rigger bouncing

[matto]

hi all
i have a h&m xzess 3 rigger with a neu 1515 1y, cc hydra 240 esc, tp 5000 mah 4s setup. with the strut depth set at 13mm, sponsons set at 3 degrees and currently using a m447 prop. now the centre of gravity is about 2 inches behind the turn fin, which is mounted at the rear of the right sponson. ran it today on dead flat water with no wind, and at full speed the rear end was bouncing slightly, not alot , just a stutter like bounce but still could hold full speed without backing off. with new props coming i hope to find more speed and i think this bounce might become a problem.
i'm still new at this, so any help would be appreciated thanks

[Simon.O.]

hi all
i have a h&m xzess 3 rigger with a neu 1515 1y, cc hydra 240 esc, tp 5000 mah 4s setup. with the strut depth set at 13mm, sponsons set at 3 degrees and currently using a m447 prop. now the centre of gravity is about 2 inches behind the turn fin, which is mounted at the rear of the right sponson. ran it today on dead flat water with no wind, and at full speed the rear end was bouncing slightly, not alot , just a stutter like bounce but still could hold full speed without backing off. with new props coming i hope to find more speed and i think this bounce might become a problem.
i'm still new at this, so any help would be appreciated thanks

There is a lot of reading to be done here for that hull.
http://forums.offshoreelectrics.com/...ead.php?t=4694

I have a hand made sort of copy of the same hull and am keen to offer advise.
http://forums.offshoreelectrics.com/...ead.php?t=6940

I have some questions first.
What is your boating experience ?
What are your goals, SAW or Oval or Fun.?
Do you have a way of measuring speed, GPS ??

I am not being rude but it helps if I or others know what you know and want to achieve. Feel free to PM me too.

[Apples1]

listen to Simon he know he's sh@t

BTW i know of people taming the "bounce" of a Xcess with a lifter prop, like a H7 or 1415,

Good luck.

[matto]

thanks simon.o
this is my first crack at fe boating. i've raced brushless offroad cars before. i'm joining an oval racing club, i'll be mainly against nitro boats in my class. and no i don't have any means to measure speed. thanks for the links

[matto]

i have a h7 on order and a p747. thanks guy's no doubt i will have a million more questions

[longballlumber]

Try putting some angle in the strut... It doesn't take much.

[Scott T]

Matt,

An H7 seems pretty big, a lot of guys in Australia have been running the 1515/1Y in riggers with an H5 with great success. I'd get one of those as well as the H7 and P747.

Which part of Australia are you from? There's a few clubs running electrics these days.

Cheers,
Scott

[HOTWATER]

Try raising the strut up a bit (1/16" at a time) to let the transom (back of the boat) settle down. Only change 1 thing at a time. Keep that prop on for now untill you check the stut height...

-Kent

[Simon.O.]

hi all
with the strut depth set at 13mm, sponsons set at 3 degrees and currently using a m447 prop. now the centre of gravity is about 2 inches behind the turn fin, which is mounted at the rear of the right sponson.

13mm seems quite high up and given that the AoA is only 3 degrees I can tell you there is a problem with the whole setup.
Andrew Gilchrist suggests 17mm and around 4 deg AoA
My one which is a little longer than the original runs 17mm on the strut and 5deg AoA.
http://forums.offshoreelectrics.com/...t=4694&page=18

Running with the cg further aft will tame the tail on a rigger. It also opens up a few other issues with handling.
fwiw my cg is a lot further back than 2" and at 55mph the sponsons are still on the water

Try raising the strut up a bit (1/16" at a time) to let the transom (back of the boat) settle down.

I suggest that he is already too high

Only change 1 thing at a time. Keep that prop on for now untill you check the stut height...

Good advise there Kent.

[matto]

thanks guys
i will let you know the results when i find time to test.
Scott i'm from gosford nsw and will be racing at maitland (possum puddle). i bought everything off Andrew gilchrist, hull, hardware, all running gear and set it up to his recommendations but also wanted to get involved in this forum and get other opinions (and stop pestering Andrew)
thanks again