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Prop Question For Boaters

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I am running a Kyosho Wavemaster outboard tunnelhull on six matched cells and I just upgraded the motor to a Trinity Monster Maxx 550. I realize that prop choice is very important in boating, and I'm wondering if the Octura 1740/3 prop (40mm diameter, pitch: .68mm, 3 blades) would work well with my setup. The stock plastic 2-bladed prop is 40mm in diameter, and the stock motor is a sealed-can 550. I just need to know if the extra power of the new motor will be able to turn the extra prop blade. Can anyone help?

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With all props it's a case of suck it and see mate. Buy lots of carbon props (much cheaper than octura) and try them on a full charge, see what you recon. I personally found carbon props gave me a higher tip speed, so stayed with them.

Graupner are best. The added benefit is you dont have to balance/ sharpen them!

If you're in the uk try these ppl: they are awesome and one call will have you chatting for hours with a really knowledgeable bloke!

http://www.astecmodels.co.uk/products.php?...selection=props

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Oh and with this motor you will find a larger prop will cavitate quite badly. Also it's quite a poor design, and you get alot of drag in the assembly, so water cool the motor. The best way is to to drill a small hole in the ride plate just above the prop, and glue in a small length of ali tube. you can then choose a cooling coil, or cool the brushes directly, but a coil will be plenty for what you are doing matey

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I'm afraid I can't order from the website you linked, ryanboard, I live in the States; though it looks like it has a great selection of props. Do you know any place else I could get carbon props? The outboard on the WaveMaster already has a water pickup mounted, I just need to add a cooling coil. That WaveMaster by Rum Runner Racing was really nice, though I don't think I'll be modding mine quite that much! There's still a lot of helpful info in that article, though. Thanks for the link, acorn!

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Read the bit about the prop. They use a Octura X640, which I also use. I use it with a 19turn motor. and it works a treat.

Also, (the boat is in storage so Im a little hazy) the Octura X640 is a 2 blade prop. Your proposed a 3 blade with a standard motor. I think a 3 blade will drag, and you wont get good performance. Of course prop selection is a black art and you may well get a good result. I'd be interested so know what you do buy and how it works for you.

But, i went with thier choice and it worked for me.

But do read through the aritcle, because it highlights inherent weakness and what to do to resolve them. Get the Wavemaster right and is a **** fast and stable boat.

Must get my boats out again......

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With all props it's a case of suck it and see mate. Buy lots of carbon props (much cheaper than octura) and try them on a full charge, see what you recon. I personally found carbon props gave me a higher tip speed, so stayed with them.

Graupner are best. The added benefit is you dont have to balance/ sharpen them!

If you're in the uk try these ppl: they are awesome and one call will have you chatting for hours with a really knowledgeable bloke!

http://www.astecmodels.co.uk/products.php?...selection=props

I agree with Ryanbored, stick with carbon props. I run a bronze octura on my El Lobo and they need to be sharpened and balanced to make them run right. (And that's a nightmare to do). Buys lots of different size carbon props and try them out. Bearing in mind that you have normal props and 'Sport' props with have a greater pitch to pull harder through the water. NEVER FORGET, which ever prop you try, put in on, run the boat at full throttle for about 30-45 secs and then feel the motor for heat. If you can't keep your finger on it for more than a couple of seconds it means that the prop is too large for it to cope. EG, if you run a 35mm prop, try the 35mm sport before you go to 40mm, and so on. And you definately want to stick with 2 blade props, because, as ryanbored says, they hold more drag.

Better not say anymore, we are on a RC car site aftr all!! LOL!!!

(Hope that helps)

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Try Rum runner racing. I think they are over your way matey. They do also have a shop- but i couldnt find the link. they sell a conversion for 12 cells, 700bb tubo motor, which should see a good 30mph+ (standard wavemaster is about 12) and is fairly cheap. (bucks per bang)

AS for props stick with 2 blade, carbon reinforced plastic, and with your set up i'd recon on about a 35mm prop

(as you wand tip speed not torque)

http://www.rumrunnerracing.com/

I warn you, Two hobbies is not good for the soul- or wife!

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Thanks for the replies! Acorn, how many cells do you run with your boat? If the X640 works well with your setup, then your number of cells could give me a good starting place for finding the right prop, since the Monster Maxx is also a 19t. I definitely want to go with a carbon prop, I was not looking forward to balancing a metal prop. Also, it seems two blades is the way to go. Thanks for the link, ryanboard, I'll try and find RumRunner's retail section. I considered using the 700bb motor with my boat, but I thought the size and weight differential between the 700 motor and a 550 motor would cause complications. Trinity is a great motor company, and the Monster Maxx motor is also rebuildable, the 700bb is a sealed-can. Two more things: I understood most of RumRunner's WaveMaster article, but I didn't get how they made the spray rails, and how they internally braced the hull. Can anyone clarify? Also, with the more powerful motor, should I replace the flexshaft to handle the extra stress?

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Thanks for the replies! Acorn, how many cells do you run with your boat? If the X640 works well with your setup, then your number of cells could give me a good starting place for finding the right prop, since the Monster Maxx is also a 19t. I definitely want to go with a carbon prop, I was not looking forward to balancing a metal prop. Also, it seems two blades is the way to go. Thanks for the link, ryanboard, I'll try and find RumRunner's retail section. I considered using the 700bb motor with my boat, but I thought the size and weight differential between the 700 motor and a 550 motor would cause complications. Trinity is a great motor company, and the Monster Maxx motor is also rebuildable, the 700bb is a sealed-can. Two more things: I understood most of RumRunner's WaveMaster article, but I didn't get how they made the spray rails, and how they internally braced the hull. Can anyone clarify? Also, with the more powerful motor, should I replace the flexshaft to handle the extra stress?

I still havent got my boat out..... and dragging this from the depths of my knackered memory:

It was probably 6 cell, but I might have been running 8 . I remember building a 8 cell hump pack at some stage, must have been for that.

You might be right about the weight with a 700motor. It would alter the C of G. I know my Super Hawaii was super sensitive to C of G, cant remember if the WM was. I have to say, I dont thing a 700 is necessary on the WM.

I stiffened the motor mounting area with ply and epoxy. Then filled, cant think of the correct term, the two hulls with expanding foam. This stiffened things up a fair bit. Added a plastic / carbon prop. Did this before seeing the article. After seeing the article I sharpened the edges and bought the Octura prop, which I had balanced sharpened buy the guy I got it from. The are very, very sharp and will easily remove a finger. (bought 2 more for the SH and another both running 14 cells and 700motors)

Dunno if any one has mensioned cooling. If not get a cooling coil, a pick up and some pipe. If you use a powerfull motor and a prop that shifts a lot of water you might want a water cooled ESC as well. IIRC, I made a bracket to hold the pick up over the back of the prop. Although that might have been for the SH, oe of them has a pick up alread moulded in. Cant remember which.

Thats all I can remember for now. :mellow:

Remember, setting up boats can be a bit of a black art. I had a nightmare making my SW work properly. The prop was cavatating and couldn't grip the water. After lots of expereminting with angles and props, it suddenly just 'caught' and went like a rocket, with almost only te prop in the water (not quite, but , you know...) I've seen two identicle boats behaving differently and needing different prop angles for no aparent reason. But keep experimenting. Fast boats can be great fun.

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