Looks great! Where'd you end up getting the internal ring gears, KHK?
Any updates to your controller since your last thermal deep dive post a few years ago? I've been kicking the tires on the H7 series for my next rev. 520MHz (550 if you want to risk turning off ECC) is a lot of compute power to mess with.
No motor drive updates, I'm still working through my supply of mini cheetah drives I ordered in 2019. Would probably switch to an STM32G4 if I did a refresh. Smaller packages, cheaper, some nice motor control features like a CORDIC unit.
Hah, yup, it makes a good controller for sure! My current controller is (rather heavily :) based on your original PCB layout, but updated with FD CAN, Rust, and the G4 [1]. It's a solid little chip; you can wire up a frankly staggering amount of hardware triggers, to the point where you're pretty much just reading memory for values to feed into your control loop.
Ring gear (and all the other gears) are from an off-the-shelf industrial servo planetary. There are some pics of post machining them a few posts back. Once I've got both drive units fully buttoned up I'll do a detailed blog post.
Really like the design of the back part. Beautiful :)
ReplyDeleteLooks great! Where'd you end up getting the internal ring gears, KHK?
ReplyDeleteAny updates to your controller since your last thermal deep dive post a few years ago? I've been kicking the tires on the H7 series for my next rev. 520MHz (550 if you want to risk turning off ECC) is a lot of compute power to mess with.
No motor drive updates, I'm still working through my supply of mini cheetah drives I ordered in 2019. Would probably switch to an STM32G4 if I did a refresh. Smaller packages, cheaper, some nice motor control features like a CORDIC unit.
DeleteHah, yup, it makes a good controller for sure! My current controller is (rather heavily :) based on your original PCB layout, but updated with FD CAN, Rust, and the G4 [1]. It's a solid little chip; you can wire up a frankly staggering amount of hardware triggers, to the point where you're pretty much just reading memory for values to feed into your control loop.
Delete[1] https://github.com/timblakely/pino-rs
Ring gear (and all the other gears) are from an off-the-shelf industrial servo planetary. There are some pics of post machining them a few posts back. Once I've got both drive units fully buttoned up I'll do a detailed blog post.
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ReplyDeleteReally cool stuff. I look forward to seeing how you put this thing to work. How did you decide to lay out the internal cooling passages?
ReplyDeleteStay tuned, working on a detailed writeup of the design/build.
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