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DK2 Build Thread: Tenkeyless Cherry MX Modded Micosoft Natural Ergonomic 4000

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Wew lads its been too long since an update so this is gonna be a lot all at once! SUPER LONG COMMENT warning, someone let me know if this messes up your viewing of the thread and I'll break the comment into a few separate comments for you!

The wrist rest, I thought, would be difficult. It turns out, not so much-ish.

I found that with care the top and padding could be peeled off the plastic intact. This enables the rest of this evolution to proceed. If they had come apart by tearing and shredding I don't know what I would have done.  But it came apart with some persuasion, and I cut down the plastic from the far right end of the long rest. This was done by eyeball-gauging and it is probably not super critical. Measure twice cut once still applies so I took it in little bites toward the end.

The injection-moulded part has some contours that were just cut off. This leaves a gap to deal with later. I suppose I could have heated and reshaped the plastic to close this gap. As I type, I realize I still could do that.

I used some spray adhesive to hold the pad to the plastic, put it all together and it looks good!

but  . . . there was an interference on the end.  The end poked up above the level of the top frame; not good.

As it turned out, I had to trim some from the frame and from the inside of the rest. Happily the glue wasn't set all the way and this worked out well

I can live with this fit

but like I said I think I may try to bend the plastic down to close the end gap. We'll see. At least it's not standing proud with a big jump like it was before the last-minute trimming.


Now to address the scroll wheel. Houston, we have a problem.

The wheel is too fat to fit into the circuit board (big problem) and the plastic mount that I think I want to try to reuse (smaller problem). Also the scroll wheel doesn't have the special disk in the middle. Time for some Irwin Unibit action!

I have a bunch of tools I didn't have access to when I build the DK1. This drill press vise is one. Actually almost all the power tools I used are new-to-me and thanks God for them, they made life easier. The problem of finding a center for a giant drill bit was obviated as the Unibit starts out small and relatively easy to center. The blocks of wood under the wheel are to give me some clearance so I didn't drill into the vise.  It worked out (thanks God again) that the diameter of my Unibit is


I mean perfectly

the right diameter to drill through from both sides and have it fit the scroll wheel guts inside.  The Unibit is long enough that this required all the travel of my press (it's a small press!) so I had to drill from both sides. It worked p.e.r.f.e.c.t!  The interrupted disk just slipped right into the hole! I took a knife to knock off one bit of casting flash but otherwise it was perfection!

The wheel can be jammed into the PCB but it takes a bit of pushing. Checking my frames with the circuit board "attached" shows there is lots of clearance. Good news, I can build whatever to mount this without running out of room!  I want to relocate the switches from the mouse and trim the circuit board down a bit, but that's for later.

The circuit board has mouse switch contacts I need to put somewhere else in my keyboard. It looks pretty simple, almost all on one side of a 2-sided PCB.

I rung out the circuits with my ohmmeter and mapped it out. The switches close to ground, which simplifies things for later.

The mount looks possible to adapt to suit the purpose. The previous axle mount for the scroll wheel had ample clearance to accept the new wheel, so the axle mount can be slipped into its slot on the base plate. It took a bit of cutting but I got the wheel to kinda-fit down in its slot:

It was necessary to cut the bottom out of the mouse for clearance as the tyre was rubbing there also

And thanks God there's no interference under this bridge. It "fits"!

But the bottom plate, which is going to be hidden anyway, had to have some of its cylindrical key plate supports cut out to fit the scroll wheel mount

With the scroll wheel mount flat on the baseplate of the keyboard, there is a tonne of room over top of the tyre.

I needed to find a spacer of the appropriate height, to give me an idea how much I would need to build up underneath the mount, and I found some handy spacers. This is looking REALLY nice!

Y'all this is not a joke. The spacers I found? This lot was the exact right thickness.

Due to recent events especially, but also my christian worldview in general, I don't believe in 'coincidences'.  Divine providence seems to be with me on this build. Three times in one build log entry I have something that works out perfectly? Come now.  Guess what was the perfect height, when I went around measuring various scraps and bits of things to make a proper spacer?  Do you recognize this?

It's a bit of the mounting plate for the keycaps from the MS4k that's being modified. 

Check out the fit

Very much trial-and-error was required, but this is almost the final version of the scroll wheel mounting frame that I ended up with.  The brown bit is slightly-burnt plastic.  I found that the little spring is critical to proper operation of the axle. I also found it was a huge deal for the spring-end mounts to be positioned exactly correctly.

I cut the circuit board to give myself more room for the other stuff that will be in the DK2.  That, plus during the very-many times I put the PCB and wheel on their mounts . . . too much stress was applied to the circuit board. She broke. right at the holes for the wires.  This board needs to be flat for the optical sensor to work. Ugh. But I did some rather ugly-ish soldering and bodged it all back together. No pictures were taken due to the lack of inclination to do anything but either scrap it all or fix it and keep going.  I fixed it and kept going ;)

You can kinda see the cut-down board here. If you look inside the rim of the tyre and squint, you'll be able to see where I plastic-welded the tyre to the interrupted disk hub.  I made very sure that the hub was in there straight, and hit it with my hot knife. It doesn't look great, but it worked great.

The spring, having finally been mounted properly and spaced and slightly bent just-so, I welded in place. Again, ugly but highly functional. This little spring tried to get away a couple of times but now it's imprisoned forever! (evil laugh)

Right about the time I was patting myself on the back for having got the thing all mounted properly I realized I'd failed to extend the wires. Doh!  Instead of risking the PCB breaking again, I cut into the wires. Note to self: extend the wires earlier in the process than this, next time!


The scrotum doesn't fit the pocket.

The ball doesn't fit either

Directly under the space bar centre there is a moulded area with a crosshair. Perfect for centering the crumb-hole under the ball mounting area. You can also kinda see how I plastic welded the scroll wheel mount into position in the next pics. What you can't really see is a little bit of wire I twisted round the axle between the disc and the spring, for a little baby spacer to make the wheel run without wobbling too much.

The ball has to go down in the frame quite a lot. I don't want it standing THIS far above the scroll wheel and surrounding area!

a small hole was cut in the top frame. Very subtle, you might miss it:

I had to cut a little channel in the supports on the bottom frame, so the wires for the scroll wheel were able to be tucked out of the way

and now the ball is able to rise through the frame. The hole is . . . not finished.

The scrotum doesn't fit still. I barely let the ball through up till now.

The scrotum was trimmed down on the top edge.  More cutting, plus a bit of added-on plastic to cover a gap that I didn't want to develop as I was cutting, and

The idea is to have the mousing parts be attached to the bottom frame only. Here's the view with the top frame removed

All the extra bracketry was trimmed off the outside of the scrotum

As well, the bottom frame under the trackball had to be trimmed to let the mount fit low enough in the frame

The PCB for the keyboard controller has zero clearance to the PCB for the trackball sensor, another "coincidence" to make my life much eaiser here

Anticipating the need for some reinforcement, and the need to cut away the spacebar supports from the MS4K keys, I added a couple of little bridges from the bridge to the front of the top frame

Then the surrounding area was cut away and I started roughing-out the switch mounting frames.

The donor plastic for these frames is from a notebook computer. Can you guess what brand?


I knew I wanted to raise the switch mounting plate higher-up into the top frame.  The new, higher plate level must be marked carefully for cutting. I made a custom tool for the purpose.  Very high teck:

A roofing nail with a little nub left over from cutting! The nub was pointy and poked out just-so that it was able to leave a scratch. The broad head of the nail acted as a nice stop to keep the point from wandering inside as I marked the frame.

The inside edges have a big gap that I wanted to close, so I cut and bent a little strip of plastic to weld in here:

I used a router bit intended for cutting plastic signs. It cuts on the edge as well as the tip and makes light work of trimming this ABS.

I like the idea of keeping the Escape key separate in its own little hole

but the hole is too small.  All the holes in the top row are too narrow front-to-back to fit an MX key cap. So I opened the escape hole

The little mounting plate for the escape key was test-fitted and sure enough, I can actuate the switch!  The hole can use a little finishing but it is functional for a start

On the backside I left these little nubbins in place. I figured out they don't reach all the way to the bottom case without leaning heavily on the top case, as the membranes of the MS4K are no longer present. Oh well. It will keep the DK2 from collapsing too far if I lean on it I guess. :\

I made a test plate for the arrow keys. Note the screw between two arrows. It turns out I'm silly and was thinking to have the two-part frame screwed together for strength here . . . but the plate is going to be GLUED together here all around and the screw boss protrudes into a switch hole so . . . I needed to cut another plate.

These are the arrow key and the half-dozen keys above the arrow key plates, shaped to fit their holes and with the key cap and switch locations scribed on.  I drilled little holes in my centering jigs for the arrow keys but soon realized I could just eyeball the switch template and the half-dozen plate went a lot faster.

Before I started gluing switch plates in place, I wanted the top frame parts to be solidly glued together. Lots of ABS slurry was made up and dumped carefully into gaps, and then I realized I had to clamp the center of the frames to get the gaps right on top of the top frame.  A bit of quick thinking later and this was my clamping setup in action:

Little tabs around the periphery that used to halfway click in place were securely glued together

The gaps between the media key and top frame areas were filled a little more thoroughly with ABS slurry, as well as the gap between the frames at the root of the bridge. The skinny bridges separating the Fkey area from the main switch area was also filled now.

A layer of goop was slooped over the bridge-gap bits to cover the seam, to be sanded down later

The narrow bridges had to be trimmed just like the escape key area, leaving a nasty edge and some gaps in the slurry fill. 

Then they were covered with a layer of slurry to be reduced later to give a nicer finish.


The little switch plates with their holes finalized using a scalpel. I only stabbed myself once before thinking to put a glove on my support hand :( (and then once more afterward!)

The little switch plates were given a rimful of fresh slurry and then they were clamped temporarily in place. A dabble of slurry around the periphery reinforces the backside of the weld seam

I was running out of ABS shavings to make my slurry glue goop so I started experimenting. The plastic in this jar doesn't dissolve properly, but it does give me this amazing cobalt blue acetone


Cutting out a trim piece to cover the three switch area over the halfdozen key area, my bandsaw made it all the way to the rough adjustment cuts and then the blade came apart. A tragedy has to have some romance, right? So the blade kissed me as it died

A layer of goop was applied to the little bridges

this was trimmed and sanded after curing

The little 3key area got its edges scratched to prepare it to take some glue when I insert the blank plate

Finally, at long last, one of the big plates is being glued. This was done in stages. The straight bit by the bridge was done first.  The gray thing screwed down is a bit of scrap plastic, used as a clamp. The clamp on the outside of the board is to keep the big plate in check as it wanted to be flopping around at improper angles

I used some scrap plastic to hold the topside clamps instead of just marring it all up with clamps

I neglected to sand the insides of the frame, but it seems to have taken the glue anyway. The masking tape left a line in the edge of the glue bead.

It wasn't pretty in all the corners

The insides look pretty good, lots of goop holding things together back here!

The plate took on the angles of the top frame, as expected. Dig the reflected lights:

But it was flat on the outside though

Time to glue on the next plate.

Both plates are in position!

After much trial and error, I found a layout that works for my fingers. A sheet of paper was cut to fit each side and the layout was done in pencil on paper first.  Happily I was able to fit all the keys in without cutting out the little bridges, which was a concern I had.  The left side looks pretty standard.

I drilled the centers of each location to help me later.

The right side is the crazy one again just like on the last keyboard. I traced around the edge of each row of keys in pencil, then cut off that row. Cutting between the keys let me draw around each key location. The holes in the paper helped bigly with alignment during this step

The little squares are etched with an awl. The big squares are pencil. The larger drill bit was a fine handle for my key switch cutout template. The chuck was used to hold the smaller drill bit to drill through my paper templates.  I eyeballed the keyswitch cutout location on each hole instead of using the central holes to align them. It wanted to squirm and some of them are not super straight but they all worked out in the end.

All the holes I initially marked were cut out. The stabilizer holes were tricky. Only one hole was cut too big by accident. I put some more ABS goop inside the hole and cut it to size again. A few more needed a minor adjustment but overall it worked great and I was pleased with the way it came out.  Notice there are no bottom-left keys or right space bar . . . those come later

I did a couple of spot checks and found that the keys from the DK1 thread work the same/activate the same keystrokes on the controller I have for this project, so I'm taking a hopefully minor gamble and proceeding as if the matrices for these two controllers are the same. This could be a huge mistake but I don't think it will be.

During several nights' work, I went through the matrix again and traced out the wire routes. On the DK1 I ran into difficulties with the case closing badly in part because wires were routed in haphazard directions; I want this board's wiring to be tidy.

 I realized that the circuit boards for the trackball and keyboard are touching and this may  be a problem for making the keyboard part in the top frame removable as an assembly from the mousing part in the bottom frame. We'll see but I may need to do something clever on the wiring for the controller. Maybe I'll connectorize it all. I'd like to avoid that.

I've traced out the wires for the favorites keys, as I think they can be reprogrammed to do custom functions and I'd like a copy and a paste key, maybe an enter key up there as well.

I'll fit some switches under the favorites keys, and then wire up the keyswitch matrix. I don't know if I should work from or toward the controller. I guess I'll have to see about the circuit boards first, then figure out which direction to start from with the wiring.

Just now I realized that the wires to the mouse right and left click buttons will have to be connectorized if I want the halves of the keyboard to be separable. We'll see about that too.

The multimedia keys rattled like mad when the top frame was shaken.  I cut little tiny strips of paper and slipped them into the slots of the keys, eliminating the rattle.  If this ever gets wet, that's gonna be a problem.

Then I welded some mouse key switches under all the multimedia keys

The keys don't sit "straight" but it's good enough for me. I don't really see these when the keyboard is in use.

On to the trackball.  I trimmed the scrotum a little more and adjusted the angle a bit, welded it in place, and the circuit board now no longer interferes with the keyboard PCB. The keyboard PCB, if mounted to the top frame, can just barely slip around the edge of the trackball mount now!

With the location fixed, I taped the controller and wires out of the way so the frames could fit together

Speaking of the frames fitting together...along the way I had to adjust the frames quite a bit. the multimedia switches now were about a centimeter too deep to fit so they all had to have the bottom frame cut out under them.

Anyway, I taped up the ball in the scrotum with a couple layers of tape, both so the ball wouldn't get stung by my hot iron, and so the plastic I was going to add didn't get added with zero clearance to the ball.  And I added some plastic, to fill in around the ball between the bridges I'd put earlier

Then I fitted some keys to see where the edges shoule lie, and added some more plastic to fill in around the keys near the trackball!

A bit of plastic work later, I had this plausible-looking trackball in my keyboard frame wheeeee thanks Jesus it looks and feels pretty okay actually

Speaking of adding plastic to fill gaps around keys...

aaaaand then I hit what we professional keyboardists like to refer to as "a problem."

I can't work with my wife in the room :( She was there when I did the layout and I put the Y key on the left side and didn't leave room for the \ on the right side.  I was gonna add plastic to go to the right of the \ key and it felt off so I checked.  Sure 'nuff. This frame is one piece of plastic and there's too much work in it now to scrap it! So I cut some little squares of plastic to fit five of the keys on the QWERTY side (which should be the QWERT side)

tack welded them

waved my magic wand and then there was a pouf of smoke and it looked like this:

or maybe I did a lot of plastic work, one. I forget. Don't ask me these questions.  Anyway, I redid the left-hand layout. I was amused to note the WERT layout is pretty normal, but the Spirit in me said to leave the Q key where she was. Glad I listened. with this in its intended-use position on my lap, I want to hit the Q with the side of my pinky, and 'way out in left field is just the place for that.  The rest of the switches didn't move much, but they moved a bit *and* there's one-fewer holes, I guess?

Anywho, back to adding plastic to fill gaps!  Here, just to the right of the \ key's hole, is a tiny bit. Scribed on the frame you can see the outline of the big bit of plastic I almost put before I checked my layout.

Then I noticed a huge offset on the right side, at the joint between the two parts of the top frame, somehow it had got out of alignment and there was a huge step change in the tops of the plastic parts.  I didn't want to just grind it down because the top of the inner edge is a reference for key caps and it would look weird. So I ground down just the outer edge of the inner top frame. Happily, the plastic is thick enough to allow several millimeters of correction here. The angle feels natural enough at the moment, but I'll check it later to be sure.

Then there were lots of rough edges all over the place. I hit these with a bunch of abrasive tools and then there were a bunch of low spots that needed to be filled, plus the big gap between the top frames where the offset was. I made a biggish batch of ABS goop and filled some gaps and covered some low spots with it

and that's out there curing or else I'd still be working on it.

The top frame is done, I think!

but first . . . there was more sanding and shaping, more adding of ABS goo to fill in low spots

Filling in the little grooves around the Zoom hole so it will be smooth. Note you can still see some of the factory texture on the plastic nearby.

I had neglected a gap under a corner of a frame, so filled that

Sanded all that down after it cured and applied some acetone to polish it and . . . the finish is, how you say, not even.  Everything is smooth, but the texture and gloss level is different. Time to keep trying.

Where I have different application techniques to add the material, the plastic looks different. I was close to accepting this at this point but I wanted to see if I could get a uniform finish instead

It looked pretty good, I thought, where it was well applied. Getting consistent texture using a q-tip to apply the acetone was tricky at best, and the difference in finish was too much.

More sanding

I added a bit around the Escape key hole, which was WAY too big for a regular Cherry MX keycap

Then I mixed up a big, thin batch of ABS goo and slathered it on. It was, at least, glossy all over the inner frame, so that was cool.

but the texture was not okay.

Add more. I added some ABS slurry to the outside edge of the frame as well. It soaked it up like a sponge

more, and a bit on the key switch frame to correct its colour

Some of the stuff got in the multimedia keys so I yanked them out. There go my little paper bits, but oh well. More sanding. Much. More. Sanding.

Then I got clever and sparyed it with acetone from a paint gun. It knocked the rough fine-sanded finish down to a very dull sheen, and was uneven. I noticed it was soft so I burnished it and it shone. Then i waxed it. Still not super stoked with this finish, but I like the colour of the outer edge a lot!

different light to show the texture out

The switches I'm using are vintage blacks. I experimented with spring weights. Turns out (big surprise) lighter springs are quieter on the rebound. As I want quieter, I had to mod some springs. I had some 62g springs left over from a previous job and these were too heavy for this application. I cut the end plus one turn off each of my gold-plated 62g springs. They ended up right about 45g which is just about right, I hope, for this build.

The white square is heat shrink tubing. I punched a hole with a paper hole punch and cut a lil' square and put one on each switch stem. This stuff has a hardness of about rockwell 80 and it's a fraction of a mm thick, so it doesn't feel very squishy which is great. It doesn't *clack* which was the idea. DIY o-ring silencers, wheeeeeee

'member how I had added some plastic on the far right of the 2nd row on the main key area? Yeah, that was because I was being lame and didn't account for the \key being extra wide. So I had to take that plastic off again from the top frame.  Too, the key caps were interfering badly on the left side of the \.  I . . . reshaped it a little. It's basically square on the left side now.

I did this carefully, with heat, slowly, so as not to let the doubleshot whitness through the black of the cap!

I need to mount the pcb for the keyboard controller. I want to have it mount to the top frame. I need some honking big standoffs here, like 2+cm.  You know who has a honking big standoff built in? the MS4k's Alt keys!  Cut...

and put about right here

add heat in a few strategic locations and light pressure, and

Drill some holes and . . .

The frames are too thick to mount MX switches properly. I hit them with a scalpel on front and back edges on the back of every hole, until the holes caught the little catchy fingers on the switches

I figured that the various areas with different textures and they kept showing up with little dents from burnishing, were that way because the plastic is different hardnesses in different places. I had chased the finish on the frame for many, many hours. many. Too many. I decided it wasn't worth another 8 or 12 hours. I also noticed the spots with funky texture were all high spots that could be knocked down a little.

I sanded, then fine-sanded, then burnished and waxed. There are still soft spots with little dents, but not as many and not as bad. When a flash is used, they show up ugly. Look at the area to the left of the trackball and all over the bridge over the zoom toggle area. ugly, right? Horrible. 

But the switches all fit and are held in place pretty well, and you can go clicketyclicketyclicka on it though!

The best part is, under normal lighting like in this blurry picture, the finish is a nice satin and it looks actually okay! wheeee! This frame is officially called as DONE!

I set this on my lap and typed out some thoughts to get a feel for the layout. It's radically different, which is obvious, but it's different to the custom board my hands are on all day at work, so it threw me for a loop. the N key is specially way off from where it's expected, but after a couple minutes I was able to deal with it. I'll do more of that sort of thing to be sure and then I'll lay on some wires!


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