Endless Sphere

A couple steel screws doesn’t seem a big deal and was surprised to find the kweld uses them. If they’re big enough maybe the conductance creeps up to equivalent to a decent conductor.

Gotta buy that cheap precision resistance tester.

What’s wrong with using screws or threads as conductors? I’ve seen them used a lot

Be easy enough if its open source like you say. Just start to learn how to code. With the Vesc being open source how hard would it be to program it to require specific input from the motor when it first came on, such as going backwards three paces, otherwise would lock the wheel? I dont know how to...

With the Vesc being open source how hard would it be to program it to require specific input from the motor when it first came on, such as going backwards three paces, otherwise would lock the wheel?

Hi yaw I just placed an order for the K-weld from Frank on the 12th and can’t wait to get it! Like a kid waiting on Christmas About how long does it take to a package from Germany to the US? I opted for the 2nd option that gives your package the Air ride vs the water ride but just curious how the C...

I can’t find an example of nasa getting the cell to 140f in your link. 140f isn’t going to send a cell into thermal runaway. If I do an IR or capacity test before and after exposing it to the heat I’ll know if the cell has degraded enough to notice. I don’t need safety advice and know the danger of ...

Can weld .2mm copper if it’s slotted. Depends on the cell but the 30q 18650 were no problem at 80j.

Can do .1mm copper no problem with much less joules

how much degradation would happen in ion or iron cells that maybe touch this temp for a couple minutes? Do you know the "BTU", friend? A British thermal unit is a measure of heat. Described as the amount of heat needed to raise one pound of water at maximum density (1/1) through one degre...

one nickel-plated copper bus bar measured 2.4mΩ ... doubling length only 2.6mΩ im confused by what youre saying...i assume doubling the length of anything is going to double the resistance produced by it. the connections maybe are a bigger loss than the distance but none the less doubling your wire...

how much degradation would happen in ion or iron cells that maybe touch this temp for a couple minutes? i imagine it's not good. id like to sink cells in https://www.instructables.com/DIY-Material-Guide:-Polymorph-Plastic--a-thermal-/ this seemingly lowest temperature meltable plastic. i think i cou...

Yes, it is 30% more nickel and 30% more resistance. My calculations showed a 39% increase in losses (1.28 Watt vs 0.92 Watt). Are you sure? My AideTek SM8124A (4-wire) tests with nickel-plated copper confirmed that there would be nowhere near a 30% increase in resistance with a 30% increase in leng...

why you space your cells apart?

i dont think people make batteries in a rectangular pattern like the drawing of the original poster. maybe they do. a waste of space and not as strong as the triangular id think in most cases. rather make a solid smaller block unless had mounting posts between. if its triangular cant do the x patter...

looks like just as much nickel needed doing an "x" as done when doing the typical square IF you orient all the cells staggered instead of in rectangular pattern as in your pic. dont know why you write .07% which is a tiny amount. doing the x on the rectangularly arranged cells would be 30%...

it saves times and nickel. seems a good idea but never see people doing it.

good idea. the amount of current going between paralleled cells is tiny, just one weld on the x is good enough.

You can get nickel in different widths, so .2x15 or something wider than typical .2x8 or around that. Or u can just stack thinner .15mm stuff and there’s no need to be able to weld thick stuff really

If u sink them in resin then u don’t have to worry about them being banged around and I think you’ll be better able to transfer heat through the resin then stagnant air. U could add a mounting fixture to the potting. Could pot them in a low temp theroform resin and extract them for recycling later. ...

With this esc doing 140 amps https://www.discoverzesc.com/raiden7-series I’m wondering how fast will it get a rider from 0-30mph. Assuming 200lbs rider. A kv that get you just up to that top speed. And the powered wheel a 20” bike wheel or an 84mm skate hub motor. I forget how to convert kv to kt to...

how bad is it to have done this already?

Being America I don’t actually find metric stuff just imperial so really I’ve been doing 5mil or .005” sheet which is .127mm. No problem. Good enough and my quest for more copper is over.

I use the included probes and if they start getting stuck I file them to their original rounded point.

You can go to 100j but that might still not work since the reason why copper is so hard to weld is its ability to conduct the heat away from the weld spot. When you set more joules that basicly means longer pulse time and that means copper has longer time to spread the heat away so at some point yo...

thanks and i lowered battery soc and can now weld with half a meter of wiring including the probes and dont get an overcurrent. I have no problem getting good welds with .1mm copper using only 25 joules on the negative and 50 on the positive A123 green cells. i imagine .2mm copper wouldnt be too har...

I’m saying if i shorten my battery wires too much I get “over current”, but when I lengthen them, to like 2meters including probes now, I have too much inductance to do more than maybe 1200 amps as shows on their posted chart. I want to do more. How?
https://imgur.com/a/qu13QBy

Where’s the best spot to weld on the cell? Center or the edge?