Help bouncing at full throttle 30 inch cat

[razzle]

Hello, I've just done the first run of my new 30 inch catarmaran hull and I can't stop the bow of the boat bouncing at high speed, I've tried raising and lowering the strut and changing the angle positive and negative. Ive also moved the batteries around forward and backwards starting of balanced at 30% from transom then gradually moving them forward, nothing seemed to work. Its level at lower speeds until I hit about 3 quarter throttle then its starts bouncing, Hardware is Ul-1 motor running 2×2s 40c 5000mah Turnigy's, Turnigy 120 amp ESC, 21 speedmaster strut, sharpened and balanced Octura M445 prop any help would be appreciated Thanks!!P1040047.JPGP1040048.JPGP1040049.JPGP1040050.JPGP1040052.JPG

[Flying Scotsman]

What hull and the manufacturer?...Your ESC and motor are on the limits for what ever expectations you may have.

Douggie

[razzle]

Its a E30 Sea Wolf 2 made by DTRC Model Co I bought it from Ebay and added the hardware?

[Snowride]

It's called porpoising and can be corrected by changing the strut angle so prop gets moved closer to the boat or trim down in nautical terms. You should check your CG first and once this is correct then make the required strut adjustment. There is a rather fine line to get to just right, too far down and the bow will plow the water and slow things down, too far up and you end up with what you have now. You simply did not trim it down far enough on your previous attempts. Hope this helps. Cheers.

[razzle]

I did the CG first and then I changed the strut angle closer to the boat also I changed the strut all the way down with different angles and all the up as well it still was porpoising do you think a prop change would help like a lifter prop to lift the back of the boat up?

[Snowride]

You need to trim all the way down to correct the issue. I still think you just never went down far enough in your testing. Just to make sure you understand this you want the prop pointing towards the bottom of the lake as much as possible to correct. Don't bother going up as or pointing towards the surface as this will only make things worse. Prop change will not correct the issue.

Looking at picture #4 it looks like the trim angle is neutral or following the same plane as the bottom of the boat if you prefer. You want to see the drive line angle pointed upwards with the prop being farthest down to rectify the porpoising.

[razzle]

I will try and get more angle on the strut so its back to the lake for more testing...This is what rc boating is all about...Cheers!!

[iamandrew]

One of my friends has one of these, but a large gas version, and it runs Bows DOWWWN!!
Do you have any other props to test with as well? maybe one with MORE pitch as it should ... "lift" the boat up at the back a little bit under load

[razzle]

I will get some more props and get the strut depth and angle sorted, I will get there eventually?

[siberianhusky]

Hard to tell from the pictures but I think the strut is to high still, mess with angles all you want, it won't solve the problem if you can't get the prop deep enough.
More prop with that motor would probably be a bad idea, as stated above you are pretty much at the limit.

[TheShaughnessy]

watch outside temps and run times with the m445. Pulling 70-80 amps constant with spikes into the 105 area with the same motor esc combo in a similar boat. I'd try a 42 something with the ul1 motor for a little bit more reliability.

[Rich]

Any pics of the layout on the inside of the boat?

[Rich]

Any news? I was thinking, a CG that is too far forward could also cause the behavior you are seeing with your boat.

[ozzie-crawl]

My suggestion would be to take it of the towel. sit boat flat on table.loosen strut, place a piece of metal/wood that is 5-6mm (1/4") thick under the strut,push strut down flat on block (make sure hull is still flat and does not lift up).tighten strut. test boat

[razzle]

Hay good to hear from another Aussie I will try that also...I'm still a newbie...Thanks!