Super Hawaii 21" brushless conversion questions

[studioRS]

Picked up a small toy version of the Super Hawaii with a hull length of 21" and transom width of 6". Pretty nice little hull, good details, just a tick heavy.

Looking for some suggestions on converting to brushless. Planning to ditch all the gear.

What would be a good brushless motor, ESC, battery, strut, stuffing tube, rudder and prop to start with? Might need trim tabs too.

I have the following and realize the motor is way too small.
Birdy 50A ESC

Rudder Set 74mm

2040SL 4800kv motor

Would be nice to have this slightly overpowered. I was planning to knock off some plastic weight on the top deck and replace with birch ply. The hull, while on the portly side, does look strong despite the weight. Totally open for suggestions, thanks!

[Southwest]

Make it a single motor for economy sake. Now 21" and a deep V would require a motor like a Turnigy 2860-2700 whcih has a max of 11.1 =29970 rpm x .80 = 23976 which is a round figure for effieiency. I made a cooling jacket out of pcv pipe and O rings for the long can it has. The end bells have no holes but had it in a 26" Arpr0 1 and ran great. Now a 632 Octura or a 435 is close. I would place motor at cg approx. 30% with lipos ( 3S ) on each side of motor close to cg line. Esc would be at least 70 amper for insurance sake and be water cooled. Plenty of floatation and i would beefup the sides with cross members as it lloks to cave in somewhat with any pressure. BTW-where did you find it? Thanks.

[Southwest]

super H

How are you at making equipment for your boat like soldering, making stuffing tube, trim tabs, turn fins and the like.? I have many monos in the 22" range and was going to make another to have something to do and ran across your posting. Nice find!!! Winter project.

[studioRS]

How are you at making equipment for your boat like soldering, making stuffing tube, trim tabs, turn fins and the like.? I have many monos in the 22" range and was going to make another to have something to do and ran across your posting. Nice find!!! Winter project.

All good with fabricating and making all of that. I used to work for Charlie Pottol at Marine Specialties back in 1976 machining water cooled heads for Veco .19s and finishing cast rudders for final packaging, been with RC hobbies for 40+ years. I have an old Hughey 3/16" flex drive, strut and might have an Octura 435 that would work. Just needed a general direction of where to start with making it brushless.

Yes, it was a nice find, the owner of where I work gave it to me.

I also build and fly scale sailplanes

http://www.youtube.com/watch?v=j3bBCzHBhvU

I'll snap off a photo of the original box and look up the motor you suggested and order another ESC.

The 2040SL 4800kv motor and 50A ESC will work for my other project, Dumas Atlas Van Lines 1/2 A size 18" picklefork hydroplane.

Thank you for your suggestions and help!

[studioRS]

Is this the Turnigy motor you've suggested?
http://www.hobbyking.com/hobbyking/s..._Inrunner.html

[Southwest]

Yes it is. I had 2-3.6 lipos in parallel for juice on a 536 Octura prop. Esc was a 90/100 HK. Motor and pcv cooling weren't heavy at all. I was impressed!! I make my own struts and stuffing tube out of brass and rudder is brass except the support portion is .064 double walled aluminuum. Also trim tabs and turn fins. I like not to use trim tabs unless hull is untrue and hops alot. Since there isn't any more of the 21" around, i'll finish my jet boat conversion. Now what catches my eye is the X-Blaze mono at 18" or a mono with turn-over control. Man i hate it when words escape me and on the tip of my tongue. Oh yes, i'm retired, but lets hear which way you go on this project. Oh yes. cooling i used conformal coating to seal O rings on can. I've got some of ED Hughey gearboxes and msc but since BL came in i haven't talked to Ed for many a year.

[studioRS]

Yes it is. I had 2-3.6 lipos in parallel for juice on a 536 Octura prop...

Could you be more specific with technical specs on the batteries please? Ok, re qty 2 batteries in parallel, just inquiring about how many cells per battery. Are each of these 2S, 3600mAh or 3S 3600mAh? Thanks again.

[Southwest]

2-3600mah are 3S 3600mah. Gives me 7200maH in parallel. I didn't think about that as i don't think 3600 come in 2S but i could be wrong, won't be the first time,LOL! Run time will be good.

[studioRS]

Ok, WOW! 2 - 3S 3600mah is going to make this little deep v fly, nice. The HK ESC of 100A should do the trick too. Thanks for your help.

[studioRS]

How about these batteries will they work ok, or do I need a higher C rating discharge?

Rated at 3S 3700mah, 25C discharge, in parallel will be 7400mah.
http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

[Gexx99]

I did this with an original Super Hawaii. Might be able to do something similar here...

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