Appreciate the detailed response, thanks bunch!
Is there a common PCD for the mounting holes at each motor diameter? Or are they brand dependent.
2 Likes
I am pretty sure most outrunner motors used for eskate (flipsky, maytech, and reacher) have 44 mm BCD, hence most motor mounts cater to that. 50XX motors (as opposed to 63XX or 64XX that are common now) used to have 30 mm BCD but they are no longer common.
1 Like
To add to what kkim0228 said, I think Maytech use the smaller mounting pattern too, you get threaded adapters but they are rare. Maytech makes motors for other brands like Bioboards in the past and Lacroix now.
1 Like
Well I wouldnāt recommend going maytech nowadays. If you go reacher you actually get a longer stator every time you step up in size, and itās overall a much better motor. Also the 75 length reacher probably already way outperforms the 96 maytech.
@That_Jamie_S_Guy you can account for reacher 6495s those have basically unlimited power if you go high voltage. Assuming you are geared for a sane speed 2 of them can have enough torque to spin race slicks under you and propel you forward with close to a G.
I run my 6495 175KV reachers at 21S 200A each, confirmed that the stator is not saturated at this current.
And forget about reacher 7490s, those arenāt that great, unless you keep them at very low RPMs.
I assume itās for your chain onewheel build? Youāll probably want to run sensors for that. Whatever size you choose if you can then opt for batch 8 motors from Radium, those have an improved sensor PCB. If the size you want is not available on their website send them a message.
3 Likes
Reachers are definitely better although maybe not by so much since the stators are a good bit shorter, maybe from the vents in the top. Iirc a few brands 63100 has >50% more stator than a reacher 6485. While I donāt think anyone is buying from Maytech there are definitely some from Lacroix floating around.
For me itās more about budget and whatās available second hand. Being 16 I have more time to fix motors, build batteries, and layup carbon than I have money for parts.
A bit off-topic but itās genuinely cheaper for me to design then cnc and hand machine brackets, pulleys, adapters and axles custom than it is to buy them. Just takes ages.
2 Likes
Itās very far from being as simple as longer stator equals better if you compare different product lineups unfortunately. The magnetic design of the motor, how copper and iron losses stack up along with cooling and winding quality is much more important.
If you run a 96 maytech at 100A itās going to cook itself. I can overheat my 6880 maytechs in 3-5 minutes of riding at 12S 70A 170ish kv without being overly crazy on the throttle.
The 95 reachers which probably have a slightly but not significantly longer stator donāt overheat at 21S 200A at 175kv. Even during racing short track full throttling acceleration and braking hard all the time, I was unable to overheat them even in 2WD, much less so in 4WD.
I hear ya, been there a couple years ago myself when I started DIY esk8 about 5 years ago (Iām 21 now). If you donāt need crazy power you can just go with what you can score a good deal on, but if you can make it happen, especially if you are already upgrading from something, it often pays off long term to just buy the right thing once.
Wish I had tools to machine that kind of stuff for myself. I only make stuff I can make with an angle grinder and a drill press. And recently acquired a welder as well. Would love to have access to a machining workshop though
2 Likes
thatās a pretty solid endorsement.
and curious, I was able to overheat the SKP/reacher 6485 173kv on v5#1 at 20s.
think the 95s are just enough more?
3 Likes
I have a box of lacroix/matech motorsā¦ most just need bearings (axle) and some help with the bell bearing interface. (like some kapton tape to stop the rattle. ).
some need a drive shaft do to wear at the bearing seat.
Yeah I think the extra stator of the 95s definitely helps. Another important thing actually is gearing so that you have enough top end if you are on high voltage, so you are tapping into the iron loss territory a bit less. I am geared to about 55-60mph (on paper) on the 9" tires. Havenāt actually tried going faster than about 44 mph so far though.
Although I am certainly not super light, but I think I also weigh less than you do? Iām about 180-190 lbs depending on the time of the year
i was geared for 49mph.
we decided it was iron losses.
yeah I think i was around 210 at the time of that testing.
1 Like
Just checked and you were on V5 reachers. Iām on V6. Iāve got weaker magnets and therefore a good bit less iron losses.
1 Like
oh thatās very interesting.
1 Like
Agreed that the construction of a motor goes far beyond size, but 2 of one being the same size as 3 of the other must have a pretty big impact on saturation, possibility of ripping off magnets and heat generation. Although would they have noticeably more iron losses?
I dont always exactly have access to a machine shop and I rely on an angle grinder for lots too lol. My school has lathes, some other handy fabrication equipment and (in need of fixing) a mill and small cnc lathes. In my case there are 2 older guys within walking distance who I will fix excavator wiring etc for, in exchange for using some machines. They have 100s of tonnes of machines from mills to power hammers.
This is painfully true. I have wasted a lot of money in efforts to save money.
That sounds like something I could work on. There was a large thread of people working on a broken 6396 which I ended up getting and fixing. I can make the axles and the previously mentioned guy has the machinery for key ways for approx 3-300mm diameter axles. I just need to learn how to do it instead of taking the time of machinist Gandalf.
fyi Reacher 6385 has a 53x50mm stator and the 6395 has a 53x60mm stator. So the 11.8% longer motor is actually 20% larger inside. Just in case there seemed to be a large performance difference for 1cm more motor.
The weaker magnets performing better is very interesting. I think standard is the second strongest to N52, N45 and Reacher was using N42 / N38.
Thereās lots I donāt understand like for racing drone motors we use concave magnets for less magnet gap and lots of esk8 motors have convex magnets for less noise which seems like the priorities are out of order.
3 Likes
Well I fed reversed polarity into my maker xdv6s, twice. I guess i check for shorts on the pcb or is that redundant because its likely dead? Also how tolerant are batteries of this? I have to redo the xt90s on the terminals. Is the battery still safe to use?
It absolutely depends on the battery but as long as it wasnāt shorted for long and got to the point of overheating the battery is likely fine. Short bursts of super high current (less than a second or two) shouldnāt kill a well made battery. This is all guessing - need more info
Probably cooked the dv6s, you can take a look at the pcb and see if anything obvious poped and test it for a short but im not savvy on best practices here so no good advice from me. if you want to go in blind use a current limited power supply first to see if it works/boots up and not a battery with hundreds of amps available.
2 Likes
I tested the mosfets and booted the esc with a 36v power supply, suprisingly nothing seems broken, im going to try the foc wizard tomorrow. The only burnt i can see is the loop key i plugged in.
Thank you for responding
The battery seems okay.
1 Like
Maker x dv6s survived, got through detection!
5 Likes
Is this still true? I was recently given the impression by several different people that itās better to have the drivetrain connected during detection and the inertia of the drivetrain may somehow help detection.
Iāve never had issues with either way. Nowadays i donāt bother to take stuff off.
3 Likes
I havenāt either, but this is the VESC project you see and I am scared of doing anything other than ābest practiceā lol