Homebuilt ROVs Forum

TigerShark wrote:Looks great, only thing is what parts of your outrunner motor are spinning? I couldn't mount mine that way since the back of the motor is the only part that doesn't turn (end you have the dome/ fairing on).

Hey TigerShark,
Perhaps someone out there can correct me if I am wrong, but I believe most outrunner motors can be "switched around" so the stationary part can be on the same side at the shaft, or be on the opposite side of the stationary part as the shaft...

Again.. I may be wrong... but may be worth looking into if it causes issues with your design!

RYan
"KR2_Diving"

Cool, I hadn't thought about that! That will make mounting the motor to the housing easier!

I don't think you can do it with any motor without modifications to the motor shaft. Each shaft has a groove for the circlips that locks the shaft/outrunner part in place. Also there is a groove for the locking hex screw that secures the shaft to the bell.

So after I crashed my 3Dprinter I had to spend some time adjusting everything back to normal.
But my second prototype is now almost ready for testing.

That is SOOO COOL! Really like that concept/design! Can't wait to see how it performs. Keep us posted!

Really nice!
I can't wait for the performance results.

Damn this is exciting I can't wait to see how this turns out. I hope to be turning out some parts like this in the near future.

Keep up the great work this is awesome,

-Steve

Finally did some testing today!
Long story short.. I need a bigger tank!

As shown in the pictures below, I tested both 4, 3 and 2 blade versions of my prop. At this point its obvious that 2blade is the much more efficient design.
But as I went over 2,5 kg of force (5,5lbs or 88oz) the prop started sucking air and the readings became very unstable. I lowered the thruster as far down in to the tank as I could, but that didn't help much. Also I think having the thruster only a few millimeters of the bottom of the tank will affect the performance in a negative way.
Strangely I was not able to recreate the numbers I posted earlier in the thruster thread from my previous test that showed approx 4kgs @ 22 amps. However time, the thruster started sucking air down in to the propeller witch it didn't the last time. Therefore I will move over to a bigger tang next time around.
Also I will make a few different 2blade props with different pitch and blade shapes for my next test.
Once I am able to get stable numbers I will post all the data and files.

But for now, this is what I got:
All numbers are when water passes from the propeller side and over the motor. Hence the optimal direction for the Rice nozzle design.
In the reverse direction I needed about one more amp to get the same force.

All @ 12V

4 Blade:
1A = 0,3kg
5A = 1kg
8A = 1,3kg
10A = 1,5kg
13A = 1,8kg
18A = 2,2kg

3 Blade:
1A = 0,45
5A = 1,35kg
8A = 1,8kg
10A = 2kg
13A = 2,3kg
18A = 3kg

2 Blade:
1A = 0,5kg
5A = 1,6kg
8A = 2kg
10A = 2,25kg
13A = 2,6kg
18A = 3,5kg

Too cool.
1.6kg @ 5amps is pretty darn good.
My jealousy is starting to get the best of me...
Keep the updates coming.

Wow, awesome progress! It sounds like you have things very optimized alread with the two blade. Perhaps with the larger diameter hubs 2 blades works better. You could try different pitches as well but you have very good results already!