This will eventually become my build diary but for now looking want to lay out my plan and check it will achieve what I am after.
Basically I am a tad on the heavy side at about 104kg (230lb) and just over 6ft 1"
I want to build a board that I can use to commute which is 3.2miles each way (along a reasonable condition cycle route and in a city that is pretty much totally flat). Ideally not wanting to charge while I am at work. I have an OK understanding of electronics from my racing drone builds.
I have read the guidance for build advice for a heavier rider (along with a ton of other threads) and come up with the plan below:
Single Drive (mostly for cost)
Board tbc prob second hand and a stiff DH board
Battery 8s2p (looking at 4 5000mAh 2x series then in parallel)
Motor looking 6355 235kv (Probably ADS with the sale they have on at the moment)
I have looked at the Europe Group buy and will probably pick up some:
90mm wheels
Maytech VESC
Pulley 36/16
Mini remote
Anti Spark switch
%battery level readout
The leads to these figures - which I am more than happy with (granted expecting max speeds to be lower due to weight)
All these settings would generally be okay if you were lighter. Here are some things you might want to think about changing
Motor - if you’re going single, get a 6374. Otherwise, you can do dual 6355’s.
Motor pulley - 16T is great for speed, but can be taxing on your motor if you’re heavier, consider dropping this down to 14T.
Motor kv - heavier riders tend to stick with sub 200kv motors. They tend to have more copper, leading to more torque.
Wheel size - you should be fine with 90’s, but if you’re worried about torque, you can drop this down to 83mm. It doesn’t have as much influence on torque as the previous three.
VESC - you may want to reconsider getting a cheap VESC as it’s arguably the most important component to not cheap out on
Not all are necessary, but all help. The most important one is motor size. Definitely go for a 6374 if you’re running single. You could consider using the 192kv with a 14T motor pulley but upgrade your battery to 10s. This will put you at roughly 25mph.
A rough range guide is 10wh = 1km. This will vary depending on board efficiency.
I went the lazy route and got Enertions SpaceCellPro 4 (10S). I was skeptical of the single 6374 over dual 6355s but wanted the range and it’s been good for me so far
Any real issues with using 2x 5s or 6s 10000mAh batteries. Charging I suppose will be a bit more of an issue but I already have a couple of lipo chargers. I was swaying towards building my own pack but I may save that for a later version.
You are probably right. There is the cost factor too. Lipos would cost me probably £160 - £180 and I already have the chargers. Building a pack would mean £160 on cells, BMS, charger, nickel plates, spot welder. Likely over £250 even if I soldered rather than welded.
I think there are some group buys coming for liion packs in Europe. Recently one has been able to provide a 10s4p for 190 € welded with copper, it was about 250 at the end including bms, charger, led status indicator and integrated switch (euros, which is something like 200 pounds). Would are probably good with a 10s3p, that would cost even less. @ajaynagra may have something for you in the near future, ask him
Good point. I have shown interest in the Europe group buy for a fair few parts so will look for a battery buy too. Still torn. With some thinking about the enclosure I am not totally sure it would be that much of an issue to open it up and charge a couple of batteries each night. That said if it can be done for not much more then it would be great to just plug in.
So the board, batteries and nickel strip are here. I feel like I have ordered parts from every corner of the globe and everyday the postie comes down the drive its like christmas!
Good deal on a benchwheel remote now too. Just to finalize my order through the group buy and everything will be ordered. Incidentally anyone know where I could get a 12mm / 14t motor pulley if they aren’t available with the group buy.
I have seen this website but not really sure what I am looking for?
http://www.beltingonline.com/timing-pulleys-bars-272/?zenid=m0jfch7qt65ked5ue6c4m025a2
I have collected all I needed now for the battery build so I have been working on that.
I have capped off all the positive terminals with insulation rings and then glued the parallel sets together.
Then I have soldered the nickel plates to the batteries and reinforced the serial connections. Next I will solder strips to connect these two halves then fold them out on themselves. I am checking connections as I go and all looks solid so far. The only thing that concerns me is how I would know if one of these solder joints was to go bad?
The glue and tape seems to hold them tight and the shrink wrap will pull around the pack so perhaps it wont be an issue. I must say soldering has been fine. Its pretty cold in the workshop at the moment (unheated) so not having any issues with too much heat in the cells.
Anyway I couple of pics to show progress and a hat tip to @whitepony for inspiration
