A UHMWPE Challenger Approaches

So who’s going to bite the bullet…for science of course.

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yolo
image

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Dude! Huge thanks for sharing. Science!

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Ha, yes!

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What would be a perfect housing for these?

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Bobba’s, of course !

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Definitely look at the disclaimer on the seller’s page. It seems that the stems may not fit into tighter tolerance housings in which category Outemu might fall into.

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I’ve heard that the other ones work really well with Cream housings - that’s why I picked up some of these. I’ll be trying them in all kinds of stuff, and I imagine other folks here will as well.

I also decided to pick up some Gateron Yellows while I was at it as a sort of comparative baseline that’s easy to reference.


It’s funny, I’ve been looking for a place that has good ol’ Gateron Yellows at a non-inflated price (looking at you, mechanicalkeyboards dot com), and/or that isn’t coming from China on a bulk shipping container with a really wide range of possible ship dates, none of which are soon.

I’d find sites that look like a really great deal until the shipping comes into the picture (hi, kbdfans I still love you but I’ve balked at the shipping stage a few times now). Across the board, the real cost of the yellows averaged in the mid to low 30 cent range. That’s not expensive generally, but it might be a little high for those switches.

Shipped from 415 to my neck of the concrete woods, they’re between 27 and 28 cents each. That’s a bit more like it. :+1: I could probably pay a little less with patience, but not having any when it comes to getting parts is definitely a factor. :grin:

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MechKeyAlpha has them and offers Hong Kong Post Air Mail shipping for $10 or free if you buy $80 or more.

So 18 cents a piece if you grab a bunch of stuff and hit the free shipping mark, or 27/28 cents if you eat the shipping.

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TESTING:

Update 1: So far, none of these are holding onto keycaps at all unless I turn the cap sideways. :grimacing:

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I am having the same issue with mine, unfortunately… Also there is some more side to side wobble than the original stems I replaced. I could look past that if the caps would stay on.

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That was my biggest complaint with the v1 Invyr’s though it doesn’t seem to be quite as bad as these. On a separate note, the Alpacas I got (from the first round I think) have really undersized stems – I can only use eBPT caps on them as brand new unmounted GMK or JTK sets fall right off.

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Update 2: More information:

Caps these don’t seem to hold onto:

  • Ducky OEM PBT
  • NK PBT
  • MDA PBT
  • Those clear caps that come on testers
  • SP SA was iffy but might be workable

Caps these stems do hold onto:

  • ePBT Cherry profile
  • GMK Cherry profile
  • (by extension probably OG Cherry if not too worn)
  • Rando thin painted ABS OEM caps that came with a budget board

This mostly jives with what Sam from 415keys told me; that the target spec for these is original Cherry.

He requested a video, so if you don’t mind my weird voice you can see how these stems fit with a few different caps here.

Also worth noting:

Housings that don’t seem to work well:

  • Tangerine (definite no-go)
  • Boba (might work with lube but I have doubts)

Housings that worked fine:

  • Cream; a little wobbly
  • Gateron (opaque black housing from Gat Yellow)

At least pre-lubing, those housings the stems did work in seemed less smooth with these stems than without, but that’s definitely first-impression territory. These might be better with lube, a break-in period, or different housings - this is just what I’ve found so far with limited testing.

When I swapped one into a Gat yellow and pushed it together with a stock one stem-to-stem, the UHMWPE stem depressed more slowly, and with some slight herky-jerky movement. The feeling is pretty similar to brand-new Cream, with those bits of “stickiness” on slow presses.

So - my recommendation for these stems is to only buy them if you have keys you know to be close to that spec; GMK, ePBT, original Cherry caps that haven’t been mounted and un-mounted a bunch of times, or caps that otherwise fit snugly - AND if you manage your own expectations for these to be an interesting experiment rather than a magic buttery-smooth bullet.

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I wonder if UHMWPE shrinks more than some of these other plastics. I feel like every iteration has had some tolerance issue.

From what I understand, yes. UHMWPE shrinks more than many other plastics and it’s apparently challenging to predict by how much.