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Author Topic: ic to electric conversion?  (Read 3155 times)

jostro65

  • Guest
ic to electric conversion?
« on: July 28, 2011, 01:48:02 pm »

hi all, looking for some help on a conversion.
i've built couple of IC airboats but looking for something without the spinning knives for my 8 year old!
built an outrigger and tried mounting a motor high up, airboat-type, but performance was pretty poor to say the least, if it doesnt impress an 8 year old it's gotta be bad!
i'm not too experienced in leccy matters so looking for a reasonably good performance at reasonable cost (aren't we all), and i do have some lipos,esc lying around from what used to be an aeroplane.....
posted a couple of pics below and i'm happy to make adjustments to the hull where need be.
the weight of the hull is around 3/4kg or 1lb10oz and is 22in long.
suggestions greatly appreciated folks!!!!





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n33h

  • Guest
Re: ic to electric conversion?
« Reply #1 on: July 28, 2011, 05:04:23 pm »

welcome to the forum

you could put an electric setup in it (something simple) straight shaft (4mm solid shaft with a 34-35mm2/3 blade prop) through the transom coupled to a brushless motor running on maybe 3s, a 3660 (36mm diameter, 60mm long) say around 1600kv would push it along nicely (a good out rigger then) you can get away with a 40a esc (watercooled/proofed

i have built a electric airboat using an old door for the hull and any other bits of stuff laying round the house

the setup i use is

1600kv outrunner motor (helicopter 500 size motor)
60a ESC (waterproofed/cooled by me)
2s/3s, 5000mah lipo battery
2.4ghz tx/rx

the motor spins a 8" plastic prop (can go upto a 10" prop if i want) the boat is very fun but had to add skegs  (3x wood line front to rear) to aid straight line stability

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jostro65

  • Guest
Re: ic to electric conversion?
« Reply #2 on: July 29, 2011, 07:52:53 am »

thanks for that n33h, gives me a rough idea to get along with.
i assume if running prop thru transom i'll have to move the existing rudder/servo, does it matter which side?
also, should the prop extend past the rudder or vice versa?
cooling is a mystery to me tho,would i have to buy a kit for that or is it easy enough to make up?
thanks again!
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n33h

  • Guest
Re: ic to electric conversion?
« Reply #3 on: July 29, 2011, 08:23:54 am »

no problem jostro

you don't need to move the rudder if you have the prop inline with the rudder and about 10mm clearence between prop and rudder

IF you decided to have the prop coming out of the transom then you would have to move the rudder to the outside aswell (place rudder to the right side looking at the transom)

i always had the rudder positioned so the prop (when looking from the side) was halfway inline with the rudder blade

watercooling/proofing an ESC is easy, you can buy cooling plates (www.astec.co.uk) which go on the fets (little black squares on the ESC)

and

- you would also need clear heat shrink (same stuff on esc's already) about 20mm wide,
- cut the shrink to length (just long enough to cover whole esc and 5mm of the wires) then warm over the oven to shrink it
- seal the open ends with hot melt glue
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n33h

  • Guest
Re: ic to electric conversion?
« Reply #4 on: July 29, 2011, 08:47:55 am »

hope this helps explain what i mean with rudder, prop placement etc

post some photos of watercooling an esc soon aswell

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n33h

  • Guest
Re: ic to electric conversion?
« Reply #5 on: July 29, 2011, 09:36:36 am »

some photos of watercooling an esc (cooling plate avaliable from most model stores, www.astec.co.uk, www.giantcod.co.uk, www.cornwallmodelboats.co.uk to name a few )
i find silicone fuel tube with 3mm inner diameter to be ample for me for water flow, some rudders for fast electric applications come with a water pickup already in the rudder

1- here is the esc with the FETS exposed (sometimes brass strips and sometimes little black squares)
2- cooling plate (different sizes avaliable)
3- cooling plate placed on the FETS (thermal paste can be used but i use the transfer material already on the esc)
4- 25mm clear heat shrink cut to length (cover esc plus 5-10mm of the wires both ends) and then seal both ends to waterproof (i use hot melt glue as this does'nt harm anything)







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MikeA

  • Guest
Re: ic to electric conversion?
« Reply #6 on: July 29, 2011, 09:50:40 am »

whats he doin then going for a conventional prop or airboat 1?
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n33h

  • Guest
Re: ic to electric conversion?
« Reply #7 on: July 29, 2011, 12:43:42 pm »

i'm assuming he's going for a convential out rigger boat because he said at the begining he does'nt want a meat grinder boat for his 8 year old so i pointed him in the direction of convention

if he wants an electric airboat then he can mount the motor and prop on the engine pylon with everything else in the hull, no altering the rudder just get the esc and battery in the hull

if he does go that way then he needs to extend the motor wires to the esc and keep battery wires short or he'll need to add a capacitor to the batery wires
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MikeA

  • Guest
Re: ic to electric conversion?
« Reply #8 on: July 29, 2011, 12:51:31 pm »

hi all, looking for some help on a conversion.

i've built couple of IC airboats but looking for something without the spinning knives for my 8 year old!
built an outrigger and tried mounting a motor high up, airboat-type, but performance was pretty poor to say the least, if it doesnt impress an 8 year old it's gotta be bad!

well from this quote it seems the propeller is a past tense comment as if hes allready done it. i think he just wants to know how he can get more power the aero prop
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n33h

  • Guest
Re: ic to electric conversion?
« Reply #9 on: July 30, 2011, 07:58:36 am »

if he wants more power at the prop then he needs to go brushless

my 25" (or so) airboat has a 1400kv motor with an 8" prop powered by a 3s lipo and that thing shifts, even now i still get a little bit shakey when running her aorund the water
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jostro65

  • Guest
Re: ic to electric conversion?
« Reply #10 on: July 31, 2011, 10:17:55 pm »

hi guys, just to clarify,already did the airboats,this ones definitely a
water prop outrigger!
the airboats are nitro and the missus (and common sense!) say they're a no-go
for junior! they certainly shift!
im afraid I did this a#$ from elbow!
I built the outrigger described above for jr and stuck a brushless motor
and prop from a plane on a pylon but it was pretty pants so just trying to
get something a bit faster without starting from scratch.
cheers for the replies so far guys!
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MikeA

  • Guest
Re: ic to electric conversion?
« Reply #11 on: August 01, 2011, 01:19:39 am »

go with the submerged prop then. keep the rudder where it is.
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Tombsy

  • Guest
Re: ic to electric conversion?
« Reply #12 on: August 03, 2011, 05:49:40 pm »

Take a look at this it might give you some ideas for parts.
http://zippkits.com/~zippkits/index.php?main_page=product_info&cPath=71&products_id=263
I built one of these it would impress the 8 year old for sure.
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