In the speed limit box, I put the potential highest speed I will go?
@thisguyhere good to know, thanks!
Yeah, put the highest top speed youāll reach (even downhill speed) or you can up the speed till you get to 60k to know your safety limit
Do I have a gear ratio of 2.18 with a 17T motor pulley and 36T wheel pulley? If so, my top speed can be 39mph before I break 60k ERPMā¦ thereās no way Iāll even go that fast even downhill. Are my calculations incorrect?
That is correct (2.118). The less reduction you have, the harder it is to reach higher erpm. Hubs are 1:1 and have low erpm. The calculator is for for standard 7 poles.
If you spin the motors max throttle on bench you may have problems though so donāt do that
Why not just buy a 15T pulley from @Titoxd10001 and keep the 37T drive pulley?
I used 10S4P on 190KV motors and 16/36Y pulleys and for me itās the perfect combination.
On the other hand Iām building a Trampa on 12S4P, dual 190KV, that setup should hit 59,052 ERPM, 30MPH on 85% efficiency. I think thatās going to be the sweet spot, perfect setup for the 4.12 VESC
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technically, 63680 eRPM on that setup. Though you may not reach full voltage duty cycle, a bit of decline could kick it over eRPM.
Yep, you literally described my exact situation right now. I started off with a single 6374, and this summer Iām planning to go dual rear 6355, for more power and less wheel and belt slippage.
What 190kv motor do you have? @pennyboard is right about having low end torque with my 245kv setup but I canāt decide if the more expensive motor from diyelectric will be needed. Iām only 135lbsā¦
Iām using the electric skateboard calculator:
8436 RPM x 7 pair of poles = 59052 eRPM
How are you getting 63680 eRPM?
Basing it off max theoretical voltage.
50.4v * 7 pole pairs * 190kv * .95 max duty cycle = 63,680
I have the 6374 190kv 3600W motor from @kaly and I also use the 6355 190KV 2500W motor from @torqueboards
Being that one is 3600W and one 2500W, have you seen much of a difference in the torque?
I havenāt used that formula before but the electric skateboard calculator usually gives me a consistently exactly the eRPM number I get on the board in real life.
I really hope so, itās a lot of difference, theoreticaly I should get more than 40% of additional power, way more torque and crazy acceleration, as Iām jumping from dual 6355 to dual 6374.
Itās the same math
Iām 165 lbs and Iāve carried another person on my back while riding that board (so over 300 lbs) and the motor was able to handle it and even carry us up a slight incline, so I think you should be alright with the lower power motor.
But honestly, itās $30 more, which isnāt much in the grand scheme of the entire cost of your board, so if youāre really worried about it, just go for the more powerful one. Just make sure you want donāt want to get dual rear motors later cause if you get the more expensive one, itās too big to fit dual rear motors so youād need to get 2 new ones (which is the problem I find myself facing now).
So what exactly happened that you āblewāā your motor?
was it because you carried 2 persons not just yourself?
ā¦ anywaysā¦ im really interested to hear the story!
No actually, the motor was fine carrying 2 people, what ended up blowing it was the bolts that hold the motor together were slowly coming loose, and I went on a 6 mile ride on a rough road, and the extra heat on the motor from it already being loose caused the loctite on the bolts to loosen up and the rough road shook them loose. The motor physically fell apart more so than it blew up.
But Luckily I was able to salvage the motor and its back to running like normal now
U wonāt get any more power unless u change ur esc settings. Have u tried simply upping the motor and battery amp settings on the motors u use now? Do ur motors get hot yet? How hot . When they put a wattage ratting on a motor it means very little
What are ur settings
I have a pretty high setting:
Motor Max: 90A Motor Min: -60 Batt Max: 40A Batt min: -10A
Max Watt: Unchecked