Whip 20 on 6s (no vid)

[RPC1]

Yesterday I took my Medusa powered Whip 20 out. This was the first time on 6s. Currently I run the 3670-1600 motor, a Turnigy 120 marine ESC, Turnigy 6s 5000mAH 25C, and an X642 B/S/DT prop. All Speedmaster hardware, rudder shortened 3/4", Kintec Racing UL-1 turn fin(shortened by 1"). The strut is set at 7/8"(set up board to bottom of hull) and down 2*. This boat is awesome. Handles great, really fast, and durable. On the second pack it blew over...and landed on its feet. Motor, battery, and ESC were all barely warm after both runs, and that is with one water supply line. Might try a V937 for fun. Anyways, any suggestions to help keep the Whip in the water? I will get some pics when I have some time. Thanks

[j.m.]

Move batteries forward?

[txboatpilot]

Where is your CG set now?? Any pictures??

[RPC1]

The battery is as far forward as it can go (runs into the canopy). The balance point is 1" behind the sponson. I would need to add weight to the nose to move the balance point forward. I will get pics posted when I get off work. Thanks for the posts.

[sailr]

sounds like a hell of a setup! Probably blew over due to 'terminal velocity'. Haha. Boats have a 'hull speed' beyond which they are out of control. You may just be on the ragged edge with that setup.

[crabstick]

The whiplash 20 has gone over 100mph so I think you can prolly go a bit quicker yet unless you are already at 100mph! :bounce: , you could try lowering the strut a little to lower the AOA, might not make it run so loose at high speed

You may need to add weight, In 2006 at a SAW event the whip 20 tumbled through the last 30 feet of the traps it was clocked at 98mph on 18 nimh cells. and a Neu 1521 ?? 18nimh cells = heavy

[sailr]

SAWS and heat racing require different setups. Which do you want to run? Everyone always wants light weight. I have found a boat with some WEIGHT generally runs better!

[RPC1]

That's a good idea. Less angle of attack. I will try lowering the prop @ 1/8" increments. I don't know how fast it is, my GPS won't fit. I would guess between 50-60.

[crabstick]

Im currently building my whip 20 and I was thinking of a little canard wing with servo controlled winglets for such a purpose. I haven't built mine light, shes got a layer of glass cloth and a couple of layers of resin on the inner floor and inside the sponson's.

Let us know how it goes and some pics would be mint too!

Wheres ur rudder ? left or right ?

[RPC1]

The rudder is on the left. Even without the turn fin it tracked straight as an arrow. Sorry about the pics. I went to work at 5:30am, didn't get home till 11:00pm. I will try tonight if I am not too tired.

[sailr]

I thought since we run clockwise (right turns) that the rudder should be on the right? I guess there isn't any particular convention for this but I have boats that are both ways and those with the rudder on the right seem to turn a lot better. Just my observation. Not saying either one is right or wrong.

I would be interested in comments as to why it having it on the left is preferable. I'm always open to learning something new!!

[sailr]

I have had several boats that run MUCH better after adding weight! Personally, I think some weight is your friend, not your enemy! The point is to keep the boat on the water so you can finish the race. 1/2mph slower is OK with me just so long as she doesn't 'fly'. You have to finish to win. You could have the fastest boat on the planet but if it won't stay planted and you never finish a heat, what's the point? Same goes with SAW. Still have to make it through the traps....both ways!


Im currently building my whip 20 and I was thinking of a little canard wing with servo controlled winglets for such a purpose. I haven't built mine light, shes got a layer of glass cloth and a couple of layers of resin on the inner floor and inside the sponson's.

Let us know how it goes and some pics would be mint too!

Wheres ur rudder ? left or right ?

[crabstick]

You have to finish to win.

This is pretty much the best advice anyone can give.

on the subject of weight, Sailr is bang on the money. Anything more than say a 700 powered Hydro, a little weight becomes useful.

I too run all my rudders on the right. Have run some on the left, but personally I prefer them on the right. My whip will weigh in at about 3 - 3.5 kg's ready to run with 6s, the canard wing and winglets I might add later for SAW if I need them, not planning them in the initial build.

[RPC1]

It is not on the light side. I would guess close to seven pounds. I think I need to move the balance point right up to the sponsons, and drop the strut a bit. Thanks for the suggestions.