What KV hub motors are you using for this? I was just looking over the specs and was surprised seeing only 26mph on a 10s battery, considering the summerboards are running 7s and getting about the same speed running belts. I’m currently upgrading my old beta leiftech with an 8s battery to see what that takes me to. Are these hubs compatible running any higher voltage than 10s? @Fosterqc
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what post are you referring to? I have been doing a lot of research but not purchased them.
The summerboard is actually 12S, it uses 5060 motor with a KV under 200
Ahh, maybe I’m just used to the old leiftech’s since I’ve got an original beta. I hadn’t seen any of the summerboards around here since the updates. Old leiftech’s are on 7s batteries.
Not referring to a post, look at your indiegogo campaign.
Original leiftech’s used a very high kv scorpion motor, like 700 kv or something like that if I recall.
400 kv is what they used 
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Prob the same as relay contacts
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Yep I’ve gotten the exact alloy figured out and everything.
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Which alloys?
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Alihomie said I want this one
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Just tossing this out there…
Do you have to use a specific type of tempering before or after stamping/forming to get the desired spring characteristics?
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I was just kinda planning on 'YOLO’ing it
I can mess around with the tempering stuff but I guess my idea was to make a jig to bend them all to the general identical shape without treating them because the material seems easy enough to work with from what I can tell from the LEIF slip rings.
One thing that might be slightly important or not is the domed shape on the end of the brush as this makes the solder you add on top to form a nice round surface to wear away. This might be able to be skipped and just a flat surface with a solder ball would be fine. I think this feature is most important for when the solder is completely worn away so you don’t end up with a copper edge to get caught and possibly bent backwards and short everything when going “against the grain” of the brushes.
this video show them well.
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Yea, I guess there’s really not much bending going on to need to deal with specific spring properties. The contact cupping sounds like a good idea to do.
The solder pad being used for a sliding contact bugs me since it’s very soft and high resistance. But if it’s worked well so far then there’s no reason to change it.
I’m wondering if using replacement relay contact arms might be an option? They’re already made of the right springy material, have hard silver contact points, and can handle lots of current (the bigger ones).
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I see what you mean, I don’t see a lot of them available for sale at first but I bet I could find something very comepelling and at a cost that makes painstakingly hand forming copys of the leif brushes seems silly.
From the ones I have seen it looks like they usually have a high spring force and I think that would cause a lot of wear on the copper rings and be hard to tune if they get messed up.
I will keep looking at them, but will go ahead with making the recreation of the leif brushes in the meantime. I could see a point in the future where old leifs need new brush assemblies and I could have identical PCBs made up as a drop in replacment. #righttorepair
I wish there were more folks out there documenting their DIY slip ring endeavors, when I search on youtube sure there are some homemade ones but none of them are high power or use Beryllium Cu that I can find.
This is a nice tech demo of some different ones by the person that designed them
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Cool video. Those tiny assemblies were wild.
Another possible option might be spring-loaded pins? Current rated at about 2A-3A but can be easily paralleled in larger numbers. That spreads out the pressure forces too. Mill-Max has a huge assortment of different individual pins and pin blocks.
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My thoughts on these is that they could be made to work for this application but i’m not sure a bout the wear from the sliding and dirt ingress, great advantage of the leiftech brushes is they are easy-ish to maintain and relatively cheap to replace due to low cost of raw materials. it might be worth contacting the company to ask if they would work for this.
Really is a great design that they went with and I hope I can find some ways to improve on their ideas.
Still have not ordered the BeCu I am just trying to figure out everything I can beforehand, it is time though.
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You bring up some very good points. Good luck!
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who the duck is pricing this shti
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They’re originally used for high speed RC helicopters I believe. I’ll pay that much per motor if it makes my board finally hover though 
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I’m working on a large ball drive version that should have a really interesting feeling. I’m not sure if I should make a ball shaped wheel on a caster or omnidirectional drive with no module rotation/caster but if able to be driven sideways with a drive system like this.
I think casting my own inflatable polyurethane wheel would be very interesting
