Brushless Motor Comparison Testing

[sailr]

Very cool! You brainiacs rock! Keep the good stuff coming!!

[sailr]

did you ever get that rocket powered starship to work? Ha! You are a riot!

[questtek]

Very cool! You brainiacs rock! Keep the good stuff coming!!

Thanks but guys like you deserve at least half the credit for keeping us innovative, honest and interested. I am just trying to help answer some questions that the REALLY smart guys are asking! This is why I think it is important to get as much real Eagle Tree data as possible and have the actual data files and spreadsheets examined and analyzed by the real brain trust of this forum. I'm quite satisfied to be a Metric 100 miler but sure admire those guys that are working in the English system.

[questtek]

did you ever get that rocket powered starship to work? Ha! You are a riot!

Wow, you certainly use much kinder words than my wife! Uniquely I had an old friend that helped to develop the Estes rockets and even those ancient JETEX rocket capsules come down with us on Sat. to watch the guys run their boats. I think I will get him involved because my batting average is 0 for 2 now. He seems to think he can come up with the right combination...stay tuned.

[scullyeng]

Are there any updates for this dyno project?

[questtek]

Are there any updates for this dyno project?

I have been out of the country for quite a while and just returned yesterday. The dyno project will be breathing new life soon. I added the large load resistors as you cas see in the test set up. I have several types of Leopard motors including several different KV large ones. I hope to compare the Leopard test results with those of the Neu's and Castle Neu's that Mark F currently uses.

The output feeds into an Eagle Tree logging system with the dual A/D converter module as well as 3 temperature probes. The load voltage will be recorded via the Eagle Tree A/D sensor module thus exactly matched to amps, current, RPM, etc.

Will keep the FE forum posted as soon as I get rid of several current projects.

[Insaniac]

One of the most important measurements to make is output power versus input power. This will tell you what the motor is capable of producing as well as the efficiency.
A few manufacturers (Leopard, NEU & etc.) provide output power in watts, but very few tell you the efficiency of their motors. This measurement will tell you in a nutshell how much you are going to load your batteries, wiring and ESC.
It looks like you might have the setup to do this with your load resistors, but you will need to monitor the resistor current along with the output voltage...JMHO

[questtek]

One of the most important measurements to make is output power versus input power. This will tell you what the motor is capable of producing as well as the efficiency.
A few manufacturers (Leopard, NEU & etc.) provide output power in watts, but very few tell you the efficiency of their motors. This measurement will tell you in a nutshell how much you are going to load your batteries, wiring and ESC.
It looks like you might have the setup to do this with your load resistors, but you will need to monitor the resistor current along with the output voltage...JMHO

Yes and I totally agree. This, in part, is why the channel A/D converterboard is necessary. In addition I have two independent Eagle tree loggers, one that can be used on the motor under test, like one of the Leopards and the other Eagle Tree logger on the "Dyno" outruller motor. I can easly synch these together.
Please keep the suggestions coming!

[Insaniac]

Check out Dr. Kiwi...he's done 100's of brushless motors...

http://www.flybrushless.com/

[questtek]

Check out Dr. Kiwi...he's done 100's of brushless motors...

http://www.flybrushless.com/

Thanks, I have een in touch with him. He has done some great work. Tried to get him interested in the larger motors but he was not interested. This is why I am attempting to do it myself. It would be much easier if I could just read his data for the motors I am interested in!

[scullyeng]

Have you seen the dynos made by Land & Sea? They have three different types of dynos (water brake, eddy current & A/C) and have units that go from 1/3 hp to 3,000 hp.

http://www.land-and-sea.com/

[questtek]

Have you seen the dynos made by Land & Sea? They have three different types of dynos (water brake, eddy current & A/C) and have units that go from 1/3 hp to 3,000 hp.

http://www.land-and-sea.com/

Yes, they all look great. Only one downside to them: prices START around $9.000.00 each. A bit expensive to test a $100 motor! A bit large too, but that should be no problem because I can put it in my wife's Walk-In clothes closet when she moves out after I buy one.

[scullyeng]

I just wanted you to see other ways of doing it for ideas for yours.

BTW- You need to land a big science grant so you can buy all the big boy toys.

[m4a1usr]

Are there any updates for this dyno project?

I hear ya. This is one of those threads that should never be allowed to quietly die. Any updates Joe? I know your busy but some of us have a winter and are bored!

John

[questtek]

I hear ya. This is one of those threads that should never be allowed to quietly die. Any updates Joe? I know your busy but some of us have a winter and are bored!
John

John, Thanks for the input and motivation!

The attached pdf file shows the test results for a Castle Creation outrunner motor that was a $40 sale item. It is a 250kv motor, too small for a FE application but great for an underwater diver propulsion system that requires high torque and thrust. The motor is a 3422 size. Several points on the tests:

1. I ran the test with a 3S and 5S test set up (I did not want to push the T180 ESC and future tests will use a new 150 AMp ESC that can take up to 10S.)

I included a picture of this giant ESC that has several of my modifications including adding dual fans to the already water-cooled ESC, adding Eagle Tree sensors (brushlss motor RPM as well as FET and Cap temperature thermistors.) The additiona plugs on the power connectons are for the spark arrestor and additional cap bank. (The new cap bank will be 50 VDC Rubycon 470 mfd caps on a plug-in board). I am working with Ben, Fighter Cat 57, on this ESC

2. The prop used was a large 3-blade carbon prop in both cases. NO cavitation at this low RPM. I will also be using some much larger props in future tests.

3. The outputs were very high in terms of force and force per HP (This is actually force per 770 watts of input power). You can compare the results to the previous Leopard test data. (remember that prop was cavitating at high RPM)

If you have any suggestions I would gladly appreciate them.

Up on the testing list is a Castle 1717 again bought on their Sale and a large Leopard both 2250 KV and 1400KV types. (This is again why I need the large, 10S ESC.)

Enjoy the test results and more to come..............