Hey guys, I’d like to preface this post by saying I’ve build a LOT of custom keyboards over the years–that is to say I’d rate myself as fairly proficient at building customs after years of learning, trial and error, and learning from others.
That said, I still have yet figure out one super frustrating issue that randomly plagues me without any seeming pattern or reason. Every once in a while I’ll have a stabilizer (mostly 2u) that encounters enough friction on key presses, to become annoying slow moving.
I recently built a Tengu and for whatever reason, all the stabilizers are super-slow moving to the point that it’s not worth using.
The first obvious go-to reason is warped key caps, and in some cases, swapping them out fixes the issue. But in the case of the Tengu for example, no keycaps, whether they’re GMK, SP, etc. seem to make a difference. I also recently had a similar issue with a Classy TKL build.
Any ideas? I am extremely consistent/conservative with the amount of lube I use (always Krytox 205g0), so it’s not like they’re over lubed. I also tend to be consistent in using Cherry stabilizers but the problem is not exclusive to Cherry. The Classy TKL has Zeal stabilizers.
Would love to see if this happens to other people and see if you’ve figured out how to troubleshoot this!
This happens to me on occasion - I feel your pain. So far, when it has happened, one of the following things has been the issue:
Reseat the keycap. Sometimes I think it’s level and fully seated, but it’s not. I’d say at least half the time, this turns out to be the problem for me - but let’s assume that’s not it, since you have tried swapping caps, and let’s also assume it’s not a warped cap either.
Check the interaction between the stab wire and the plate. Is the wire making contact with the plate at any point during the stab’s motion? If it’s a PCB-mount stab housing, how tightly is the housing sitting in the plate cutout?
Is the stab wire perfectly straight along its length?
Are the stab housings properly mounted on the PCB or plate? Specifically, are both housings parallel to each other and perpendicular to the PCB/plate? I’ve found that even small deviations can be enough to lead to “sticky” motion. Also, are the screws/clips for the stab housings properly seated/mounted? Every once in a while, with a screw-in stab, I’ll discover that the end that clips into the PCB has become slightly unseated in the PCB hole, presumably while I was screwing the other end into the PCB, throwing the housing slightly out of alignment and leading to sticky stab performance.
If you use cloth washers for the stab screws, have any of those slid to one side of the screw, causing the screw to sit a little out of alignment?
Is there excess plastic (flashing from injection molding) on the stab housing or stem that is interfering with stab motion? This requires looking very closely at the housing, possibly with a magnifying glass, around the opening where the stem slides through the housing.
If you use foam or sorbothane or some other case dampening material, is that material pressing too hard on the PCB when the case is sealed, causing the PCB to bend slightly, and throwing stab alignment out of whack?
Related: are the case halves screwed too tightly together, causing excess pressure that is pressing on or near a stab housing?
And one more - it might not be the stabs at all, but the switch. Is the switch perfectly flush with the PCB?
I’ve had this problem with a few different stacked-acrylic alice/arisu boards where the fit of the plate is off by just enough to make the stabilizer function so slowly, and inconsistently, that I end up getting destroyed in multiplayer games or just annoyed in desktop usage. It is extremely frustrating and loosening the stabilizer screws helped a little, but the only thing that really fixed it in the end was replacing the plate. It’s a nightmare and the one board I have left from that group buy sits in a drawer because I hired a popular streamer with a desoldering tool to fix it, and now it has other issues with the PCB occasionally bridging some contacts and causing various switches to light up when only one was hit. Waste of 65 good switches.
Well just as suspected, I got a ton of really good tips from some very smart people. Thanks everyone for the ideas. In particular I want to thank @jshufelt for his definitive guide on stab troubleshooting!
The faulty/misaligned plate idea is the most compelling theory I’ve seen so far. I’ll report back once I’ve been able to successfully troubleshoot.
As fate would have it, I ran into this for the first time last week - the stabs were a little too tightly screwed into the PCB, causing the spacebar to chafe against the keyboard housing just enough to be incredibly annoying, and loosening them a bit did the trick. Thank you for adding to this thread!
And, I ran into the overtightened-screw issue again a couple of weeks ago, this time with GMK QMX stabs. At first I was thinking “man, brand new hyped stabs and they’re worse than the originals?” But, finally I remembered skepp’s advice, loosened both screws slightly, and voila! Crisp and clean.
I put together an Aero75 w/ TX AP stabs recently and was experiencing a really terrible Enter key. All the other stabs were perfect, and I tried a completely new stab assembly in the Enter location w/ different lubing technique, still terrible. Screws untightened, etc.
Turns out the issue was the PCB itself - for whatever reason the measurements at that location made the stab housings a miniscule amount closer to the switch, but enough to cause extra resistance. I solved it by wedging in a small piece of Band-Aid (not the typical Band-Aid mod) vertically sort of in between the stab housing and plate, enough to push the housing away from the switch. That immediately loosened up the key.