darticus

What is the difference in flying a light 6oz plane with a 9050 prop and a 8040 prop. Asking as I don't know the difference and which to buy. Recommendations wanted.

Dr Kiwi

On a plane that small you might have torque roll issues with a prop as big as a 9x5.... and can your motor cope with such a prop without exceeding its amp limit? What motor/pack do you have?

darticus

running a 24g HC 1500 kv motor. Do you think a smaller prop. What is a torque roll Issue??? Thanks Ron

ENUT

Ron,What is max amps will the motor draw? This will help determine which prop you use.Bigger the prop, the more load or work the motor will have to do.If for instance the motor is rated at 18amp draw and you try to draw say 24amps ,you will have problem.But that was just hypithetical figures.Also when you draw high amps with the motor,it also makes the battery work harder A high amp draw makes for shorter time and life of battery.Post all the spec's on your planes components: battery,esc, motor.

ENUT

darticus

With a 8040 prop the 1500kv motor 7A with a 10A ESC 500MAH 7.4V battery. I got the following readings. These are the readings after I unhooked from the ESC. 7.92V, .022Ah, 19.6Wp, .1Wh, 3.43 Ap 5.70 Vm.

I hooked up the WATTS UP again. After I ran the motor at full speed with a 9050 prop the 1500kv motor is 7A and using a 10A ESC and 450MAH 7.4 battery. I got the following readings. These are the readings after I unhooked from the ESC . With the 9050 prop. 7.87V, .013Ah, 39.5Wp, 0.0 Wh, 6.49 Ap 6.03 Vm. Looks like the amps are up but still could run a larger prop.

These are the readings after I unhooked from the ESC 450MAH 7.4 battery. with the 1060 prop. 7.86V, .015Ah, 55.2Wp, 0.1 Wh, 8.81 Ap 6.16 Vm. Looks like the amps are up and reached its peak.
I'm thinking the 1060 prop is over doing the motors 7A capacity so it looks like the 9050 would be the choice. OPINIONS WANTED. Ron

ENUT

RON,9x5 looks just about rite.If you can get a 9x6 or 9x7 you will get more thrust in the air but not more speed.

ENUT

darticus

Is it stupid or can a 1060 be sanded down to a 9060? Ron

Bub Steve

Sure it can,, It'll be more a 9/5 or 9/4.5, I cut a 10/7 down for my sea-plane to fit! ( bout 8.5/5 now or there about) just keep her balanced and chop away!! bub, steve

flydiver

You could cut that prop down but it's probably not necessary. What the Wattmeter does is show you the operating conditions and 'hopefully' the motor manf. gives you the proper operating boundaries (don't believe them until proven otherwise).
Then you take that data to the flying field.
The 9x5 is probably safe. Try flying it. If it's good enough, then you are home. If it's not try the 10x6. If you find you are having to fly it at WOT a LOT then you are pushing the limits of the motor. A rough way of determining this is to fly WOT for 1 minute, land, and feel the motor. Warm is OK. Too hot to hold on to is not good (for any motor). You can do the same thing with a 30 second bench test because the isn't any cooling airflow.

If you go up to a 3S battery then you have to prop DOWN, as the RPM's go way up and the work load on the motor goes way up.

darticus

Thanks Guys
Some great stuff here but how do I know if she is flying good? I usually just fly stuff. Sound stupid but what does WOT mean? Thanks I'm learning. Ron

BUCKSHOT

World of terror



naw.....wide open throttle

flydiver

OK, the plane you showed is a flat foamy. Flat foamies are the realm of acrobatics-most often. Generally they are not a first, usually not even a 2nd, and are often farther down the list for something to learn on. If you don't know if it's flying well then I can't help a lot with that any more than I can critique your skiing over the net.

Put it this way-if it flies, you are happy, and the motor doesn't burn up, then you are doing OK for now.