Project Genesis II - the 10s SAW Build

[FighterCat57]

Yep, going to spin up a 1520 I have here with 10s and see how it holds up. At least that's the goal. Will start with 8s, then 9s first. Have a newly designed 1520 sized motor mount that fits right into the hull and a Castle ICE 160 HV so I can get some data logging on the runs. I could use another HV ESC, but will start with the ICE for the run time data until it's dialed in.

This will be a SAW boat and my first attempt at SAW speeds. Wish me luck!

Starting with a BONE STOCK Genesis from HK, pulled the motor mount and here's where it is. Waiting on a new 1518 cooling can from OSE, fits in the mount with the motor.

(This is the mount that crrcboatz would have had in his Daytona if they had been available at the time)

[LarrysDrifter]

My eyes are wide open on this one! Best of luck Ben.

[RCKong]

Say Ben, are you going to reinforce the hull a little ? I don't think the stock hull will take a 90mph flip.
RCK

[FighterCat57]

Say Ben, are you going to reinforce the hull a little ? I don't think the stock hull will take a 90mph flip.
RCK

Nope. Not a bit. Going to use the stock driveline too. Until it breaks.

I'd like to test the limits of the stock setup.

If it cracks, breaks, I'll reinforce it then. I'll be using DOW Window & Door expanding foam to fill the front of the hull and the rear under the antenna area and under the hatch in case it comes loose. This way, no matter what, it'll float.

Not sure about the ESC though, it's not a hydra, so curious if I could pull it apart and spray it with conformal coating.

[supafastsupra2]

1520 on 10s.. Hmm i did that same setup on a kyosho inferno GT not too long ago. 120mph+ on the street let's see what it can do in the genesis.

[satan_in_secret]

i hope that>>>>> 100+ mph

[RIPFENCE]

sweet ben...thats going to be ridiculous...is an air dam in the plans between the sponsons?

[FighterCat57]

sweet ben...thats going to be ridiculous...is an air dam in the plans between the sponsons?

I don't think it'll be necessary. This hull should air out and stay level to 90+.

Wish I had known about RPM and prop sizes last year when I had the 1527 Neu motor. Let's hope this Castle holds up to the same abuse!

[Boaterguy]

What prop are you spinning?

[Fluid]

Running 10S and a prop with 3" of pitch, you'll need a motor with a Kv of around 1500 to reach 100 mph. Be certain to reinforce the hatch, no need to test it to failure and ruin/lose your motor and packs.


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[FighterCat57]

What prop are you spinning?

Starting with 40mm and working up from there.

Running 10S and a prop with 3" of pitch, you'll need a motor with a Kv of around 1500 to reach 100 mph. Be certain to reinforce the hatch, no need to test it to failure and ruin/lose your motor and packs.


.

Help me out with that please, what size prop would have 3" of pitch? I know a little about prop sizes, but not enough to pick them by inch pitch measurements. I'm thinking there's a couple Prather props that will get me there, but not at that crossroad just yet.

Hatch locks going on for sure, possibly pinning the front of the hatch too. Extra flotation as well. Inside the hatch and inside the hull, just in case it rips apart, the pieces should still float. Planning for the worst.

Baby steps with this one. I'm expecting the drive cable to break loose, but want to note the max capacity of the 4mm system. I have some spinning up to 40k rpm and holding up well into the 60mph mark, but know they won't spin a 47mm prop without breaking the square end of the prop shaft.

Once the 4mm novelty wears off, I'll step it up and install an 078 wire drive.

If it becomes problematic, then I'll jump to the Hughey 3/16" .187 cable I have here. I'm not expecting any problems running the .187 cable, except adding thrust bearings at that time. Have some RC Boca thrust bearings ready to install if need be. The motor bearings will be stressed enough running the high RPM.


I'm going to start small and work my way up in RPM and prop sizes. I'm guessing there'll be about 10 different prop sizes and RPM combinations before I hit 80mph.

Want to get some good data out of this experience and get a good handle on the watts required to hit certain speeds in this hull. Will be a great reference for those building the Genesis/Daytona hulls.

[Punisher 67]

Good luck with your adventure Ben..................

[Fluid]

Help me out with that please, what size prop would have 3" of pitch? I know a little about prop sizes, but not enough to pick them by inch pitch measurements. I'm thinking there's a couple Prather props that will get me there, but not at that crossroad just yet.

Props which could work include the S230 Prather as you thought, the Octura x648 or v940/3. The latter has to be run deep to work and is really a SAW-only prop for this hull.

Once the 4mm novelty wears off, I'll step it up and install an 078 wire drive....If it becomes problematic, then I'll jump to the Hughey 3/16" .187 cable I have here. I'm not expecting any problems running the .187 cable, except adding thrust bearings at that time. Have some RC Boca thrust bearings ready to install if need be. The motor bearings will be stressed enough running the high RPM.

Save yourself further grief and go straight to the 0.187" cable. As far as thrust bearings are concerned, few SAW record holders use them. Just change out the rear motor bearing to a highew quality one - or not. Most "RC thrust bearings" are not suitable for 40,000 rpm use at high loads and most users do not pre-load them correctly anyway.



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[RCKong]

Save yourself further grief and go straight to the 0.187" cable. As far as thrust bearings are concerned, few SAW record holders use them. Just change out the rear motor bearing to a highew quality one - or not. Most "RC thrust bearings" are not suitable for 40,000 rpm use at high loads and most users do not pre-load them correctly anyway.

yep I wouldn't bother with the small drive stuff = props at the bottom of the lake... thats gonna be to high power of a setup for that.

[FighterCat57]

yep I wouldn't bother with the small drive stuff = props at the bottom of the lake... thats gonna be to high power of a setup for that.

Well, I really want to know how much power I can put through a 4mm system. They've been pretty strong when setup right.

what I've found is when getting to an x447 at 30k+ RPM, it will sheer the 4mm prop dog's set screw. I've updated the set screw with stainless and deepened the notch on the shaft. This should help with the slippage.

There's a common misconception that the 4mm systems are weaker than the .150 when in fact 4mm is larger than .150 and being two piece, they can contract without creating more friction at the prop shaft. Not to start a debate on the two, because it is quite debatable, but just to provide some performance benchmark to help guide sport system builds a good reference for choosing hardware.

=)