I’ve been doing lots of reading as I plan my first build. Where I am coming to at the moment is set out below but i still have some decisions to make and hopefully you guys can help!
- Loaded Cantellated Tesseract for the deck
- Caliber II 44 deg trucks (as the tesseract adds 3 deg on truck angle)
- 85mm wheels in the first instance to help avoid chance of wheelbite - might increase size later
- 10s4p (20700 cells) likely battery set up for space, weight and budget constraints - gives a high voltage to help reduce current, but leaves a bit of headroom before the VESCs max out on voltage
- Dual rear set up with 6355 motors to fit on the calibers
- VESC - ideally with a heatsink, or i’ll attach my own - 4.12 version from hobbyking or similar
- I’ll likely run in BLDC mode to avoid any potential implications of FOC with the 4.12 VESC
- i’d like to target a max speed of 50km/h and will probably cruise most of the time up to around 35 km/h.
- I’d like it to pull / accelerate well right through the range of speeds
My use will mostly be on the flats, but we do have a few hills on the cycle ways and paths ill be using - so needs to be a combination of hill climbing / speed - a set up that is good for both but not excellent at one i guess.
I weigh about 90kg, so with the board im guessing will be a 100kg being hurtled around.
I am now struggling with what kv motor shall I select. I have looked at the calculators and with have two scenarios below which id love to get some of your feedback on that target a 50km/h top speed. Which one will be easier / less strain on the electric gear? I’ve tweaked gearing for each kv option to target 50km/h.
- 6355, 230kv motor, 85mm wheels, 14 motor pulley teeth, 36 wheel pulley teeth (2.57:1 ratio). (I think this calculator is for a single motor - so current would halve to each motor). ERPM at 57k. Motor rpm 8280.
Calculates current of 51.9 A at full throttle on flat (~50km/h) Calculates current of 55.4 A at half throttle up a 20% gradient (25km/h)
- 6355, 190kv motor, 85mm wheels, 17 motor pulley teeth, 36 wheel pulley teeth (2.12:1 ratio). (I think this calculator is for a single motor - so current would halve to each motor). ERPM at 47k. Motor rpm 6840.
Calculates a current of 52.4 A at full throttle on flat (~50km/h) Calculates current of 55.6 A at half throttle up a 20% gradient (25km/h)
So if I tailor the gearing for a 190 or 230 kv, it looks like the current demand is the same - so i could go with either kv motor and gearing to target the 50km/h target and have the same hill performance?
Are there any other considerations I should assess in this decision of motor kv?