Need help/advice restoring Marquardt Butterfly Keyboard
Posted: 22 Oct 2016, 22:08
Hey guys,
This is my first topic here and I hope I went for the correct subforum
Anyway, I recently got a Olympia Orbit typewriter in an antique store for next to nothing. I noticed it had clicky Marquardt butterfly switches hidden underneath a pile of dust.
I have taken out the keyboard module and cleaned up the surface dust and found the switches to be quite nice. The feel is similar to a Model M, but lighter and the sound is much louder. It does not have the (annoying) spring resonance of the Model M, but it does click very noticeably on the up-stroke.
The keyboard has a model sticker that says:
67.006 4090.2 IND 03
AT 93 (83
766 397948
As far as I know the typewriter was made in either late 1982 or early 1983, judging by the date code on some of the ICs in it.
The keyboard module consists of a PCB and thick metal mounting plate with the switches on it and a thin sheet metal frame around the sides and back.
The PCB also has a lot of diodes, so I guess it has N-Key Rollover. The whole keyboard matrix is exposed to the main controller board of the typewriter via cables. The keyboard pcb doesn't have any ICs on it.
The caps are black with off-white or beige double-shot molded lettering. I think they are made from ABS. Most of the letters and numbers have turned from beige to peach/orange, but a few have persisted and the original color is visible in the molding mark on the backside of the caps.
Here's my plan with this thing:
I'd like to reverse engineer the keyboard matrix and use a microcontroller to scan the matrix and send scancodes to my computer via USB. (Don't worry, I study computer science ^^)
Do you guys have any tips for me where I could start? I know, there are projects and solutions like this for other old keyboards, but I have never actually used one.
Unfortunately some of the switches feel a bit stiff and I think they got dirty inside. Maybe they were also exposed to liquid and not cleaned afterwards. (The mounting plate has some rusty spots and the model sticker has been stained by liquid. Did I mention it was covered in dust and dead insects when I got it?)
I think that the switches were originally lubed by Marquardt. I've found small remains of brownish grease on the end of the springs and the "butterfly" click leaves feel a bit sticky. Also they seem to have attracted dust. The same brownish grease was on the stabililer of the space bar and since it was exposed it got very filthy. I have cleaned it out, because the space bar kept getting stuck.
So I have been pondering about cleaning the switch internals and re-lubricating them, to get them back to how they are supposed to feel. I have never done this on any other keyboard and I'm anxious that I might destroy the switches or kill the tactility and sound.
My plan so far is to clean the springs, butterfly leaves and the sliders in IPA and get some Krytox 205 and experiment on one of uncommonly used switches to find out which parts need lubrication. So far I think there are three main points: The bottom of the spring where it meets the butterfly leave, the butterfly leave itself and the sides of the slider where it touches the switch housing. To me the most logical place to put grease is the bottom of the spring, because most of the moving parts meet there. The well working keys on the keyboard don't seem to bind and don't feel scratchy, so I think the slider walls aren't so much of a problem. I'm unsure about spreading lube on the whole butterfly leave.
I'd welcome suggestions, warnings and tips and will take some pictures when I have better lighting conditions
This is my first topic here and I hope I went for the correct subforum
Anyway, I recently got a Olympia Orbit typewriter in an antique store for next to nothing. I noticed it had clicky Marquardt butterfly switches hidden underneath a pile of dust.
I have taken out the keyboard module and cleaned up the surface dust and found the switches to be quite nice. The feel is similar to a Model M, but lighter and the sound is much louder. It does not have the (annoying) spring resonance of the Model M, but it does click very noticeably on the up-stroke.
The keyboard has a model sticker that says:
67.006 4090.2 IND 03
AT 93 (83
766 397948
As far as I know the typewriter was made in either late 1982 or early 1983, judging by the date code on some of the ICs in it.
The keyboard module consists of a PCB and thick metal mounting plate with the switches on it and a thin sheet metal frame around the sides and back.
The PCB also has a lot of diodes, so I guess it has N-Key Rollover. The whole keyboard matrix is exposed to the main controller board of the typewriter via cables. The keyboard pcb doesn't have any ICs on it.
The caps are black with off-white or beige double-shot molded lettering. I think they are made from ABS. Most of the letters and numbers have turned from beige to peach/orange, but a few have persisted and the original color is visible in the molding mark on the backside of the caps.
Here's my plan with this thing:
I'd like to reverse engineer the keyboard matrix and use a microcontroller to scan the matrix and send scancodes to my computer via USB. (Don't worry, I study computer science ^^)
Do you guys have any tips for me where I could start? I know, there are projects and solutions like this for other old keyboards, but I have never actually used one.
Unfortunately some of the switches feel a bit stiff and I think they got dirty inside. Maybe they were also exposed to liquid and not cleaned afterwards. (The mounting plate has some rusty spots and the model sticker has been stained by liquid. Did I mention it was covered in dust and dead insects when I got it?)
I think that the switches were originally lubed by Marquardt. I've found small remains of brownish grease on the end of the springs and the "butterfly" click leaves feel a bit sticky. Also they seem to have attracted dust. The same brownish grease was on the stabililer of the space bar and since it was exposed it got very filthy. I have cleaned it out, because the space bar kept getting stuck.
So I have been pondering about cleaning the switch internals and re-lubricating them, to get them back to how they are supposed to feel. I have never done this on any other keyboard and I'm anxious that I might destroy the switches or kill the tactility and sound.
My plan so far is to clean the springs, butterfly leaves and the sliders in IPA and get some Krytox 205 and experiment on one of uncommonly used switches to find out which parts need lubrication. So far I think there are three main points: The bottom of the spring where it meets the butterfly leave, the butterfly leave itself and the sides of the slider where it touches the switch housing. To me the most logical place to put grease is the bottom of the spring, because most of the moving parts meet there. The well working keys on the keyboard don't seem to bind and don't feel scratchy, so I think the slider walls aren't so much of a problem. I'm unsure about spreading lube on the whole butterfly leave.
I'd welcome suggestions, warnings and tips and will take some pictures when I have better lighting conditions