Scratch-Built Hydro

[FloatDaBoat]

M545 Sharpened, Balanced, & Hand Polished

Finished work on one of the props I'll try out later on down the road. The one for the initial run will be an X447 that I de-tongued & cleaverized down to a 45 mm diameter. The Sea King 180A ESC & Leopard 4074 2200 KV motor should handle that quite nicely.


I used Blue Magic Liquid Metal Polish on the M545. It can be applied by hand using only a cloth (info for all you out there like me that have no fancy polishing equipment). Blue Magic is sold in automotive stores.


Here are the pics; she'll never look this way again, as the lake I run on is filled from water pumped straight from an aquifer that's loaded with minerals. Copper-Beryllium props turn almost black & lose their knife edge sharpness after only a single run.


Now's the windy season here, & hydro's don't perform well in gusts of 70 MPH. So, I've no idea as to when I'll be able to make the 1st test run . . . .

[FloatDaBoat]

Another Prop

Completed mods on an Octura X646/3.


Detongued, sharpened, & balanced it. Afterwards, I still felt it would be too much prop. So, I decided to further reduce prop loading by removing ~ 3mm from the trailing edge of the blades to eliminate some of the built-in cup. To my surprise, after removing the material, the prop was still balanced - - HAW !!!


Still too windy to test, but here's DaPic . . . .

[TotalPackage]

Thats a odd looking puppy but let me say this. NICE BUILD! you got skills.

[FloatDaBoat]

Oddity

Yeah, curves are appealing to the eye, but I designed this beast with functionality as the 1st consideration. I wanted to minimize any aerodynamic lift generated topside, so I stayed away from any airfoil shapes when feasible, & made the decks flat from stem to stern. Will that provide any enhancement to performance??? - - I don't have the means to prove that theory.

As to my skills, I try to utilize the basic tools available to me to the best of my abilities. Also, I rely heavily on templates whenever possible.

Thanks for the compliment.

[FloatDaBoat]

Too Windy

Too Windy . . . .

[Boaterguy]

I've Tested the GT3B Radio I purchased for this build - - everything works OK. The throttle channel had to be set to reverse for the motor to spin normally using the SeaKing 180A ESC. If channel 2 is set to normal, the Leopard 4074 motor will only spin when reverse/brake is applied to the XMTR trigger.

If you take two of the motor wires and switch them, the channel will not have to be reversed, because the motor direction will be reversed.

[BakedMopar]

If you take two of the motor wires and switch them, the channel will not have to be reversed, because the motor direction will be reversed.

No that's not right. If the motor spun in reverse with the trigger pulled than you swap the wires around. In his case the brake was the throttle so th transmitter needed to be reversed.

FWIW all my seaking/turnigy models had to have the throttle reversed using a tactic 2.4.

[Boaterguy]

Oh, I must have read it wrong.

[FloatDaBoat]

Oh, I must have read it wrong.

I must be more senile than I surmised. Let me try to explain it this way . . . .

After performing Throttle Range Calibration (with channel 2 set to NORMAL), the motor didn't spin AT ALL when forward trigger was applied. When channel two was set to REVERSE during calibration, the motor did spin when forward trigger was applied.

The user manual for the "SEAKING" Series ESC's states, "If you are using a Futaba transmitter, please set the direction of the throttle channel to "REV"." Apparently, the GT3B radio operates on the same basic throttle principle as the Futaba radios.

You are correct, though. Switching any two input wires (also stated in the ESC manual) on any three phase motor will reverse the direction of rotation.

Thanks BakedMOPAR

[Rumdog]

You need to wake up early and beat that wind to the pond!

[FloatDaBoat]

I had to awaken at 0530 this past Friday in order to make it on time to Jury Duty - - Way Too Early for me ... HAW !!!

[FloatDaBoat]

First Run

Finally made the Maiden Run this morning.

Batteries: Two Turnigy 2S2P Hard Case Packs, 5000 mAh in series.
Prop: X447 de-tounged & Cleaverized [back cut] to 44 mm diameter.
Speed: 45.5 MPH

Temps:
Ambient Air – 91 F
Motor [Leopard 4074 2200 KV, measured at Rear End Bell] – 117 F (front end bell/mount/coupler area were five degrees cooler)
ESC [SeaKing 180A] – 109 F
Cap Bank [DIY] – 100 F
Batts – 104 F

I had another set of batteries, & was going to slap on an M545 for a second run, but a Fugly Irate Fisherman came over to state that I was scaring all the fish & that I should leave & “Go some F****** place else”. I didn't need a confrontation with the Moron, so I departed for home. The fish weren't biting anyway, & I doubt that four minutes of being disturbed by an FE Boat running 50 yards away would put them off-their-feed. I hope he stayed all day & at the least caught one CARP, plus a case of Heat Stroke - - HAW !!!

[FloatDaBoat]

Packin' Air

I fabricated a couple of trial air traps constructed of 1/16” ply & 4 oz glass, in an attempt to get the hull to run a mite freer over the water. They extend 6 inches rearward of the sponsons, a shot in the dark guesstimation.

Hopefully, I'll test them next week. Depending on the results, I might have to make some adjustments to their final length. Once I'm satisfied, I'll fashion the permanent traps from aluminum sheet. If the trials end badly - - Oh, Well!!!

Pics . . . .