I'm not sure what to do with the trackpoint assembly just yet. I am assuming I'll figure it out somewhere down the road. The board has big components on one end and little components on the other. This means it sits at an angle relative to the top of the keyboard, which is also at angles relative to everything else. I don't know if there is a "better" angle. The manufacturers who use trackpoints tend to make them flush with the top of the keys or just a little higher, but then they usually have to consider "don't smash the LCD" as a major design point. I don't. I can make my nub flush with the plastic of the keyboard as just a tacky spot for my finger to touch (hold the jokes, please) or I can make it maybe as high as flush with the keycaps. Probably it will be somewhere in between. Possibly at an angle. I dunno. Maybe I will find a way to experiment with this. Maybe I will find one of the 'cat's tongue' texture round tops and the angle will be a moot point. This is just one of those minor crises that comes along when you start out on a project without a 100% definite Plan to work off of. Oh well.
Have I missed something? Is it better proud, or recessed/shrouded? Is it better (or good enough) half-exposed?
(https://i.imgur.com/pY90UNE.jpg)
A wider PCB for the trackpoint by even a millimeter or so would require some fancy fabrication but this one is exactly as wide as it can be without considerably cutting up the top of the keyboard panels or the PCB. Some other Lenovo trackpoint PCBs are too wide, as are the HP ProBook trackpoints I have seen. Dell trackpoints have no conjoined PCB and the electronics for the pointer seem to be on the motherboard somewhere.
The pointer switches could be be tricky. I did some experimentation and comparing dimensions for alternate switch mounting locations and a few switch types, and usable options are limited. The middle keyboard mounting plates are secured to the underside of the bridge just "North" of where the zoom control lives, and it's an important structural area for putting the keyboard together right. It's either external switches there (inelegant) or internal switches somewhere else. Seeing as I HATE the back and forward keys*, and seeing they fall right under the tip of a thumb, it makes sense to me to cut the traces on the existing controller PCB and repurpose those two switches as right and left click buttons for the trackpoint.
This could, of course, possibly be done with a custom key map - but I want this to be a (relatively) plug-and-play affair. No custom programming of the keyboard controller (if it even can be done) and no custom programs on the computer so the keyboard can be taken to a different computer and still work properly. The Microsoft software that tries to install when you plug in this keyboard (via an optional Windows Update) may allow some key mapping to be done; I don't know, I never used the software. The only thing that program ever did for me was bring up unwanted webpages or programs when I accidentally hit the web/search/mail buttons when I missed the Escape key.
If someone wants to implement a middle click button (linux users come to mind) I guess the easiest place would be to slip a switch under the My Favorites button if you don't want to use it for your Bookmarks. There are really no simple options for extra switch placement near the home row that aren't already taken or have stuff behind them. I think I'll do this and if I never need a third mouse button it won't hurt anything. If it ends up being in the way, I could always go back in and cut the wires. A $$$ production version should have a jumper or DIP switch setting for this. Proof-of-concept items get "maybe I'll cut the wire later" haha.
As I typed out the notes for this update, the inconsistency of the Microsoft keyboard was slowing me down, again. I have GOT to get this project done.
This is how the trackpoint looks right now, by the way:
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Inset is the model of the converter. The converter is potted in solid, or else it'd be smaller but at least I got the plastic case cut off. I'll pretty this up a bit before I'm done, and probably cut off the Keyboard input cable.
(https://i.imgur.com/yYNKCpG.jpg)
I chucked up a bull-nosed end mill bit in a vertical press and took off most of the mounting bosses from the button mounting plates. This resulted in about a liter of ABS shavings and dust when I swept up! Fortunately, even on a slow speed, the (sharp!) mill was able to work fast enough to prevent melting the plastic. It didn't stink up the place or send scalding drops flying at me. Unfortunately it went a little past where I wanted to go on a couple of spots, and the rest still need minor clean-up with a dremel or something. I'm not sure I'm even going to use these mounting plates though, so my feelings aren't too hurt.
Gratuitous picture of half-done milled plates:
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(https://i.imgur.com/8O1OSL2.jpg)
I'm considering more layout changes. I could add a duplicate backspace key where MS put a (useless!) BACK key over the tenkey. Maybe instead of a large delete key, a duplicate Enter key over the Delete or in place of the FLock key (the two Enter keys do different things in Photoshop)
22 hours
* my work uses custom web-based software and the back/forward buttons under the space bar navigate away from the page in use, deleting all the data that have been input. These buttons are occasionally pressed by accident and losing a half-hours' work is a pisser, so I pull the back and forward buttons off all my MS4K keyboards immediately upon putting them into service.