b16a2sir

My Feedback: (3)

OK, this one is made of insulation foam like the last, but bigger, and more power! NITRO power! The dimensions are 24" x 12.5 x 2.
The rest of the information is on the page I made.

Please give all comments and suggestions, good or bad.

Thanks


LINK: [link=http://www.altech.ab.ca/jared/RCVID.htm]MY RC page[/link]

Jared

Crazyrcer

Looks like it will work well. I just finished my second homebuilt airboat also. Unlike the first one I built, this one was made from all spare parts I had from RC planes. It's ALOT better than the first. Hardly even touches the water at full speed.

b16a2sir

My Feedback: (3)

Well, I found my first problems. My propeller mount and rudder mount. I think I have a fix for the prop. But need suggestions for the rudder. I was thinking a couple angle supports on the side.
New pics [link=http://www.altech.ab.ca/jared/2nd_home_made_airboat.htm]available[/link]

jasperrc

You could add wire or cable support. I used wire on this one. You could add a wood plate at the base of the rudder mount and run wire from the edge of the plate to the top of the rudder mount. That would strengthen it quite a bit.

http://www.rc-airboats.com/gallery/v...id=AC1_01b_001

Mr Cajun Gator

You can also add a small bridge over the top of the rudder support, something like what you have for the engine stand. With this you can also control some of the airflow. Good looking build. Be careful with the wood prop, water does weaken them.
Where are the electronics? Its best to have them in a water tight compartment.

mike hockswell

Assuming that's a 2.5cc engine (0.15 cubic inch) you're likely to get more thrust with a smaller prop, like 9x4", 8x5" or 7x6". The 7x6" would give more clearance for your rudder control snake, if you can find one in a pusher. As CajunGator says, plastic/ nylon would be safer. I would use a small tank (4 or 6oz) and mount it in front or by the side of the motor, with a small plastic food storage container or similar on the deck.

Your rudder looks about the right size - the boat should work fine.

With a flat smooth bottom you'll probably find the boat gets blown sideways on water - you could add a couple of 1/4" square rails underneath to keep it running straighter.

Good luck.

b16a2sir

My Feedback: (3)

Thanks for the replies.
I was trhinking of tieng string for the rudder, then I would have to add some wood for it to suppoirt to, So I just addes a 45 degree brace on each side, counter sunk into foan and epoxied it all up, Seems ALOT more stable.
I have heard about the wood prop no good for water, but, all i had on hand and maybe go pick up a variety on payday!!

I do not have my electronics in yet, they are going tonight, or by the weekend anyway!.

With the flat bottom, I am looking for some 'drifting' turns kinda like some of Cajun Gators I seen a while back, I will add rails after the first try, easier to ad then it is to remove.

The gas tank i am going to use is a 125cc, pretty small and oddly shaped, i might get a new one.

So the 7x6" means 7degrees of pitch, 6 inch diameter?
This motor mount can very easily be turned around to be a puller if I need to.

Jared

ryan_t888

7X6 means a 7 inch diameter and a 6 inch pitch. Meaning for 1 rev of the prop the boat will move 6 inches assuming no slip.

Unless the flywheel is serving a purpose in your prop mount, I would remove it. The prop replaces the need for a flywheel.

Edit: I was just looking at the pic again and it looks like a Traxxas TRX. I would use an extremely small prop as they are made to rev at 34 000RPM. You will never see anything close to this much RPM, but it would be more effective to get the engine in its powerband.

Ryan

Tim Wiltse-RCU

b16,

That's a nice looking boat you have started there. Here is a couple of thoughts though. Like it has been said already you need to get rid of the wooden prop. Water spray can cause it to splinter. The prop is backwards as it it now and you will lose alot of power with using the prop this way. The car engine you are using is a tricky little thing, number one it's powerband is such that it won't like turning a prop anyways. You may end up having to run an over square sized prop i.e. a 6x6, 6x7 to get it to run well and finding props in that size in pusher form might be next to finding teeth on a chicken. What are you using to mount a prop to the engines SG style cranksaft? It might be alittle late for it now but if you want to use that engine then I would turn your engine mount around and have it be a tractor setup. Going this you would also be able to mount the top of your rudder mount to the back of your engine mount. Ditch the car engines airfilter and you could also lose the top half of all those cooling fins on the head as well because the prop will help alot with cooling the engine now, saves weight and drag. Again cool looking boat just need to make a few changes.

LAter,
Tim

jasperrc

Tim is right, the prop is on wrong for a pusher setup. To get the most out of that prop without turning the motor around, flip the prop over. Then you got you a pusher setup.

b16a2sir

My Feedback: (3)

I have picked up a couple new props, one 9x6 pusher, one 7x5 tractor, one 7x10 tractor all composite props. I haven't mounted the engine yet, so turning it around is easily done.

I got a pocket pc phone today, so i have been playing with it and not working on the boat. Tomorrow, I am going to do the electronics box and servo linkage, mount the engine and its pretty much ready!

Vids soon hopefully

Jared

b16a2sir

My Feedback: (3)

OK, It has started and moved under its own power on the grass. I havent done anything to the bottom, so hopefully its a little better. Maybe my balance is off.
I decided to go with a puller setup. tell me what you think!

[link=http://www.altech.ab.ca/jared/2nd_home_made_airboat.htm]new pics at bottom[/link]

b16a2sir

My Feedback: (3)

well, it floated great, i was in a rush/excitement that i didnt even look at side to side balance, so it turnes beautiful left, but right, it kinda catches an edge. So i think it needs a very slight V in the rear end, and/or maybe just an angle on the sides.
So i was driving it around for a couple minutes, brought it in to check it over, all ok, went back out and was testing full throttle, seems to bog a little with this prop, as in, should be faster rpms!

Well anyway, it could turn left at full power ok, just being careful, but then i did it right and, BAAAM, it flipped.
maiden voyage = DISASTER.

!@#$ !@#$ $@#@$

Jared

PS. on a good note, i got it all on video!

TERBObob

My Feedback: (21)

First ... would LOVE to see vids

Next ... usually , when you get the boat flipping , when making a right , is caused by :

a) over powering the size of the boat
b) top heavy - or width not wide enough


putting a slight vee in the bottom will only make it more tipsy when turning . Angling the sides might help some though ..

b16a2sir

My Feedback: (3)

The video is now available. I must say, i was impressed, just needed to modify the sides of the hull and it would have been awsome!

[link=http://www.altech.ab.ca/jared/images/OTHR/Jareds%202nd%20HM%20airboat%20vid.wmv]CLICK HERE for video[/link] 14 Mb

Jared

TERBObob

My Feedback: (21)

Yep ... VERY nice runner there . Your problem is no doubt the sides ... This can be seen as the boat "throws" chunks of water when making turns at times .
Otherwise ... VERY nice

jasperrc

Yep, if you round off the corners where the sides meet the bottom of the hull, or even better, angle the sides all the way down, you will solve that problem.

Looks like a good running boat

b16a2sir

My Feedback: (3)

Thanks Jasperrc, I will modify the hull/

The boat was RECOVERED today. ALready has stuff growing on it from under the water. GROSSE!!

Well, a few repairs are in order, rudder didn't survive, and something chewed a strip out of the bow!! i don't know how!
will take pics if anyone cares to see.
Jared

jasperrc

Alway love to see pics of boats, no matter what

hse32

if you remove the air filter the engine will git some power and rpm

89ram

that traxxas motor looks like it works pretty good! how many rpms can you get? your boat biter was maybe a snapping turtle?

bign

i agree with Jasper if you angle those sides she will do a lil better on the turns, Awesome little boat bro, she runs great !!!

hse32

I don't know but i was trying to git a air filter and i found out I would get less power and rpm

89ram

i've got a traxxas 3.3 from a revo, but it would probably be simpler to stick with airplane motors, since i have some of those too.