Search found 198 matches

by thepronghorn
Jan 23 2019 3:11pm
Forum: E-vents
Topic: Sea Otter Classic 2019, April 11-14, Monterey California
Replies: 5
Views: 244

Re: Sea Otter Classic 2019, April 11-14, Monterrey California

only bikes operated by the following systems may race: Bosch, Brose, Shimano, or Yamaha
:(
by thepronghorn
Nov 15 2018 9:44pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Neu 8057 6kW left hand drive hardtail with vesc and encoder
Replies: 36
Views: 2854

Re: Neu 8057 6kW left hand drive hardtail with vesc and encoder

Can you go into more detail or show some more pictures of your bottom bracket and mounting plate setup? I had the same idea of mounting a motor in front of the bottom bracket and driving the rear wheel directly on the left side. Specifically, it looks like you are running an ISIS bottom bracket? Is ...
by thepronghorn
Oct 29 2018 4:02pm
Forum: Electric Aircraft
Topic: practical range
Replies: 7
Views: 537

Re: practical range

Beautiful picture. The Tetons are one of my favorite national parks.
by thepronghorn
Oct 19 2018 1:41pm
Forum: E-Bike Non-hub Motor Drives
Topic: My RC Mid Drive with Single Stage Reduction
Replies: 101
Views: 6161

Re: My RC Mid Drive with Single Stage Reduction

Would using a 60kV motor such as this one: https://alienpowersystem.com/shop/brushless-motors/aps-5065-outrunner-brushless-motor-60kv-1800w/ potentially open up higher voltages or simpler reductions? Nope, changing Kv does nothing to change a motor's torque capability, it only changes the voltage/c...
by thepronghorn
Aug 29 2018 2:44pm
Forum: E-Bike Technical
Topic: Kv * turns = constant?
Replies: 10
Views: 467

Re: Kv * turns = constant?

Markz, ProxRB is not messing up the turn count thing. He's just recognizing that spinning faster and gearing down to the same speed results in more torque capability. ProxRB, you don't necessarily need to increase Kv to increase speed. You could also increase your battery voltage. Besides being able...
by thepronghorn
Aug 27 2018 1:38pm
Forum: E-Bike Technical
Topic: Kv * turns = constant?
Replies: 10
Views: 467

Re: Kv * turns = constant?

First, I'll define my variables just for clarity's sake. Kv: rpm/volt Kt: torque/amp Rm: motor phase resistance P: power I: current V: voltage w: angular velocity T: torque Yes Kv is proportional to the inverse of turns. A 200Kv, 4 turn motor will be 100Kv if wound with 8 turns. Rm is proportional t...
by thepronghorn
Aug 07 2018 4:25pm
Forum: Motor Technology
Topic: Minimising rotor losses
Replies: 94
Views: 2967

Re: Minimising rotor losses

larsb wrote:
Aug 07 2018 3:44pm
This paper explained a lot to me on the harmonic losses, when they occur and some of the compromises in motor design:
Slot pole Combinations Choice for Concentrated Multiphase Machines.pdf
Very good read. Thanks for posting that!
by thepronghorn
Jul 26 2018 5:53pm
Forum: Motor Technology
Topic: Minimising rotor losses
Replies: 94
Views: 2967

Re: Revolt RV-series motor review and comparisons

Lol I spent like four hours reading and writing this post, so hopefully we can get this useful conversation moved to its own topic. I have read all the posts and links in this thread, and I think we all agree on a lot of things and disagree on just one thing. Agreements Different motors have differe...
by thepronghorn
Jul 25 2018 6:06pm
Forum: Motor Technology
Topic: Minimising rotor losses
Replies: 94
Views: 2967

Re: Revolt RV-series motor review and comparisons

My comments and conclusions from this article: "Reducing PM Eddy Current Rotor Losses by Partial Magnet and Rotor Yoke Segmentation" Regarding magnet segmentation right up front this article says this which basically maens magnet segmentation is not ever going to be something any manufacturer will ...
by thepronghorn
Jul 20 2018 12:37pm
Forum: Motor Technology
Topic: Minimising rotor losses
Replies: 94
Views: 2967

Re: Revolt RV-series motor review and comparisons

"..It's actually increased stator hysteresis losses not stator eddy losses from higher electrical frequency." @thepronghorn:As the frequency is one of the factors in below formula i doubt that you are correct. (It's from Wikipedia). Eddy current losses are proportional to the square of the frequenc...
by thepronghorn
Jul 19 2018 1:46pm
Forum: Motor Technology
Topic: Minimising rotor losses
Replies: 94
Views: 2967

Re: Revolt RV-series motor review and comparisons

... Of course that means you have a motor with 200 poles to eliminate the eddy currents. Clearly there has to be a middle ground between ridiculous magnet counts and minimizing eddy losses. I think this may be the reason why hubs and outrunners have lots of magnets. This may be the place where eddy...
by thepronghorn
Jul 18 2018 3:29pm
Forum: E-Bike Non-hub Motor Drives
Topic: RC motor on swingarm
Replies: 6
Views: 503

Re: RC motor on swingarm

I = 0.5*M*R^2 Inertia is directly proportional to mass but proportional to the square of radius, so moving mass closer to the pivot point will decrease inertia a lot. Your example of replacing a 4kg hub motor with 2kg of motor at let's say 1/2 the radius results in (1/2 the mass)*(1/2 the radius)^2 ...
by thepronghorn
Jul 18 2018 11:57am
Forum: E-Bike Non-hub Motor Drives
Topic: Castle LINK programming kit - is it necessary/worthwhile with CA V3?
Replies: 11
Views: 415

Re: Castle LINK programming kit - is it necessary/worthwhile with CA V3?

Yes definitely get the Castle Link. The CC ESC needs some settings adjusted out of the box.
by thepronghorn
Jul 12 2018 6:35pm
Forum: E-Bike Non-hub Motor Drives
Topic: Dave's 80:1 RC mid drive kit build log
Replies: 1361
Views: 156238

Re: Dave's 80:1 RC mid drive kit build log

Drive unit weight: 7.5lbs Dimensions: 100mm diameter, 120mm length Engine: Neutronics 3215, 225kV Controller: Castle Talon 120, custom mount/heatsink, QS-8 main battery connect Performance (calculated w/ 120A phase): 135ft-lbs crankset torque 400RPM crankset 48t cog: 216ft-lbs wheel torque, 21mph 4...
by thepronghorn
Jul 05 2018 7:03pm
Forum: General Discussion
Topic: Why Is 18650 So Popular?
Replies: 11
Views: 587

Re: Why Is 18650 So Popular?

I'd say they still sell 1000+ tool packs for every Tesla that gets sold. Most of the tool packs aren't sold to average consumers for occasional use, they're sold to trades people that burn through these packs at a rate of several per year. Not sure about that... 2000 Model S and X last week = 16 mi...
by thepronghorn
Jul 05 2018 5:30pm
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 66
Views: 4442

Re: Revolt RV-series motor review and comparisons

Generally it's easiest to measure the width of 10 or 20 lams. The specs we need to characterize the performance of a motor are phase resistance, speed constant (aka Kv, rpm/volt is a common unit), and losses at no load at two different voltages. The page below discusses how to measure them all. http...
by thepronghorn
Jul 05 2018 3:26pm
Forum: Motor Technology
Topic: Revolt RV-series motor review and comparisons
Replies: 66
Views: 4442

Re: Revolt RV-series motor review and comparisons

Like madin88 said, measure the Rm, Kv, and no load losses at two different voltages, and then we will be able to compare these two motors performance wise (inductance would be nice as well for an indicator of the "controllability" of the motor). You have already covered their mechanical design fairl...
by thepronghorn
Jun 29 2018 8:27pm
Forum: E-Bike Build Threads / Photos & Video
Topic: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
Replies: 331
Views: 24427

Re: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar

Did anyone else spot the super soaker water squirt gun strapped to the trike? What's it for?
by thepronghorn
Jun 27 2018 2:29pm
Forum: Battery Technology
Topic: DC/DC converter 72v to 36v?
Replies: 5
Views: 245

Re: DC/DC converter 72v to 36v?

Many 36V controllers will not appreciate being fed 84V from a full 72V pack. 63V rated capacitors are pretty common in them. Do some research first. .... I think you're talking to me here? That's why I said to use a 72V controller. If you're talking about my last sentence, I guess I should clarify ...
by thepronghorn
Jun 26 2018 1:45pm
Forum: Battery Technology
Topic: DC/DC converter 72v to 36v?
Replies: 5
Views: 245

Re: DC/DC converter 72v to 36v?

Motor controllers are buck converters. If you don't want to "crack the battery in half," you can just use a 72V controller to buck the voltage down to your motor. You can even limit throttle to 50% or whatever throttle position corresponds to 36V (I believe most cheap controllers just map throttle p...
by thepronghorn
Jun 12 2018 1:20pm
Forum: E-Bike Non-hub Motor Drives
Topic: Hub installed on bottom bracket
Replies: 4
Views: 446

Re: Hub installed on bottom bracket

There's this. I wonder how much it would be for just the motor...

viewtopic.php?f=28&t=90548&hilit=bikee
by thepronghorn
Jun 11 2018 3:33pm
Forum: E-Bike Non-hub Motor Drives
Topic: Hub installed on bottom bracket
Replies: 4
Views: 446

Re: Hub installed on bottom bracket

Is this what you are trying to describe?

https://www.bikeebike.com/
by thepronghorn
May 27 2017 8:51am
Forum: E-Scooter and Motorcycle General Discussion
Topic: Noob Attempts EV Conversion: reVOLT
Replies: 19
Views: 1859

Re: Noob Attempts EV Conversion: reVOLT

Have you looked at QSmotors? Some people are using their motors with success. Maybe just another option to compare with.

Building batteries is a lot of work but should give you the flexibility you'll need to try and keep the styling organized.