what would be the modern day equivalent? I’m building the same setup.
guess any cheap 14-18V charger will do - it somehow gotta withstand the constant shorting though. basically when I close the copper bar circuit, the supercap is unloading its whole charge into the spot welding points and the charger is basically briefly shortened. recharging of the cap then takes about 3-4 seconds!
possibly you can put a resistor between charger and supercap to be a little easier on the charger, but then recharging might take even longer! 
how long does recharging normally take for you?
I dig the 180’s 
Do you think you’ll use reverse instead of brake on the VESC so you can go in both directions?
yea, that was my plan 
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Might have to cop 
your carbon fiber 
build. Off da chain yo. 
What kind of vacuum are you using for this compartment build? I’m starting my build in a month, and I’m really digging the vacuum style boards.
my small laboratory pump manages -900mbar! 
why are’nt we using the reverse like the boosted board anyway???
dunno, I never really wanted to go backwards with a board and its cool to just hit max brake for when you want to fixate a board thats already standing still for example. this should be much harder with reverse function. doesnt happen often, but more often than driving backwards for me. 
think its braking regeneratively until the motor reaches low enough erpm to switch direction:
“Max ERPM at full brake” (should change the name…) is the highest opposing RPM at which a direction change is allowed. Setting this too high will cause cogging when moving in one direction and giving high throttle in the other direction. On my longboard I have it at 300 and my RC car has it a bit higher.
Ok thanks !!
just need to pop 360’s
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Amazing… I need to actually use my freebord bindings now I like the ollie…
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Seems like bindings add a whole new dimension to the game!!! I’m thinking curbs would no longer be an issue and that would be worth it just for that. However, it could bring a whole other level of SYF. Helmet time, people! LOL
@onloop “Potters Prophecy: Ulfbehrt will get bindings for his board and then proceed to knock himself retarded trying to 360 over a curb” 
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It there somewhere where you discuss where you got the supercap and the battery charger? Is it somewhere on ES?
not much more info: https://endless-sphere.com/forums/viewtopic.php?f=35&t=70435&hilit=50km#p1062504
battery charger is something my dad build himself about 40years ago, supercap is just from ebay - looked for a cheap large cap (2F).
Thanks you so much for the info. I really needed a cheap welder cause I only plan to use it only a few times for batteries. It looks very simple but effective! I will totally make one. Here’s two questions. To operate the switch would I just quickly push it down and then release? Also should I wear gloves when working with the charges capacitor?
EDIT: Though of another question. How often should I recharge the capacitor when welding? Keep it fully charged or does it even matter?
I plan to get this cheap capacitor (has good reviews): https://www.amazon.com/Soundquest-SQCAP2M-Capacitor-Digital-Display/dp/B00381UKD0/ref=cm_cr_arp_d_product_top?ie=UTF8
another DIY spot welder with car battery instead of supercap
yea, Im stomping my foot on the copper bar and release right away. basically the weld point is eating the energy 0.5CU^2 (energy stored in a capacitor) instead of a constant voltage pulse with a well defined time like a “normal” spot welder.
if the energy is well tuned, youll have a nice spot - its the same for normal spot welders: youll have to choose the time length of the pulse appropriately.
the capacitor needs to be recharged after every pulse, since the whole stored energy is used for the spot welding.
in the endless sphere thread there is a short youtube video of me welding - basically the recharger is directly hooked up to the supercap → pulse for welding → charger starts charging right away since its essentially shortened.
its probably a little easier with a well defined pulse spot welder that is hooked to a large energy reservoir like a battery. if the energy 0.5CU^2 isnt approriate, then your weld spots will suck. I was lucky enough to find a good C and U. you can still fine tune that energy with the cap loading voltage (careful, it enters the energy squared!) or additional parallel caps!
I found these instructions on how to do a similar built to yours but with the addition of a silicon controlled rectifier in cause anyone is confused about how to hook up a welder like this. The scr is unnecessary cause your version of the switch works just as well and is much cheaper. I will definitely give your version a try cause the only thing I need is the capacitor and the wire. Thanks and love your board!!!
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