Space Invaders had always intrigued me... So I bought a couple

First one showed up today. Here it is in all its gross glory. This one’s going to need the most work. NCR 4950 with linear white Space Invaders. Teardown, cleaning, and switch lubing is in short order. Seller figured out the pinouts so I should be able to adapt it fairly easily.

Currently the switches feel eh… Terrible. But the board is filthy and the switches are super susceptible to dirt and dust so I’m hoping they’ll feel much better after a restore. The spacebar is unsurprisingly way too heavy, which I expected but wasn’t prepared for how heavy it actually was. I’ll probably do the standard spring swap with a less used key to make it lighter.

I’ll update with progress and when the clicky ones arrive!


Can’t wait to see progress pics of this one! I quite like the one or two loose space invaders I have.

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I’ve got it disassembled and am in the process of cleaning. I’m doing the keys individually by hand because they’re so bad. Check out the difference though:


Please take a video of lubing space invaders! I want to learn what the best method is for mine. I have tactile two-eye grey (they’re meh) and clicky blacks (they’re amazing).

Will do! I heard the tactiles were meh too so I stuck with this linear one and have two clickys on the way. One is basically BNIB though, so that will probably stay unmolested

I think I figured out an easy-ish way to remove the sliders without having the springs fly everywhere which will hopefully work for the clicky ones as well. It still makes me nervous with the way the contacts are, but I haven’t fucked one up yet… I was most nervous about ruining a keycap since they’re impossible to find replacements.

Those would be heaven beneath my fingers, maybe in the future we can work on a good way to adapt them for modern use. Maybe with an Alps size so they would work with modern plates…

The dust problem comes from the sides all around the slider being totally open. It’s almost like using a switch that doesn’t have a top housing, because they really don’t. The slider is the top housing and the whole thing moves. The dust and dirt settles into the bottom of the switch and then gets up into the slider. Plus the contacts are totally exposed under the keycap and if anything gets between those hands the keypress won’t register.

I thought i had a good method as well, but I still broke my neon green spacebar linear :frowning: it was so good feeling.

I think most issues can be avoided with a heap of caution and a touch of luck. I used needlenose pliers from the bottom of the switch to hold the tabs in and pulled up with my fingers.

…how long until someone posts a tutorial here on ultrasonic switch cleaning? That’s really what you need here. I’m glad, though, that you seem to have figured out how to remove key caps from these guys without pulling the slider with them and making the spring go flying. Doing that is zero fun. I think about rotating the key cap off to the side instead of pulling it straight up.

I’d lube these with Krytox or a very light weight silicone oil with Teflon, if at all. If you get them really clean (with an ultrasonic cleaner) and there is no surface damage they’re quite smooth.

Space Invaders have separate mechanisms for sensing and tactility. Linears will always feel the best IMO.

@PyroL I use a very small flathead screwdriver between the front of the slider and the housing to release that clip and then gently pull the back up to fully release it. It’s probably dangerous having the slider at an angle half off like that even though it keeps the hands in the correct position until the slider is totally out. I’ve had very good luck so far and I’ve had multiple switches apart and back together without any obvious damage (including the pre-converted one that showed up today and both those switches continue to work flawlessly.)

@XMIT I think my grandmother has an ultrasonic cleaner for jewelry… I should really just go visit Grandma instead of trying to hand clean these things. Any ideas what solution would go in it?
And which lube would you recommend specifically? I think all I’ve got laying around is some VPF 1514.
I used the Chyrosan method of carefully pulling one off and using my finger from the side to rotate the rest of the row off. I’m excited to get this one up and running so I can really try the linears. The clicky one that showed up today is fantastic as well but I’m going to skip the tactiles.

These boards have always fascinated me. They’re so weird and no one I’ve ever talked to outside of the hobby even knows they exist. I’d love to own a tactile or clicky one of these someday just for the sheer novelty of it.

Clean linear space invaders are delicious.


I do ultrasonic cleaning with distilled water at about 150 F with denture tabs (safe for ABS though I still try to avoid space bars after some bad experience with warping at 160 F). Works great.

That KimTron keyboard, quite literally, has my name all over it. How intriguing! Never heard of that company. What’s it like to type on? Have you used it with a modern machine?