I’m here with my first build and I must admit that I’ve started this “project” about a year ago, as you can see I’ve got basically nothing finished (not sure about what parts to order and how to mount it/slap it on the board).
Now I understand I need to do these things:
Connect the motor with the weels using a belt drivetrain, however I’ve got Rogue trucks which I’ve never seen on any build, is it even possible to create a drivetrain for them?
Now for the motor I was planning on using the [Axi V2], however the it’s 305rpm/V which could be hard to gear down?
Has anyone done a drivetrain with a gear ratio this big?
Now I understand that I should use a VESC as it’s specifically enginerded for electric longboards. The motor’s max (60s burst) is 56A, does it really mean 56A in the real world? Can VESC even handle that (different versions with different max A?).
I’ll also have to get a reciever of some sort and origin, as I’m only sixteen I’m planning on not dying on my board asap . What is the most reliable connection between me and the VESC??? I really wouldn’t cheap out and just get some wii home-brewed reciever. Is the most reliable system the GT2B?
However the most problem I see with the battery overall, I have 12x A123 26650 cells (43.2V max) the motor’s recommended voltage is 6-8S lipo (33.6V) what should I do? Does the VESC have a step-down voltage function? I really will need a reliable BMS for these cells but all BMSs I can find are really cheaped out looking boards, is there any way of stealing the boosted’s BMS?
You’ll either need to change the motor or the batterys. Your motor KV is too high for your 12s voltage. It’ll fry the vesc. Have a look at <200ish kv motors.
EDIT:
Most reliable remote -> GT2B. Yep, not the most compact but there are DIY mods for it.
And no 60A burst is not the real-world application. It’ll be around 5-15amps continuous when riding the board. Going uphill is a different story.
There are good options for BMSs. No need to rip off the boosted board bms.
My rebuttal to the two above comments about having a high KV motor. MoeStooge has this setup running well last time I read. As long you geared it correctly you cannot blow up the speed controller. However, a 192kv motor is fine.
Gearing has absolutely nothing to do with blowing the speed controller.
The vesc 4.12 can handle 60.000 erpm devide by 7 pole pairs 8570 rpm.
At 40V his motor will do 13000 RPM and absolutely fry a normal old vesc.
You can always change the KV of the motor… can be done quite easily without rewinding the motor. Almost all outrunners are connected using a delta-connection. By removing the heatshrink of the motor wires, they can be split up and reconnected in a star-connection. This reduces the KV by a factor of sqrt(3) = 1.73.
Thank you very much for all the info I missed. I’m definitely going to read more about VESC and it’s limitations (erpm). I’ll take a look a look at the motor and it’s limits (high rpm namely). For now I have to unfortunately finish some school work.
Might be, I’m an EE so i studies a few Courses on Electric Power and motors back in uni.
The BLDC motor is essensially the same as a 3 phase AC motor. (without the commutator obv)
Read up abit on it if you’re intrested, the actual wiring change shouldn’t require much prestudy however. It’s practically three terminals.
If you look at the Picture that some Bright guy posted above, you can see that wounds inside the motor is drawn as an inductors(the curly things). If you where to dissaseble your phase wires going out from the motor, they should consist of two strands of Cables if Delta wired. Leaving you with 3 pairs of strands when fully dissasembled. Now, using these 6 strands you connected them as a star configuration (right part of the Picture) and there u go, lower kv(by a factor of 1.73)
So If I want to keep this motor I’ll have to rewire it to a star configuration.
If this reduces the KV by a factor of 1.73 does it increase the torque accordingly?
If I do this:
motor’s max recommended voltage is 8s lipo = 33.6V = 9.3 Lifepo cells
If I used 9s (1p only - not enough cells) A123 26650 = 32.4V max
Motor - 305 rpm/V = 32.4*305 = 9882rpm (note however that the voltage drops almost immediately withe these cells = less rpm)
If the motor had 7 pole pairs (I’ll ask the manufacturer)
than 9882rpm * 7 (let’s assume) = 69174 erpm
If I rewire the motor it’s 69174/1.73, right? = 40.000 erpm
Now the regaular VESC could handle this if I understand corretly
. What is the most reliable connection between me and the VESC??? I really wouldn’t cheap out and just get some wii home-brewed reciever. Is the most reliable system the GT2B?
!
) brings up to fully rewind a motor, not just rearranging leads