which props for smooth flight
« on: December 17, 2016, 10:57:04 pm »
Hi there,

Im searching good props for smooth flight for 930kv motors on f450 frame. Lets say 10x5. Any experience/ideas are welcome...
Hardware: F450 Frame--Revolution Board--EMax 2213-935kv--BullTec 30A Opto--5000mAh 3S 30C LiPo--NEO M8N GPS+MAG--Fr Sky Taranis Plus + OPLink Mini
Addon: sj5000x + two axis gimbal + minimosd + eachine VT + easycap
Software: Black Rhino, LP2GO

Re: which props for smooth flight
« Reply #1 on: December 18, 2016, 07:48:14 am »
I use 10x4.5 props on 2212 sized KV930 motors on a 500 quad on 3s lipo.  10x5 are also good.  I use 10x4.5 because they are cheap and easy to get.  I also use 10x4.5 cut down to 9 inch on KV1000 motors on a 330 quad.

You didn't mention number of cells or motor size.  A big KV930 motor can spin a bigger prop than a small KV930 motor.  :)

It is best to assume that all props need to be balanced.  Many motors also need to be balanced and straightened.

Re: which props for smooth flight
« Reply #2 on: December 18, 2016, 08:15:56 am »
Look at my signature...lipo is 3cell 5000mAh...props are balanced...but are cheaper props not too thin and flabby? I thought about graupner e props, but theyre really expensive...

How to straighten a motor?
Hardware: F450 Frame--Revolution Board--EMax 2213-935kv--BullTec 30A Opto--5000mAh 3S 30C LiPo--NEO M8N GPS+MAG--Fr Sky Taranis Plus + OPLink Mini
Addon: sj5000x + two axis gimbal + minimosd + eachine VT + easycap
Software: Black Rhino, LP2GO

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Re: which props for smooth flight
« Reply #3 on: December 18, 2016, 10:32:20 am »
The reinforced props from Flyduino are very good, pretty rigid and well balanced.
But seems in backorder now:
http://flyduino.net/1045-GF-reinforced-Propeller-Set-Black

Re: which props for smooth flight
« Reply #4 on: December 18, 2016, 10:35:12 am »
In short, you just need everything well balanced.

High powered motors or high flip rate stunts need strong expensive props.

The motors I fly are 250 watts or less and generally 1000KV or so on 3s.  I use cheap (less than $1 each) eBay props.  I do flips, but I limit config to 400 degrees per second flip rate.  More may still be safe, but that is what I use.  My largest are 500 quads with FPV and landing gear but no camera/gimbal.

I balance props by first marking the heavy blade for future reference.  I trim a bit off the tip, round the corners, and retest.  Some really bad cheap props need a lot taken off one blade.  That isn't a problem.  There even are such things as one blade props (the fewer the blades the more efficient the prop).  Props can be out of balance "leading edge to trailing edge" in addition to "tip to tip".  I generally don't worry about "leading edge to trailing edge".  If I got one that was too bad I would just use a different prop.

Make sure you also track your props so the tips of the prop are in the same plane.  A C shaped layer or 2 of paper or index card between prop and hub on the low side will get it tracking right.  At the field, if needed I will bend it back into shape to get it tracking correctly again.  I am still flying a prop that bent about 90 degrees in the middle of the blade that I carefully straightened.  The plastic is a little white in that area, but you can't see any difference in the shape and it feels strong and isn't in a high stress location.  I wouldn't have done it if it were bent at the hub at all.

Motors that have bolt on prop adapters can be straightened by a small number of layers of paper on one side between the motor and adapter.  Spin with power (not hand) as slowly as possible and watch where the wobble ends as the motor stops.  If you can see a wobble, you can make it better than it is.  This is for new motors.  If I bend an adapter I use a new one.

Motors can be balanced (prop off) by using the FC to graph vibration and find the right place to put a small piece of electrical tape on the motor to reduce vibration.  Location of tape and amount of tape.  Tape stickum may get soft with motor heat so you may want to use super glue to glue the tape down (adds weight) or just convert the tape into a couple layers of super glue now that you accurately know the location.

I've actually straightened a few of the steel prop shaft (3mm) motor type by hand and eye and pliers.

You can always do a final balance pass with FC vibration graph after the prop has been bolted on "permanently".  Don't loosen the prop.  One motor at a time to find which side and how much to adjust.
« Last Edit: December 18, 2016, 10:38:28 am by TheOtherCliff »

Re: which props for smooth flight
« Reply #5 on: December 18, 2016, 11:03:24 am »
Wow! Thanks guys! And thanks for this detailed report! That helps a lot.
Hardware: F450 Frame--Revolution Board--EMax 2213-935kv--BullTec 30A Opto--5000mAh 3S 30C LiPo--NEO M8N GPS+MAG--Fr Sky Taranis Plus + OPLink Mini
Addon: sj5000x + two axis gimbal + minimosd + eachine VT + easycap
Software: Black Rhino, LP2GO

Re: which props for smooth flight
« Reply #6 on: December 23, 2016, 12:28:22 am »
I've tried several props.  My S450 and SK 450 quads are powered by Multistar 2216 800 KV motors on 3 cell LiPoly's.  I tried cheap slow flyer props like GWS.   They require fairly extensive drilling out the hub to fit the shafts.  I've tried 10X4.5 and 9X4.5.  The 10 inchers develop sufficient thrust, whereas the 9 inchers are pretty marginal.  Neither give smooth flights.  My favorites are 10X4.5 APC multirotor, which are relatively cheap from Tower Hobbies.  They balance fairly easily, don't require a lot of hogging out to fit the motor shafts, are stiff enough to fly smoothly, and have enough thrust.
I balance the props with a Power Point magnetic balancer and scrape/sand the heavy blade until they balance.  The motors are pretty smooth and the props track well out of the package.
 

Re: which props for smooth flight
« Reply #7 on: December 23, 2016, 08:36:20 am »
:-) i got exactly the same props running on my quad now...apc seems pretty good...my local shop keeper told me that apc should work well...and both of you are right :-)

Graupner E-Prop 10x5 are the best ones but also the expensive ones...but they are really smooth in flying
« Last Edit: December 23, 2016, 08:42:16 am by DocHardinger »
Hardware: F450 Frame--Revolution Board--EMax 2213-935kv--BullTec 30A Opto--5000mAh 3S 30C LiPo--NEO M8N GPS+MAG--Fr Sky Taranis Plus + OPLink Mini
Addon: sj5000x + two axis gimbal + minimosd + eachine VT + easycap
Software: Black Rhino, LP2GO