Impulse 31 bouncing baby boy

[Skullcracken]

I know guys have already commented on this but crap. I have adjusted the COG, I've adjusted the strut - what helps this thing's bouncing. I wouldn't call it porpoising, it pops up out of the water fully , instead of bobbing up and down at the front like when boats porpoise. I've seen vids with this thing glued to the water. Can't figure out how to keep it down.

[roadrashracing]

On mine I found the best way it ran at higher speeds was the trim tabs just bent down a little, bit.

[Darin Jordan]

What prop are you running??

At certain speeds, it gets to the point where the lift of the hull is too much for the power. When you hit that point, the solution is to add weight to the centerline on the CG... When I run mine in P-Mono, I run 4S2P and an additional 6-12oz of weight added under the battery tray or just aft of the motor.

[Bullwink]

Darin what prop are you running in P-Mono?

[Darin Jordan]

Darin what prop are you running in P-Mono?

That's not a safe question for me to answer at this point.... Thus far, I've been playing with motors and most of what I currently have has been way too "hot" for an actual P-Mono setup.

The one setup I used that does work is the Losi Xcelorin 1/8th scale buggy motor @ 2100KV. Nice motor. 4-Pole, has HUGE 8mm shaft, turned down to 5mm, so solid bearing setup. With this motor, I was running an X447/3 and having decent results.

Again, I'm still playing with these setups and certainly don't have all the answers for the higher power stuff in this hull. Like I mentioned before, it's designed for P-Ltd power and to work well in the power range. When you start adding more power, you'll need to add some weight as some point.

[Skullcracken]

First just tinkering with it stock everything. Bounces on 4s and 5s. I have a leopard 2200kv on the way. I've bent the trim tabs down some, but I didn't want to over do it and kill speed with drag. I've moved the lipos forward and adjusted the strut positive. Trying negative initially made it worst. Don't know. In any turn, slight or hard, doesn't bounce at all.

[Skullcracken]

That's not a safe question for me to answer at this point.... Thus far, I've been playing with motors and most of what I currently have has been way too "hot" for an actual P-Mono setup.

The one setup I used that does work is the Losi Xcelorin 1/8th scale buggy motor @ 2100KV. Nice motor. 4-Pole, has HUGE 8mm shaft, turned down to 5mm, so solid bearing setup. With this motor, I was running an X447/3 and having decent results.

Again, I'm still playing with these setups and certainly don't have all the answers for the higher power stuff in this hull. Like I mentioned before, it's designed for P-Ltd power and to work well in the power range. When you start adding more power, you'll need to add some weight as some point.
How are you increasing prop size? Did you change out the rudder assembly? In a full left turn, my 40mm prop is very close to the rudder, and a 42mm nearly touches the rudder. (Bench tested)

[de-pro]

it shouldnt be. this is a 447 prop in the picture

71265

[de-pro]

it shouldnt be. this is a 447 prop in the picture

71265
71266

[stadiumyamaha]

It depends on your steering rate. I have to turn mine down when running a larger prop. Found out the hard way too.

[Skullcracken]

[QUOTE=de-pro;395817]it shouldnt be. this is a 447 prop in the picture

Have you rotated the prop so the blades are horizontal and turned the rudder fully left and looked? This is the stock 40mm prop, probably only about 3mm's from touching the rudder... Looks like I could only go up to a 42mm prop, unless I sacrifice turn endpoints and lose maneuverability.
71383

[Skullcracken]

It depends on your steering rate. I have to turn mine down when running a larger prop. Found out the hard way too.
Posted before I saw your reply. Thats what I figured. Don't know how that guy is using a 47mm prop though. I don't want a 30ft turn radius...

[Skullcracken]

Fixed the bouncing. I increased the positive on the strut, and bent the trim tabs to the point where they are level with the bottom of the hull but mounted a couple of mm's higher than the bottom. (meaning bottom of the hull relative to the location of the mounts - obviously not the actual bottom at the apex of the "V" bottom) No more bounce but seems to be a good amount of drag. Noticeably slower.

[Skullcracken]

it shouldnt be. this is a 447 prop in the picture

71265

Actually looking at this angle, maybe the longer length of a bigger prop would extend the blades past the rudder?

[de-pro]

Steering rate at 100% and no it doesnt turn like a Mack truck :)
Here is some more photos

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[Skullcracken]

Steering rate at 100% and no it doesnt turn like a Mack truck :)
Here is some more photos

7145671457
Good to know. I've been wanting to go up to an X445 but thought anything bigger would touch.