What is SpaceFN and why you should give it a try
The SpaceFN concept - setting up your space key as a layer switch when held - is probably one of the most useful tweaks in the keyboard hobby. Let me explain how it works. My SpaceFN article on kbd.news made some rounds recently - quite surprisingly given the age of this concept. This piece you're reading is a condensed version of the full post. If you're left with unanswered questions, you'll most likely find the info you're looking for in the original write-up. On my imaginary top list of the most useful keyboard features, tweaks and hacks, SpaceFN would deserve a podium finish for sure. But what makes it so special? In short: SpaceFN is easy to implement, easy to learn, costs nothing, can be used with any keyboard, and can improve your productivity instantly. I will list its benefits below, but can state right at this point that the SpaceFN concept, setting up your space key as a layer switch when held, is clearly one of the most useful tweaks in the keyboard hobby....
Apr 30, 2024
Bad thing is that there is a mistake on the spacebar size: the spacebar size should be 6u in Hacker Bottom Row kit, but I got a 6.25u spacebar in my package. So I have to use the 6.25u spacebar and two 1.25u alt keycaps for my HHKB, before the MD support could resend me a 6u spacebar in the right size. :-(
PS: This is my daily drive. HHKB pro2, with JTK sliders installed. Holes are drilled for 2u keys. Housings are removed and costar stabilizer is installed for spacebar.
First, remove the spacebar keycap and open HHKB. Take out the top plate. And then take a look at the HHKB spacebar housings, you could press these bumps(marked in red circle in the following picture) on the housings to remove the housings from the top plate. let's steal a picture from @rixtox. The housings are like
After the housings are removed, you could install costar stabilizers into the plate. Glue or other padding could be used at the contact point between top plate and the costar stabilizer, in order to make the position of these costar stabilizers into the housing holes fixed. I used some small cutouts of plastic bag in pieces for padding. I put two small pieces of paper to cover the rest of the housing holes as dust guard, as seen in the following picture:
Then put everything back together. That is all. Now it's ready to install usual 6.25u spacebar(and two 1.25u alt keys) into HHKB. The spacebar of size 6.25u is popular. You could find any of SA/DSA/GMK profile and use it for HHKB after this mod.
@rixtox shared a better way to do this mod, using 3D printer. Refer to https://www.massdrop.com/buy/the-amazing-chocolatier-custom-sa-keycap-set/talk/1643481
The mod I did is much cheaper, all you need is a proper set of tool, and a set of costar stabliziers. Bad thing is that the spacebar wobbles a little, just like normal costar stabilizers on MX spacebar. Take whatever way which suits you.
Happy Hacking.