Prather electric conversion help please

[ericrechlin]

I have a Prather 40 hull with all the hardware. I'd like to make it electric. Steven from offshore electrics gave me a few ideas like the Leopard 5698 motor with 240amp swordfish esc. Is there any other ideas for motor esc combo that anyone could help me with please? Thank you everyone for your time

[jhl1963]

We have one to build with a neu 1527 1y and swordfish 240 on 6s.

[FlogginHarvey]

Hello Eric.

Not sure how much actual help I can offer but I am working on a "similar" project here. I have a Prather Commander II (46") hull and am going to do twin counter rotating TFL P1 drives. Not planning a speed demon, just a play boat that I can turn the EPA WAY down and let my daughter get a taste of RC model boating. Going 3S and OSE 160 ESC's. I have an old Nitro hull of the same that my dad and I built in 1989 with a nitro Rossi .90 and thought it would be fun to recreate and old boat he owned when I was a kid. We'll see how it turns out. Parts incoming now on mine.

I was told by Steven it wouldn't be enough in singles but might just be on the edge of okay as a twin.

When I sit down to start the first thing I'm going to do is square up and blue print the hull to inspect and remove any hook if necessary. Something similar to what I did on an old Dumas 38KV Scarab a few years back.

Good luck and keep us posted!

[ericrechlin]

Thank you for the response. I'm making my list to order the motor and esc soon so everyone's input is very helpful on my decision. I'm going all electronics being waterproof so I won't need much of a electronics box. This boat has 2 individual covers on it so it will help with the water intake

[Jamey]

I had a Prather 40" when I was in high school with a 7.5 OB. For the longest I kept the hull in the attic thinking I would convert it to electric. Finally got rid of it one day and regretted ever since lol

Do you know what voltage you want to run? I would suggest at least 8s though I am sure 6s would be fine. Once you decide on the voltage you will need to pick the appropriate motor KV. Take a look at the Swordfish 300amp too. I don't think it cost much more than the 240.

Good luck!

[Fluid]

Running such a large obsolete hull on 6S will be a mistake. Huge wetted surface and high weight means it will take a lot of power (amps x volts) just to get it on plane. These hulls are not known for low drag or high speeds. Amp draw will be very high, a minimum voltage should be 8S and 10S is better. On 6S the amps will be Almost twice of the draw you will see on 10S.

Even if you just want a play boat, it is no fun if it won't plane off, or if you keep burning up equipment. This is not a ground-breaking project, some of us run big cats and monos, and we have learned a thing or two. Those who only read about them, not so much.

Feel free to ignore the above. It's your money.



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[jhl1963]

Eric, I don't want to give out bad info, so by all means go with the other more experienced guys. I saw a guy running one with an 1100kv motor on 6S and it ran mid 30s just fine. I can always go 8s, but my setup isn't for racing so 30 will be fine (for me).

[Prodrvr]

turn the EPA WAY down and let my daughter get a taste of RC model boating

Doing that will cook the esc

[ericrechlin]

I can run 8s or 12s with the batteries I already own. I posted this for all helpful input. I'd run the 300 amp with 1100kv motor on 8,10, or 12s. I'm not looking to race just have fun screwing around but I'd like to blip the throttle hear and there for nice speed runs.

[Fluid]

I can run 8s or 12s with the batteries I already own. I posted this for all helpful input. I'd run the 300 amp with 1100kv motor on 8,10, or 12s.

Bad idea, the 1100 Kv motor is too much for 8S let alone 12S. For 8S try a large-format motor with 700-800 Kv and swing a big prop like the hull was designed for. Amp draw will be lower, everything will be cooler and the setup more reliable - and more fun.

I'm not looking to race just have fun screwing around but I'd like to blip the throttle hear and there for nice speed runs.

Even more horrible of an idea. Running an FE boat at part throttle for an extended time can overheat the ESC and burn it up. Best to prop the boat for the speeds you want while at full throttle most of the time. If you want to go fast, put on a more aggressive prop just for the speed runs.


Feel free to ignore the above. It's your money.



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[Jamey]

Hi Eric, Fluid (Jay) is your guy, he knows his stuff!

I did exactly as he recommended with a similar, old nitro/gas hull design and it works very well and reliably. Specifically I run my boat with 800kv on 8s. I have the option to run a huge range of prop sizes very reliably to suit the speed I want. Keep in mind a realistic goal speed for a hull like this isn't going to be nearly as high as the modern fast electrics. Stability becomes an issue at much lower max speeds. So you don't want to build it out like most of the examples out there. If you already ordered that 1100kv I would seriously consider trading it for the lower 835kv version so you can at least run 8s. I think you would be happy with a 5692 730kv actually, 8-10s

Is the hull already built out as a nitro boat? If so do you have some pictures you can show us? Is it surface drive?

[ericrechlin]

Thank you Fluid for the recommendations. I'll go with 700-800kv on 8s. I don't know a ton about the boats so I'm glad everyone is chiming in and giving me help and advice.

[ericrechlin]

I have no clue how to add pictures. I tried to copy and paste from my phone and couldn't get it to work. I'm sorry guys

[FlogginHarvey]

Upload to photobucket (or similar) and copy / paste the image link into the box here.

Or you can email to me pricetrey@gmail.com

[Mat sprague]

Just seeing if you have info
On motor esc and batteries and prop
When converting the king of shaves gas boat
Into an Fe boat