Search found 2079 matches

by justin_le
May 31 2019 3:27am
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Re: 2019 Motor Simulator, Mid-drives and other updates

wiht a 72v pack and 29" wheel (would need some kind of bolt-on adapter replacing the "rim" it comes with) teh simulator shows it could push me on my trike to 19mph on a 1% grade, and still stay just over boiling water temperatures. :lol: Even if you were going downhill on a -2.9% grade where the mo...
by justin_le
May 31 2019 2:56am
Forum: E-Bike Technical
Topic: Variable regen drag brake for tandem bike w CA3 & PhaseRunner
Replies: 15
Views: 445

Re: Variable regen drag brake for tandem bike w CA3 & PhaseRunner

Variable regen braking would be perfect for this application. I envision a small potentiometer (or perhaps a switched pot) that can be rotated up from its zero position to engage regen that is proportional to the pot’s position. Variability of regen is important to tune speed. After descent it will...
by justin_le
May 31 2019 1:59am
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Bafang Wheelbarrow Motor

Another oddball motor from Bafang isn't even on their webpage but is something that fits an interest of ours is this geared motor designed for a wheelbarrow. Bafang Wheelbarrow Hub.jpg There are many times when we have customers trying to find a hub motor for really high torque and low speed applica...
by justin_le
May 31 2019 1:25am
Forum: E-Bike Technical
Topic: Bafang G3xx series high reduction ratio geared hub motors
Replies: 50
Views: 3773

Re: Bafang G3xx series high reduction ratio geared hub motors

The G370 is really interesting, has anyone tried it yet? You mean this little guy? G370 Disassembled.jpg Cutest hub motor on the planet I'd say. When I'm finished the testing on it I'll be posting the results in this simulator thread here https://endless-sphere.com/forums/viewtopic.php?f=2&t=100461...
by justin_le
May 30 2019 7:01pm
Forum: E-Bike General Discussion
Topic: Grin trip simulator core temp
Replies: 10
Views: 288

Re: Grin trip simulator core temp

Well it is called a "trip simulator" after all. :^) I know, one of my big regrets! The current name is indeed misleading for what my intentions are. I'm thinking to possibly rename it as "trip modeler" to avoid this. "Time domain EV simulator" doesn't have quite the right ring but would be more acc...
by justin_le
May 30 2019 5:43pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Bafang D410 Scooter Motor

While bafang is mostly known for geared motors, they do have a few direct drive models for scooter wheels and I got my hands on a D410 in an 8" wheel. https://www.bafang-e.com/en/oem-area/components/component/motor/fm-d410250d/ Which is this one in the dropdown menu Bafang D410 8in Scooter.jpg Bafan...
by justin_le
May 30 2019 5:19pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

G360 vs eZee, MAC

With all this empirical test data and a nicely fit model we could get to the real point which is to compare the this new G360 to other motors in the same power class, and this is where things got interesting and a little bit disappointing. In order to facilitate doing those side by side comparisons,...
by justin_le
May 30 2019 4:43pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Re: 2019 Motor Simulator, Mid-drives and other updates

Qwerkus, you jumped the gun on me! Anyways, onto the G360 motor performance. What I got was an 11T winding, which had a winding resistance of 79mOhm and a kV of 9rpm/V. Core Loss Data The no load core drag varies from 2-2.25 Nm at ebiking speeds, and doesn't increase too much with RPM which we can a...
by justin_le
May 30 2019 4:13pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

The Bafang G360

One of the motors that I was sooo anxious to get my hands on for characterizing was the G360 motor from Bafang. I've made no secret of my love for the smaller G310/311 motor series with the inrunner design and helical cut gears with a high ~11:1 reduction ratio, and the G360 motor promised to be a m...
by justin_le
May 30 2019 2:49pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Additional Motors

Kudos for adding these (and mid-drive calculation) to the simulator, I really dig it! I'd love to see how the G510 (Ultra) and the newer M600 perform on your test bench when you get around to them, Well unless one just shows up on our doorstep don't hold your hopes for that yet ;-) (the simulator f...
by justin_le
May 30 2019 2:00pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 121
Views: 15683

Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

Awesome reply. Thanks a lot for the details. I'm in - though I doubt the small g311 can handle a lot of regen heat, even with ATF cooling, so I'm going for the larger brother g360.500... as soon as I find a seller for it! I'll be posting my disassembly analysis and test results on the G360 on this ...
by justin_le
May 29 2019 11:36pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Re: 2019 Motor Simulator, Mid-drives and other updates

This is super cool, and confirms some performance implications that others have found with these BBS motors, Roshan at Biktrix has been telling me for years that the BBS02 really is the better motor all around, especially considering the lower stock weight and cost... Seeing this all summed up with...
by justin_le
May 29 2019 4:11pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Re: 2019 Motor Simulator, Mid-drives and other updates

As a result of this, (higher mass and larger size for shedding heat), once I added the thermal model to the simulator properties then we do see a difference in what the BBS02 and BBSHD drives can cope with. For instance, climb a 9% grade hill with the following gearing until steady state and the BBS...
by justin_le
May 29 2019 4:06pm
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Re: 2019 Motor Simulator, Mid-drives and other updates

The stuff with the BBS02/HD is really interesting. It really is. Of course the other part of the motor performance is the thermal side of things. If you have two motors with identical KV and winding resistance then their off-the-line performances are mostly indistinguishable, but if one motor has b...
by justin_le
May 29 2019 3:02pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 121
Views: 15683

Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

That's an awesome picture - thanks. Always wondered how those cheap "thrust bearings" look like. Here's what they look like installed behind the planet gears, it's pretty slick since they fit inside a recess in the gear casting and don't add any width to to the gear assembly. ThrustBearingInstalled...
by justin_le
May 29 2019 5:01am
Forum: E-Bike General Discussion
Topic: Grin trip simulator core temp
Replies: 10
Views: 288

Re: Grin trip simulator core temp

along the straight part the watts used show 0, however the core temperature (red line) keeps rising. Notice though that even though the electrical power is 0 watts, the motor mechanical power is showing -23W? This is the amount of core losses going into the hub motor to keep it spinning (assuming t...
by justin_le
May 29 2019 4:47am
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

Re: 2019 Motor Simulator, Mid-drives and other updates

One thing that you do notice from the normalized graph above is that the BBSHD has a slightly higher efficiency. This is because when we look at the motor core losses, the BBS02 has higher motor drag than the BBSHD at the the typical pedal cadence range. BBSxx No Load Losses.jpg They both have simil...
by justin_le
May 29 2019 4:15am
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

BBS02 and BBSHD

One of the steps to make this new simulator feature useful was getting the two most popular after market mid-drive systems modeled, namely the Bafang BBS02 and BBSHD drives. At our shop we don't deal much with mid-drives for the reasons outlined here but we were able to receive some sample units fro...
by justin_le
May 29 2019 3:26am
Forum: E-Bike Technical
Topic: 2019 Motor Simulator, Mid-drives and other updates
Replies: 30
Views: 1574

2019 Motor Simulator, Mid-drives and other updates

Sharp eyes may have noticed that we added a 'mid-drive' option to the online motor simulator last month and have been incrementally flushing out the details. I alluded to this plan earlier here https://endless-sphere.com/forums/viewtopic.php?f=2&t=89877&p=1386574#p1386574 and it's finally live now. ...
by justin_le
May 29 2019 3:03am
Forum: E-Bike General Discussion
Topic: Grin trip simulator core temp
Replies: 10
Views: 288

Re: Grin trip simulator core temp

Thanks amberwolf. I'm thinking that maybe the MAC is being modeled as a direct drive here - Correct conclusion! The trip simulator doesn't currently have any facility for modeling freewheeling motors, it treats it as though the motor is always engaged since that's a much more interesting scenario t...
by justin_le
May 29 2019 2:32am
Forum: E-Bike Build Threads / Photos & Video
Topic: My Sun Trip Bike, Back to Back Tandem Trike with Rowing Generator, Pedals, +Solar
Replies: 334
Views: 31346

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

There must be an abundance of data form all those data Loggers. There IS an abundance of data, but just a shortage of time. I has one of our software co-op students working on parsing and organizing much of it (and also fixing/correcting a bunch of corruption that managed to make it into a lot of t...
by justin_le
May 29 2019 2:28am
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 160
Views: 13403

Re: Reference Tests, Tabbed Washers

Can you provide more clarity why the Bafang washer provides advantages? Seems to be that while the tab is further away from the centre of the axle, this advantage is exactly offset by the tab also being further out and producing greater leverage on the dropout arms? If the dropouts were actually sp...
by justin_le
May 28 2019 10:45pm
Forum: E-Bike Technical
Topic: Bafang G310 geared hub - 11:1 reduction ratio!!!
Replies: 121
Views: 15683

Re: Bafang G310 geared hub - 11:1 reduction ratio!!!

It's not, due to the freewheel/clutch. If you want to do regen in a geared motor, you can either buy a clutchless one (such as this ) or weld the clutch fixed in your G310. Actually, while that advice holds with most geared hub motors, it wouldn't be advisable on the G310 because of the helical cut...
by justin_le
Mar 16 2019 12:33am
Forum: E-Bike Technical
Topic: Definitive Tests on the Heating and Cooling of Hub Motors
Replies: 2080
Views: 345985

Re: Definitive Tests on the Heating and Cooling of Hub Motors

Hello, will such a thing work: the wings stretched between the spokes , directly near the hub , directed along the wheel ,deflecting air flow to the hub ? I would say in generally no. The air flow you get from the forwards velocity of the bike is much higher than the rotational component from the w...
by justin_le
Mar 16 2019 12:24am
Forum: E-Bike Technical
Topic: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers
Replies: 160
Views: 13403

Re: 2018 Torque Arm Tests, Splined Interface Design and Tabbed Washers

Well,....It may be that the screws just aren't tight enough. Quite probably. Luckily for us the plate design has 12 threaded hole locations in it, so we were able to rotate the arm by 30 degrees so that the 6 arm holes now line up with the unused 6 threaded plate holes, and this let us tighten them...