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Thread: ABC super hawaii powertrain options

  1. #1
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    Default ABC super hawaii powertrain options

    Hi all, I am new around this forum but not to rc. I have an old ABC hobby Super Hawaii I have just bought off facebook. I used to have one of these way back when they were new. Lost mine along the way somewhere and so jumped at the chance when I saw this one pop up for sale.

    These things used twin 550 motors that ran thru a gearbox to a steerable drive via a ball and cup flex joint. I remember with my old one back in the 90's the cup wore out pretty quickly and eventually the gearbox blew out. While the motor pinions and the drive output gear are all metal, the spur between them all is plastic. If they didn't last back in the day, I strongly suspect there is not going to be any point expecting it to now that its 25 years old. Back then I am pretty sure I used a 750 motor from Graupner maybe? I know I had a Graupner speed controller and strut/rudder setup that I had in there. It was pretty quick and great fun. I'd like to do the same here but of course everything has changed since then so I am somewhat at a loss as to what motor to look for.

    So, I am here looking for as bit of advice. What would you do? This thing is all original, even still had the mechanical speed controller in there. Both the servos and both motors were seized. Looks like it was literally put away wet 20 years ago and then I got it. I have pulled all the electrics and managed to strip down the gearbox and outdrive off the back of the thing. I appreciate that it may have "some" collector value as it is all original, but I don't really care. I would much rather build something fun and fast to use than sit around hoping the Tamiya guys all decide ABC hobby boats are going to be the next big thing.

    I am 1/2 tempted to do what I had back then, but I don't know what size brushless motor would be roughly equivalent to those old 750 size Graupner motors? But is a strut and rudder combo the way to go? should I use a better quality steerable drive? or a pair of them? Or a twin strut and rudder setup? What would you do? Its bang on 3 feet long transom to tip and weighs nearly nothing without batteries in it. Its a V hull with 2 steps, and they always handled pretty crummy back in the day. I remember it used to spin out pretty regularly with the drive, but stopped doing that when I switched to the strut/rudder setup.

    I am totally up to speed on LiPo power so will be using that (I have a sizable RC car collection). Just have not done boats in decades and need a bit of help. What do you guys think?

  2. #2
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    Do you care about the scale aspect or just want the best performance?

    A 2860 is comparable in power to the Graupner 700 BB turbo my dad raced his similar ABC Cesa 1882 with in the early 90s.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  3. #3
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    Yep. the 700BB is exactly what I used back in the day. Google imaged it and remembered immediately.

    I suppose scale realism would be my preference, I would rather not have all sorts of massive hardware hanging off the back of it (on the other hand it is a big hull, so I suppose I could probably get away with a lot before it started to look silly), and I don't want it to get to a point where it is jumping out of the water when power is applied as I see some of the newer stuff do with way too much power. I'd rather it was pretty fast and good in rough water, rather than VERY fast but needs to be on glass. I did see another guy who had a twin steerable outdrives on one and it looked bloody outstanding. Said they were off an "sv27" but my google fu tells me that's a boat with a rudder and strut so who knows.

    So, if I look for a 2860 Brushless motor, and run that thru the standard transom plate to the stock out drive. Is there a way to convert my ball and cup to a u joint? should I switch to a metal prop? (I really want too..... they look much cooler).

    Or am I better off just buying a completely new out drive? or for that matter a rudder and strut setup? I see there are complete setups all over eBay with trim tabs and turn blades and the whole shooting match for chump change. They any good?

    *!***!***!***!** I don't know. I am all over the place with this thing. Perhaps I need to do a bit more research and come up with a plan.

  4. #4
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    You probably won't like this then, and under the caveat that while I believe they are very similar shapes with similar flaws and the hulls have the same basis, the Cesa is an unstepped hull and thus are not exactly the same. Back then we had archaeic rules that meant that stepped monos had to run with riggers, while this is now thankfully fixed, my only experience is with the Cesa, not the Hawaii.

    While a 2860 1380kv on 4s spinning an x445 would be a good power match for a 700bb turbo on 12 cells, it will weigh less than half and wont be anywhere near the scale waterline, without a lot of ballast it will look a bit like a cork bobbing about on the water when static, for scale looks maybe consider a 3674 1400kv and 4s2p just to make the ballast work for you.

    To get them race worthy we had to replace the steerable outdrives with stand alone struts and rudders which got them reliable with the extra power, but like most RTR FE boats of the time the hulls had a large amount of rocker at the rear of the hull to get the nose up and look "fast" with a very limited amount of power, and once the power level was increased the rocker was way too much, and the handling was very poor indeed. The mod needed to solve this was rather extreme, we would cut the transom off vertically about 5mm in front of the transom, then with a ruler underneath the hull find where the rocker started which from memory was somewhere near the wing, and cut the rear of the hull off vertically and throw this highly rockered section in the bin, then turn the short transom piece around and glue it inside the new rear of the hull. It leaves you with a very lightweight and great handling boat about 27" long which while it doesnt specifically look like the Cesa any more does have a decent scale appearance IMO.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  5. #5
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    i went thru a very similar experience with a Graupner Monster Vee... steerable outdrive and all... but as Paul said, the old hulls have massive rocker built in... i put a 2100kv brushless setup on 3s in my monster vee, and it was completely uncontrollable porpoising...anything over the 14-15mph the hull was designed around and it was a nightmare.... my opinion is your best bet is to keep the speed similar to stock... my monster vee ran fine on the pair of speed 600s in a 1.5:1 gearbox... once you got faster than the pair wired in series on 3s (even that was a hair much) it was completely unusable....

  6. #6
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    Thanks so much for the input both of you. I must admit I hadn't even considered how the lighter powertrain would effect the draft in the water, but it of course seems obvious now that you say it. I do have a few pairs of massive 8000mah 2s LiPo hard packs that I run in 1/8 buggys. they weigh damn near as much as old tech 6 cell sticks did. But I do remember that 700bb motor was pretty heavy in the hand and of course a brushless motor, even a big one is nothing like that. I very well may throw some ballast in to get it to sit right.

    While I can appreciate the dedication at the time, there is no way I am cutting and shutting this thing, so that's off the cards. And I think you may both be right, I am best off just running it around the same speeds I did back then. Around 30MPH i think. That porpoising you describe is EXACTLY what I want to avoid. if I get the itch for something faster, I will just have to pony up for a modern hull. the only shame is none of them look particularly scale anymore, or perhaps the 1:1 Boats all just looks like toys these days.

    In any event, thanks for the input, very helpful.

  7. #7
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    There are plenty of scale boats out there, but race boat builders have discovered aerodynamics and there is not much in the way of full size open cockpit racing boats these days, and thus not many models of them. Have a look at MHZ and Hydro & Marine for good handling modern scale boats.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  8. #8
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    Hi Blaize,
    on my Super Hawaii, I removed all the original drive system and put a 3556 1800Kv motor from Aquacraft with HobbyKing 90A Esc and 4 cell 4000mAh LiPo battery.







    Attached Images Attached Images

  9. #9
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    That looks very close to what I had way back when, mechanically at least. The real trouble I am now having is working out the motor and prop combination that will work without having to buy 3-4 setups before figuring it out. its just been so long I forgot all the specs, and none of them would be relevant with modern stuff anyway. So thanks for the details as I now know a motor size thats about right. Nice transom extension as well, I presume that is 3d printed?

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