New Hummie Hubs!

Thanks @bigben this helps a lot…Really appreciate you taking the time to open her up!!!:grinning:

1 Like

Nice idea with the charge port and switch, did you drill all the way with the same size drill bit?

No I stepped it down to the smallest I could to try to keep as much of the integrity. Seems fine, so far…

Yeah, that’s exactly what I was thinking

Will try to do something like that, but somehow make everything sit flush with the side, don’t know if it can be done when using the rubber cover

1 Like

@hummie would you be able to re-terminate for a delta version & more top speed but less thrust? it would appear using the same current settings, efficiency would be also be greater during full throttle acceleration with the higher kv motor (green line, top left chart - electrical to mechanical conversion efficiency %), since with the same motor current settings and 1/3 the electrical resistance with the delta version, less heat is produced via I^2R=W loss (green line, bottom middle chart - ohmic heating watts 2 motors).

wye 75kv * delta sqrt(3) = 129kv

top speed: ~35mph → 50mph (yellow line, bottom left chart - vehicle thrust in pounds) thrust: 81lbs → 47lbs (yellow line, bottom left chart - vehicle thrust in pounds) peak copper loss (60a motor current limit): 504w → 167w (green line, bottom middle chart - ohmic heating watts 2 motors)

2 Likes

I think the motor efficiency would be the same but the overall system efficiency would be lower with the higher kv as the esc will have more losses as it’ll have more current needed through it. But the motors are terminated wye inside the motor already and you can’t change them back to delta. If someone wanted delta for maybe a different esc I’d do it but for the vesc the lower kv and higher cell count seems ideal.

Esc will have more loses at lower than 100% duty cycle but the vesc only ever goes to 95% anyway making the difference in kv less important for esc efficiency. But we’ll do some comparisons sometime.

1 Like

@Hummie for the same torque you are correct, both motors are the same efficiency & greater esc loss with the higher kv due to more amps required for the same torque-- but for the same motor current through both (not the same torque), the higher kv is more efficient in the motor, due to the significantly lower copper loss with 1/3 motor electrical resisitance via I^2R=W loss.

But then the high kv is less power output. For same power output think should be the same efficiency. In the motor. Think better to compare with equal power output.

right but imagine a series of stop signs (never constant speed), where you are either accelerating full throttle with the same motor current settings on both (60a) or coasting… the higher kv gets more range (significantly less heat generated in the motor) but won’t accelerate as quickly.

The efficiency could be emulated w the low kv and reducing throttle, and will have the ability to have more torque when wanted vs the high kv which would limited to that lower torque output w vesc

Damn, that’s really nice touch with the drill.

2 Likes

100a on each motor? what size is your batt?

motor amp is independent from battery amp. I’m running 10s4p sanyo cells 20A, so im runing 40A on each FOCBOX. I’ll switch to 30Qs very soon.

Also, man, for everyone that ordered the these hubs, you HAVE to run 12s. It has so much torque and I feel like I hit top speed too fast. I need that 5mph speed boost and a second or more acceleration.

15370642320625473712561079681978 These are the best PU man, hitting 100 miles and still dont see a dent on then. they have sharp edges and coreless. im surprised how well they hold together. (well I was there sleeving them onto the CAN, and I guarantee for some of them, it took my whole weight to push them down.)

I know not a lot of you got the japanese bearing. but trust me, they are worth every penny. Butter smooth and rolls like crazy.

did I mention that these hubs are completely silent on FOC.

14 Likes

I got mine this afternoon, haven’t done anything other than take them out of box, but damn they are pretty.

I knew in 2 seconds they are more solid than any of the Chinese hubs I’ve ever seen… By miles, better.

Damn good job @Hummie.

15 Likes

IMG_20180905_161525

9 Likes

im learing as I go and realizing that if the motor is especially tight to spin in your hand it can be the big bearing could be suffering from compression and when the final c-clip is snapped on, if its needed to be done with pressure, then the two bearing races can be pressed out of alignment and there’s a big drag on the bearing. But its hard to tell if it’s this is possibly the case with a tight feeling motor because there’s the thick grease I go on about and also the motor has a magnetic cogging when unpowered so has a resistance in your hand and you cant distinguish between what is what. its an easy enough fix and the c clip can be replaced by me with a slightly thinner one. its hard to tell but if your big bearing goes bad early on that’s the problem and send it to me and i’ll get it as should be the magnetic cogging of the motor that happens when coasting, if I get the bucks I’ll definitely be getting a custom stator made to get rid of it. luckily no motors have been sent far yet and figured this out. I can check all the parts before assembling the magnets and make sure in the future.

4 Likes

@Hummie so are you giving a recommendation on new hubs evaluation to ensure reliability? I am still waiting on battery before running what are you suggesting?

don’t get stuff in the holes and write me if after a month or two you think your bearing is tight or having problems and may be compressed and I’ll get them right and back out. I just went through and checked the rest of them and maybe 2 or 3 in ten is tight and needs adjusting, but Id been checking things for fit after the magnets are on and hadn’t realized and was chalking tightness up to bearings or magnets. im learning.and its an easy fix so no big whoop and if you want to send them back just to be sure theyre right please do. i’ll pay the shipping back to you. pm me. still on track to have all the rest of the motors out on Monday.

3 Likes

Wait, your large bearing is press fit at both the inner and outer race?

Neither side press fit and uses retaining fluid. But the support on the big bearing’s side can be compressed when the final c clip is installed. And won’t run smoothly and will likely kink out early too

I’d like press fits maybe on both sides of both bearings. Kind of a bitch to assemble then but when it’s figured correctly figure would be ideal for such loads