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by liveforphysics
Jan 17 2019 2:44pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3016
Views: 176910

Re: Sur-Ron - New Mid drive Bike

OMG! Drool!!! Beautiful belt conversion! After market, why would surron make that kind of stuff =) With the help from Madin it looks like the next season for Light Bee will be very quiet! I will start offering these quite soon. Dont ask questions yet, full disclosure will be made once we fully test ...
by liveforphysics
Jan 16 2019 3:43am
Forum: General Discussion
Topic: Telescope design; eliminating mirror-support diffraction
Replies: 11
Views: 278

Re: Telescope design; eliminating mirror-support diffraction

https://www.surreynanosystems.com/super-black-coatings/vbx-coatings/vantablack-vbx-2 Spray the mirror supports with that stuff, as well as inside the tube walls, and it will help a bunch. If you don't have reflective surfaces, just blocking light there isn't such a big deal, because any single point...
by liveforphysics
Jan 14 2019 6:33pm
Forum: Battery Technology
Topic: Losing Lipo cells
Replies: 6
Views: 181

Re: Losing Lipo cells

Mechanical stress to the pouches causes cracks in the coating layers that makes self-discharge and gas production in the cells which causes capacity loss when the gas is trapped between layers.

Also, nice bikes! Looks like a blast!
by liveforphysics
Jan 11 2019 6:02pm
Forum: Battery Technology
Topic: VW e-up Li-ion cels
Replies: 42
Views: 5569

Re: VW e-up Li-ion cels

Thanks for sharing my friend. :bolt:
by liveforphysics
Jan 07 2019 3:12pm
Forum: Large EV General Discussion
Topic: Tesla M3 teardown information video - Hallbach Array Motor
Replies: 15
Views: 394

Re: Tesla M3 teardown information video - Hallbach Array Motor

I think the root cause may be that nobody at Monroe seems to grasp basics of EV energy storage or powertrain.
by liveforphysics
Jan 06 2019 3:30pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Toyota Prius A/C Compressor Motorbike: The Bike of IPM Motor Science
Replies: 43
Views: 2940

Re: Toyota Prius A/C Compressor Motorbike: The Bike of IPM Motor Science

I don't know how I missed this thread until now. Wow! You are a rockstar Fpvdude! Lowest effort and lowest performance way to build your IPM tables at higher RPMs may be a woodworking router motor. They should run fine on DC for speed control, and some achieve 18krpm+ More effort, but a second of th...
by liveforphysics
Jan 06 2019 3:11pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1794

Re: SPM VS IPM Motor - And Field weaken, is it worth it

[quote= If the rotor iron is well designed for leveraging reluctance torque, this will have a ~neutral efficiency impact to use the additional torque. Coming up with that amount you want to deviate from in phase requires a lookup table from characterizing the rotors iron characteristics. Also, take...
by liveforphysics
Jan 06 2019 1:15am
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1794

Re: SPM VS IPM Motor - And Field weaken, is it worth it

Dont know about the James Mevey thesis, but I remember that in the early 90ies at the technical university of Eindhoven I had a 'electronic machines' class where the professor told us that making power with a motor comes down to stuffing current into the bemf... That's how you win at power factor o...
by liveforphysics
Jan 04 2019 12:55pm
Forum: Motor Technology
Topic: SPM VS IPM Motor - And Field weaken, is it worth it
Replies: 82
Views: 1794

Re: SPM VS IPM Motor - And Field weaken, is it worth it

I've experienced hundreds of controller faults from various types of field weakening controllers while deep into field weakening and never had that damage anything. This seems odd because the BEMF if you spun the motor up with a drill to that same RPM you faulted at would be above Vdsmax for the mos...
by liveforphysics
Jan 02 2019 3:27am
Forum: Large EV General Discussion
Topic: RIPPY KART
Replies: 28
Views: 1768

Re: RIPPY KART

Beautiful kart my friend!
by liveforphysics
Dec 28 2018 12:50pm
Forum: E-Bike Build Threads / Photos & Video
Topic: 55.2kw bicycle
Replies: 36
Views: 1799

Re: There's a new sheriff in town (new pics on p5)

I want to see it if its 60kW. JohninCR would want to see it too!
by liveforphysics
Dec 23 2018 9:09pm
Forum: Motor Technology
Topic: Brushless motor efficiency
Replies: 25
Views: 1111

Re: Brushless motor efficiency

You're looking at current values in Amps that are around and amp with instrumentation thats +-2amps or more.
by liveforphysics
Dec 21 2018 9:47pm
Forum: Motor Technology
Topic: Brushless motor efficiency
Replies: 25
Views: 1111

Re: Brushless motor efficiency

The current values seen on that software is well inside the current measurement noise expected. If you load it, things will look much different.
by liveforphysics
Dec 21 2018 4:04pm
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 354
Views: 26400

Re: Nucular electronics - complete kit for ev! [beta]

So can i set FW at rpm-dependent value? Like 20% at 100 rpm 50% at 2000 rpm 80% at 5000 rpm I think you should add 24F estimated specs, price and timing on first post in this thread You want to have mechanically optimized commutation event timing for as long as you have pack voltage > BEMF. For thi...
by liveforphysics
Dec 21 2018 1:58pm
Forum: Motor Technology
Topic: Brushless motor efficiency
Replies: 25
Views: 1111

Re: Brushless motor efficiency

Motor current at no load is just the torque to overcome core losses normally. If you have high motor phase current it means high motor torque output if that current is being applied at the right commutation timing.
by liveforphysics
Dec 20 2018 11:32pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3016
Views: 176910

Re: Sur-Ron - New Mid drive Bike

While power washing those parts directly, other parts may be damaged by spray back, but it's your bike to do what you want. I moved to wiping with a damp rag and not cleaning whatever isn't practical to clean in a few minutes with a rag. This was by far the best longevity of dirtbikes strategy i fou...
by liveforphysics
Dec 20 2018 9:19pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3016
Views: 176910

Re: Sur-Ron - New Mid drive Bike

As someone whos had dirtbikes of sometype for 30 years, the bikes I power washed would have all the bearings and suspension bushings fail and random electronics and switching fail. The bikes I would then hose and scrub off would have all the bolts rust and still often fail suspension linkage seals f...
by liveforphysics
Dec 20 2018 9:13pm
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 354
Views: 26400

Re: Nucular electronics - complete kit for ev! [beta]

It's not so good for this, it uses a lot of amps to get any effect. It would be awesome if we could get anything like even a 40% increase in rpm on our normal surface permanent magnet motors but unfortunately so far im not seeing it, not without them being IPM, so im curious Vasilisk what sort of r...
by liveforphysics
Dec 20 2018 4:51am
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 354
Views: 26400

Re: Nucular electronics - complete kit for ev! [beta]

VasiliSk wrote:
Dec 20 2018 3:31am
Mine surron motor is not IPM, it is SPM
My bad, I was thinking of the GoGro scooter IPM rotor, you're right Sur Ron is SPM. Should take around 50-70% above base RPM before getting a bad efficiency hit then.
by liveforphysics
Dec 20 2018 1:47am
Forum: E-Vehicles General Discussion
Topic: Cheap VESC (VESC 4.12 redesign)
Replies: 65
Views: 1888

Re: Cheap VESC (VESC 4.12 redesign)

Love it. Any shot at a 12f layout or a 6f TO247 package version? I would chip in a few hundred bucks to cover some board spins.
by liveforphysics
Dec 19 2018 11:32pm
Forum: E-Bike Non-hub Motor Drives
Topic: Sur-Ron - New Mid drive Bike
Replies: 3016
Views: 176910

Re: Sur-Ron - New Mid drive Bike

Im going to try a riser bar now, sounds great. How tall are you?
by liveforphysics
Dec 19 2018 10:32pm
Forum: Battery Technology
Topic: VW e-up Li-ion cels
Replies: 42
Views: 5569

Re: VW e-up Li-ion cels

I built a 13S pack with those (which I think came out of a Ford?) and it's the most satisfactory battery I've ever used. It's 26 pounds including enclosure, but worth it. My previous 18650 pack seems like a toy by comparison. I'm only pulling up to 35A, so they'll probably do that job longer than t...
by liveforphysics
Dec 19 2018 10:00pm
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 354
Views: 26400

Re: Nucular electronics - complete kit for ev! [beta]

It's not so good for this, it uses a lot of amps to get any effect. Because the motor is IPM not SPM, it takes an additional look up value for rotor reluctance torque compensation to field weaken efficiently. The beautiful thing is, SPM motors rarely can field weaken more than 70-100%, and some IPM...
by liveforphysics
Dec 19 2018 9:07pm
Forum: Battery Technology
Topic: 144v or 72v for motorcycle?
Replies: 11
Views: 452

Re: 144v or 72v for motorcycle?

The hit is small, just the power density difference in 200Vdc mosfet dies to 100Vdc mosfet dies. It's going to be single digit% at most. The other aspect is cell string having few cells to manage and corrosion effects being milder and shocks being milder.
by liveforphysics
Dec 19 2018 11:41am
Forum: Items for Sale - New
Topic: Nucular electronics - complete kit for ev! [beta]
Replies: 354
Views: 26400

Re: Nucular electronics - complete kit for ev! [beta]

Maybe it's already been tested, but has anyone tried the 24F model on a Sur Ron motor? If it's giving 500amps phase current and has field weakening for top-end, it should offer incredible hot-rodding potential. Thank you VasiliSK for making such a cool controller! I wish you well, and remember all ...