

My brother and sister weren't too pleased that the typewriter went away to college with me because they both thought they would get to use it as they started going to high school.  We were not very well off money wise so they were even more upset that when my father got them a replacement.  It was a used mechanical monster that my sister still has.  That's all my parents could afford, and they got that one at a pawn shop for all of $10.00.  

The really neat part is that I still have the Selectric, and it still works.  It's been a long time since I last used it.  I doubt the ribbon is any good though.  Durable?!?!  Hell yes!  Since my father rebuilt it, there must be about 6 or 7 thousand pages that have passed through the rollers.  

Oh, and BTW...  If anyone is interested, sorry.  No, I don't want to sell it.