Search found 1420 matches

by Hummina Shadeeba
Jun 24 2019 3:16am
Forum: E-Bike Technical
Topic: Battery Voltage and Motor choices
Replies: 21
Views: 807

Re: Battery Voltage and Motor choices

the speed difference between unloaded and loaded is strangely large

It’s unlikely the escs are both programmed to be speed limited but it could happen. But if the speed is dropping while riding I doubt that would be part of a program and just the normal drop in voltage likely causing to be slower
by Hummina Shadeeba
Jun 23 2019 9:39pm
Forum: E-Bike Technical
Topic: Battery Voltage and Motor choices
Replies: 21
Views: 807

Re: Battery Voltage and Motor choices

The motor? Can go as fast as physically possible before flies apart as you increasing voltage, assuming the magnet wire insulation is good for the high voltage and won’t short which it very likely would be. But that’s extreme limits and ur limited by ur esc voltage limit and battery voltage (maybe p...
by Hummina Shadeeba
Jun 23 2019 4:41pm
Forum: E-Bike Technical
Topic: Battery Voltage and Motor choices
Replies: 21
Views: 807

Re: Battery Voltage and Motor choices

Think ur limited to higher voltage battery and esc or another esc with field weakening. Or rewind the motor.
by Hummina Shadeeba
Jun 21 2019 8:48pm
Forum: Battery Technology
Topic: Legality of shipping cylindrical cells with tabs and homemade batteries generally
Replies: 13
Views: 358

Re: Legality of selling cylindrical cells with tabs

What jurisdiction(s) you talking about? I only know of shipping regs, and in the US crazy torts liabilities, expensive insurance, but no laws per se afaik It may be just a shipping restriction. I’d heard it was more but didn’t find anything. I have yet to see how the language of the law will be sat...
by Hummina Shadeeba
Jun 21 2019 2:58pm
Forum: Battery Technology
Topic: Legality of shipping cylindrical cells with tabs and homemade batteries generally
Replies: 13
Views: 358

Re: Legality of selling cylindrical cells with tabs

those are some weird tabs. so thin. But I don't see anywhere selling cells with tabs attached. https://www.clsmith.com/hazplus-hazardous-material-packaging/battery-packaging/lithium-ion-battery-packaging/prototype/small-prototype/ I couldn't find anywhere that could legally sell me a flexible batter...
by Hummina Shadeeba
Jun 21 2019 1:14pm
Forum: Battery Technology
Topic: Legality of shipping cylindrical cells with tabs and homemade batteries generally
Replies: 13
Views: 358

Re: Legality of selling cylindrical cells with tabs

I’m finding u can get away with not doing the certification testing if it’s a prototype battery of less than hundred made and shipped ground and with the nine label and a bunch of specific packaging. I’m trying to figure the details of those requirements now. Surprised no one is selling cells with t...
by Hummina Shadeeba
Jun 21 2019 2:16am
Forum: Battery Technology
Topic: Legality of shipping cylindrical cells with tabs and homemade batteries generally
Replies: 13
Views: 358

Re: Legality of selling cylindrical cells with tabs

It’s hard to find info on the law. Selling cells with tabs attached seems ok I guess but can anyone sell a welded or soldered battery as long as it’s going by ground transportation if labeled hazmat nine.
by Hummina Shadeeba
Jun 20 2019 11:57am
Forum: Battery Technology
Topic: Legality of shipping cylindrical cells with tabs and homemade batteries generally
Replies: 13
Views: 358

Legality of shipping cylindrical cells with tabs and homemade batteries generally

It seems connecting any lithium cells and selling them requires expensive certification but what of just attaching tabs, would that be legal to sell?
by Hummina Shadeeba
Jun 20 2019 11:54am
Forum: Battery Technology
Topic: BOSS LEVEL CUSTOM SPOT WELDER
Replies: 437
Views: 39368

Re: BOSS LEVEL CUSTOM SPOT WELDER

Is the speed the welder can work limited only by heat? Can I weld repeatedly in succession if staying under the 40c?
by Hummina Shadeeba
Jun 14 2019 12:07pm
Forum: Items Wanted
Topic: Meanwell S-350-24 or 48 volt DC power supply
Replies: 6
Views: 547

Re: Meanwell S-350-24 or 48 volt DC power supply

I am hoping to mod one of these for less current output: https://www.amazon.com/Adjustable-Converter-110V-220V-Switching-Transformer/dp/B0777MH681/ref=mp_s_a_1_9?keywords=adjustable+power+supply&qid=1560530834&s=gateway&sprefix=adjustable+power&sr=8-9 I have two that are broken but it’s still a pret...
by Hummina Shadeeba
Jun 12 2019 3:49pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 11
Views: 781

Re: Discharge unbalanced battery

https://www.homedepot.com/p/Everbilt-4500-Watt-240-Volt-HWD-Element-15026/205681009 4500w/ 240 volts= 18.75 watts per volts. 4v x 18.75w =75 watts id be discharging from a single 4 volt cell. that would be 19 amps. that sounds good to me. for a burst just to balance. maybe it wont need to be submerg...
by Hummina Shadeeba
Jun 12 2019 1:43pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 11
Views: 781

Re: Discharge unbalanced battery

What you think of my link will it work as I think? I’d rather use something high wattage. What about niochrome wire or whatever that heating wire is called? Don’t want to spend long discharging and the cell can individually put out 15 amps no prob
by Hummina Shadeeba
Jun 09 2019 12:23pm
Forum: Battery Technology
Topic: Adhesive-backed copper tape ampacity
Replies: 10
Views: 379

Re: Adhesive backed copper tape ampacity

a shame as the thickness at .06mm makes it good for cell to board connections in my case. Ill try welding it. It would be ideal if it welds as the glue is really good and will reduce stress on the welds and the tape is cheap. Thanks for you help!
by Hummina Shadeeba
Jun 09 2019 1:29am
Forum: Battery Technology
Topic: Adhesive-backed copper tape ampacity
Replies: 10
Views: 379

Re: Adhesive backed copper tape ampacity

My multimeter is crap. But the goal is to use the adhesive. can you decode this math? https://www.researchgate.net/publication/273248165_Electrically_conductive_acrylic_pressure-sensitive_adhesives_containing_carbon_black The copper content should be good and conductive enough I think but getting to...
by Hummina Shadeeba
Jun 09 2019 12:40am
Forum: Battery Technology
Topic: Adhesive-backed copper tape ampacity
Replies: 10
Views: 379

Adhesive-backed copper tape ampacity

I got some adhesive backed copper foil off amazon and probably asking way too much of it but would like to connect these to 18650s and do 15amps through it. My bad calipers show the copper and glue are .1mm thick and maybe assuming the copper were only .5mm thick at a 15mm wide strip the copper is c...
by Hummina Shadeeba
Jun 03 2019 2:27am
Forum: Battery Technology
Topic: BOSS LEVEL CUSTOM SPOT WELDER
Replies: 437
Views: 39368

Re: BOSS LEVEL CUSTOM SPOT WELDER

Hows the minA compare to the boss? I just ordered it. I had the boss and blew up some copper and then sold it but the miniA seems the next step up in ease but is it as robust?
by Hummina Shadeeba
May 28 2019 1:23pm
Forum: E-Bike General Discussion
Topic: Finding a machine shop for a simple milling job?
Replies: 12
Views: 433

Re: Finding a machine shop for a simple milling job?

Noisebridge in San Francisco is a free anarchist run work place with machine tools. There’s other maker spaces around that are free. I think that’s the term and you could search for that
by Hummina Shadeeba
May 18 2019 10:43pm
Forum: Motor Technology
Topic: So why exactly are RC motors so loud anyhow?
Replies: 19
Views: 2347

Re: So why exactly are RC motors so loud anyhow?

I changed the switching frequency to Thirty kilo hertz and its much quieter. Since hobby escs often will play a tune in the motor without spinning it I think the sound comes from the vibration of the ferromagnetic material in the stator. But if the iron were vibrating I’d think that would be due to ...
by Hummina Shadeeba
May 10 2019 10:49pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 67
Views: 2684

Re: Why never see metal cast around wound stators?

I’m limited to this size motor. If I can get a high thermally conductive material between the windings and an external heatsink...it could have a continuous output of a much bigger motor. Peak power was never a problem even with motors I sold half this size. If I wasn’t so close to flat broke I’d ac...
by Hummina Shadeeba
May 10 2019 3:11pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 67
Views: 2684

Re: Why never see metal cast around wound stators?

If it takes maybe a half pound of indium to even increase the motor continuous output by 25% that’s a good deal to me. But I think it could do much better than that. One day.
by Hummina Shadeeba
May 05 2019 5:41pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Steelhubs.com
Replies: 346
Views: 52722

Re: Steelhubs.com

https://www.makeitfrom.com/material-properties/7075-T6-Aluminum https://www.makeitfrom.com/material-properties/SAE-AISI-1020-S20C-G10200-Carbon-Steel Tempting but the fatigue strength is higher with the mild steel. Without being a master of stress simulations on a computer I like going the safer rou...
by Hummina Shadeeba
May 05 2019 2:13pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 67
Views: 2684

Re: Why never see metal cast around wound stators?

https://youtu.be/rQgiN-vpiNA Shameless plug! But I do have a lot of experience making motors now if someone wants help. These have shown to be the most powerful and durable in the maket If I get the bucks for sure I will try potting a stator in indium with a new aluminum hanger design that will make...
by Hummina Shadeeba
May 05 2019 1:27pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Steelhubs.com
Replies: 346
Views: 52722

Re: Steelhubs.com

https://youtu.be/rQgiN-vpiNA It’s been a long time and there are many changes. I make the motors now instead of getting them made in China. After many years of selling and testing this latest version rocks. The best ingredients and more powerful than the the past. Being able to do the local mount Ta...
by Hummina Shadeeba
Apr 08 2019 5:11pm
Forum: General Discussion
Topic: Discharge unbalanced battery
Replies: 11
Views: 781

Re: Discharge unbalanced battery

I’d like to discharge at maybe 10 amps from the single 4v packs to balance. https://www.ebay.com/itm/New-6x-5-Ohms-50W-Aluminum-Housed-Wirewound-Power-Resistor-5ohm/141006406040?epid=1307735573&hash=item20d4a30198:g:9CsAAOxyi3FRzaAv .5 ohm resistor w 4v battery should get about 8 amps current draw a...
by Hummina Shadeeba
Apr 01 2019 10:16pm
Forum: Motor Technology
Topic: Why never see metal cast around wound stators?
Replies: 67
Views: 2684

Re: Why never see metal cast around wound stators?

It is better to get thinner laminations! Also, if you can find some (more like make some) square or triangle magnet wire, get way more copper fill and copper cross sectional area. Always good! Then its all about heat management, so perhaps more metal, which adds more weight to soak up the heat to t...