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BuildIts in Progress
Personal blog · build-its-inprogress.blogspot.comhardware
BuildIts in Progress is a personal blog at build-its-inprogress.blogspot.com about hardware. Since 2014, 17 different Hacker News readers have linked it 21 times, most often “The Rubik's Contraption”. It is still writing: the last post was on 2026-02-05, and you can follow it by feed.
Too few sampled comments (11) to say how often HN recommends it.?
Why HN links it
Ben Katz's build log on robotics and motor control, covering the MIT Mini Cheetah and HobbyKing Cheetah actuators and a desktop inverted pendulum. Commenters cite it for design and testing details.
Summarised by Claude from a sample of 11 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
motors and things...
Most-linked posts?
- /3 people · 3 mentions · first linked 2020-05-27
- The Rubik's Contraption3 people · 3 mentions · first linked 2018-03-08
- /2018/03/the-rubiks-contraption.html2 people · 2 mentions · first linked 2024-06-06
- Mini Cheetah Clone Teardown2 people · 2 mentions · first linked 2022-12-20
What Hacker News says?
Very impressive. Comparing the slow-mo to one of a different rubik solver [0], there's much less overshoot in this one. [0] https://build-its-inprogress.blogspot.com/2018/03/the-rubiks... (see first video)
Comment linking /2018/03/the-rubiks-contraption.html
on “Mitsubishi robot solves Rubik's Cube in 0.305s”Submitted The Rubik's Contraption as a story · 297 points
HN discussionSorta related: (if this video triggers some brain neurons from the past) In 2018, this was solved by some guys (I believe one worked for Boston Dynamics) in 0.38s. Video: https://www.youtube.com/watch?v=nt00QzKuNVY Hardware Info: https://build-its-inprogress.blogspot.com/2018/03/the-rubiks... Software Info: https://cactus-zone.blogspot.com/2018/03/rubiks-solver-softw...
Comment linking /2018/03/the-rubiks-contraption.html
on “Mitsubishi robot solves Rubik's Cube in 0.305s”Submitted The Rubik's contraption solves a cube in 0.38 seconds as a story · 4 points
HN discussionYou’re assuming they’re using a linear controller, and they’re way ahead of you [1]. But I don’t think they’re overshooting per se. I think they’re landing the centers in the right place, but the outer pieces account for most of the moment of inertia, and they’re flexible, so the overall assembly is deforming. Deriving the optimal control law for that could be a bit messy. I would guess that it involves bringing the…
Comment linking /2017/12/controls-ramblings-how-to-get-from.html
on “The Rubik's Contraption”Submitted Coreless Axial Flux Motors (2015) as a story · 3 points
HN discussionRead this: https://krex.k-state.edu/dspace/bitstream/handle/2097/1507/J... It's a thesis from James Mavey titled "Sensorless field oriented control of brushless permanent magney synchronous motors". Other good resources: http://build-its-inprogress.blogspot.com http://discourse.odriverobotics.com/ https://things-in-motion.blogspot.com
Comment linking /
on “Electric motor design claims remarkable improvements”Submitted Motor Temperature Estimation Without a Sensor as a story · 3 points
HN discussion> Nice build :) Have you checked out EasyEDA + jlcpcb? It can improve the electronics aspects of robot projects. Thanks! Yeah, the electronics is a bit gross. This build was probably 6 years ago perhaps? I got it to the point that it worked and then it was kinda "done" and all that was left was polish, but it was really a toy so there wasn't much point and I left it. Planning on building something for slug and snail…
Comment linking /
on “Venom: All Terrain Autonomous Quadruped”Submitted Desktop Inverted Pendulum (part 1) as a story · 2 points
HN discussionNice build :) Have you checked out EasyEDA + jlcpcb? It can improve the electronics aspects of robot projects. I searched a bit now to see if any new projects have shown up. Came across this one: https://hackaday.io/project/167845-mjbots-quad Could maybe be interesting, but I haven't looked into it. Here is a chinese motor manufacturer that makes more sane motors: http://www.gyems.cn/product.html Getting a drone or…
Comment linking /
on “Venom: All Terrain Autonomous Quadruped”Submitted Mini Cheetah Clone Teardown as a story · 2 points
HN discussionNot industrial espionange. This robot is heavily based off of the MIT mini cheetah, which most of the design for is opensource (e.g. [0], [1]). Ben Katz has an amazing blog[2] which if you dig through you can read about a lot of the design decisions and testing for the mini cheetah. Funny enough, after designing the mini cheetah for his master's thesis Ben went to work for Boston Dynamics (I think he started there t…
Comment linking /
on “Unitree’s Go1 Robot Dog Looks Pretty Great, Costs Just $2700”Submitted Motor Temperature Estimation Without a Sensor as a story · 1 points
HN discussionIf you're looking for a good place to start, I highly recommend reading Ben Katz' blog and thesis: Blog posts: "HobbyKing Cheetah" http://build-its-inprogress.blogspot.com/search/label/HobbyK... Thesis: "Low Cost, High Performance Actuators for Dynamic Robots" https://drive.google.com/open?id=0B2x3Di8kVjT3N3BkQzhSQ3FwTU... (Edit to note: Ben's design uses gears and thus is not direct drive, but his bot still has lot…
Comment linking /search/label/HobbyKing%20Cheetah
on “Ghost Robotics' Minitaur Quadruped Conquers Stairs, Doors, Fences”Submitted Mini Cheetah Robot – Clone Teardown as a story · 1 points
HN discussionThis is a clone of a friends project, http://build-its-inprogress.blogspot.com/2014/05/external-di... Remind me again, what is the £165,000 for, R&D?
Comment linking /2014/05/external-display-from-ipad-lcd-part-2.html
on “Packed Pixels – An extra monitor for your laptop”Submitted Varying Pitch Screw Robot as a story · 1 points
HN discussionThat channel owner, Ben Katz did the mechanical hardware, motor control PCB + firmware for the MIT Mini Cheetah as part of his PhD, here is his blog post on it[1], which links to a full technical report. The latest firmware is here [2] [1] http://build-its-inprogress.blogspot.com/2019/03/hello-there... [2] https://os.mbed.com/users/benkatz/code/Hobbyking_Cheetah_Com...
Comment linking /2019/03/hello-there-mini-cheetah.html
on “Two-legged robot mimics human balance while running and jumping”Submitted The Rubik's Contraption (2018) as a story · 1 points
HN discussionHere part 2: https://build-its-inprogress.blogspot.com/2016/08/desktop-in...
Comment linking /2016/08/desktop-inverted-pendulum-part-2-control.html
on “Desktop Inverted Pendulum (part 1)”
