Making a HiPro TKL, and the problem that comes along with it

[cgbuen]

I came up with an idea for a mod that I don't know had ever been discussed, which is to transplant switches/keycaps between a Realforce HiPro ("104UG" or "YK2100") and a Realforce 87U - I love the HiPro feel but not the form factor.

Background

Here are things I noticed right off the bat, without opening either keyboard:

- You can't perfectly swap keycaps between the two without swapping the switches. This is because the HiPro switch is much taller than a normal Topre switch. YK2100 caps have the possibility of fitting normal switches fine, but bottom-row profile 87U keycaps can't be pushed down properly into a HiPro switch. Switch pic below via 002 on the deskthority wiki.
- The feel of a HiPro switch seems very different - it seems like the cross-walls coming from the inside ceiling of a HiPro keycap hit the tall portion of the HiPro switch with much more impact than a normal Topre keycap on a normal Topre switch.
- Due to the above two notes, the idea of simply putting YK2100 caps on an 87U means you won't get exactly the same feel, and you'll essentially have an unusable YK2100 since your 87U caps wouldn't fit.
- The YK2100 does not have LEDs.


The Process

Along the way, I've come up with mostly non-destructive techniques to get this to work. Here's what I found:

More

- The plate cutouts and the switches are compatible with each other. While not a huge surprise, I couldn't find any confirmation of this anywhere, but it was nice to find that it was in fact possible to swap when I tried it myself.
- You can skip swapping a number of keys, outlined in several in the next bullet points.
- The HiPro's stabilized keys are no different than the 87U's stabilized keys - they are not HiPro.
- Since the HiPro does not have LEDs, Scroll Lock has to be modified when placing a normal switch onto the YK2100. The 87 plate has an extra indentation for the LED that the HiPro does not. You could mod the YK2100 plate, or you can remove/sand down the portion on the switch where the LED rises up. I went with the latter and just used some pliers to pull it off. As a result on the 87U, a HiPro switch will just sit on top of the LED, and you really just have less of an idea when it's on.

- The YK2100 Caps Lock (between Tab and LShift, which I should specificy because of Caps/Control swappability) is stabilized. But you can also skip this because, as above, stabilized keys on a YK2100 are not HiPro. As a result on the 87U, you have a better idea of when the LED is on because you're still using the same switch with the hole for the LED.

- The YK2100 bottom row switches are not HiPro.

Examining LCTRL

That is, the Left Control key (bottom left corner, which I should specify because of the Caps/Control swappability). On an 87U, this key is incredibly weird compared to all other normal Topre switches, due to the presence of the LED when swapping for Caps Lock. The nubs on the slider are horizontal instead of vertical.


The 87U LCTRL key (plus swappable 1.5x Caps Lock key) has a rotated mount. The HiPro LCTRL key looks like how all other keys are.


The plate cutout is extremely different with the bottom right corner tapered, the bottom left/top right not rounded out, and upper left with the LED hole. I believe the cutout is just the slightest bit shorter, too, because the LCTRL housing is loose in any other cutout.


In examining the switch, both the outer housing and the slider are totally different. LCTRL on the left, normal switch on the right.



The YK2100 switch (as mentioned before, the bottom row is not HiPro) should be no problem after a small mod. I broke the talon on the slider to release it, and then just rotated it 90 degrees easily. On the left, the slider legs are on the original housing rails. On the right, the rotated slider doesn't move through full-on rails, but it can still extend all the way through the housing opening. This way an 87U LCTRL keycap can be placed on easily.


The Current Problem

There is a huge issue in the opposite direction - if you try to place a YK2100 keycap on an 87U. Rotating the slider just doesn't work, because there is nothing resembling usable rails on the other axis, and the opening contains a "rim" that only fits on the original axis. On the left are the slider legs on the original housing rails, and on the right, rotating the slider gets stopped and can't fit all the way through the opening.



Potential Solutions

1. Modify the plate to fit a separate, normal switch. Not necessarily a real feasible idea for a number of reasons:
a. My ability to modify a metal plate is extremely limited at the moment, because my toolkit is very plain (screwdrivers, pliers, knives, etc.).
b. The weird switch will still need to be placed somewhere else. (Well, maybe not - I could maybe buy a Realforce keychain, but that seems like a real intense amount of money for one switch.)
c. Not very reversible.

2. Modify the YK2100 LCTRL keycap. I can't just cut in another axis into the current stem, because the cap feels brittle, and the parabolic shape opening on Topre keycaps seems crucial for mounting/"clicking" onto the switch. I'd probably need to remove both pieces and re-attach them in the rotated stance. But this would need a ton of care - I'm not sure of the safest way to detach the parts from the cap, and what the best adhesive would be when putting them back on. This doesn't seem very reversible either.


3. Get access to a mirrored version of the slider. With a mirrored version, it would sit inside the outer housing in the correct orientation for the HiPro keycap. This seems like the best/safest way to do it, given easy reversibility, and seemingly very possible given the MX-compatible slider can be had via Shapeways. However, I don't have any background on where I could begin with this.

Anyone have any other ideas I'm missing?



P.S. After slaving over this over the past week, I'd feel pretty disappointed if a manufactured HiPro TKL came out anytime soon  )

Album here.

[CPTBadAss]

I think you've got the right idea. You've either got to do a stem mod or print a different stem off Shapeways.

I think AkimbrO used to do stepped caps lock stem mods. Perhaps he could be of more help. But I think you cut or Dremel down the stem in the original cap then carefully cut a donor stem from another cap. Then epoxy the stem to the cap. I believe that the caps are PBT and, if I recall correctly, people have used JB Weld as their epoxy of choice. I also have used and like the Loctite epoxy.

If you go the Shapeways route, I suggest learning Solidworks or AutoDesk Inventor. You create a 3D model to send to Shapeways to have them print the stem.

I can see why you did this, those HiPro caps are lovely . Keep us updated on this.

[mtl]

Thanks for the great write-up. Do you see any issues with performing a silence mod on the HiPro, with either EliteKeyboards' soft-landing pads or dental bands?

[remdell]

Great and unique write-up you have here.  I also own a HiPro -- didn't like it at first, but once I became proficient with typing with all my fingers, the HiPro easily became one of my favorite Topre boards.  Personally, I'd like to see your opinions on your HiPro TKL with 55g domes and/or with dental bands.  I found that the profile and keycaps of the HiPro gave a sort of floaty typing experience, as if you're typing on a typrewriter with 30g Topre.  The bottoming-out experience and light actuation are unique traits to the HiPro, and I wonder how it fairs with the smaller form factor, deadened bottom-outs (silencing), and medium actuation (50g).  Silenced 45g and 55g really took away the thock experience, but I think the HiPro's more distinct thocks and clacks will make silencing it a lot more tolerable. 

Thanks for bringing new light to more Topre mods!  I'd probably make an HHKB HiPro if I ever get one.   

[intelli78]

Remdell recently helped me with another project, and in the course of doing so, he uncovered some info that may be of interest to you, cgbuen: the RF86u doesn't have the irregular left control housing. If I'm understanding the OP correctly, this was the last remaining problem for you. So if you can track one down, you should be able to complete this mod.

[MJ45]

You could get a small square file and make the plate opening square to rotate the switch housing or put a regular one in. The led may also have to removed to clear the housing.

[jomiro477]

Great and unique write-up you have here.  I also own a HiPro -- didn't like it at first, but once I became proficient with typing with all my fingers, the HiPro easily became one of my favorite Topre boards.  Personally, I'd like to see your opinions on your HiPro TKL with 55g domes and/or with dental bands.  I found that the profile and keycaps of the HiPro gave a sort of floaty typing experience, as if you're typing on a typrewriter with 30g Topre.  The bottoming-out experience and light actuation are unique traits to the HiPro, and I wonder how it fairs with the smaller form factor, deadened bottom-outs (silencing), and medium actuation (50g).  Silenced 45g and 55g really took away the thock experience, but I think the HiPro's more distinct thocks and clacks will make silencing it a lot more tolerable. 

Thanks for bringing new light to more Topre mods!  I'd probably make an HHKB HiPro if I ever get one.   

THIS PLS 1000TH TIMES! Inspire PFU to make HHKB Pro 3 with HiPro   

[Oobly]

Or you could get a Novatouch and SA keycaps...

But seriously, nice job on the conversion.