Search found 11781 matches

by spinningmagnets
Jan 18 2023 8:25am
Forum: EScooters/EMotorcycles
Topic: Arctic Leopard dirt-bike, 72V
Replies: 9
Views: 334

Re: Arctic Leopard dirt-bike, 72V

Luke, I know you are a busy guy, but if you ever pull the motor open, please take pics? I can tell by a pic how many laminations it has, and if you measure the lamination stack width, we can calculate each lam thickness.
by spinningmagnets
Jan 16 2023 12:39pm
Forum: EScooters/EMotorcycles
Topic: Arctic Leopard dirt-bike, 72V
Replies: 9
Views: 334

Arctic Leopard dirt-bike, 72V

The 560, 680, and 800 model designation seems to be the newton meters of torque at the wheel.

Front wheel is 21-inch moto (80/100-21), and rear is 18 (110/90-18)

https://arctic-leopard.com/en-us/index.html
ElectricArcticLeopard1.jpg
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https://www.youtube.com/watch?v=I_AQ07rh-mU

by spinningmagnets
Jan 16 2023 8:29am
Forum: Battery Technology
Topic: Magnets holding copper bus onto cell, no-weld no-solder
Replies: 49
Views: 4280

Re: Magnets holding copper bus onto cell, no-weld no-solder

I would be hesitant to use a magnet as an electrical conductor in the circuit, they have high resistance, and if they get got, they will start losing their magnetism. Copper is cheap and available, an excellent conductor. If reasonably thick, it would not get hot under the load of one cell, so...I r...
by spinningmagnets
Jan 13 2023 8:43am
Forum: EBike Technical
Topic: Starting From Dead Stop Bafang G311 Geared Hub Motor
Replies: 20
Views: 236

Re: Starting From Dead Stop Bafang G311 Geared Hub Motor

If you are not overloading the hubmotor so that it gets very hot, you can definitely use a hand throttle to get going from a stop.
by spinningmagnets
Jan 13 2023 8:38am
Forum: EBike Technical
Topic: How to Build a Safer Battery - Looking to Collect Knowledge
Replies: 38
Views: 1014

Re: How to Build a Safer Battery - Looking to Collect Knowledge

Bottom balancing is a strategy that seems to have some smart and passionate followers when using LiFePO4. Vehicles generally continue to use NCA/NCM lithium-Ion chemistries due to them providing the most power and range in the smallest package. LiFePO4 is very fire-safe, so I've seen it used on smal...
by spinningmagnets
Jan 10 2023 7:35am
Forum: Battery Technology
Topic: Spot Welding Copper Strips to 18650 Battery Cells
Replies: 555
Views: 114167

Re: Spot Welding Copper Strips to 18650 Battery Cells

Those pictures were produced by a different builder, and he made a press and die set. I don't remember the original link, but the press and die are similar to the one in this thread: https://endless-sphere.com/forums/viewtopic.php?f=14&t=57810 https://endless-sphere.com/forums/download/file.php?...
by spinningmagnets
Jan 05 2023 3:10pm
Forum: Battery Technology
Topic: kWeld - "Next level" DIY battery spot welder
Replies: 1618
Views: 262386

Re: kWeld - "Next level" DIY battery spot welder

The picture of electrodes look like there is a nickel core, or some silvery-looking metal.

I recommend thick pure copper for the tips.
by spinningmagnets
Jan 02 2023 11:11am
Forum: EScooters/EMotorcycles
Topic: The Vectrix VX-1 info thread
Replies: 5
Views: 106

Re: The Vectrix VX-1 info thread

reserved for future data
by spinningmagnets
Jan 02 2023 11:11am
Forum: EScooters/EMotorcycles
Topic: The Vectrix VX-1 info thread
Replies: 5
Views: 106

Re: The Vectrix VX-1 info thread

reserved for future data

A custom wooden shell by boat-builder Steve Patmont
WoodenVectrix5.jpg
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WoodenVectrix3.jpg
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WoodenVectrix3.jpg (463.49 KiB) Viewed 101 times
by spinningmagnets
Jan 02 2023 11:09am
Forum: EScooters/EMotorcycles
Topic: The Vectrix VX-1 info thread
Replies: 5
Views: 106

The Vectrix VX-1 info thread

I knew of these a while ago, when I started at the VisforVoltage forum. They are no longer sold in the US, but they are an incredible deal now. I just read about an owner who bought a VX-1 with a dead 125V NiMh battery for $500, and then swapped-in a pack he made from 18 Leaf modules, for 36S, 130V ...
by spinningmagnets
Dec 29 2022 5:33pm
Forum: Electric Aircraft
Topic: Joby eVTOL
Replies: 17
Views: 334

Re: Joby eVTOL

I recall Joby has the highest-quality laminations, and they were using ones that are 0.20mm. I don't know what the current standard is, but if you make laminations thinner and thinner to reduce eddy current waste-heat, there is a point where the thickness of the insulating shellac adds up in a lamin...
by spinningmagnets
Dec 23 2022 11:24pm
Forum: Battery Technology
Topic: Pulsed Charging will speed up the charge, less heat
Replies: 7
Views: 284

Re: Pulsed Charging will speed up the charge, less heat

Luke, without revealing anything that's classified by NDA, is dendrite formation more of an issue with charge, or discharge?

Does regen erode some of the dendrite formation, extending battery safety and life?
by spinningmagnets
Dec 22 2022 12:35pm
Forum: EBike General Discussion
Topic: More thinner strands vs less thicker strands
Replies: 31
Views: 894

Re: More thinner strands vs less thicker strands

In a 3T kV model of motor, there are not 3 super-fat wires wrapped around each stator-tooth. Since skinny wires can bend easier and also conform to the available window shape between the stator-teeth, a 3T motor would have a fat bundle of many thin wires wrapped around the each stator-tooth, which h...
by spinningmagnets
Dec 22 2022 12:17pm
Forum: Battery Technology
Topic: Pulsed Charging will speed up the charge, less heat
Replies: 7
Views: 284

Re: Dendrite build up, killing batteries

If I understand him correctly (no guarantee of that) he seems to be suggesting that if the high current portion of charging a battery is rapidly pulsed, then the charging time can be dramatically reduced without the cells reaching 50C / 122F. He mentions data-logging a Tesla fast super-charger, and ...
by spinningmagnets
Dec 21 2022 11:35am
Forum: EBike General Discussion
Topic: More thinner strands vs less thicker strands
Replies: 31
Views: 894

Re: More thinner strands vs less thicker strands

I am still learning, and if something works for a builder, I don't need to understand why to believe it. Years ago, there was a discussion about...is it better to have a high top speed, and constantly run at half- throttle, or make the top speed your normal cruise speed and run at full throttle? Whe...
by spinningmagnets
Dec 21 2022 8:40am
Forum: EBike General Discussion
Topic: More thinner strands vs less thicker strands
Replies: 31
Views: 894

Re: More thinner strands vs less thicker strands

I've always heard that the motor is at its most efficient at around 80% of its top RPM. That being said, when choosing between two kV's for a motor, liveforphysics has persuaded me that the low-turn count option is better (for most applications). Use fewer turns of the thickest wire that will fit. T...
by spinningmagnets
Dec 20 2022 11:33am
Forum: General Discussion
Topic: gas price thread
Replies: 1737
Views: 111405

Re: gas price thread

$2.48 at the Sams Club in Salina Kansas. Requires a $50/year membership fee.

$2.77 at the local Walmart.
by spinningmagnets
Dec 19 2022 8:22am
Forum: EBike General Discussion
Topic: More thinner strands vs less thicker strands
Replies: 31
Views: 894

Re: More thinner strands vs less thicker strands

Yes, what ou are describing is the "kV" of the motor, and the major effect is that fewer turns provide a higher top-speed, if the voltage stay the same. The minor effect is that a few turns of thicker wire has less inherent resistance, because the length of the wire-runs are shorter. The l...
by spinningmagnets
Dec 18 2022 9:26am
Forum: EBike Technical
Topic: Considerations for using two 14S packs to achieve 28S
Replies: 17
Views: 344

Re: Considerations for using two 14S packs to achieve 28S

I just saw a youtube with a dirt bike conversion using 28S, and he used a VESC from 3Shul. The builder stated that it was not difficult to program, which is something I've been searching for. If it was just for me, I would pay an expert to program a controller to match a certain motor, but I want to...
by spinningmagnets
Dec 17 2022 7:08pm
Forum: EBike Technical
Topic: Considerations for using two 14S packs to achieve 28S
Replies: 17
Views: 344

Re: Considerations for using two 14S packs to achieve 28S

There may be others who have series'ed two packs that may benefit from a discussion of this. 2X 36V = 72V, etc...which was common about 12 years ago, when high amp cells were hard to source. I am thinking I might run without a pack BMS, and I would attach a wiring harness that would allow each 14S s...
by spinningmagnets
Dec 17 2022 10:00am
Forum: EBike Technical
Topic: Considerations for using two 14S packs to achieve 28S
Replies: 17
Views: 344

Re: Considerations for using two 14S packs to achieve 28S

Just curious, not good at spotting trends. Is the mind set on higher voltage changing? I live in tornado country. I like my odds of avoiding major damage, but regional power outages are the norm (on occasion). The batteries that are 13S / 14S (48V / 52V) are able to run an common and affordable inv...
by spinningmagnets
Dec 15 2022 6:01pm
Forum: EBike Technical
Topic: Considerations for using two 14S packs to achieve 28S
Replies: 17
Views: 344

Considerations for using two 14S packs to achieve 28S

I am curious about what issues would occur if I wanted to use 28S, like Zero motorcycles, but...using two common 14S packs.. If the packs are connected/separated electrically by a large DC switch(s), then I imagine it would be very easy to charge the two sub-packs with readily available 52V chargers...