jester_s1
05-31-2015, 11:09 PM
The brushed motor finally bit the dust tonight. so I have a good excuse to go brushless now. I have a new 1900 KV motor that had been sent as a factory replacement on a Thunder Tiger Desperado Jr. It's also the same motor (or nearly the same) that they used on the Outlaw Jr. boat which is close to the same size as my Shockwave. So I think it will work, right? I would like to stick with the 3 cell 2200 mah batteries I had for the Desperado Jr and still use in my electric airplanes. If I'm doing the math right, the RPM difference between what I'll be doing and the standard brushless Shockwave 26 isn't terribly large. 7.4vx2900kv=21,460 RPM is the stock setup, while mine will be 11.1vx1900kv= 21090. I do realize that real world voltage will be different, but it looks to me like the difference between the Kv of the motors will be pretty much absorbed by the difference in voltage. That is, of course, unless I'm missing something?
I'm not looking to push the boat to its limits, just wanting to improve a bit on the brushed setup putting around on the lake and keep it reliable and stable. If I can keep a solid 6-7 minute run time I'd be happy. From what I've read, the Octura X435 prop is a good replacement for the stock brushless Shockwave 26 prop. Is this what you guys would go with? Where I'm not too sure is the runtime I'll get with the 2200mah batteries. Proboat recommends a 5100 mah .74v lipo, so that's more than double the capacity of mine but still 2/3 the voltage. I know I won't draw as many amps for the same wattage with the 3 cell, but I'm not clear on how much of a difference it makes? Should I go down to a smaller prop or switch to the M series?
I'm not looking to push the boat to its limits, just wanting to improve a bit on the brushed setup putting around on the lake and keep it reliable and stable. If I can keep a solid 6-7 minute run time I'd be happy. From what I've read, the Octura X435 prop is a good replacement for the stock brushless Shockwave 26 prop. Is this what you guys would go with? Where I'm not too sure is the runtime I'll get with the 2200mah batteries. Proboat recommends a 5100 mah .74v lipo, so that's more than double the capacity of mine but still 2/3 the voltage. I know I won't draw as many amps for the same wattage with the 3 cell, but I'm not clear on how much of a difference it makes? Should I go down to a smaller prop or switch to the M series?