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Author Topic: Outrigger hydroplane  (Read 3025 times)

Will01

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Outrigger hydroplane
« on: February 10, 2017, 09:28:29 PM »

Hi Guys, still with my starter posts on MBM.
I have made a few other posts of hobbies and projects, but there is one I have been working on for too long now. I started it at uni in spare time and never really got to point of finishing.
Now I want to push ahead and change plans to make my outrigger brushless.
I have no real intention to race, more for fun and also built for running choppier water as I intend to run on the estuary near to where I live.
I made this outrigger purely from pictures and am trying out some prop shaft and tunnel mods to see if this will help with flow of water around the prop.
Pictures to follow.
I am sure plenty of learning to be done along the way.
I am also toying with the idea of making this a 3 channel hydro to see if I can trim the boat at speed with a wing or tab . I was a keen rc flier so hopefully that will come naturally, but we will see.


Rough guesses so far are starting with 3s with intent to progress to 4s and some crazy prop and motor combos. Still learning on the brushless side but looks good fun
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Will01

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Re: Outrigger hydroplane
« Reply #1 on: February 14, 2017, 12:44:09 PM »

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Will01

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Re: Outrigger hydroplane
« Reply #3 on: February 14, 2017, 12:58:15 PM »

I should also explain that is not the fixed angle for the propshaft. it is not fixed yet and i may be switching to a flexible shaft.
Problem is i started the build in Uni to keep my mind functioning and an excuse not to get compltetley plastered on booze!
There are still many things that require alot more thinking and sorting out, but i don't think it will take much to get it running for some fun to be had on the estuary.
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Tombsy

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Re: Outrigger hydroplane
« Reply #4 on: February 14, 2017, 07:14:52 PM »

Usually riggers use a flex cable with a slight s bend in the stuffing tube, a "ski" on the bottom and a strut set level with the ski. Zippkits has great info and a great strut. Have a look thru this build guide for pictures.
http://http://www.zippkits.com/12G4.pdf
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Brian

Will01

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Re: Outrigger hydroplane
« Reply #5 on: February 14, 2017, 07:56:56 PM »

Very helpful. Thanks Brian
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martno1fan

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Re: Outrigger hydroplane
« Reply #6 on: February 14, 2017, 09:42:39 PM »

The angle of your prop is going to cause a few problems for a rigger . Riggers are designed to run on the prop so they should be a surface drive set up . As Tombsy says a flex cables setup is the way to go using a strut , this should put the prop lower than the tub so its roughly level with the sponson bottoms so when shes running at speed shes running on the sponsons and the prop only .
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Will01

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Re: Outrigger hydroplane
« Reply #7 on: February 18, 2017, 03:21:51 PM »

Thanks guys. Flex prop shaft will be on order soon. I decided to do a floatation test and she floats well. If anything too well. I was expecting it to almost be sinking. Just means I will load with more batteries. :)
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martno1fan

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Re: Outrigger hydroplane
« Reply #8 on: February 18, 2017, 09:37:43 PM »

You can buy nice kits for outriggers from zippkits in the states if you ever fancy building another i think also hobbyking do their kit too .Zippkits probably more reliable to order from though.These riggers are proven winners too  holding world records .

http://zippkits.com/~zippkits/index.php?main_page=product_info&cPath=71&products_id=258




https://hobbyking.com/en_us/zippkits-jae-21fe-fast-electric-outrigger-kit.html
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Will01

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Re: Outrigger hydroplane
« Reply #9 on: March 13, 2017, 12:56:18 PM »

So i have decided to just go give this a go based on many searches online looking at what other people have done.

Info below(cheap China thing)
Package List:RM7718
 1 * GoolRC 3650 4300KV Motor
 1 * GoolRC Waterproof 60A Brushless ESC

It will take 3S and the ESC has a large burst current rating of 320A so should be great for allowing her time to get on plane. ESC also has little cooling fan which should help.

Also tied up with another China item rudder set and flex drive.

Just need to find a 3.2mm to 3.2mm coupling now to suit and i have a start for getting this hydroplane moving for first time since i started making it 10+years ago
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martno1fan

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Re: Outrigger hydroplane
« Reply #10 on: March 14, 2017, 06:06:47 AM »

Just be carefull with the cog,it needs to balance near the transom of the sponsons fully loaded .
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Will01

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Re: Outrigger hydroplane
« Reply #11 on: March 14, 2017, 12:44:41 PM »

Thanks for advice.
I would say since i have built this rigger from my head only and seeing a few pictures i want to keep the boat as adjustable as possible.
I am planning to be able to move batteries fore & aft in order to help with tuning the COG.
That for sure is the best place to start and i can balance with how much thrust/lift the prop gives.

Others have also said about introduction of a turning fin up front, however they are normally used for clockwise or Counter clockwise circuits. I am intending on having a good balance as this is more for high speed fun. Does it sound better to centrlise a turning fin under the central hull?

I was also intending on running the rudder inline with the prop, but still open to advice on that one.
One thing for sure is i need to add a reinforced rear bulkhead to mount the prop and rudder to.
I am also thinking about some way to be able to change the angle of the front sponsons until i tune a good setup.
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martno1fan

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Re: Outrigger hydroplane
« Reply #12 on: March 15, 2017, 07:18:10 PM »

Hydros and riggers are meant to just do circuits usually right.The idea of the fin is to keep them on the water at high speed when cornering.You cant put one on each side either  or it will act wierd and try to act like a hydrofoil on the fins.Fin should go on right side sponson transom inner edge.A central one wont help anything really .
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Will01

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Re: Outrigger hydroplane
« Reply #13 on: March 23, 2017, 12:50:45 PM »

I understand.
I think i will just have to experiment with it i suppose. To start off i will run without and then add one or two and toy with their placement.
As i say this is more fun outright speed and a bit of fun. I actually quite like the idea of toying with a hydrofoil by running opposite turn fins and seeing what it will do.

So last night the first of a few packages arrived containing the rear strut, flexible shaft and rudder assembly. Pictures to follow.
The rudder i have purchased is only 75mm length, so i am looking at running it so the servo linkage is sitting just slightly higher than the max possible prop i think i will run. so it will sit quite deep, i can always trim it down or move it up if required.

The strut isn't quite long enough for what i need becasue of the rear tunnel i have constructed, so i will be looking to adapt this slightly. I may be lucky by just enlarging the hole.
Currently the setup means the prop centre line is directly in line with the bottom plane of the hull. I think i need to get it ever soo slightly lower otherwise my prop will be running without water.
Are there any rough dimensions to follow for prop centre line under hull?

My next area of concern is the propshaft where it will join the motor. I am going to have to order a new coupler which is longer, as there is just too much flexi-shaft sticking out which i don't think will work very well.
What do people use to lubricate these teflon lined flexi-shafts? I guess they will burn out eventually.
I also am going to make a small adjustable bulkhead plate which holds the internal end of the brass flexi tube. Next month motor & esc will be on order so i can do some trials. So i better get on with finishing my sponson covers.
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Tombsy

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Re: Outrigger hydroplane
« Reply #14 on: March 23, 2017, 05:16:36 PM »

I can try to help with a couple things. I think you should start with the strut set at a neutral angle with the center line just below the bottom of the boat about 1/8" to 1/4" to start. These are surface drive props they are meant to have 50% of the prop in the water at any given time, it allows the running of bigger props with the same motor as a sub-surface drive.
The flex shaft should be cut to fit your set up, leave it long enough that you can leave a small gap between the drive dog and the strut about 3/16" to allow for wind-up where the cable can shorten when running. It can easily be cut with a dremel cut off wheel and any sharp edges filed or ground smooth. Some people solder the end by dipping it in molten solder but I've never had to with mine.
The flex shaft even with the teflon tube should be lubed every few runs with a good marine grease.
The online manual for the zippkits jae rigger has some good instructions for measuring your flex cable to cut it.
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Brian

martno1fan

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Re: Outrigger hydroplane
« Reply #15 on: March 25, 2017, 05:23:04 PM »

Tombsy covered the flex shaft cutting  etc i dont have any pics of a rigger showing strut depth placement etc but i do have one on my gas hydro,same principls apply and as Tombsy says set the prop hub level with sponson bottoms not the transom of the tub .Prop tube runs under the tub into the strut so you need to have a nice smooth bend in your brass tube,i do mine with the flex inside to avoid kinking and i just use steady pressure between thumbs if you understand me never had to heat the tube up .
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Will01

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Re: Outrigger hydroplane
« Reply #16 on: March 26, 2017, 10:00:03 AM »

Thanks guys you have both been very helpful.
For the bending I did start to bend slightly by hand.
Without this sounding wrong I rubbed the shaft until I got some heat into it and then started to bend very gently and this seems to have worked so far. I just need to get the S bend in now.


I done some reading and it appears the s is better than c bend. Different to what I had thought myself.
Need to get the.motor ordered up before I put final bend in to make sure it's right.


Unfortunately my vertical strut is not long enough.
So I guess as a temp measure I will use a intermediate alloy spacer. But I am going to look at either buying or making longer strut.


The zipp kits instructions are very helpful. I am going to try and incorporate some of their design features in my sponsons.


Thanks again guys. The pictures also help visualise everything a bit better. :)

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martno1fan

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Re: Outrigger hydroplane
« Reply #17 on: March 28, 2017, 11:28:03 AM »

Your right an s bend has been shown to be better but sometimes its not practical a gentle single bend will work just fine so dont worry too much.
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Will01

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Re: Outrigger hydroplane
« Reply #18 on: July 19, 2017, 12:00:58 PM »

Been far too long since i contributed back to this thread. Many other things have just got in the way.

So a 2.4ghz receiver, Gool RC 4300kV motor & 60A esc capable of running the boat on 3S have all arrived.

Unfortunatley my old servo seems to be dead, so it will need repalced, but that does at least mean it can get upgraded and made smaller and lighter than before.

I am just toying with the idea of making an adjustable variable height platform for the flex drive.

Also have a few plans to change the material used for the outriggers and make some sort of adjustable height system for these aswell so it can be tuned.

Unfortunately photobucket issues means i cannot post any pictures until i change which service i use. So need to sort that aswell.
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