need help converting a jae .12 zipkits rigger to electric

[crazyprophead]

hi everyone, i have a JAE .12 zipkits rigger that is getting close to being finished. but i have decided to go brushless.

the engine i was going to install had around 1.5 hp (kyosho CRF .12)

But i want to match it with brushless.

im thinking of the XK2860-B-5050kv motor with a max rating of 120Amps

since 1.5 hp = 1118 watts i want to run it on 4400 3s (2x2200 3s in parallel fits in hull) to get out 1000watts or so but that will put me in the 60000rpm range which im not sure thats good with the 35-40mm prop. i know thats unloaded rpm but will the amps just sky rocket above 120 when it is loaded with a 35-38mm prop?

i will have to push the motor right back into the radiobox, and install the 400 gram battery where the original engine would sit to get the CG right.

i could go with the xk2850-B-4400kv but it is only rated at 75Amps and it certainly wont put out or handle 1000watts plus.
or if i go to a 36mm motor it will be too heavy.

i have some experience with high power 2000watt setups on v hulls but am not sure about this rigger.

Any help or advice will be greatly appriciated. Cheers.

[crazyprophead]

I guess what im trying to say is, will the xk2860 5050kv motor handle 3s? Or is it better go with a xk2850 4400kv motor on 3s? And will this setup get me close to the 100 kmh mark, and if not what do you think will?

[Chuck E Cheese]

4400 on 3s?????? wow you better use a small prop!! 4400 x 11.1 = 48,840 rpm... your goal should be around 30k... my feelings are it will be a pig with 28mm, needs to turn a bigger prop than that can pull. especially trying to run that kind or rpm, i think you will cook the motor and esc's. 5050kv is just crazy talk!!
here is my jae 12 fe, i use the ul1 36-50-2030kv on 4s.
http://forums.offshoreelectrics.com/...-fe&highlight=

http://www.youtube.com/watch?v=bmQ3cK0rVPs

[crazyprophead]

hey, yeah i was dreaming of getting that sort or power out of a 28mm, not to mention the crazy rpm. yeah your jae rigger runs really well, i think this motor will be more suitable XK3665-B-2300KV Brushless Inrunner and its 30grams lighter than the 2150kv version. it is a bit longer than your 3650 ul1 but i think it'll work. and was your 4000 4s ok with weight? or should i go a bit smaller mah sacrificing runtime? cheers. :)

[martin]

Go with the 36mm size motor, the 28mm motors are suited to the JAE Mini Sprint which is a smaller boat.

[crazyprophead]

Thanks, yeah ill probably get the xk3665-2300kv motor with either a 3600mah 4s or a 4400mah 4s. On a 120 amp esc. I know what your thinking, wierd battery sizes, well a 4000 4s is too long and i dont want to move the rear sponson tube, but with a series parrallal configuration of either 1800 or 2200 cells it fits in like a treat. And as long as i keep them well balanced i shouldnt have a problem. And i wont be charging them in parallel. Cheers :)

[crazyprophead]

and thanks for the help guys :)

[siberianhusky]

Any pictures of where you're at so far? Been thinking of converting my .12 but am half convinced it would be easier to build another from the plans, could make some changes to ease location issues. Think the only real change would be moving the rear boom tube as you mentioned. I could just build new sponsons I suppose then drill some new holes in the tub. Problem with that is I wouldn't own yet another boat!
Cheers

[crazyprophead]

hey, i will get some pictures up this week.
my rigger tub is just missing the top sheeting. And you Dont have to move the boom tubes,
1. im putting the motor(xk3665-2300kv) inside the radio box and cutting the brass stuffing tube almost to the floor. the motor will then be angled.
2. i will grind out the pine engine mounts to make room for a 4s 4p lipo which Will fit between the original rx box wall and the boom tube wood blocks. this lipo will be made from 4x 2200 2s 40c packs. being (2 sets being wired in series to get 2x 2200 4s, then those two 2200 4s will be conected in parallel to give a 4400 4s, being made to unplug seperately for charging. 3 packs together fit in the hull, then the last pack will sit flat on top, only calling for a 18mm raised hatch cover. its a bit complicated but it will fit with about 10mm left to slide the battery.
3. and the esc will go where the fuel tank goes.
this is my plan and it should work, i spent a while looking at battery sizes and that is one of the few options for leaving the boom tube in its original place. because one 4000 4s pack is too long. so as long as the parallel packs can be unpluged and charged separately, it shouldn't be a problem.

so if your boat is already running on nitro, its not that hard to convert.

but if i wasn't clear ill explain it with a few pics this week.

cheers.

[crazyprophead]

ive got some build pic up here http://forums.offshoreelectrics.com/...369#post419369
cheers.