Model Boat Mayhem

Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: ChrisF on October 12, 2017, 09:43:11 pm

Title: ESC Query
Post by: ChrisF on October 12, 2017, 09:43:11 pm

To have a margin of safety and no overheating problems I'm looking to use a Hawk (my preferred make) 75 or 100 amp ESC for my motor which requires a min. 60 amp ESC.


Only thing is I notice is that those ESC state the use of 4 - 12 LiPos and I'm only intending to use 3.


I'm guessing (always dangerous!) that the minimum of 4 is because the cut-off/low voltage can't be set lower than for 4 cells?


If needs be I could go to 4S, though I'm not looking for manic performance, and that would also give more benefits as regards cool running and greater run time?


Chris
Title: Re: ESC Query
Post by: McGherkin on October 12, 2017, 10:00:26 pm
To be honest I'm using motors with a recommended 60 amp rating, with Hawk 60's.

Not so sure on what happens if you try and run a minimum 4s ESC with 3s, probably best not to.

If you can afford to carry the weight a 4S lipo could well be a good plan, I went with 4s for my boat because you can get 16ah lipos in 4s and the joy of brushless motors is that they're very frugal at part throttle, so you can over-battery and just use less stick for longer runtimes.

Title: Re: ESC Query
Post by: ChrisF on October 12, 2017, 10:17:44 pm

Thanks for the reply.


Since posting I've found an Overlander 80 amp ESC for 2 - 6 LiPos. Just checking out with them that it has forward and reverse.


But as you say 4S would be good for a longer runtime.


What size boat is yours. Mine is to be a Fairey Swordsman at 33" long.


Does your ESC stay cool enough?


Chris
Title: Re: ESC Query
Post by: McGherkin on October 12, 2017, 11:15:06 pm
A Model Slipway Tamar, 1m long. She's not finished yet but the setup has been used by others with good, cool results. Bench testing in a bucket of water doesn't even get them warm.
Title: Re: ESC Query
Post by: ChrisF on October 14, 2017, 12:25:14 pm
Thanks.

It's a more expensive way to go than water cooling, but I'm going to go with my first thoughts which is a bigger than needed ESC, likely the Hawk 100 amp which has a fan, and 4S, so if I do any high speed running I'm well over engineered!
Title: Re: ESC Query
Post by: ChrisF on October 16, 2017, 10:31:04 am
I've heard back from Overlander and their ESC's don't have the facility for forward and reverse.

That makes the decision easier!