@Whosa_whatsis @Taylor_Landry1 depends on the ESC, if it’s a reversible DC ESC then yeah it needs one H-bridge per motor. Lower switching speed (like 2 kHz). One-direction ESCs don’t need H-bridges, just one FET for brushed or three for BLDC motors. Compare to a stepper driver with two H-bridges and two sense resistors switching at 40 kHz or whatever. I think the small chip package size on the stepper drivers we use also makes a difference… not sure if that’s just a surface area issue for heat dissipation rate or if the smaller silicon die makes much of a difference too.
@Whosa_whatsis just made me think it would be really cool to have a long 20mm wide board with a few holes to bolt it to a piece of 2020. Could sink heat into the bolts and/or back onto the 2020. I guess it would have to avoid through hole connectors though!
A typical BLDC is has three wires, each of which has to be able to be both the positive and negative side. I think they’re built with 6 discrete MOSFETs, 3 P-channel and 3 N-channel, but that’s basically what’s in 1.5 full H-bridges, isn’t it?
With requirements like that it’s gonna have to be a market that doesn’t get served, at least for the short term. I suspect that with a different motor choice you wouldn’t need such current capacity, unless we’re talking about bigger than desktop class printer. At that point cost sensitivity needs to go away as you’ll blow a lot of money feeding the machine.
You don’t NEED to use the full current rating of the motors. They will just run cooler if you tune them below their maximum…
Yeah well I’m tempted to design it myself. Wouldn’t take more than a few weeks of my spare time.
I need to finish my #Quadrigotion debugging (SPI of TMC2660 seems to behave differently than datasheet says) and and build a Pocketbeagle breakout for it, then this is a powerful 32Bit solution when run with #BeagleG (up to 8 motors with 1Mhz step frequency…). BeagleG is flying under the radar for many, so still used too rarely.
The whole combination could probability be in the $100 range.
TMC 2660 are crap stay away from them. They are not smooth as 2130 and they tends to fail. Extremely hard to find.
@George_Novtekov granted they don’t have the latest smoothing but they are extremely reliable. The board they’re put on needs to be properly designed to dissipate the heat.
I’ve had good success with 2660s on Duets.
@Liam_Jackson Is this close to what you want?https://github.com/hzeller/quadrigotion
https://github.com/hzeller/quadrigotion
Old design I did based on ATSAM3A8C and stepstick/polulu drivers. Very simple 2 layer with minimal connectors. https://github.com/StephS/Espressylu/blob/master/Espressylu-0.7_Board.jpg
I’m sure there’s better mcu choices now. I’m not fond of the polulu stepper drivers because it’s very limited on connectors for new features.
https://github.com/StephS/Espressylu/blob/master/Espressylu-0.7_Board.jpg
I saw “Espressylu” and thought “You’re using an Espressif chip? Is there firmware that supports that?”
I like coffee. Lol. Espresso=fast and small.
I might get back to designing. Kicad is finally getting useful.
@Jeff_DeMaagd Just search Duet forum and you will see how many TMC2660 they have failed. My Duet3d wifi came with tmc2660 doa. They had a lot of complains about dead drivers and doa with this chips. If you search same for 2130 products it different story. Also sensorless aligment with this drivers is not reliable. Basically this is old chip with a lot of problems. TMC got much better chips atm and I dont see point of 2660 to be integrated recently.
OK I hadn’t heard of the problems. I can’t use 2130 on my big machine which does need the amperage. I hadn’t heard of it in the RailCore II community either, their machines are designed around the Duet 2 boards and their expansions too.
@Stephanie_A just for an old printrbot? Why not just fit an X5 mini in it with 2224s and call it a day?