Miss Geico Lets see what this thing can do!

[dana]

im curious about air damns on cats. ive thought about trying it with my MM.

[tiqueman]

im curious about air damns on cats. ive thought about trying it with my MM.

theres a few that have done it. Bonewar did a servo controled one on a Matrimo cat and I believe there is a fixt tunnel dam for the Toysport cat.

[Rumdog]

They work! I run one on my sprintcat and my Maritimo. A few inches (4 on my timo) back from the leading edge of the tunnel. About 3/16" tall is all, entire width of the tunnel.

[JPriami]

I have a sneaking suspicion that this part of the boat at high speed is acting like a wing of sorts and air pushing on that high angle is creating lift to the nose of the boat.



I've made places for my lipos to go way forward in the hull to add weight up front to help keep the nose down. And I wonder about making an air dam or clear lexan wing to stick on the front to add the necessary down force. Or just add negative angle on strut. But not fond of that idea just yet.

[JPriami]

Show some pics rumdog. If u don't mind.

[jac4412]

JP I just took a quick look at mine... you might be right... I didn't think of that before and it's sitting right there in front of us. But the key to fixing that of course is still proper balancing of the lipos and weight in the boat. Interesting but I'm sure that could be contributing to the hull hop.

[JPriami]

I'm going to try making a lower air dam first that will stick to the front lower part between the sponsons and see if that counter acts the lift. If that don't work then maybe a small clear angled lip on top that adds down force.

[JPriami]

Got to run one time today. First time with the packs way up front COG as balancing point on the boat was about 12.5 " hard to say exactly because its near the first step in the hull. Boats goes through the water at the lower speeds really well. But once you get going above 50 it starts picking the nose up. I then tried the temp test air dam I made that goes between the sponsons up front on the lower side of the hull. and that did help. it still had some bounce across the water at full throttle but it never blew over. Best recorded speed today was 58.6 MPH on a x642 prop.
Im going to try and make a wing to mount up front that adds down force to the nose. I am thinking I can make this out of a Mini revo vxl wing and use weather proof 3M stick tape to mount it between the sponsons right in front of the bow before it sweeps under the boat. if it doesnt work then I'll just have an extra wing for my mini revo vxl. if it does work then I can perhaps start moving my batteries back to be closer to the 30% COG mark of the hull.

[Brushless55]

where and how is your strut set?

[JPriami]

Level and level

[ron1950]

i beleave you are right about the lift under the hull as the air has to go faster over the bottom then the top so lower pressure...ran mine to day twice in rough water and flipped it several times still no prob with hatch...knock on wood

[Brushless55]

Level and level

Maybe 1 or 2* prop down

[JPriami]

I tried a little negative angle and it still wants to pop up. But I had my COG further back like 10.5/11" at the time.

[JPriami]

Just roughing up another idea I had to add down force. This angle covers up the high angle below. But it might add too much.

[JPriami]

This was from today. I had to enhance the lighting to show up better because I went later in the day and it was getting close to dusk.
Eagle Tree data logged GPS 58.6 MPH on a x642

YouTube Video