First foray into Twins

[John Beardslee]

Is there a reason you didn't go with counter rotating props. I know the selection of RH props is more limited, but I would think canceling the torque effects would be worth it.

Lohring Miller

Not sure about Tyler, but from our testing years ago with nitro twins, the boat is like on rails going straight but it wouldn’t turn!
We tried everything, in the end, handed the info off to the drag boat guys where they were trying to go straight and the rest is history.
Thanks John

 

[RaceMechaniX]

Is there a reason you didn't go with counter rotating props. I know the selection of RH props is more limited, but I would think canceling the torque effects would be worth it.

Lohring Miller

Hello Lohring,

I do not intend on running this as a SAW boat where the counter-rotating props would have an advantage. This is only for heat racing so normal rotation props help rotate the rear around the turns. It tracks pretty straight, so prop walk is not an issue.

-Tyler

 

[HTV Boats]

In my recent experience with an FE Q twin I bought a counter rotating shaft, collet and then found severe lack of RH props. So we went with out counter. The boat tracks straight and turns well. What I did notice was a mild difference in load with the inside RH motor pulling more amps and watts in turns. To even it out I tried a 2217 inside (Right) and a 2219 outside (Left). No change whatsoever in tracking but load was closer. Unfortunately the Castles didn't work well together and knocked out a BEC even with one red wire in the "Y" connecter cut to run off only one BEC. After a lap or two one ESC would shut down even eliminating both BEC's.
Mic

 

[Mark Bullard]

That is common power on all twins. The right motor has to be richer than the left. I even bend on the props to make the motors sound better.

 

[RaceMechaniX]

In my recent experience with an FE Q twin I bought a counter rotating shaft, collet and then found severe lack of RH props. So we went with out counter. The boat tracks straight and turns well. What I did notice was a mild difference in load with the inside RH motor pulling more amps and watts in turns. To even it out I tried a 2217 inside (Right) and a 2219 outside (Left). No change whatsoever in tracking but load was closer. Unfortunately the Castles didn't work well together and knocked out a BEC even with one red wire in the "Y" connecter cut to run off only one BEC. After a lap or two one ESC would shut down even eliminating both BEC's.
Mic

Hey Mic,

I found it's best to not rely on the BEC in the Castles especially when you have a high torque rudder servo. I just isolate both positive leads coming from the Castles and run a receiver pack and a switch. This has made the ESC's more robust.

To balance the load we tried raising the inner prop which helped. I am seeing about 30-40A higher on the inner motor on a 6S system when set at the same height. I would to try depitching the inner or reducing diameter on the inner prop as time allows, but I am pretty happy with how she runs as is and the power system is happy.