"Absolute Magic!" - Building a Keyboard Using HOT AIR SOLDERING

[@BenVallack]

Subscribe to my new custom keyboards channel! www.youtube.com/@BenVallacksKeyboards

[@chrisjohannes179]

If you don't have content on that channel, can you at least create a library for the keyboard build videos on this channel? Great content, keep it coming!

[@wtfusernamecrap]

As someone who hasn't made the jump to hot air soldering yet, I hugely appreciate beautifully shot "isn't this neat?" videos.

[@BenVallack]

Sorry about autofocus on the studio shot! Forgot to turn on face detect.

[@malpern]

Thanks! For your detailed Keyboard videos. Very inspiring and educational.

[@BenVallack]

Thanks so much!!

[@nate_wil]

Ben I just want to thank you so much for making this fantastic hobby which has cured my RSI not appear so daunting. This is such a great video. Ordering some solder paste right now!!!!

[@janniksco]

Thanks!

[@BenVallack]

Thanks so much for this! Really appreciate this.

[@MakenModify]

Nice video :D honestly there is no real right or wrong when deciding on reflowing or iron. It's a good to just try stuff and see what works best for you. Btw you can also go hybrid, sometimes using past and a soldering iron to melt it also works great.

[@BenVallack]

Thanks! That’s interesting, will give that a go cheers.

[@yellowcrescent]

Looks good. You should give solder paste stencils a try next time you order your PCBs! I typically do non-framework, 200x200 custom size, default settings. Then throw it in a reflow oven (T962A or T962), which gives great results (although hot air gun works too). Also, "paste in hole" (PIH) is a legit technique, although I haven't tried it myself -- you have to be careful because many THT components may not be as resilient to high temps as SMD components that are made for reflow.

[@WoutStandaert]

I've got this reflow kit from Beta Layout, it's a pizza oven with a custom temperature controller made by them. Used it to make hundreds of boards with 0 failures so far, it's very easy to do. You can also DIY your own temperature controller with a microcontroller. Doing double-sided SMT I haven't tried yet but it should be possible with 2 solder pastes with different melting points. Also, tip for the small JST connectors: get yourself an Engineer PA-09 and it will save you so much time. You should crimp them on stranded wire without twisting or tinning the wire, that gives the best connection.

[@tookitogo]

We have the reflow oven from Beta Layout at work, can confirm it works beautifully. (We have an actual mini reflow conveyor belt oven, but the Beta oven works better.)

[@lukemarvin]

PCBway should send over a solder paste stencil. You just spread the paste on like screenprinting a t-shirt. I haven't used one myself but it looks like you get a consistent amount of paste.

[@BenVallack]

Yeah I will get that next time - looks really cool.

[@PCBWay]

Suggestion accepted 😂👌

[@cybyrd9615]

@@PCBWay yo you guys should just have a click store for keyboard pcb orders

[@punkish7]

I used solder paste on a build, and a couple things to consider. I would advise against using it for the MCU, at least if you are socketing it. In my case the solder flowed down into the socket, making the socket useless. I would also be careful about how much paste you use. I had the solder flow through from a socket, and interfere with the switch plugs. Then when I removed the socket to replace it, I must have damaged the board, as the key would not function with the replaced socket. I like the paste, as my wire soldering did not come out well, but still need to use it with care. I used a single use dispenser, and the needle was not real thin, might have better luck with a smaller needle where I could control the amount of paste better. I like the paste, and will try it again, if I can get my MCUs cleaned up enough to use them again. Thanks again for sharing this technique Ben!

[@calmpuffin]

Good advice! Hot air soldering is great but not for everything

[@_lededje]

I'm quite impressed. I've only ever used solder paste with a stencil and it's a lot more painful than the method you show here. I'll get a syringe and give it a go. Overall it looks very clean, I'd recommend against the through hole as the solder can wick up and form a bridge between the board and the chip, something that isn't as likely when heating one pad and pin at a time with an iron.

[@BenVallack]

Good info cheers! It actually looks pretty solid on the top of the through holes - the wider part of the socket pins seems to have sealed the hole nicely with nothing flowing out on the top. Even the JST pins which are very close together have formed nice little cones up the legs on the top side.

[@johnmichaels4330]

I've had this happen. Easy to fix if you don't fry anything, but annoying to figure out.

[@mraarone]

This is phenomenal! I was just now going from 3d printing to PCB printing, and I ran across this amazing custom keyboard engineering and design area. I see how you got into it. I’m going to follow the ergogen workflow you laid out in your previous video. I’m interested, the ZMK code, the switches, all of that… how did you learn about those pieces to add them in your designs?

[@saeedb3r]

please make a video of the building process of your keyboard, what parts should we get, how to flash the framework and share link to your keyboard layout, appreciate your hard work and passion.

[@BenVallack]

Try this playlist in order kzbin.info/aero/PLCZYyvXAdQpte8dkCPz72m_O-Od9fVEqD

[@martinw5480]

Great video- as a soldering neophyte I get where you’re coming from but as I said in another vid, if you’re into ease and efficiency you really need to get yourself a proper crimping tool - the IWISS tool is 20 quid, gives a far better join and is much faster and easier than using pliers or tweezers. Give it a try.

[@BenVallack]

Totally agree - if I ever need to do another one I will. But that was the last battery I should need to do - I have 4 done now so can just move them forward board to board.

[@AX-fx7ng]

Which tool is this? And how is to to be used for soldering? - A video link to show how? Cause when I think Crimp = RJ 45, Solder = PCBs - Different worlds?

[@BenVallack]

​@@AX-fx7ng He was talking about the bit where I crimp the batter plug terminal onto the battery wire. I added that in here as a bit of an extra to show my whole keyboard build format as the shots weren't as clear the last time I showed it.

[@AX-fx7ng]

​@@BenVallack - Ok. Interesting. Will have to see again. Thanks. PS: Can this also be used to UNDO / REMOVE existing solders - of custom DIY or factory OEM solders?

[@JB-fh1bb]

Just last month I actually made a post with a title like “I solder wrong. fight me?” and it’s clear that we have similar views and goals when it comes to soldering. You might like the technique I use: apply flux to the joint, set the iron to the minimum it takes for the solder to melt properly, load the iron with just the right amount of non-flux solder, then rest the solder on the joint until it flows through and burns off all the flux. One of the big benefits is that you can solder with one hand and hold components with the other. It’s also more meditative and forgiving. I’m going to try out some of your techniques and wonder if I’m going to end up with a soldering iron and solder paste...

[@JB-fh1bb]

For the record: almost all the responses were open-minded and informative. Apparently it’s very similar to a few industrial techniques such as wave soldering.

[@BenVallack]

Awesome!

[@BenVallack]

Very interesting thanks for sharing.

[@SianaGearz]

This is actually the standard technique for SMD hand soldering. Since you need the non iron hand for your tweezers. But you can fundamentally use it for through hole soldering as well especially if you have a hoof/cup style tip, but works with other tip styles in a pinch. Though i find myself through hole soldering the usual way, just cranking up the temperature and going at things way fast. Just feel it's quicker that way. I do still end up sometimes adding flux and going over once more but extra quickly.

[@felix.paradis]

Thanks for the beating the path, mate.

[@KyekOfficial]

The part where you solder the jumpers almost looks like it's playing in reverse

[@BenVallack]

Extraordinary isn’t it!

[@hamgelato8143]

the magic of surface tension Ü

[@TCL987]

You should checkout bismuth low temperature solder for these quick prototypes, it melts at a much lower temperature (~137°C) than silver solder (~217°C). Just don't mix it with leaded solder or it'll melt at an even lower temperature and get brittle (

[@BenVallack]

That’s good info cheers! Only used lead-free.

[@sqwert654]

@@BenVallack 60-40 flux cored solder is very good. Silver is terrible to solder with.

[@Scripterrific]

Hi Ben. What if you put TTP223 capacitive touch switches underneath a key cap and wires the switch to the PCB board so that the switch is a key press of a key. Then, you place the key cap onto a mechanical key switch of course so the key switch is also a key press connected to the keyboard. You can design a Planck keyboard with 47 keys all with the capacitive touch key caps which would give you a total of 94 programmable keys for the board (47*2). Halve of the programmable are touch bases and are held down as you rest your fingers. This makes for a very interesting dimension to the keyboard especially when it comes to switching layers or modes: default layer would be toggled if you rest all 8 fingers in the home row; a number and special character layer could be enabled when you move all 8 fingers to the row above. Any combination of finger resting positions could change the layers, but what’s most important is that the layer mode is always known to the user because of their awareness of their finger positions.

[@BenVallack]

Very interesting idea! This might open things up to avoid the issues around the delays associated with home row mod style layer switching.

[@amrunwerhekau9001]

I know it has been a year, but nonetheless here's an idea: If you solder the double sided holes with hot-air and it does not fill neatly, you could pass once more with a normal soldering iron. The solder already presend will make it take the heat much quicker and you can just add a dab of solder and let it flow nicely, without having to heat the thing for ages.

[@janniksco]

The rabbit-hole continues 🐇

[@BenVallack]

Thank you so much for this!

[@dru6809]

I just realized after watching it again... you are using a hot-air gun instead of a hot air station. wow. the result looks great and those are less expensive.

[@BenVallack]

Yep. Paint stripper for the win!

[@DarrienGlasser]

What the heck it looks like CGI when the solder paste just "magically" goes shiny and into place. Very convenient!

[@BenVallack]

Yeah it is magic. To think how much of a mess I made with a soldering iron compared to this!

[@CristianHeredia0]

Very nice. I ruined a couple of reset switches because they were so small. This method should get me past my chunky hands handling hot delicate parts.

[@joshedwards3204]

Are you able to use this hot air method for connecting the headers to the nice!nano?

[@perplexedon9834]

Definitely faster on the jumper pins, though may unnecessarily heat up the board if it isnt a sacrificial one. Definitely slower than even my very first beginner effort at doing switches

[@modii4441]

does it also work with switches?

[@ernam6740]

Ben, amazing videos about these small keyboards, really got me thinking about building one myself. I have a question about how this kbd, for example, could be adapted to have a bottom plate, so the components would'nt touch the surface of a table.

[@BenVallack]

There are a few ideas for that - Ergogen can actually generate proper 3D files for 3D printed cases. Alternatively you can sink it into some kind silicon. Or you can just order another PCB in the same shape and screw together with spacers. However I just stick some hot glue over the shortable connections (you can see this on the red board at the end) and then I'm happy with it as-is. The hot swap sockets make the back of the switches nice and neat.

[@ShawnFumo]

@@BenVallack Oh that's what that was. I was like "just how much flux did he use???" 😆

[@ShawnFumo]

You also could add some feet to the bottom that are just high enough to raise the components over the surface, or add a tenting puck to put it on a low tripod or magic arms.

[@AX-fx7ng]

@@BenVallack I was wondering the same - Thanks for sharing - One could always have Ultra Slim "1 mm" bottom & low height sides cases that could be as easily removed at will or put on (for use or protection when traveling or dumping bags)? Wouldnt that make sense?

[@sqwert654]

I might just 3D print a key holder and hand solder it up. I solder fpv drone flight controllers up so easy for me. The key is a good iron, have a Hakko temp controlled iron.

[@LifeHackerMax]

Amazing!

[@barbazzfoo]

So with the JST connector, you don't need to solder the battery directly to the controller? Instead, you only need to attach the JST connector, then plug that into the socket?

[@BenVallack]

Correct

[@realkill7928]

why i cant find anywhere these switches

[@pariahzero]

It's been more than a year, but there are shockingly good hot air pencils (Digital temperature control, cooldown, safety shutoff, variable airflow), for about $30 USD. They're better *and* less expensive than the average 20W "dumb" beginner soldering iron used to be.

[@jasonm.7358]

I notice you sometimes have your keyboard connected to your iPad; do I really need the Apple Camera kit to hook up a keyboard or mouse? Any way to hook up both at the same time? The internet seems to think not but… the internet is often wrong…

[@BenVallack]

If the iPad has a lightning port I’m not sure what the deal is. If it’s USB-C though you can just connect directly. You can use a Bluetooth mouse with a usb keyboard or a Bluetooth keyboard and Bluetooth mouse at the same time. Or get a dongle like this to expose two use ports. amzn.to/3QAYrGb

[@adamadoch6320]

Ben I noticed you didn't cover the grey and pink colours in your overview video, is there any way you'd be able to show these? There's little to no content showing the grey soldermask

[@BenVallack]

Yep - stay tuned!

[@adamadoch6320]

@@BenVallack Thank you! Appreciate your content 👍

[@gothicchocobo]

I've never thought about using a hot air gun with solder paste, I've got a YAMpad and the metal pads to solder the LEDs and resistors on are so small I've been putting off trying again after getting really frustrated with it the first time trying to solder it. I may have to look into getting the hot air stuff to give it a try.

[@BenVallack]

I think the proper way of doing it is with some kind of oven or hot plate - I think the hot air gun is a good cheap alternative though! Just make sure it’s not on full airflow like I did first time. I blew half the stuff off the board and melted the rest lol

[@gothicchocobo]

@@BenVallack Yeah, slow and steady sounds like a good idea. I melted half of the first LED when I tried to solder it on first time but I think it was just the plastic, so it should be okay.

[@gothicchocobo]

@@BenVallack Not sure if you've had the need to use the hot air gun since you posted this video, but if you have, is the hot air gun still working well for this? I was going to look into getting one next payday. Would you recommend the Amazon one you've linked in the video description?

[@jenniferbrien3408]

Thinking more about this layout - could you get rid of the mouse/touchpad by having scroll wheels instead of thumb keys?

[@BenVallack]

Yeah I've wondered about that - etch-a-sketch style. I don't want to loose those thumb keys though!

[@alvarogomessobralbarcellos7587]

Great!!!! Any link to list of materials, software etc ?

[@BenVallack]

See the other videos in this playlist - component links etc in those kzbin.info/aero/PLCZYyvXAdQpte8dkCPz72m_O-Od9fVEqD

[@alvarogomessobralbarcellos7587]

@@BenVallack kzbin.info/www/bejne/i3zJln2oh66Wrtk :) thanks

[@JohnDoe-qz9ji]

Just wait for Ben to stop making videos on any topic, because at that point, that specific workflow would have been perfected.

[@BenVallack]

Hah yeah the elusive endgame.

[@makingvideogamehistory3028]

Great video as always Ben. I use a moonlander and am currently working my way down in key count / looking aT building some portable custom boards in the future. I was wondering if you have any issues using hot swap switches without a plate, do they stay in well enough? Also, I was wondering what resources you used for building wireless boards with the nice nano(s).

[@BenVallack]

Cheers! No issue with chocs on hotswaps. Wireless boards with nice!nanos are pretty straightforward using ZMK. Jump on ZMK discord and you’ll find everything you need :)

[@RichestTea]

is there anywhere you have a keymap?

[@BenVallack]

github.com/benvallack/zmk-config-piano

[@julianhummel6118]

I‘m wondering how you implemented the on/off switch with the Kicad software. Do you have any tips, how to add the 8 feet button to the PCB?

[@BenVallack]

It is a footprint in Ergogen - if you follow this one along it should make sense kzbin.info/www/bejne/g5C5pouMetd3bKc

[@julianhummel6118]

Awesome thank you! :D

[@gianlucarenzi7706]

Just a simple question: are the choc low profile switches compatible with standard cherry mx based stems on normal keycaps?

[@BenVallack]

Nope

[@gianlucarenzi7706]

@@BenVallack So I am forced to choose: normal keycaps (with normal switches) and low profile keycaps with low-profile switches. Is this correct? 😞

[@StephanGelenscher]

I *really* want to see you typing on this layout. Still wondering if this piece is for the left or right hand. And not knowing drives me nuts 🎹😵

[@BenVallack]

Heh yep will get onto that soon!

[@BenVallack]

The double outer key is the thumb 🙂

[@StephanGelenscher]

Thanks 😅

[@guruprasadkulkarni635]

which controller are u using?

[@BenVallack]

nice!nano

[@disarmyouwitha]

Do you still prefer this method of soldering?

[@punkish7]

Can anyone comment on the risk of using this method to attach the MCU? That is the single thing that is stopping me from trying to assemble my own KB, I don't think my soldering skills are a match for the close spacing of the pins on the MCU. Thanks for the video Ben!

[@BenVallack]

I will test this if no-one else can offer insight!

[@yellowcrescent]

Yep, it's a common method of soldering SMD components. Either use solder paste in a syringe like Ben showed and manually dispense lines of paste, or use solder paste stencil (if it's a PCB you designed), which is preferable especially for higher pin count or fine pitch components. Then use your hot air tool to slowly heat in circles, being careful not to leave it pointed in one spot for too long. You might have to use solder wick to remove excess solder if you dispensed it manually, but it's usually pretty easy to do.

[@ShawnFumo]

@@yellowcrescent Is there such a thing as SMD sockets for a pro micro controller? Seems like that'd make that side of it easier, though I guess maybe mike h meant getting the pins onto the controller itself?

[@yellowcrescent]

​@@ShawnFumo There are ZIF sockets for SMD components (mainly QFP and QFN packages), but they are very expensive ($50 ~ $200+) and usually meant for programming fixtures. Also many of them also have SMD pins themselves, so you'd just be shifting the problem :P Although 3M does have some that feature THT pins on the bottom, but they are around $100 each. (Example: 3M 248-5205-00)

[@punkish7]

@@ShawnFumo yes, I was referring to soldering the pins to the MCU. Thanks for the clarification. I am feeling better about through-hole soldering with an iron, but if I end up with a board that I have to do SMD diodes I will be looking at using paste! Thanks again to Ben for bring up this technique

[@katharinasick]

That's awesome! Did you ever try this method with LEDs - does it work for them as well or will they get goo hot?

[@BenVallack]

Not tried that I'm afraid - stopping them blowing off may also be an issue.

[@katharinasick]

@@BenVallack thank you :) Btw, thanks for your content - I enjoy it a lot!

[@Mixail747]

I wonder if this method should be safe for switches as well?

[@BenVallack]

You mean if you weren't using the hot swap sockets? I reckon they'd be fine is they're on the other side of the board to the heat etc.

[@Mixail747]

@@BenVallack Yes, without hotswap sockets. I remember damaging bottom plastic on some switches that I soldered, those were from PC which is apparently the least temp resistant.

[@tookitogo]

8:34 I’m not sure why you think soldering experts would a) prefer hand soldering in general, and b) avoid using reflow on through-hole. Reflow soldering has completely taken over the industry, and for good reason. The latter is called “pin in paste” and it’s an up-and-coming thing in electronics manufacturing. They’re now beginning to make connectors with the pin length optimized (shorter) for pin-in-paste.

[@BenVallack]

Good to know cheers - there seems to be quite a lot of resistance to the idea from some people!

[@tookitogo]

@@BenVallack Well they’re just being silly geese! :P I’m a skilled hand solderer, but I’ll take reflow any day if I can. It’s just way faster and easier, and produces a more consistent result if the paste is applied correctly. I’ve got a board to assemble tomorrow with somewhere around 40 0603 resistors and caps, 5 ICs, a dozen SMD LEDs, and a 40-pin flat-flex connector, and you bet I ordered a stencil for it. Other than two ICs that have only pads on the bottom (no leads, and thus MUST be reflow soldered), I could hand solder it all, but why? It’d take way longer.

[@tookitogo]

@@BenVallack The only thing the objecting commenters are sorta right about is that using a hot air unit for pin-in-paste may not result in proper reflow, since it might not get hot enough throughout. A reflow oven using a proper reflow profile will ensure the components are “soaked” with heat, ensuring a reliable reflow. Using hot air alone, I have had paste that didn’t melt properly under a component. (Though I don’t think that looked to be the case with your IC sockets.)

[@AX-fx7ng]

Terminator mercury man has been conceived.

[@Nesten-zi1oz]

Hey,man. Are these keyboard N-key-rollable?

[@BenVallack]

Yeah looks like it zephyrproject.org/zmk-state-of-the-firmware-5/

[@Nesten-zi1oz]

@@BenVallack Thanks!

[@ShawnFumo]

Going down the steno rabbithole? That's why I'm getting into making my own board, is a slightly alternative steno design..

[@gazehound]

even simpler and straightforward-er is using a soldering stencil with your paste

[@BenVallack]

Yeah I had one of those sent and did some tests - certainly makes it easier to apply.

[@alimoff8760]

Unrelated, but you should voice audiobooks.

[@lunaumbra5179]

I really want to make my own customer low profile small keyboard like you have, but I have so many other projects to do first. Dual split bt designed for lying in bed with your hands at your side, using a massive thumb cluster for specials. One day. One day

[@mcbrite]

3:56 What the hell? - Like the DAY after I convince myself I don't need to buy a hot air station because it is useless for my split keyboard build, you go and show me it would make soldering everything I ever dreamed of it being! 😲I'm going to finish the video, but you likely just cost me 200 bucks/euros... 👿🤣🤣

[@BenVallack]

He - and this is just using a cheap heat gun!

[@lunaumbra5179]

But can we go .. . SMALLER!?!

[@BenVallack]

Been there - came back. 18 keys is perfect!

[@lunaumbra5179]

@@BenVallack do you mean 18 total? I could see 18 per hand maybe. Maybe I missed your smaller ones but this piano seems tiny!

[@sectorx20]

You will end up doing Morse code

[@karthickb1973]

Dear Ben, I could not check the price. I am from India and sadly many of the products are not available to purchase here. My guess is it will make a hole in my pocket. Makes me long for The Piano. Is it possible for your to arrange a special package for 3rd world countries like us.

[@edwardfletcher7790]

I really wish you'd practiced a bit more with your hot air soldering before doing this. I wouldn't have used hot air at all. Standard solder and iron would have been so much easier.... If you're having trouble with a normal iron adjust the temp and switch to lead/tin solder.

[@BenVallack]

I did say I thought there would be plenty of people saying an iron would be easier/better/faster. Bottom line is for me after making a whole bunch of boards with an iron I find paste and hot air so much easier and it results in a much less messy board. The goal here is to make the workflow as simple as possible to iterate through these boards quickly. Soldering the pads on those tiny switches with an iron is basically a nightmare! Paste makes it seem far less daunting and there is less/no chance of burning the pads off the board.

[@JipperGoneWild]

@@BenVallack I agree, whatever works for you. I would be wary of doing this for the through-hole parts. The headers pins are pretty thick, and takes a lot longer for them to heat up. When you do this, you're potentially causing weak joints by having hot solder try to bond with relatively "cold" header pins.

[@BenVallack]

@@JipperGoneWild Ah yeah they did take longer to heat up - great point thanks.

[@edwardfletcher7790]

@@BenVallack You might want to look into toaster oven reflow of you're making a lot of boards as your method is very time consuming. Just be very careful to test what temp the switches can take.