One great thing about Kosmo is that essentially it’s electrically identical to Eurorack. (There’s no +5V rail and no CV/Gate lines on the power header, but very very few Eurorack modules use those either.) The only difference is the panel size. In principle you can take (almost) any Eurorack module PCB and mount it behind a Kosmo panel.
Except of course Eurorack uses 3.5 mm jacks, and usually Eurorack knobs and switches are too close together for Kosmo users’ tastes. So most board-mounted components need to be replaced by panel-mounted ones, wired to the pads that would have been used for the board mounted components. And you may have to rig up some kind of bracket or standoffs to mount the PCB if it was originally designed to attach to the panel via those same board mounted components. Or in some cases there’s a main PCB and a panel PCB, in which case you could design a Kosmo-sized panel PCB that connects to the main PCB.
This is called Konversion.
So there’s some work involved, but if you do it then there are hundreds of Kosmo DIY boards on the market, mistakenly labeled as Eurorack.
Yep. Most IC’s datasheets will give details on the temps. And that’s for oven reflow where they’re totally baked. With handheld hot air unless you’re reckless you’ll probably never reach those levels. I’ve done fine pitch CPLD’s and FPGA’s by hand and it’s possible…but much easier with hot air.
In the video I was lingering longer than required with the hot air - I was still getting a feel for it and learning how to tell when it had actually liquified. Plus trying to record and solder at the same time was a new experience as well
I usually keep my hot air station at 316c - but that’s measured in the handpiece. So I expect the air to loose a bit of heat on the way out. I use MG 63/37 paste (cat no 4860P-35G) and keep it in the fridge when I’m not using it. One syringe has lasted me over 5 years and is still mostly full despite having done about a dozen boards of various complexity. Technically it’s probably “expired” by this point…but still works just fine for me. Again as DIY hobbyists we can get away with a lot that wouldn’t fly for industrial production.
I don’t think I’ve ever damaged anything with hot air yet (as far as I know…though I do seem to be having issues with the SMT DAC on my current project) but I have damaged parts in the past with an iron and too high of a temp back when regulated irons were less common.
Honestly though it looked like he got more paste than necessary on even with his stencil. Not sure if it was his stencil or his technique…but I generally use considerably less than he did.
They’re eurorack…but some of the nonlinear circuits modules are small/cheap/simple enough they may be good first SMT projects to get a taste for it and you can always re-panel them for Kosmo if you prefer.
Hills:
Playing around with a design based on a section of the Kaussutronics Variable Waveshape LFO.
The Triangle to Sine Convertor section is what piqued my interest as I am working on a device that produces 6 variable triangle waves (called Slopes/Swoops) and figured this would be a great addition to my design!
Further reading and diagrams show the Triangle wave section above heading on down to the TL074 and I cut off the upper section as that will be the input.
One thing I learned the hard way. The “tips” actually have a small dimple on them and twist into position. It’s very subtle though and easy to miss…which I did the first few times I used it. So I push pushed them on and pulled them off. Which eventually led to the one I used the most breaking. I got a set of new tips from banggood for a few bucks that included more sizes though so it worked out in the end.
