Submitted by Miiyoo t3_10m3i05 in MechanicalKeyboards

-- TLDR --
Halo stems are fatter than they were before, so no, you can't make Holy Bobas anymore unless you shave each stem by hand. Which is what I'm doing. :')

-- Glossary --
OGHalo = old halo stems
NHalo = any stems bought recently
If you have polia stems, use Polia interchangeably with Halo.

-- Intro --
So it all started when I decided that I wanted to put some Bykos in my new keeb. (BobaU4T tops, Halo stems, Zealio bottoms). I had a couple of old Halo stems (OGHalo) from ages ago when I decided to build some Holy Pandas, but not enough so I bought 90 new switches from Drop (NHalo). My old stems all fit in the boba housings perfectly. But my new Halo stems all were too fat and had a friction fit. Interesting. I also tried ordering a batch of Polia stems and they were also too big to move properly in the boba housings.

-- What's going on here? --
I perused some old posts, and it seems like people that had been trying to make Holy Bobas were having the same issue.

-- Is it now impossible to make Holy Bobas? --
Well. I decided to whip out the ol' caliper and see what was going on here.

So here in this image, we have two Halo stems. OGHalo is marked with black sharpie, and NHalo is clean.

OGHalo is marked with black sharpie, and NHalo is clean.

​

The front to back was within 0.5 thousandths of an inch. That's an acceptable deviation range for cheap calipers imo. OG Halo measured in at 0.2170 in, and the NHalos at 0.2175.

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OGHalos front-back

NHalos front-back

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Things become weird when we start measuring the side-to-side width. We see a still small, but no longer acceptable deviation range. 1.5 thousandths of an inch!! That doesn't seem like a lot, but within the scale of a switch, that's quite a bit.

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OGHalo side-side

NHalo side-side

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So there's no way that all of the new stems are too fat right?
Well. I measured 20 of them. All of them were around 0.2850, some even hitting 0.2855, but again, that's an acceptable deviation range here. So. I came to the conclusion that maybe Halos are now made in a slightly different mold from before, and no longer really fit in boba housings.

The Boba Housings themselves have an interior size of 0.2855. So theoretically the stems would fit? Well. No. Once the tolerances are that tight, there's just no room for things to actually move smoothly. Not to mention, my calipers might have been digging into the housing plastic.

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BobaU4T top housing interior measurement

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Also, if we look at the NHalos, we can even visibly see a difference in the side "bolsters" pictured here.

NHalo closeup

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The thing is. These bolsters exist on the OGHalos too. They're just about 0.5 thousandths of an inch smaller. Well shit.

-- So I guess we just can't make holy bobas anymore? --
Welllllllllll. That wasn't going to stop me. So I padded my pliers with some cork to hold the stem shape a bit better and went to town with my Xacto knife. Surprisingly after a bit of practice, getting a consistent side-to-side measurement of 0.2830 - 0.2825 was fairly achievable.

Pliers with cork padding

Xacto knife demonstration

post shave measurement

​

So no, I'm not going to give up. Is it worth it? Most likely not. But hey, I'm just going to take it one stem at a time, do a few a day and I'll be done in a couple of months right? Copium HAHAH.

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Comments

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darknessblades t1_j60rhch wrote

Why not measure with metric in mm?

it should be a lot more accurate. since calipers will round Inches down or up depending on the size.

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Miiyoo OP t1_j617s8c wrote

I totally should have done metric measurements. Inches was just a force of habit, I'll post a comment with the metric measurements in a bit!

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Zaphod_Heart_Of_Gold t1_j61ecc9 wrote

Calipers measure to .001in or. 01mm. .001in is .025mm so measuring in inches is technically more accurate.

Should still measure in mm though

−2

darknessblades t1_j62sjv4 wrote

The problem is that most digital calipers use metric as their base, then convert it to inches.

meaning the inches you on screen see are rounded up or down.

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Miiyoo OP t1_j626exv wrote

So the cheapo Calipers I have actually only go to a half thou. Soooo I guess it'd measure 0.005in or 0.127mm, so the mm is actually a bit more accurate on my tool.

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beebo_bebop t1_j645cyb wrote

based on the appearance of the calipers they probably have an effective tolerance of +- .05mm or more anyway

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Miiyoo OP t1_j618k5j wrote

Metric Update:

OGHalos: 7.20 - 7.21 mm
NHalos: 7.25 - 7.26 mm
Shaved NHalos: 7.19-7.21 mm

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darknessblades t1_j62sftr wrote

Looks like the reason why you have a large difference in size is mostly due the manufacturer having a 0.01mm error margin.

Shaving off a few 10ths of a millimeter is quite hard, since giving just a little bit too much force will result in large differences.

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Miiyoo OP t1_j62ut3w wrote

Oh yeah 100% agreed, precision like that by hand is proving to be super inconsistent. I'll also take some measurements with my micrometer for posterity's sake and post a comment as well!

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laffeybunn t1_j623ln8 wrote

The end to this "COPIUMA AHAHAH" made me die inside. I would do the exact same thing. Inb4 this reaches top post

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schao001 t1_j622m0j wrote

This is kind of old news. It was known that halo stems have changed, but I don't think anyone did measurements. V1 stems are still out there from other people. It's just hard to differentiate until you test with a boba top.

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Miiyoo OP t1_j626gku wrote

Not gonna lie, didn't know for sure if it was old news, but makes sense, they've been around for a while. But heyyyy now we got measurements hahah

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MayAsWellStopLurking t1_j62pvwz wrote

well appreciated. Lots of people kept blaming gazzew for his boba housings not fitting when it was highly suspected kailh made the change.

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Noobshift3r t1_j62czlq wrote

another W for zyko enjoyers

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beebo_bebop t1_j645spj wrote

downside: no easy bykos upside: probably a lot of other tops can be used now & have similar tolerances to the old bykos combo

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Tenochticlack t1_j64kvth wrote

I tried putting MX clear stems into boba housings, didn't fit either :(

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