What are the structural limits of carbon fiber Shocker and Daytona hulls?

[lt130th]

I want to run a twin setup of two TP 4060 3Y 1870kv motors with 6 LiPo cells per motor. I was thinking 48mm props, but I don't really know what I'm doing here since this is my first RC boat. Two things to consider: 1) I overkill everything...and 2) I'm kind of stubborn when I get my mind set on something. So I need to know what to expect if I were to put a setup like that in one of these small 37" CF cat hulls. What kind of speed should I expect and can those hulls handle it? Should I back off in prop size or voltage to prevent a cabin fire? I'm at a crossroad right now. Need some experienced words of wisdom to help me decide which route to take...

Thanks,
Michael P.

[srislash]

Which 37" hull are you looking at is the real question here. They are very different.Which controller's? I think t-180's would be minimum and actually think the Swordfish 220' would be be best. As far as the hulls themselves,,, they are all thin in CF and a layup inside is good peace of mind. Depending which hull the 4060's may be too much. Too much weight for a Daytona I would think.

[lt130th]

Just the carbon Fightercat Daytona or Shocker. I know the Shocker can be purchased already strenghtened for SAW. And I have the Swordfish 220A Pro. I had been wondering why I see CF layers added to CF hulls. So the carbon hulls are not stronger than their fiberglass twins (both platforms require additional support)? I have a pair of Leopard 4082's & the TP 4060 is noticably heavier than the Leopard. Is the weight going to be a big issue? I really want a Fantasm or Zonda hull, but they're obsolete at the moment. Daytona & Shocker hulls are more readily available new & used right now.

Thanks.

[srislash]

Just the carbon Fightercat Daytona or Shocker. I know the Shocker can be purchased already strenghtened for SAW. And I have the Swordfish 220A Pro. I had been wondering why I see CF layers added to CF hulls. So the carbon hulls are not stronger than their fiberglass twins (both platforms require additional support)? I have a pair of Leopard 4082's & the TP 4060 is noticably heavier than the Leopard. Is the weight going to be a big issue? I really want a Fantasm or Zonda hull, but they're obsolete at the moment. Daytona & Shocker hulls are more readily available new & used right now.

Thanks.

I think the SAW Shocker would be adequate for putting together but the rest should really have a layup put in. I had a Shocker before and am running a Fantasm currently(both CF). The 4060's would be at home in either of those but the Daytona would likely drown. I have a FG Daytona here and they are not big and sit tail heavy in the water with 4074's.

Scott(tiqueman) may be able to get you a Fantasm.

[lt130th]

Actually I think I just closed a deal with Scott for his last carbon SAW Shocker. I looked on every continent for a Fantasm/Zonda hull and found zero, except for the ARTR from Kinetic, and that's not what I wanted. I think I'll be happy with the Shocker, though. Scott made me an awesome pitch. Now I need to get in touch with the folks over at Airbrush Alley for one of their killer paint jobs and order the other half of the twin setup. Woohoo! I hope this works, LOL!

[srislash]

For inspiration this is my old build http://forums.offshoreelectrics.com/...ker&highlight=

[lt130th]

Nice. I've seen your vid's on youtube, also.

[lt130th]

Hey, why are those plates on the rear popped up? I see those held in with tape in a lot of pic's on new hulls being sold. I only assumed they were access points for attaching stinger supports...no??

[flraptor07]

Those hulls can handle the speed, it's the sudden stop from the crash that they can't handle...

[kfxguy]

Hey, why are those plates on the rear popped up? I see those held in with tape in a lot of pic's on new hulls being sold. I only assumed they were access points for attaching stinger supports...no??

Mine came with those and I have no idea what they are for

[lt130th]

It looks like srislash's Shocker had some Knight Rider action going on. Air-brakes? Spoilers? Air-cooled ducts?? LOL

[iridebikes247]

6s with your setup should be awesome. I think the motors will take it but running anything that long that high of an high rpm you might have a rotor failure. As for props you have a lot of options. I would buy the sf220/300 I hear its great or two seaking 180s with a nice cap bank setup.

I run 4082 leopard 1600kv on 6s in a twin cat, with 57s reduced to 50mm, handles it fine but is the max I will push it.

To give you some speed ideas, I got 11 mph going from a 447 to a 57 red. to 50mm. I think a 447 will be your best option for that boat! Big props tend to change how the hull handles at speed so keep this in mind.

[lt130th]

I already have a 48mm, 67.2mm pitch, 2-blade for the mono setup I was initially putting together. That manufacturer doesn't seem to make a counter-rotating prop to match it, though, so I'll be buying a new pair of props. I want to push this thing for all its worth so as long as I don't start any fires from overheating electronics I'm down for large diameter props.

Speaking of handling at speed... In every video I see, guys take long slow turns with all these catamaran's. I've seen cat's slide, spin out & flip on too much throttle. The only thing I've read on how to help a tiny bit with this is to have a longer rudder. Anything else that can improve cornering at speed for these hulls? Even the full scale 4,000+HP cat's I see in open class offshore superboat races just skip around the turns...they don't really turn, haha.

[properchopper]

Those hulls can handle the speed, it's the sudden stop from the crash that they can't handle...

But they air out nicely https://www.youtube.com/watch?v=H4nkk_AWdfI

[lt130th]

Thats my 32 rivercat in the video

Did it survive? How much did that boat weigh? I can't imagine the wieight of two of these TP 4060's plus 12 lipo cells lifting off the water like that. That is crazy. But lift force of an airfoil is a function of its coefficient of lift, surface area, fluid density and freestream velocity. You get going fast enough... Also the coefficient of lift increases with angle of attack. All of that is pretty intuitive/common sense, but still the fact that the boat can fly out of the water like that seems nuts. I was told the Shocker rides very flat on the water, and it was recommended that I put the motors close to the back and use the battery position to tune the balance/CG...