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Lasgweloth PCB, a "leaf-spring tray-mount" 60% (UPDATE: sound tests added)

by Gondolindrim

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byGondolindrim

Description

(Sindárin, Gnomish) Lasgweloth (n). Leaf-fading; autumn. It is said to describe the feeling of leaves fading and falling in the middle of the fifth week of the elven year. (Source: "A Gateway to Sindarin: A Grammar of an Elvish Language" and "The Etymologies").

1. Introduction: a PCB to rule them all

Hey guys, what is up?

So this time I want to bring a new PCB that I have been working for almost a year now: the Lasgweloth (pronounced "les-gweh-loth" in the old Sindárin language).

This PCB is a universal 60% PCB aimed at mitigating the shortcomings of tray-mount 60% cases like the TOFU, the 5 degree, the Klippe and the Fjell. I don't know about you guys, but I absolutely love my TOFU and I think that it is the best cost-per-benefit board out there (kudos to Wei and KBDFans!). However, as you might expect, the T1s I put on it (then again, kudos to Wei) don't make the best sound ever, and the feeling is also less than stellar due to the rigid plate killing the flex. So I tried devising an improved mounting scheme to help with both feeling and sound of my tray-mount boards. I honestly also dislike this dis-taste we have for traymounts, like they are unevitably faded to sound/feel bad.

As we know, these are exactly the two main shortcomings of tray-mount boards. They are cheap and easy to produce and easy to assemble; however, the uneven pressure from the screws on the PCB makes sound propagate to the case raw material in a very harsh PCB-to-metal contact, making the keyboard not sound as better as it could. Also, since the screws are stiffly mounted, the whole PCB-plate kit is itself very stiff and that kills the fleXXX, meaning tray boards also tend to feel not so good as top mounts for instance.

2. What's up with the name and the weird characters?

The name Lasgweloth comes from the word in Sindárin language, which is (one of) the language of the modern Elf people. It was derived from the Eldarin, the old language of the Eldar elves, this one deriving itself from the language spoken from the Valar and Maiar peoples, the caste of demi-gods created by god Eru, that shaped the Earth and battled Melkor according to Tolkien Lore.

As a HUGE Toliken nerd, I have grown up reading the tales of Middle Earth and adopted my own nickname as an elven nickname -- Gondolindrim meaning one from Gondolin, the hidden elven city that was ultimately betrayed by one of its own for a pitiful power struggle. I invite you to read The Fall of Gondolin, the last published book in the Tolkien world which was in fact posthumously published. I also invite you to hear the song "Mirror Mirror" from the band Blind Guardian, which tells the story of why and how the elven king Turgon built the city of Gondolin.

The reason I chose this particular theme is because the open-source Acheron Project, the compendium of my open-source works, already has PCBs named after my dear friends Mister Keebs (the KeebsPCB) and Arctic Fox (the ArcticPCB), and I wanted a PCB that had my specs with my signature features. I chose a universal 60% with the most common layouts (see below) with no LEDs and no RGB.

3. The PCB and the leaf-spring tray monting system

Now that is a mouthful, isn't it? I came up with this idea when taking a look at the leaf-spring mounted keyboards and noticing how that mounting system promotes the fleXXX we want and need. The idea there is simple: isolating mechanical vibrations inside the plate medium and isolate them from the keyboard case, so they don't propagate through the keyboard case. It also reduces the stiffnes of the plate and makes the sound concise.

The idea here is the same. We all know tray-mounts are not ideal because the uneven pressure from the screws on the PCB or plate makes the sound and pressure distribute unevenly; that destroys fleXXX and the sound. My idea is then to use the leaf-spring idea to isolate sound and make the PCB fleXXXier.

What I did was, understanding that the propagation of sound is basically the travelling of mechanical waves through a medium, there are particular shapes which can promote destructive interactions from the wave with its reflexions; that means that we can cut certain shapes in the PCB that concentrate sound in the screw centers and do not let that sound propagate from the PCB to the case.

The shapes I came up with are illustrated in the next figures. They show the mounting screw holes of the PCB, isolated by "leaf-spring" shapes that aim to sonically isolate the screws from the rest of the PCB; also, they concentrade stress on the necks, making them fleXXXier. The particular shape was determined through numerical simulation in SolidWorkds of the propagating sound through the PCB, using normal values of medium characteristics for FR4. This was then used to determine the "neck shapes" needed to promote destructive iteration of sound.

And here are images of how they will look when implemented on the actual PCB:

Of course, I had to fleXXX my nerdiness with a label and an Acheron Logo written in Tengwär alphabet . The figures below show the whole PCB, without components. Of course, the PCB also features seXXXy stress-relief cuts, ESD protection, USB type C, voltage supression on USB power lines, ARM processor, QMK and VIA support.

4. What is this GB and prices

Since the PCB is going to be open-source and no one is paying me to do it, I need prototyping money. Given the recent sucess I had with the Doddle60 project, I want to do something similar now. I reached out to Quakemz and he agreed to do the same thing Jae did witht the Doddle60. I will raflle 10-15 spots (depending on my capabilities) and Brian will proxy the PCBs, at the cost of one unit for himself. Since Quakemz is US-based and we want to keep this simple, we will limit the raffle to US addresses and to one unit per spot.

The unfortunate part is that due to the COVID pandemic, shipping and materials cost have increased significantly. Each PCB will cost 45 USD. This covers one PCB unit and the shipping from me to Brian; after he gets the PCBs, we will calculate shipping prices and it will be charged then.

Additionally, I will also offer FR4 60% plates. These will be plated, that is, have a "chromed" effect -- see the image below for an example. Each will cost 10 USD and will be optional (limited to 2 units per spot). They will also feature the Lasgwelot logo.

Below there are two renders of the plate. The plate I will ship will have the Lasdweloth logo on it (then again, metallized-plated).

5. Timeline

Doddle60, however, had a problem with its shipping and this time around I want to get a better shipping to make sure everything arrives on time. I expect that, between taking the money and deliver to Brian, 3-4 months should pass. In this interim I intend to prototype these PCBs before making any final version. However, since we are in the middle of the whole COVID sh**show, I can't guarantee anything time-wise.

6. Final thoughts

- Open-source PCBs with novel mounting system that makes tray-mounts feel and sound ever so slightly better
- 10-15 raffle spots, US-limited, 45 USD each PCB plus shipping within US
- Each spot can also buy at most 2 10-dollar plated FR4 plates;
- I will assemble the PCBs myself;
- ESD, USBC, ARM, QMK, VIA, OSH, and more acronyms I can't remember
- ETA 4 months

To enter the GB, fill this form. It will stay open for two weeks couting from today (april 21).

7. FAQ

Q: Why so much time to deliver? Well, shipping to Brazil is that slow. Albeit hiring a better shipping, I still am skeptic of its effectiveness, specially in this pandemic. I also intend to make prototypes BEFORE handing the "final versions" to you.

Q: Will this new mounting system make my aluminum plate unlubed stock Gateron Yellows TOFU with post-retool Cherry stabs sound, feel and look like a 1500-dollar custom-cut POM plate TGR with NK Creams spring-swapped with SPRiT gold-plated springs and Zeal stabs lubed with St. Nathan Kim's holy oils? I'm an engineer, not a miracle worker, but I have faith that this PCB will make tray-mount cheap keyboards feel more premium and better sounding. I also am short of St. Kim's blessed oils at the moment.

Q: Why Brian? Because I promised him I'd do a similar thing I did with Jae. Also because he too is a huge LoTR fan. Also because he's amazing. Also because he's beautiful.

Q: Will this PCB be available at a vendor after this? I haven't been in touch with any vendor about this, but I am open to the idea. The PCB will be open-source, so... Yes, this will be available at Jae's store for EU and CannonKeys for US after this GB has ended.

Q: Why limit this to US? To make proxying easier and cheaper. It is what it is, I'm sorry. I can try to futurely do an european proxy. See question above.

Q: Why only MX support? No ALPS, buckling spring, electrocapacitive, choc switches, Romer G, Razer Green, or my custom ALPS-SMK hybrid switch with quantum activation system and Ferrari springs? No, I prefer Lamborghini

Q: Can I get this PCB with RGB, LEDs, Bluetooth, rotary encoder, an FM radio, Alexa/Siri support to play me despacito and a loudspeaker to play a recording of Hineybush tucking me asleep as I lay in bed with my HBCP in my arms? No. Seriously, the featureset is as it is. No LEDs, no RGB, no BL. Maybe rotary encoder support somewhere, probably the 1U key of the split right shift. I love you Hiney

Q: Are you Canadian? No, and we do have maples in Brazil so I won't take that "stole the maple leaf from Canada" shenanigans. I also absolutely did not steal Maple Design's logo. Totally unintended Chris, I'm sorry

Q: Is this a 4/20 reference? If you smoke imaginary elven maple leafs then yeah sure I don't judge, you do you

Q: I'm an influencer with 100000 million subscribers on Instagram, TikTok, Facebook, Twitter, Google Plus, WeChat, SinaWeibo, MySpace, ICQ, MSN, my high school, the local church, the Holy Roman Church, the Orthodox Catholic Church, the Satanic Church, the gods of Olympus and the Illuminati. Do you want to give me a free PCB for a sponsored post? No, I have none of these nor am I part of any of these

Q: Can I get a spot for XXX amount of dollars / euros / pounds / Middle-Earth pence / star credits / energy credits? No, I'm alredy rich with love and friends

Q: Can I get a free No

Q: Can I please stop

8. Sound tests

The complete test build is: