Micro Switch 60% "buildlog" (SD-16127)

Slom · 05 Mar 2017, 16:14

This "little" Board has been lying around in pieces for many month. Not any more ...

First lets have a look at all the material we can use. Lets hope we don't have anything left in the end.

: overview.JPG (911.16 KiB) Viewed 3561 times

The first step is putting the switches back into the plate.

: plate top.JPG (563.67 KiB) Viewed 3561 times

: plate bottom.JPG (554.13 KiB) Viewed 3561 times

: switches.JPG (966.47 KiB) Viewed 3561 times

The most interesting part here is probably the stabilisers.

: stab right.JPG (618.31 KiB) Viewed 3561 times

: stab left.JPG (607.25 KiB) Viewed 3561 times

: stab top.JPG (571.87 KiB) Viewed 3561 times

: stab bottom.JPG (717.3 KiB) Viewed 3561 times

: stab back.JPG (621.15 KiB) Viewed 3561 times

At first I was worried that I could not remember which way the spacebar should go on. Turns out it only fits one way, and if you do it wrong it will simply not move.

: spacebar stab insert.JPG (638.9 KiB) Viewed 3561 times

: spacebar stab mount.JPG (741.91 KiB) Viewed 3561 times

Pressed and released state of the stabiliser:

: spacebar stab pressed.JPG (726.47 KiB) Viewed 3561 times

: spacebar stab released.JPG (725.11 KiB) Viewed 3561 times

And here's some detail on the way the switch fits the spacebar. There was a tiny piece of felt there, which I forgot to put on again

: spacebar switch mount 1.JPG (653.89 KiB) Viewed 3561 times

: spacebar switch mount 2.JPG (642.3 KiB) Viewed 3561 times

Here's all the switches and the stabs done:

: switches and stab holders.JPG (782.7 KiB) Viewed 3561 times

Next we have to place the caps back onto the keyboard.

: keys mounted.JPG (905.18 KiB) Viewed 3561 times

And then we have to *carefully* put the PCB back onto the plate. I didn't desolder the hall sensors from the pcb ...

: pcb docked.JPG (521.3 KiB) Viewed 3561 times

The PCB is fixed with 4 screws. These are screwed into the hole under the spring in the bottom of the keyswitch housing, not into the plate.

: pcb screwed.JPG (857.74 KiB) Viewed 3561 times

Now, before we come to the case, let's have a look at the connector. The external part seems to be some kind of centronics connector.

: external connector head on.JPG (519.67 KiB) Viewed 3561 times

: external connector label.JPG (509.89 KiB) Viewed 3561 times

The internal connector fits onto the PCB only in one way.

: internal connector head on.JPG (452.79 KiB) Viewed 3561 times

: internal connector label.JPG (515.59 KiB) Viewed 3561 times

: internal cable top.JPG (546.05 KiB) Viewed 3561 times

: internal cable bottom.JPG (571.35 KiB) Viewed 3561 times

The case is a simple 2 piece bend metal case. The top part is screwed onto the bottom part, and the plate with the keyswitches is hung from the top part.

First some views of the top housing:

: upper case top.JPG (753.25 KiB) Viewed 3561 times

: upper case side.JPG (705.12 KiB) Viewed 3561 times

: upper case bottom.JPG (895.78 KiB) Viewed 3561 times

: upper case back.JPG (624.35 KiB) Viewed 3561 times

: upper case detail.JPG (490.05 KiB) Viewed 3561 times

And here are some pictures of the spacers between the upper case and the plate:

: plate spacer 1.JPG (599.48 KiB) Viewed 3561 times

: plate spacer 2.JPG (506.57 KiB) Viewed 3561 times

All that's left now is adding the lower case with 4 Screws.

: lower case top.JPG (759.79 KiB) Viewed 3561 times

: lower case side.JPG (773.63 KiB) Viewed 3561 times

: lower case bottom.JPG (697.98 KiB) Viewed 3561 times

And finally some pictures of the complete keyboard:

: done 1.JPG (825.44 KiB) Viewed 3561 times

: done 2.JPG (637.14 KiB) Viewed 3561 times

: done 3.JPG (950.44 KiB) Viewed 3561 times

: done 4.JPG (575.78 KiB) Viewed 3561 times

Slom · 05 Mar 2017, 16:15

pcb front:

Spoiler:

pcb back:

Spoiler:

hall senor labels:

Spoiler:

seebart · 05 Mar 2017, 16:25

Really nice Slom!

I was looking at that erase key earlier in the header thread and thinking...where is that from?

How do you like those switches?

Great pictures, thanks for this post.

Daniel Beardsmore · 05 Mar 2017, 16:49

I didn't realise that the sensor PCB was removable — is that normal with SD series?

seebart · 05 Mar 2017, 16:59

I don't believe it's easily removable on mine, I'll have to check.

Slom · 05 Mar 2017, 17:08

Yes, I think it is normal that the hall sensors can be pulled out from the bottom of the switch.

To remove the whole PCB, I had to unscrew the 4 screws and also bend the 8 small clamps on the underside of the PCB together. Forgot to mention these, as I didn't put them back into their original position for now.

: plate bottom.JPG (508.23 KiB) Viewed 3525 times

//gainsborough · 05 Mar 2017, 17:43

This is super cool! The stabilizers on the space bar look industrial in strength! How heavy is the board overall?

Slom · 05 Mar 2017, 18:05

seebart wrote: ↑Really nice Slom! I was looking at that erase key earlier in the header thread and thinking...where is that from? How do you like those switches?

Great pictures, thanks for this post.

Thank you

The switches are ... underwhelming. Really stiff and still quite scratchy, even after using an ultrasonic cleaner on them and applying lube. Maybe I need to get a more powerful ultrasonic cleaner ...

I have another SD series keyboard where the switches are stiff as well. Not even in the same league as SW series.

Daniel Beardsmore · 05 Mar 2017, 18:08

What part numbers are on the switches? I can't make them out from any of the photos.

Slom · 05 Mar 2017, 18:11

They are all 4A3A.

seebart · 05 Mar 2017, 18:13

Slom wrote: ↑The switches are ... underwhelming. Really stiff and still quite scratchy, even after using an ultrasonic cleaner on them and applying lube. Maybe I need to get a more powerful ultrasonic cleaner ...

I believe you and I have heard that here before. I can say that the Micro Switch SD Series switches in my Pertec feel fantastic but that keyboard is like new. The SD's in that large Micro Switch I linked in my PM don't feel so smooth and there is variation in feel and sound across the keyboard. Micro Switch SW Series is another feel alltogehter.

Daniel Beardsmore · 05 Mar 2017, 18:15

OK, so a bog standard 0.695 N switch. Just wanted to be sure they weren't intentionally heavy!

Slom · 05 Mar 2017, 18:16

//gainsborough wrote: ↑This is super cool! The stabilizers on the space bar look industrial in strength! How heavy is the board overall?

Surprisingly light for its size actually. There's a lot of air inside that case. I can't give you exact numbers, as I don't have a scale right now

Slom · 05 Mar 2017, 19:43

Daniel Beardsmore wrote: ↑OK, so a bog standard 0.695 N switch. Just wanted to be sure they weren't intentionally heavy!

Do we know anything about the weight of the SW switches? I would not count out the fact that my fingers are just to weak ... I don't really like buckling springs either for example

Daniel Beardsmore · 05 Mar 2017, 20:01

No that I'm aware of; SD is the only type for which the specs have shown up so far.

seebart · 05 Mar 2017, 20:36

Slom wrote: ↑
Daniel Beardsmore wrote: ↑OK, so a bog standard 0.695 N switch. Just wanted to be sure they weren't intentionally heavy!
Do we know anything about the weight of the SW switches? I would not count out the fact that my fingers are just to weak ... I don't really like buckling springs either for example

Mine also have 4A3A switches they are not particularly "heavy" in keyweight, I'd rather not estimate.

Mattr567 · 05 Mar 2017, 22:04

Nice.

I thought it was going to end up with a USB conversion or something, looks usable.

Slom · 06 Mar 2017, 21:51

Slom wrote: ↑
//gainsborough wrote: ↑This is super cool! The stabilizers on the space bar look industrial in strength! How heavy is the board overall?
Surprisingly light for its size actually. There's a lot of air inside that case. I can't give you exact numbers, as I don't have a scale right now

Bought a kitchen scale "just for you"

It's almost exactly 1.5 kilos.

I also bought a 50W ultrasonic cleaner (my old one had < 5W), but it will be a week or two until I will find time again for keyboards.

Slom · 06 Mar 2017, 22:26

Mattr567 wrote: ↑Nice.

I thought it was going to end up with a USB conversion or something, looks usable.

Yeah, that is a long way off ... I wouldn't even know where to start something like that

XMIT · 09 Mar 2017, 17:30

Slom wrote: ↑
Mattr567 wrote: ↑Nice.

I thought it was going to end up with a USB conversion or something, looks usable.
Yeah, that is a long way off ... I wouldn't even know where to start something like that

Start here:
workshop-f7/converting-my-wang-t12379.html

Beautiful work! I recall proxying this board for you, nice to see it again!

dorkvader is working on this. 4A3A is the "good" kind of switch which holds output low when pressed as opposed to pulsing it.

wiki/Micro_Switch_SD_Series

So you could either do protocol conversion, or, replace the controller. I wish my Wang board had 4A3A switches!
workshop-f7/converting-my-wang-t12379-30.html#p279867

Slom · 16 Mar 2017, 20:41

Some anecdotes and a tiny bit of progress ...

1) You may have notice the grey "dirt" especially on the darker key caps. At first I was hopeful this would turn out to be dust, but when the board arrived at XMITs, we saw that it was indeed some chemical damage to the plastic.

Here are some of the photos XMIT took when he checked the board for me (including graphic close-ups of the damage):
https://photos.google.com/share/AF1QipN ... c5cm9Lbk93

2) When pulling the key caps, I found that they really stuck to the switches. Almost like they where glued in, and probably related to the chemical damage mentioned above. After breaking a switch, I build myself a small helper to avoid further damage:

: cap remover 1.JPG (486.04 KiB) Viewed 3252 times

: cap remover 2.JPG (537.2 KiB) Viewed 3252 times

This way there is some pressure on top of the switch housing to counter the pressure coming from the stem being pulled up.

3) Todays edition of "Multimeters are fun", brought to you by mister Paint. This is basically the same information as in Halvars table here. The only difference is that my arrow keys are all directly routed to the edge connector.

: sense lines 1.jpg (1.01 MiB) Viewed 3252 times

: sense lines 2.jpg (1002.46 KiB) Viewed 3252 times

4) The connector at the back of the keyboard is indeed centronics, and I now have the matching piece to connect a cable:

: centronics 1.JPG (778.63 KiB) Viewed 3252 times

: centronics 2.JPG (647.3 KiB) Viewed 3252 times