.90 cu in, 30,000 RPM, 7.2 HP custom built nitro engine

[strictlybusiness1]

Hugh,

I have been told by several boaters that they purchase several pieces in an attempt at getting something that is usable (running true). Any part rotating at 20,000 RPM + needs to have a total indicator run out of less the .0005". You won't be able to feel the vibration in a model boat running across the water at 80 + MPH, unless you plan to ride in it. LOL.

JA

[DRT]

Take a second look. Unless this was just hurridely staged for the photo op what is the purpose of the thrust bearing at the front of the strut? Do you see the angle of the leading edge on this strut and its abruptness? I dont know about this James. The finish is immaculate and it looks plenty stout, but I dont think the design is truly one that will produce the least drag on a scale boat. I also wanted the drive dog grub screw to be able to go through a hole in the propshaft and actually be able to bite the wire.  Quite possibly the stut works for the op because it is encircled by a rear ski on the tub where the only thing that's truly seen is the bottom of the strut and the prop .

[DRT]

Check this out James,

Something that can ride in the boat at >80 mph and tell me the vibration. A piezo film vibra tab vibration sensor. You have to clamp it with a zener diode to prevent the 70 volt output capable analog device from overloading the 5 volt input on the MCU. Also the inverter that I'm running Is the currently best the market has to offer. APD. It is a military grade specified piece and has the ability to further quiet the motors sonic and ultrasonic vibrations as well. Teamed with a beta flight FC It has low and notch pass filtering capability . It can attenute or bypass triplen commutation frequencies increasing the power factor and efficiency. It can also avoid frequencies that resonate with the frame of the craft that it is in. , It listens through a GPS acceleraometer and watches the electrical revolutions through its telemetry tach. In addition to the dedicated tach output, through the servo plug it can use a digital protocal "DSHOT", this technology is driven by the drone industry with support from companies like Martin Lockheed. The programming enviroment is open source so as long as you can put the hardware together mechanically (servos,gearboxes....) someone else thats proficient in programming and coding can program the things like self leveling autonomous cannards (anti blowover system) for you . It is a user friendly world for people that may or may not be computer program savy. With servral PIDs onoard you have limitless options. The hv pro drive pictured with the Nue outrunner is capable of 40 kW and it is the smallest and lightest most capable drive on the market. The Aussie made inverter alone cost a RTR scale boat. The motor pictured stock which it isn't is capable of 6 grams of thrust per watt with a carbon fiber Marcel sawblade leadiing edge prop 12 inches in diameter with 24 inches of pitch. What is typical in a thrust to watts ratio is about half that. The fight card can report back real time speed and many more operation parameters user defined to the radio, a FPV HUD or even a smartphone  and may more operation parameters user defined. The flight card can also be configured via smartphone. APD sent me the prototype pro high voltage drive for evaluation 2 years ago at Mercedes. It has taken over the F5D competition flying world and the heart of Current world Champion. I'd be the first in the world to introduce this motor drive that can be used for EV traction applications with torque control into rc boat water.

https://oscarliang.com/betaflight-filtering/

We will talk more about this privately if you'd like. I'm getting a bit too wordy here. Id rather "them" in  the IMPBA and NAMBA find out another way

Regards
Hubert

[DRT]

Check this out James,

Something that can ride in the boat at >80 mph and tell me the vibration. A piezo film vibra tab vibration sensor. You have to clamp it with a zener diode to prevent the 70 volt output capable analog device from overloading the 5 volt input on the MCU. Also the inverter that I'm running Is the currently best the market has to offer. APD. It is a military grade specified piece with a 7 layer pcb. It has the ability to further quiet the motors sonic and ultrasonic vibrations as well. Teamed with a beta flight FC It has low and notch pass filtering capability . It can attenute or bypass triplen commutation frequencies increasing the power factor and efficiency. It can also avoid frequencies that resonate with the frame of the craft that it is in. , It listens through a GPS acceleraometer and watches the electrical revolutions through its telemetry tach. In addition to the dedicated tach output, through the servo plug it can use a digital protocal "DSHOT", this technology is driven by the drone industry with support from companies like Martin Lockheed. The programming enviroment is open source so as long as you can put the hardware together mechanically (servos,gearboxes....) someone else thats proficient in programming and coding can program the things like self leveling autonomous cannards (anti blowover system) for you . It is a user friendly world for people that may or may not be computer program savy. With servral PIDs onoard you have limitless options. The hv pro drive pictured with the Nue outrunner is capable of 40 kW and it is the smallest and lightest most capable drive on the market. The Aussie made inverter alone cost a RTR scale boat. The motor pictured stock which it isn't is capable of 6 grams of thrust per watt with a carbon fiber Marcel sawblade leadiing edge prop 12 inches in diameter with 24 inches of pitch. What is typical in a thrust to watts ratio is about half that. The fight card can report back real time speed and many more operation parameters user defined to the radio, a FPV HUD or even a smartphone  and may more operation parameters user defined. The flight card can also be configured via smartphone. APD sent me the prototype pro high voltage drive for evaluation 2 years ago at Mercedes. It has taken over the F5D competition flying world and the heart of Current world Champion. I'd be the first in the world to introduce this motor drive that can be used for EV traction applications with torque control into rc boat water.

https://oscarliang.com/betaflight-filtering/

We will talk more about this privately if you'd like. I'm getting a bit too wordy here. Id rather "them" in  the IMPBA and NAMBA find out another way

Regards
Hubert

If u look in the attachment of various hardware u can see in upper left corner youll see the flex hex and thru hole wire collets ive used in the past with success. The main difference now is the motors have much larger motor shafts.

Regards
Hubert

[lohring]

We ran an accelerometer on an Eagle Tree to measure the G forces from wave action.  It was to give me an idea of the forces a full size boat might experience.  A gas mono experienced nearly 4 Gs.  Now that I've ridden in a real offshore mono, I believe it.

Lohring Miller

[DRT]

Hi !
So do I Lohring,

Big boats going fast on ocean water toss you around alot. It doesn't have to really be that fast either 30 knots is more than enuf.  I don't know if eagle tree has open source options but with the flight card it is the gyro itself they use to listen to the vibrations. Obviously an acceleration meter's input signal into the mcu can be coded for interpretation by the MCU's brain in various ways to carry out different operations. Proficiency in coding is super useful in these instances. The new technology is amazing.

BTW how far consistently off is the eagle trees speed versus reality. When it acts right hows its accuracy? How often is the sample cycle?

@ james
If I wanted to use o1 drill rod for stub shaft in my own setup how would I approcah it to bore a .125 hole. It comes in a water hardened state. Would it need to be annealed and approched with the 6 points? If its a bad choice what material would you use and how would you approcah it operationally?

TIA
Hubert,

[strictlybusiness1]

Hugh,

I would not use "water hardened" O-1 steel for a stub shaft, especially if I wanted to drill a hole through the center for a .125" wire shaft. A 1/4 " OD Thompson rod (case hardened) would work much better & could easily be machined (drilled, bored & reamed) with carbide tooling. I have used 1/4" standard dowel pins as rudder pivot shafts after drilling the center to reduce the weight. Thompson rod would be hard enough to run against needle bearings.   

JA

[DRT]

Are you reading my mind? Wow when you mentioned the needle bearings you made me feel like you knew i was looking at the sustrut (beryllium octura strut )for sport 40's and scales It comes with needle bearings installed. I do plan to use the strut on the 3 wing Circus but I'll probably omit the needles.

Now that's a RUDDER! The kind I want for the scale saw boat. I have been looking the blacksmiths make blades and think forging and grinding a bearing steel or tool steel one is still an option. I have to idea how you machined the turn fin wedge out of the spring steel but I sure need to learn that. No ones hardware looks more effective for the purpose of low drag under the water line. It's nice man. I can tell you that . If you would have made hardware no one would shop anywhere else. From me to you. I think its the best I've ever seen and that no kissing up. U build incredible hardware.

James, the one thing about the shop is 3 phase power so before I can really go hard I have to build a rotary phase converter using a 20 horse 3 phase baldor as the pony motor. I already have the VFD to vary the speed of any induction motor. Did you have issue with this? How do you get around it in your shop?


Also what were the fastest props diameters and pitches on the engines you built here? The engines are 30000 at 7.2hp so this is @ about 1.3 ft pounds of torque. What props allowed the motor to unload close to 30000 and produce >99 mph? Any special ear cuts ,leading edge bevel on the backside etc......

Tia
Hugh

[lohring]

We did a lot of checks on the Eagle Tree GPS speed readings.  The early units were slow to update and ran a little behind the actual speed.  We ran a Garmin GPS and got peak speed from it and a radar gun as well.  The later Eagle Tree GPS units were tested against the trap speeds at Legg Lake and against another GPS speedometer in our full size electric hydro.  We also checked the Garmin GPS against a car speedometer at high speed.  The Eagle Tree units as well as the Garmin agree well in all these comparisons.

Lohring Miller

[strictlybusiness1]

Hugh,

I never used 3 phase 220 for any of the machines. However, I always had a 200 amp, 220 line put into the custom built houses with a 42 breaker box. No lights inside the houses were affected even when every machine was turned on.

The best prop for the lake we used for straight aways was a 2267, 2.550" in diameter, 5.375" leading edge pitch, 8.125" trailing edge pitch. The engine had enough HP to turn the same diameter 2267 prop with 5.500" leading edge pitch, 8.250" trailing edge pitch but needed much more water than the 2,000 ft lake we used. On longer lakes the boat easily reached speeds beyond 100 MPH. The heavy weight of 13 lbs 8 ounces was never corrected.

All steel rudder blades were machined to a true wedge, from the  front edge to the trailing edge, from 1/8" thick, AISI-01 tool steel, in a holding fixture. They were heat treated to a spring temper & then blackened with steel black to prevent rusting. The rudder blade in the photo is more than 25 years old. 1/16" thick skid fins were machined to a true wedge, from the front edge to the trailing edge in a holding fixture. They also were blackened with steel black to prevent rusting.

Jim Allen

[DRT]

Hi James,

That hardware is tops for low drag. It is beautiful. Let me ask you. Do you stll hold the picture of the fixture. Did you set your angle with a sine bar. How did you do this? What was the 4 sided dimensions on your largest wedge fin? It didn't flex as you aproched it with the mill? Do you have a print you can send me?

About the SFD drive system I recieved. I recieved the .125 shaft and 8mm-3.175mm split collet. I checked the fit. The coaxiality and cocentricity are acceptable. The polished stainless shaft came in a long padded box priority USPS then additionally inside a capped plastic tube to ensure it wasn't deformed and stayed true.
 
Thanks
Hubert

[DRT]

James can I see a photo of how Andy finished the stainless PH 17-4 props casted from cnc'd plugs.

 

Regards
Hubert

[strictlybusiness1]

Hugh,

I could not find the fixture for the skid fins, however the technique & fixture used to mill them is very similar to the technique & fixture used to machine a full wedge rudder. In both cases, a simple fixture holds the piece, rudder or skid fin, with SHCS's in a area that is cut off after the angle is milled on both sides. In both cases the original pieces are machined over sized to facilitate rigid holding to a fixture that has the correct angle milled onto it. The final shape of either piece is always cut after the wedge shape is milled. Since the fixture remains in a fixed position, reversing the skid fins or rudders gives the same angle on both sides. The largest skid fin was approximately 2.000" high X 2.500" wide with about .500" in the water a speed. All skid fins were machined from .0625" spring steel using carbide end mills.

[DRT]

 WOW.....

Regards
Hubert

[strictlybusiness1]

Hugh,

I should have told you that a carefully drawn view of exactly what the wedge shape will look like helps to determine if the calculated angles involved are correct. I made these drawings at a scale of 1:10 using 10 X 10 grid graph paper, which was 11" X 17". At a scale of 1:10, measurements could be made from the drawing using simple tools such as a machinist protractor & a machinist scale. Using this method allowed a 5/32 " water pickup hole to be drilled in the 1/4" thick rudder blades used on my hydro & cat boats.

Jim Allen