1/16th Scale Hydro - Which motor?

[trialsguy]

1/16th Scale Hydro (wood kit from ClassicHydros) - Which motor would you recommend?

There are several versions to pick from (below).

Leopard 2845 Motor:

winds/rpm:

2230Kv 4Y (5)
2550Kv 3.5Y (12)
2960Kv 3Y (5)
3300Kv 5D (8)
3650Kv 4.5D (8)
4420Kv 2Y (5)
4700Kv 3.5D (3)
5460Kv 3D (9)

[JimClark]

I bought the 3650 for mine though i have not used it. Going to use a single 2s lipo also

[trialsguy]

I bought the 3650 for mine though i have not used it. Going to use a single 2s lipo also

Jim,

Have you tried the 3650 kV in your 1/16 hydro? How did it work out?

[I am getting ready to build again.]

Thanks.

Dave

[JimClark]

No I have not used it I have shelved the build.

[trialsguy]

Ok, Thanks. Did you select the 3650 kV based on past experience with something similar, or was it just a guess at what might work?

[JimClark]

A guess and also other's recommended it on OSE

[PROP]

What esc and prop would you use that motor with?

[JimClark]

not really sure but I was going to start with an x430 but maybe an x435? I was going to set it up to turn left so there are limited righthand props to try

[trialsguy]

I'm also planning to have mine turn left, like the full size ones. I might also try a smaller, vintage scale like turn fin - that way I'd be forced to slow down for the turns, just like they did in the '60's.

[JimClark]

Here is a gallery I did on my first 1/16th build with some video of it running I can dig up the specs for it

http://www.photosbyjimclark.com/Hobbies/Radio-Control/Boat-Builds/Jims-Build

[trialsguy]

Very nice! Thanks Jim!

Dave

[Fluid]

What speed is the OP looking for? In the larger format 3650 2-pole motors my club members have used the 3500 Kv motor on 2S and the x440 prop for speeds in the mid 40s. Boats are a bit larger, 23" to 25".

For similar rpm with 4-pole motors I would choose a higher Kv. The 2845/4420 motor should see around 27,000 rpm loaded on the water, with an x430 that should give ~mid-30s which was the speed most of these boats ran with they raced with 7 round cells - I raced them at several APBA FE Nats in the mid-late 90s.

An x435 might increase speed to close to 40 mph if the motor will turn that much prop, but also increase prop walk and handling woes, especially with a tiny turn fin. Note that a turn fin as mounted in the photo above will cause lifting of the inside sponson, the faster you turn the worse it will be.


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[trialsguy]

What speed is the OP looking for? In the larger format 3650 2-pole motors my club members have used the 3500 Kv motor on 2S and the x440 prop for speeds in the mid 40s. Boats are a bit larger, 23" to 25".

For similar rpm with 4-pole motors I would choose a higher Kv. The 2845/4420 motor should see around 27,000 rpm loaded on the water, with an x430 that should give ~mid-30s which was the speed most of these boats ran with they raced with 7 round cells - I raced them at several APBA FE Nats in the mid-late 90s.

An x435 might increase speed to close to 40 mph if the motor will turn that much prop, but also increase prop walk and handling woes, especially with a tiny turn fin. Note that a turn fin as mounted in the photo above will cause lifting of the inside sponson, the faster you turn the worse it will be. .

The motor that OSE recommends/sells for their 1/16 Miss K wood hull is the Leopard 2845 Motor (4 pole). They recommend 4420 kV version for 2s, and the 2250 kV for 3s. The details are shown in this link. I plan to run 2s, as the boat is only 22.5" long.

http://www.offshoreelectrics.com/pro...o-2845&cat=148 There must be a typo as there is no 2250 kV option shown.

As far as desired speed - I'd like to go real fast, but not spend a huge amount of money doing it. [ I was pretty good at setting up and racing nitro hydros back in the '80s]

[NativePaul]

I ran a leopard 2860 3400 KV, on 280g 3s 4500mAh, spinning a detounged X432 for a few seasons. The speed in a JAE.12 or 25" wooden cat was about 40mph, with a 5min 20sec runtime or an average of about 45amps.

With only 3550kv on 2s, I doubt an X430 would get up on the plane if it carries a full size 2s pack unless you can build it out of helium. I would have thought an x637 would be more appropriate to the setup, but they are not available southpaw, maybe something from Propshop or ABC.