General discussions - FAST RC boat

[King blitz]

I ride a skateboard pretty often. Just this past weekend.
Can still drop down and knock out 30+ pushups

I can ride a skate board fast ,but I don't know how to stop .I just keep going straight

 

[LibertyMKiii]

I can ride a skate board fast ,but I don't know how to stop .I just keep going straight

This sounds like a theme.... first the swimming now this

 

[kspitters]

This sounds like a theme.... first the swimming now this

Let’s hope he drives better than that
He’s the kind of person my dad told me to watch out for going down the highway… with headlights facing me…

 

[King blitz]

This sounds like a theme.... first the swimming now this

Just like my speed passes I just keep going .no stop

 

[LibertyMKiii]

Well I couldn't wait.

I had to see what the R6 rigger will look like. They don't sell the kit yet but they sell a few pieces like the motor mount plate. This gives an idea of the width the R6 will have. Should be good enough to fit an 8s setup inside.

This is my 33 fe for comparison.
I can squeeze two slim 3s packs in this boat. Some have managed to fit slim 4s packs to run 8s on them. The larger width will allow for healthy size batteries.

 

[LibertyMKiii]

New PB today.
94 mph on 4s. Logs show it's got more. The goal is to break 100 mph on 4s.
I wanted to go back out and run one more time with a more aggressive props but the wind picked up.

Maybe next weekend.

 

[Big Kid]

Very impressive speed ... What prop was used on latest run ?

 

[Tex Koder]

New PB today.
94 mph on 4s. Logs show it's got more. The goal is to break 100 mph on 4s.
I wanted to go back out and run one more time with a more aggressive props but the wind picked up.

Maybe next weekend.

Sir,
I can see how this custom rigger can go helluva Faster!!..
You just need is a Bigger pond!

 

[LibertyMKiii]

Very impressive speed ... What prop was used on latest run ?

This was an ABC 1819

Logs show it's got a little more in it!

Sir,
I can see how this custom rigger can go helluva Faster!!..
You just need is a Bigger pond!

Yes a longer slower throttle pull in a big pond will be up next!

This rigger isn't all that custom. Riggers are just faster than any other styles of boats. They can go 100+ with a RTR 6s system.
Just working my way up on 4s for now and will go to 6s later.

 

[Big Kid]

So a 1.8" diameter being @ 45mm X 1.9 pitch ratio = 85mm

Sounds like it may be time to try the Octura V945/3

 

[Big Kid]

If or when you power up further and think you got the Horse power .... I have a prop that should work AWESOME. I'll give it to you for postage
That being an ABC Stainless 65x120/2. I oval raced with for years in Gas Sport hydro and it would run 70+ at @16,000 rpm
It is cupped & modified being low lift in spite pitch ratio. I no longer have either of the 2 boats I once ran with this prop. ( It set a NAMBA 6 lap oval 1 mile national record in both boats being a BLAZER Marine Whiplash & Backlash
This Pic shared previous .. is said prop at @ 72 mph on the Whiplash running in OVAL trim .... SAW would be faster yet !!!

 

[LibertyMKiii]

If or when you power up further and think you got the Horse power .... I have a prop that should work AWESOME. I'll give it to you for postage
That being an ABC Stainless 65x120/2. I oval raced with for years in Gas Sport hydro and it would run 70+ at @16,000 rpm
It is cupped & modified being low lift in spite pitch ratio. I no longer have either of the 2 boats I once ran with this prop. ( It set a NAMBA 6 lap oval 1 mile national record in both boats being a BLAZER Marine Whiplash & Backlash
This Pic shared previous .. is said prop at @ 72 mph on the Whiplash running in OVAL trim .... SAW would be faster yet !!!

View attachment 361042

I appreciate that offer!
That would require some setup changes.

Your boat was truly flying in that picture.

 

[BudUMfan]

Just my first starter but I’ll have a SonicWake by next week! Baby steps.

 

[LibertyMKiii]

Just my first starter but I’ll have a SonicWake by next week! Baby steps.

View attachment 361072

View attachment 361073

Looks great, if you have not done so already... play around with battery placement to reduce how much of the boat sits in the water at speed.
This will help it run better and turn better. The goal is to get enough of the boat out of the water to have less drag, but keep enough that its not bouncing or blowing over.

On mono hulls / deep v's its all about weight balance. My riggers don't seem to care at all because they get lifted up out of the water.

 

[Big Kid]

If one who likes to run boats is serious ... Look up an IMPBA or NAMBA racing event for either Nitro/Gas or FE ( Fast Electric )
What you can learn watching, then walking the pits talking with those who race can be VERY inspiring & helpful.

On mono hulls / deep v's its all about weight balance. My riggers don't seem to care at all because they get lifted up out of the water.

Riggers very much care on weight distribution, Prop lift characteristics, Strut trim & depth etc ....
Once you start or become able to stay on the power longer than a couple seconds ... it starts becoming very apparent.
* Rear hop, water getting pushed by front sponsor, type/shape of roost leaving prop etc are very telling where improvements in trim & set up might be improved.

I have extensively actually.
It is something I would like to play with at some point.

The issue that I have not solved yet is that the hydrofoil creates lift that elevates the boat out of the water at specific speed ranges. At too high of a speed the boat will "pop up" and then dive under. You would basically need a way to control the amount of lift with flaps much like an airplane wing has. It would require a fast reacting microcontroller program to drive a servo for any level of real control. My reaction speed would be to late or over reacting I am sure.

The hope on this one is to reduce the center contact point using a center "ski" under the main hull of the boat.
View attachment 152470

Center keel flats or heavy radius will require small props to run well. Prop torque increases with diameter & bite it has on the water. A center ride pad design with Chine walk quite badly.
Sharp V with strakes allowing hull to settle into the water slightly having the strakes stop how deep hull settles in while at planing speeds is a lot faster & more straight line stable.
The slightly wider stance where the water lifts the hull adds greatly to the overall stability and ability to run larger props.

 

[LibertyMKiii]

Riggers very much care on weight distribution, Prop lift characteristics, Strut trim & depth etc ....
Once you start or become able to stay on the power longer than a couple seconds ... it starts becoming very apparent.
* Rear hop, water getting pushed by front sponsor, type/shape of roost leaving prop etc are very telling where improvements in trim & set up might be improved.

Center keel flats or heavy radius will require small props to run well. Prop torque increases with diameter & bite it has on the water. A center ride pad design with Chine walk quite badly.
Sharp V with strakes allowing hull to settle into the water slightly having the strakes stop how deep hull settles in while at planing speeds is a lot faster & more straight line stable.
The slightly wider stance where the water lifts the hull adds greatly to the overall stability and ability to run larger props.

I could imagine for racing or bashing that would be the case. For now all I do is SAW runs. So far I have not encountered bouncing issues with my riggers, but have seen it in other's videos. I can imagine that is very hard on the components being torque loaded and unloaded over and over.

I had a 4s 8,000 mAh brick in my 33 fe sitting just in front of the servo and it handled all that rear biased weight like a champ (88 mph). If I had been taking high speed turns or going through disturbed water it likely would have been very different.

 

[LibertyMKiii]

My previous run with the Seaducer 39" Mono / Deep V hull it was running to wet as the CG was too far forward.
I made a big adjustment and it was too much. The boat fully came out of the water today and only the prop and rudder were skimming the surface. Luckily I could see it occurring and got off the throttle.

The good news is that I picked up 6 mph and didn't get full throttle yet so it's got a few more mph in it yet. Just a matter of finding that perfect balance point.
It was also about 560 ft distance so a longer run should net better results.

 

[BudUMfan]

God I love boats. I just sold my Fireteam and TA Reflex B 1/14 scale to buy a Sonic Wake and maybe some other stuff the wife need not know about. Did good. Learned a HARD lesson on fleabay fees. Yikes. But the products on here are usually pristine. Mine looked pristine with a brand new never ran body. But I told the truth. Ran 10 packs and never changed a thing. I can’t wait to get that 6S soon to be 8s boat. I’m new so I want fast. Reliable. Upgradable and self righting! lol. I have a 4s boat and it is a blast. 86? It looks like 186. That’s so dope @LibertyMKiii!

 

[Notoriousone]

My previous run with the Seaducer 39" Mono / Deep V hull it was running to wet as the CG was too far forward.
I made a big adjustment and it was too much. The boat fully came out of the water today and only the prop and rudder were skimming the surface. Luckily I could see it occurring and got off the throttle.

The good news is that I picked up 6 mph and didn't get full throttle yet so it's got a few more mph in it yet. Just a matter of finding that perfect balance point.
It was also about 560 ft distance so a longer run should net better results.

Nice run! That boat is a rocket.. Did you have the strut at neutral or a little positive angle?

 

[LibertyMKiii]

86? It looks like 186. That’s so dope @LibertyMKiii!

LOL thanks man!

Nice run! That boat is a rocket.. Did you have the strut at neutral or a little positive angle?

Thanks! Despite all the bad talk I hear about Seaducers I am really impressed with it so far.
The strut is neutral.

That is literally the 3rd time the boat has been in the water and I'm talking about making 1 pass like you see in the video and brining it in... So needless to say very little testing done with it yet. These Seaducers don't run trim tabs... so its all about the weight balance with the LiPos. I am really close to having it dialed in.

After moving the LiPos, if it still has issues I'll adjust the strut and possibly play with the rudder angle too. Then I can play with different props too, but I think this one is a winner. It is a Dasbota x645 and is my favorite for Mono hulls.

I pulled the data and it was over 500 amps, but I guess that is the nature of the beast with a short run