![[Lab Update 4-7 Board1.png]] ![[Lab Update 4-7 Board2.png]] ### Lab Update *2025-03-04 -> 2025-04-07 | [[#Pretty Pictures|Skip to Pics]]* [[Lab Update - 2025-03-04|Previous Lab Update]] | [[Lab Update - 2025-05-08|Next Lab Update]] Last month was a lot of learning. This month was a lot of building. So less notes and more logs & photos. Spring is wonderful. Still targeting Biweekly, but it's more like monthly currently. Q1 reflection and Q2 roadmap below. --- #### Highlights - Joule Thief - [[Joule Thief R0 - PCB Design Review Points|PCB R0 & Design Review]] - Took everyone's advice. I mean everyone's - Revised it like 8 times in one day, finally got it looking good - Ordered chips, but got stalled 2-3 weeks on shipping times - Battery Holders don't fit into the THT, so I have to drill out the hole - Rat Rig - Gizmo - First Gizmo turned out to be 220VAC, I was lied to on eBay - Second Gizmo worked out great! Currently in operation - Titanium Tube - Had to do another hot tighten and burned my arm again - Overheated the Belts and they got soft and loose - Thermal performance is slightly worse than CF, but seems more stable - Rapido 2F - Superfast temp climbs, capable of 40mm3/s. Excellent results - MGN9 Rail Swap - Decided to double down and go for the MGN12->MGN9 conversion to shed an additional 200g off the gantry - This allowed for a new top speed of 1500mm/s (up from 1000mm/s) - This required me to purchase, build, learn, and use a drill press for the first time - Now I finally have to go set up a proper workbench - Calibrations - Going great so far #### New Notes: - [[March 2025 Rat Rig Mod Run]] (big) - [[!Joule Thief]] - [[Digital Pot Application Circuit Examples]] - [[Quick Note - Setting AD5280 Address]] - [[Erratic Behavior on Breadboard]] - [[Joule Thief R0 - PCB Super First Draft Notes]] - [[Joule Thief R0 - PCB Design Review Points]] - [[SMT SPDT PCB Footprint Redraw]] ### Project Status #### Joule Thief I spent the first 2 weeks or so of March really digging into the PCB design for Joule Thief. I've done some tutorial boards before and some lazy work on an analog synth without any concern for best practices or what really goes into making a "good board", but that's more or less my main focus this year. I had a feeling if I just posted my best attempt on twitter some people would be willing to give me some review points, but I got wayyyy more than I was expecting. It was super helpful and I wrote every single one down and incorporated it. Went through in replies and DMs to interrogate conflicting advice as well. I learned soo much off of this board. After redesigning it some 7-8 times over 12 hours on a single Saturday I decided enough was enough and sent it for fab. It actually only took a week to get here, faster than most of the chips. Really the main bottleneck in pulling the trigger was making sure I had all the right parts selected. Footprints are a bit of logistical friction, but I found I didn't really have the knowledge necessary to confidently pick out components. But I think I'll get there. After spending so much time tracing and rerouting over and over and over I was seeing 45s and vias in my dreams. I also am finally starting to develop a little bit of intuition on the visual pattern matching when I look at boards. They were completely inscrutable hieroglyphs to me maybe 1-2 months ago. But now I'm getting the hang of it. There are some people who really can just look at any old board and tell you exactly what it's doing, and immediately parse the design space and specific choices made. It's cool stuff, and I hope to get there soon. It seems like it's mostly a volume thing though. Need a lot of exposure. The boards came in and look great but the battery holder pins are flat and broad and not round and thin, so I have to drill out the holes a little bit. It doesn't matter how hard you try to get it right the first time, there's gonna be *something* wrong. It's good timing though, since I just bought a drill press for completely different reasons and already have tiny PCB mm/sub-mm drill bits. I'm looking forward to assembling it and inevitably redesigning it. It's been a fun project so far, but I've been a bit antsy waiting for Open Sauce to get back to me re: my application to exhibit this thing. I definitely lost some momentum pivoting to Rat Rig and then taking a break for a few weeks, but it'll come together soon. #### Rat Rig The Rat Rig worked pretty well prior to me installing all of these mods. But it has a very sticky sunk cost trap. It's a $2k kit printer that I've heavily modded. To the extent that it's inconsistent or not user friendly for someone else to use, it's worthless. And if it isn't a reliable workhorse and instead a constantly evolving problem and money pit, well then I'm basically just stuck repairing a printer forever instead of learning and building new things. So I decided to drop the next $500 or whatever it needed in order to get it to the peak conceivable performance. So far it's been going pretty great. The Titanium Tube install looked a bit sus at first, but after pairing it with the chamber heater to keep thermal saturation consistent throughout, I'm getting very good results. I am fairly confident I'll be able to get to the 500mm benchy without significant rework/rebuild at this rate. At time of writing I'm printing the 6th 1x size benchy. Once I'm satisfied with the quality/speed tradeoffs, I'm going to scale by +0.25x until I reach the build volume's limit. I'm also going to set up the PiCAM and the 1-click macros for preheat, etc. in the meantime. Completing the 500mm benchy livestream will be my hard milestone to say that the Rat Rig is finished. I'll wrap up the documentation, cleanup, streamline whatever needs it, and then move into a more complete focus on developing the next project. In this case, I've got a toss up between three things: Designing the Breadbox for productization, Designing the Acetone Vapor Chamber to pair with the Rat Rig and generate print contract revenue, and Building out my DIY PCB Fabrication toolchain. They all kind of bleed into eachother, but I'll have to choose one soon (after Joule Thief). ### Q1 Review, Q2 Roadmap #### Q1 Review - Roadmap - Targets were to start posting build logs on twitter and see if it felt worthwhile, it absolutely was. I love you guys - Joule Thief development has gone slower than expected, but I feel very confident in the processes I developed for this kind of R&D - The Rat Rig Mod Run was not planned originally, but I decided to double down and get the machine to hassle-free 1-click so I can (hopefully) free up some of the space in my mind this thing occupies. - I intended to push harder on Breadbox development, but I reallocated those points to Rat Rig instead. - Created a brief portfolio & updated my resume to pass around as many people on Twitter are interested in scheming and building together, which I find wonderful. - Twitter - Account Started: January 15th - 500 Followers: February 5th (Day 21) - 3000 Followers: March 21st (Day 65) - Current State: 3,202, Day 83 (April 7th) - Nearly 50 followers/day up until my 3/20-4/6 break - Joule Thief - Started - Ordered a good handful of equipment and learned how to use them - Learned how to actually design a PCB with intention - Learned how to SMD Solder & breakout chips for breadboarding - Successful Proof-of-concept: Alkaline AA trickle-charging an 18650 - Ordered a board and immediately saw it wouldn't work right :^) - Rat Rig - Printed and shipped ~50-100 maglev orbs - Printed some robot arms - Optimized Support Interface settings for ASA - Upgrades - Put the rat rig into a grow tent - Added a 5kg filament dryer - Replaced the carbon filter for fume exhaust - Installed a Titanium Tube to replace the CF gantry - Installed a Phaetus Rapido 2F (Fiber) Hotend - Switched from MGN12 to MGN9 rails to save 200g gantry - Installed a Chamber Heater #### Q2 Roadmap - 500mm Benchy - Building out Garage Workspace - New Breadbox - Acetone Vapor Chamber R0 - Content Series: Chip of the Week/Chip Spotlight/Chip Select - Datasheet Blog - Awaiting Open Sauce Confirmation (...) - Joule Thief Completion & Writeup - --> PCB Fabrication & Tensegrity Robotics ## Pretty Pictures ![[Pasted image 20250407085701.png]] ![[Pasted image 20250407085709.png]] ![[Pasted image 20250407085737.png]] ![[Pasted image 20250407085746.png]] ![[Pasted image 20250407085755.png]] ![[Pasted image 20250407085810.png]] ![[Pasted image 20250407085819.png]] ![[Pasted image 20250407085830.png]] ![[Pasted image 20250407085839.png]] ![[Pasted image 20250407085929.png]] ![[Pasted image 20250407085942.png]] ![[Pasted image 20250407085952.png]] ![[Pasted image 20250407090000.png]] ![[Pasted image 20250407090010.png]] ![[Pasted image 20250407090042.png]] ![[Pasted image 20250407090052.png]] ![[Pasted image 20250407090101.png]] ![[Pasted image 20250407090119.png]] ![[Pasted image 20250407090131.png]] ![[Pasted image 20250407090144.png]] ![[Pasted image 20250407090213.png]] ![[Pasted image 20250407090225.png]] ![[Pasted image 20250407090240.png]]