72 mph / 115 kms/h FE JAE

[ALIENALESSIO]

Good water conditions for 2nd run FE JAE 21

http://youtu.be/DmIl_U2jnYg

Leopard 3674 3270kv, Turnigy Marine 180 esc, EZ Power 6200 50C lipo, X 442 prop
esc timing 0°, strut flat on ski, temp motor 40 C° & ESC 50C°.
You can see and hear the boat bouncing on the ski/strut so i will reduce a little the ski surface at the back close to the strut and see if it will stay more level.
At the end of the video the flex got loose from the coupler so i lost the whole flex/prop, almost lost the boat, recoverde just in time.

[martin]

I think making the ski narrower at the rear will not stop the bouncing, the JAE is a proven design that works so well. you need to look towards cg position ( how far in from the rear of the ski is your cg position ) needs to be 60/40 percent ratio. You may also need to look at diff props like detonqued props or specific hydro props like Octura 14 series or ABC H series.

[Serpents811]

Try m440

[raptor347]

That hop is all prop and setup related. Is the weight distribution at 60/40 like it calls for in the plans? It the thrust line parallel at ride attitude?

[Serpents811]

That hop is all prop and setup related. Is the weight distribution at 60/40 like it calls for in the plans? It the thrust line parallel at ride attitude?

raptor check my video , same setup but ice240 and m440

http://www.youtube.com/watch?v=NtN_LDFAIiM

tell me what you think , i do have room to prop up

[raptor347]

I'd say cup the tips of that prop a little or add an ounce or two of lead to the tail.

The fronts look to be running a little wet still. Just my guess from the video.

[Serpents811]

I'd say cup the tips of that prop a little or add an ounce or two of lead to the tail.

The fronts look to be running a little wet still. Just my guess from the video.

I'll give that a try thanks

[ALIENALESSIO]

JAE21 72 mph

That hop is all prop and setup related. Is the weight distribution at 60/40 like it calls for in the plans? It the thrust line parallel at ride attitude?

The weight is set 60/40 cg, could give less angle to the strut that is flat on the ski but will have to shorten the ski a little or as others suggested try a different prop. Will try the OCT H4 and ABC or some Grimmracer props. If I can get it to run flat without bouncing so much I'm sure I can gain extra speed and get really competitive with the other FE hulls.
Handeling is great at all speeds and I slow down in curves just to save some lipopower and reach the 5 minutes required, I tried full throttle in the curve and it's riding like on tracks, great hull

[jcald2000]

Strut should NOT be flat on the ski, it has a 2 degree angle. It should be flat on the set up table.

[martin]

I think from my experience when they say strut is flat on ski its just the front of the strut thats pushed hard down onto the ski but then sits paralell with the setup table. You normally then end up with a gap between the end of the ski & bottom of the strut because of the angle of the ski bottom against the parralel strut. All this is not to say the strut isnt set parallel though in this case, to help you can also add a bit of positive to the strut ( prop end up 1 degree ) to help with boucing but best to get any cg or prop problems sorted first.

[ALIENALESSIO]

the strut is flat on the ski giving the strut a negative angle aprox 2°. If I make the strut level flat 0°ang. as you quote there is a small gap between the strut and the ski beacuse of the angle of the ski. If I level the strut flat level to setup table the strut is slightley higher than the ski.
What should I do to have the bottom of the strut at the same height of the end of the ski ?? trim the ski end so it ends right where the strut starts ??
The cg seems to be ok set at 60/40 but will try also different detounged props. thanks for any ideas or support.

[jujux1]

Nice !
Have you tried a ABC H7 ?

With mine jae and the same rmp but with 3674 2200kv on 6S top speed : 84mph...

[martin]

The strut needs to come up prop end so the strut is paralell & neutral, the way you have it set prop end down is causing the hop.

[martin]

With the design of the ski you end up with a small gap between the strut bottom & ski, dont worry about it just set the strut paralell & run it. Are you running the Zippkits Z strut or something else.

[ALIENALESSIO]

yes Im running the Zippkits strut.
I will give the strut a 0° ang, and try to narrow the gap betwween strut and ski with a little sanding the ski and file the strut a little.
I will load the whole video of that day on this string where you can see the JAE on the table before running.
I did notice an incredible difference in running speed and time related to the lipos. I usually run the Turnigy 5000mah 40C and had a max speed of 65 mph and almost 4 minutes run time, I tried the Lipos from a local racer and his EZ power are unbeliveable........ speed and time as in the videos.
Will also try different props and hopefully will have a very fast and stable JAE.

check this vid

http://youtu.be/DalWuljy80s