Author Topic: DK2 Build Thread: Tenkeyless Cherry MX Modded Micosoft Natural Ergonomic 4000  (Read 4896 times)

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Offline VoteForDavid

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Update: I finished it thanks Jesus it works and everything wooooooooooo

. . . with a trackball!

The DK1 is a battleship with a trackpoint and scrroll wheel. That build thread is here:

User Lanx did something along this line but used the original inner frame as a PCB mount, which is interesting, instead of frame mounting the switches. Sadly many pictures are gone but the archive has a few of them, enough to get a good idea of what was done.

The DK1 board is for my use at work. Now I've started writing and I want one for the house.  Instead of having a giant trackball next to it, this will have a trackpad a meter-ish away. Instead of being on the desk it will probably be on my lap or on top of my laptop's keyboard area. The onboard pointing device will be used heavily on this board, I'm pretty sure. Having learned some lessons along the way with that build, I hope this one will go smoother.

  • That sweet custom layout
  • ...with MX switches
  • ...on that sweet Microsoft Ergonomic platform with all the angles
  • An integrated pointing device. It turns out I don't much like trackpoints and prefer trackballs over trackpads. So a trackball
  • ...with at least right and left click buttons
  • ...with a scroll function of some kind, probably a scroll wheel like on the DK1 but better positioned
  • No major compromises on positioning of the mousing componentry, within reason
  • Serviceability, meaning the ability to remove and replace/clean/repair switches. This likely means plate mounting, not PCB mounting, and probably individual wiring
  • Internal tidiness. The DK1 is kindof a mess inside. I may be able to plan construction of the wiring so it's much (much) more tidy. We'll see. At least, hopefully, internal structure that doesn't prevent the thing from closing like happened (repeatedly) with DK1
  • Quietness. This will be used in the still of the night and be the loudest thing. Blues are out. I'm leaning heavily toward o-ring'd Black stems.

Secondary goals:
  • Plate cutouts to allow opening the switches without removal. This would be super duper duper helpful if I end up using a PCB here
  • Maybe do something to have this sit on top of my laptop without hitting any keys?
  • Use nicer switches for the right and left click if practicable
  • Make the borders nicer, fill in the gaps around key areas. MAYBE make this actually nice enough to show off.
  • Fill in the multimedia key area instead of leaving the stock silver keys in place
  • Install the 'enter' key from the tenkey area in the main panel again. The carriage return key does different-enough things for this to be useful to me personally.
  • Some kind of spill tolerance. Drain holes or liquid channels or something. I haven't needed this yet but my home environment involves children so God only knows.
  • Possibly a 2U tall delete key instead of having an Insert key. This may require stabilization.
  • Move left-control over to the left more. DK1 has it too far inboard
  • Maybe a larger left shift key if it will fit
  • Maybe (maybe) make the middle-enter key a 1.5U cap
  • Some kind of way, make the cut-off right end of the frame not look horrible. This will be a challenge!

Lessons already learned/wisdom I bring to this show:
  • Prepare and mount the switch frames, THEN do the paper layout of the switches
  • Solder the switches AFTER the wiring is all done
  • Tack the wiring in place with baby dabs of hotglue as it is being installed between switches
  • Wear gloves for this part!
  • No wiring around the extreme outside edge of anything if it can be avoided
  • Many keys can be safely eliminated. I have never used the Insert, Pause/break, or Scroll Lock keys. The FLOCK key on the MS4K has to be retained in some vestigial form because I'm paranoid about actuating it by accident and not being able to un-do the actuation without a switch. This may be a tiny button hiding somewhere in the build, I'm not sure
  • At work I sometimes use the left space key. At home the thumb hovers. This build will have no leftspace, and that area may be used for trackball works or custom copy and paste keys. I may also put the right and left click there, or just a thumbrest. We'll see.
  • I breifly toyed with the idea of using a full-sized trackball like in my Expert Mouse but it would mean so much work to the MS4K's frame that I may as well just do a fully custom frame. I want to avoid that for this build.
  • I started looking for a small trackpad to integrate after I realized it will be difficult to integrate a large trackball. I was shopping for pricing when I realized I don't especially like trackpads and want a trackball. So it's gonna be a trackball.
  • Build threads are a lot of work and so are custom boards. Expect updates every few days at the oftenest. This will DEFINITELY not be updated nightly!
  • Custom boards are a lot of work. DK1 has consumed at least 120 hours. I don't want to know how long this takes so I won't keep track.

If God so chooses to bless me I'll be able to accomplish this build for $0 as well  ;D

There will be many pictures coming soon, and lots of wordswordswords, as with the DK1 build. I hope you enjoy this process as much as I do!  If you have any ideas or constructive criticism, please feel free to chime in! I'm about to start digging through the archives to see if anyone has made a similar build in the interim. If you know of one here or on another site, please gimme a link!
« Last Edit: Mon, 27 June 2022, 21:47:53 by VoteForDavid »
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Offline VoteForDavid

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I've got kind-of a handle on the keyboard side, I think, so I'm starting on the trackball part first.  TW: many pointing devices will be harmed in the making of this project!

First unfortunate victim: the Logitech TrackMan Wheel T-BB18

Four screws on the bottom and

It almost comes apart easily. The LOVELY thing about this mouse is that the circuit boards are all VERY small compared to what I've dealt with in the past. If it proves out that they can be separated by longish ribbon cables, my life just got a lot easier!

I have separate modules for the optical engine, the brains, and the switches and scroll wheel. Nice.

this is where the magic happens. A little optical filter window hides the sensing element from the world

The size of this gap between the ball and the scrotum is probably pretty important.

Yes I said it. You'll see why in a minute LOL

the scroll wheel mounting is looking a little complicated. I'll figure that out later. I don't like these plastic wheels anyway. I want to see if I can figure out how to get a metal wheel in there, and preferably a larger one. We'll see how that goes. Later.

While trying to pop out the optical engine, I broke a little clip somewhere and things went flying. The filter turns out to not be glued in position.

I've been able to swap out the red/dots balls with fancy metal-flake balls before, and I like 40mm better than 34mm a lot. I want to try to use this fancy gray/silver job:

It turns out I was able to just hamfist this all together with gravity holding the filter on the optics, plug the cable into a computer, and verify the thing still tracks with the little ball. Baby steps.

It did. But it didn't track properly with the silvery ball. So I hoped it would work with things spaced out properly.  I had to slice open the mouse's scrotum to get my big ball to fit. This was a job for tin snips.

aaaaaand it didn't work still. Happily I also have a red/dots 40mm ball so I tried that and it worked well:

which at least showed me the ball size is not the critical part and I can keep using the big ball.  If I had a 50mm red/dots one I might try to fit that, but the mechanics are looking pretty tight already under the hood of the microsoft keyboard, and I think full-on Expert Mouse size balls may require something much more drastic than I would be mostly able to fit in the Microsoft keyboard chassis.

Look at my balls.

Time for our next victim! Enter the T-BC21 Marble Mouse. One of these (don't ask why I have several in a bin) donated the red/dots 40mm ball. Note that the ball in the Marble Mouse is retained slightly even when held upside-down. This matters for ball-retention purposes in my final product. The hole is all of 0.1 or 0.2mm smaller than the ball. You push a little and the ball pops out. OR  if you're my children you drop the thing and the ball goes under the couch.

four screws later

Can you tell? There seems to be a family resemblance here!

Does the sensor of the one fit the other? Yes!

when taking the buttons off the top case, the scrotum fell off the mouse

The scrotum cups my ball properly on its three little bearings. As it was designed to do. I shouldn't have been surprised here.

Two little nubs poking out into the opening are all that effectively retains this ball. Simple, elegant. Nice.

The scrotum nestles nicely in the base plate, if a bit loose when it's not screwed up tight.

but to have the ball opening something like horizontal as I want it to be on the keyboard, I would need to have the baseplate at a drastic angle inside the chassis of the keyboard, which seems bad. So the baseplate goes in the recycle bin. The angles on top of the mouse are all funky too. I don't want laser rocketships here I just want a ball on my keyboard looking like it belongs.

But . . . hey, do you know who made a nice flat top opening for their trackball?

The Orbit has been a favorite of mine for a long time. This one may just have to die, unless I can sculpt a nice flat-topped ring opening for my trackball. Then again, I have some thick black plastic I may be able to roll into a top of my own. Hmm.

spare switches. You'll see why later if I end up using them.

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Offline VoteForDavid

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The axle on this side of the scroll wheel is held on by a spring/clip. This is also a hinge, to allow the other side to be used as a switch operator. I don't like scroll wheel switches so I may dispense with this. Anyway, pull the spring off:

and the scroll wheel and switch operator both pop right out. The little slider is lubricated, which makes sense.

The axle only protrudes past the wheel on one side. The other side is supported inside the width of the wheel

The black plastic bracket protrudes into the wheel and supports the inner axle. The spring provides click detents. I want a smooth scrolling experience, so this is going away or at least being minimized.

The soft plastic on the scroll wheel pushes off from one side, and is retained by little tabs in slots on the other side. This came off easily, thanks God

The whole thing seems fairly weak, so maybe mounting that weak axle on a weak spring was a good idea IDK I'll have to consider whether I want to keep using this wheel or try to find something that seems sturdier. I am thinking about cutting a nice fat aluminum disc to make a new scroll wheel for this board. We'll see.

The sensing is via infrared optical interruption with this little sensor. So I'll have to mount that in pretty stinking close proximity to the wheel. 

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Offline VoteForDavid

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Now that I have an idea of what I'm going to be putting in here, it's time to open a keyboard frame to do some actual physical comparisons & whatnot

There are 3 different-length screws out here

There are 3 different lengths of screws under  the palmrests and space bar:

Relative positions of screws in the cap mounting plates:

and I can finally compare ball sizes. Look how much deeper into the frame the larger ball protrudes! I don't know what I was expecting, but for a system with a captive ball, this big one is not going to make my life easy. So I've settled on using the smaller ball.  If it's not a 50mm ball it may as well be small.  I found a 50mm ball by the way but it's just too big, unless I wanted to make a big bulbous protrusion thingy and I don't.  Looking at these pictures made me realize I will have to be careful to not mount the scroll wheel so high up that it activates by accident when I am using the trackball (!) so I guess I'll have to do the trackball mounting bits first, then figure out the scroll wheel later. This should be tricky but do-able.

Okay so that's decided.  On to the scroll wheel.  Here's the stripped-down wheel inside the Zoom slot on the keyboard top frame:

It's too small. IF I wanted to keep the original size and material, it would have worked. I don't. I want an awesome big aluminum knob here, not a reused plastic dial.  I really think I'll stand firm on this point. If I just can NOT make it happen, I have a backup mouse I can use the scroll wheel from. Mounting would be simpler too, I think. But for now, I want to go bigger.  The gap in the frame is about 9 to 10 mm wide depending where you measure. So I can have a nice FAT wheel with big rounded edges and chunky texture for my fingertip to grip.  Also, There's room for a larger wheel. After some experimentation, I came up with "about" 30 mm as a good diameter to shoot for. I used some foam scrap for prototyping purposes LOL and there's plenty of room (I hope) for mounting under there.

The next step may take a while: I have to come up with a suitable scrap of aluminum (or maybe copper?) and cut a wheel.
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Offline VoteForDavid

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I've been working in two locations on this project. Here's a report from the second, for the last few weeks' work. It's a long, image-heavy post!

A reference photo, for use later:

Showing the back side. Note the board is flat across the bottom, but there is a big swell in the middle; this goes flat well before the cable exits the back of the board

The feet on the back corners really kick this board up in the back. I don't like 'em kicked up in the back. This will be going away.

Reference photo of the bottom.  You can better see how the swell in the middle goes flat toward the tenkey end of the board. Note also: the very large protruding feet in the rear

I really like the layout of this model. Too bad the switches are regular membrane switches and they fail because [reasons], and the keys don't all have a very nice feel when pressed.

After taking out the screws on the bottom case, there are a bunch of screws holding the top case to the middle, and holding the angled key plates in position.

Please excuse the filthy mess from whoever used to use this board and look carefully at the shape of the keycaps. This is one of the main reasons the MS4K will never be a *really* good candidate for a straight switch modification. Look at the shape of the 6 and F5 keys, for example. Look at the Z, it's subtle but still not square. They also played tricks with cap heights to get the gentle curves on the final product.

Also: look at the spacing for the G and T keys. Crazy. They did that a lot, on this board!

note: there are screws holding the top frame to the middle frame hiding under key caps! The central bridge also has a clip holding the frames together

The back feet stick out like a lot

Look at the fasteners for the wrist wrest. Then look at how much of it needs to be altered to fit a tenkeyless format:

THREE sets of top frames died for this project (so far). You can see the different paint colours on two, that I knew I was going to be sacrificing, on this test cut fitup. It looks do-able to reuse the right end of the frame, but the nice little "microsoft logo" area is going to be troublesome. There is a little sliver of black plastic between the shiny silver and the main frame area that needs to be dealt with, to fill the gap neatly.

but it looks like a TKL frame mod is going to be possible AND possibly look really nice!

On the "final" frame, I glued that sliver of black plastic to the edge of the frame.  I didn't want to get ABS funk all over the finished parts, so I used liberal amounts of masking tape before applying ABS slurry and clamping the parts together.

And by "glue" I mean "ABS shavings left over from 5 years ago when I made the last keyboard, dissolved in acetone until they become goo"

Very handy tools for very very fine adjustments during fit-up: a dremel vibratory tool and a razor knife

After the glue had cured and the tape was off, I had one solid piece of plastic to grind down to size. This was WAY easier to work with than when the black sliver was loose and jumping all over the place!

The fit-up was slow going but this WIP shot shows it coming along pretty nicely!

I realized after I glued the ends of the frame together to eliminate the tenkey area, the top and middle frames were going to be permanently bonded. So I thought it may be a good idea to sand the insides of the joints between frames, in case I would want to inject acetone in the gaps later, to turn the loose-fitting parts into one part. We'll see how it goes but I did this anyway:

The glue-up was done in two stages. The top was left open so I could adjust it. First stage done:

It's a focus miss but you get the idea: there was a difference in angle on the frames from the arrow area to the TK area. I'll have to deal with this later.

I was pretty happy with the way I was able to get the big ridge on bottom of the frame lined up pretty straight. I think that will help me later.

The top corner was left open so I could do the fine adjustments without having to fight the frames moving against each other. I want this joint especially tight. Adjustments were made with a razor knife. It was tricky.

More masking tape for the second glue-up

The backside is a lot uglier:

With the tape off, here's the result of the second glue-up. Note that several of the key locations have been ground down so c-clamps could be fitted in the depressions in the keyboard for glueing time.

Another focus miss :( but the shiny and dark place at the corner of the joint is a gap that I accidentally left during the fit-up. I filled it with ABS slurry LOL

I like the gap between the light and dark frame areas, but not the one between the dark plastics. I filled that, as well as adding a glom of plastic for the big offset by the bottom/right and top edge:

I've been considering how to cut the top frame to fit all the switches I want to fit. The DK1 has kindof an awkward set of curves. I'm thinking maybe something like this could be better. We'll see how she ends up!

I put the bottom frame back on loosely to check clearance. I found kindof a problem.  To have the keys kinda normally "about even with the top of the frame" like this

The mounting plate needs to be 'way up high in the frame. Just setting a switch on the bottom plate got me a good height. This puts  the mounting plane of the switch several millimeters higher than the plane of the stock mounting plates. 

I put the switch mounting plates in the DK1 at the level of the Microsoft mounting plates on the MS4K. It has the key caps *really* low in the board, sometimes the lower-height caps are lightly under the edge of the frame!  I am pretty sure I'll trim the frame up on the DK2, so the caps can be a more ordinary height, protruding from the body of the keyboard.

Okay on to the bottom case. I had to do a lot of eyeball measurements and ended up with some pretty big gaps on this, unhappily. Oh well. I'll weld it up later.

Look at the big jump on the bottom corner. That's gonna be tricky to fix!

In order  to get the top and bottom frames to mate on the end, I had to grind down this one screw mounting boss that's no longer used. It was hitting a screw mounting boss and the bottom of the media keys.

Taped and clamped for the first glue-up of the bottom case:

I left the bottom edge untaped because I knew it would need to be trimmed and bent to match the edges on the front of the board. But I clamped the area together because I am trying to have the bottom of the board reasonably flat.

After the tape came off, I noticed the little ridge around the label is preventing said flat-bottomness. The ridges around labels shave off pretty easily thanks God!

There was a big gap at this corner and I filled that in a separate glue-up:

The front edge of the frame was cut a bit to allow the plastic to bend. I jammed a bit of plastic in the end of the gap to get the edges lined up properly, and welded that in place with a hot knife. Then I put another little tack weld in the middle of the open space to keep the gaps about right on that end too. The clamp shown here is holding the various open/cut ends on a plane. Since the sheet of plastic was twisted into shape, they wanted to point their own directions several degrees from flat. CLAMP and they were flat. Tape to keep the ABS good from running out the giant gaps during glue-up.

Here's the glue-up for that

There were some pretty big gaps left.

Another fill of ABS slurry

And a bit of filing. This may be close enough to a "flat" surface for this project. I'm not sure.

I briefly toyed with the idea of adding the cut-off rear foot back to the now-shorter end of the board. I decided I want the feet gone instead and ground off most of the remaining foot. I didn't cut it off altogether because I want to reuse as many case screws as possible and here's a screw boss I may want to use later. So I fixed this gap in a two-stage glue-up.


and then a bit of plastic removal:

after the second filling:

The level of the foot area is depressed relative to the surrounding plastic. I'll have to fill that in. So I put a coat of ABS slurry on the whole area except for the screw boss, let it cure, then filed it down. Most of the depression is filled. This will take at least one more round of filling with fresh (recycled) plastic then more filing to shape, but this is looking good for now, I think!

I realized the screw holes in the middle with little protruding cylinders of plastic around them, were not going to be used. They're right in the middle of nowhere now and I don't know that I'll want those screw holes on my soon-to-be switch plates:

So I trimmed off their cylinders from the bottom of the case. I didn't cut the screw hole out entirely because it's offset and I think it will leave a hole. Plus I might want that screw location later. I also shaved the ridge from around the rest of the labels


The scroll wheel was giving me difficulty. I didn't know what I wanted to make it from, until I saw this:

a big chunk of plastic just a bit larger than the 30mm initial diameter estimate!  Here's a circle about 32mm diameter. I'll cut it out large, then fit to size!

some quality time on the bandsaw to cut off the end, then a rough taping to give a guide line at "about" 1cm thickness and that was cut off too.

The initial fit is . . . not great

and the rough cut part is not exactly round LOL

So I drilled a hole on the central mark left by the point of my compass and put a screw in there and chucked her up in my drill press! The file took it to close-enough to round at about the right diameter, with a rough profile shape on the edge, fairly quick and easy. Nice!

The fit was much better at this reduced diameter thanks God!

But my fingers have seen lots of use and are not super sensitive. I like big chonky grippy textures on things like this. So I chucked up a baby little ball mill and . . .

Now THAT's what I'm talking about!

To be continued!
« Last Edit: Sat, 02 April 2022, 12:41:09 by VoteForDavid »
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Offline VoteForDavid

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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

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Offline VoteForDavid

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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

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Offline VoteForDavid

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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.
« Last Edit: Wed, 25 May 2022, 20:41:53 by VoteForDavid »
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Offline VoteForDavid

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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.
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Offline VoteForDavid

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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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Offline VoteForDavid

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First: one of the finer things in life: a GIANT nub on the home keys:

To save you scrolling through several pages of very similar-looking things, here is the link to an imgur album of the matrix:

Each pin on the controller goes to one or more dots under a key. Drag a wire to it and then do that for all the pins and switches, and you've got a working switch matrix. I used these images to verify my matrix after it was wired up - this is my THIRD take on this matrix and I think this is the most usable version. You should be able to wire up your own MS4k controller from these pictures, I hope! I was wary of the matrix changing, but this exact layout has worked for both controllers I've used from a random sampling of these boards, so I hope it will work for you also! I don't show wiring to them, but I left in all the dots under all the keys for the tenkey section in case someone cares to wire up a battleship version later, I think this should be all you need.

I decided to wire this board from the end of a string and then work my way back to the controller. If I were smart, I would have labeled these wires as I went along. If I were smart, I would have remembered the mirror image problem I had last time and saved myself a lot of confusion and rework hours. But . . .

here's the whole board wired up, complete with a few wires going to where they ought not because of the aformentioned forgetting about things being backwards when you look at the backsides of them :(

and here it is after a bit of rework AFTER soldering most of it up, realizing my mistakes, and redoing the wiring. In this condition, I had most of the keys registering keystrokes properly, so it was a funkctional-ish keyboard

I ended up reworking so much that a switch lost a leg and had to be replaced. I verified the non-registering keys were only not working because their wires weren't making good contact, and soldered the wires to all the switches. I verified it all worked again, then dressed the wires a bit more neatly.

and then came time to try to close the cases. It didn't, quite. I had to trim the stuff that used to press the matrix to the controller. Wires are thicker than the old plastic sheets that used to be there.

Having figured out the mouse controller would fit nicely in the gap under the keys, I shortened the wires, attached the left and right click wires to their keys on the keyboard, ready for one final operation check and I'd close it up

and . . . the trackball stopped working. The trace for one of the sensor wires was lifted during the shortening. The picture is bad but you can see that one of these joints is not like the others:

But I got it fixed and then it as on to fit and finish stuff. The F Lock key doesn't fit. It pokes up a little, the back of the switch hits the bottom frame. That doesn't look horrible so I'm leaving it:

The wrist rest on the far right side was heated with my plastic welding soldering iron tip and carefully bent, and the gap is now tolerable-to-me:

The holes for the multimedia keys got patched-over. If I have to open this board again, I hope I don't find I got plastic in these switches' wires because I'll be breaking that to open the cases :( but I can always redo plastic work :p

It doesn't look perfect back here but it's the bottom of a keyboard so it doesn't bother me. It's sanded smoothish and doesn't feel bad to touch. Good enough.

The cable exit had to be moved closer to the middle of the board because the cables were interfering with too much stuff under the keys and wires and whatnot inside. No biggie. Check out the super high teck new hole for cables

And then it was done! Except that it rocked instead of sitting flat. The vestigial feet by the cut end of the board were interfering with the thing sitting flat! Those got heated and mashed flat into the board, then it was sanded smoothish:

And she goes! It will take some time to get used to the layout but I don't hate it and the key action is already sheets better than any membrane board. The typing is about as quiet as the MS4k this is replacing. I hover when I type so the giant nubs on the index keys help with location, bigly. The 45g switches aren't too light for me, and they don't clack much on rebound. Overall it's a success and I imagine I'll like it more, the further I get toward completing the book I'm writing that made me want a keyboard for the house in the first place.

These pictures were processed and this post was typed up on this keyboard:

She's alive and works! Here's my new DK2 keyboard sitting on my notebook computer. It doesn't press any keys or mess with the trackpad so that's great. Thanks to Jesus for the ability to do this sort of thing, and thanks to my wife for her support and encouragement, especially when I was frustrated at my mistakes in-process.

Thanks for looking! I hope you will remember to keep geekhack updated on your next project as well, with plenty of photographs!
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Offline treeleaf64

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Why is the Q key in a weird place
Has continued talking in third person

treeleaf KB concoctions:

Offline PlayBox

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wow its amazing you finally did it. you are awesome would love to see mechmodded logitech g102
propably sent from my amazon kindle 10th gen

Offline Rob27shred

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Alice the hard way

Offline VoteForDavid

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treeleaf64 the q is in a strange spot because that's where my pinky fell when I was making the layout. That's how my hand likes to move, is why.

PlayBox thanks for the kind words!

Rob27shred you are pretty much correct. I'd recommend someone without the tools and ability to consider an Alice style instead of doing . . . all of this.

I've been typing on this for several ten-thousands of words now and it's pretty okay. I ended up having to move the N key just a little, by approximately the same process as I used to fix the QWERTY section, but less drastic. I found I kept mis-clicking the mouse keys so I put a gaint nub on the left-click and that's worked out great. The spring on the space key was a little too firm and I would sometimes not press hard enough, so I put a lighter spring in there.  The trackball in the middle is brilliant.  I haven't really missed having a left spacebar but I did strike a mouse key by accident a few times.  I haven't felt the need to do anything with the custom keys on top, but the calc and audio control keys are nice to have.

Overall I'm pretty happy with this effort.
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