3s 10in prop? 4s 8in prop? general rule?

K

kikorafael

Member
ive read and searched a lot in this forum and other forums, and i get conflicting views....

1. some say the general rule is: 3s for 10in props and 4s for 8in props, but others say its OK to use 4s for 10in props....... im confused could the gurus shed light on this matter thanks....


xaircraft hexa
dji naza, gps
dji 920kv
30a esc
go pro, gimbal, vtx
845 dji props
4s 4400 for hexa, 3s 500ms for vtx
total weight 2.8kg

i feel under power with the 845 props on my 4s lipo...
your suggestions are most welcome

ps: i also dont understand how to use the ecalc
 
Last edited by a moderator:

kloner

kloner

Aerial DP
your trying to get the prop loading right, makes it fly happiest. in anything motor, there is a max watts, voltage times amps. besides getting the proper loading, your trying to stay under your max watts with said prop. Bigger makes it go over, smaller makes it under. the only way to see it is with a logger or osd in fpv......

That said, i assume your stuck on dji props. I'd suggest trying different brands to open up whats available. look at apc slo fly in 10x4.2 or 10x3.8 for more torque, less bogging and more weight lifting power. for a little more money but worth it if your not crashing alot is the graupner. they have a 9x5 that is more power than 8x5 dji, they also have a 10x5 that uses less watts but has more power than the stock 10" slofly props they come with. Those are so heavy and big, they eat alot of power standing still. I've found 8" props like 1000-1200kv motors of 4s best. that same setup but heavier likes 9" and the 10" do best on 3s 900-1000kv or 4s with 750-900 kv motors, kv depending on weight to fit the perfect prop. I fly right around 1600 grams and 9" are too much, 8" aren't enough. on 3s the same setup on 10" props is dead on perfect. The most noticeable thing without a logger to see this is how much the craft jumps when you flip to atti from manual, or vice versa. You'd like to see it hover midstick in either mode. Too big of props makes manual hover at 1/4 throttle and atti at half stick.when you flip to atti, you have to noticeably increase the throttle or it hits the ground. too small a prop wants to hover at 3/4 throttle in manual, 1/2 stick in atti and does the opposite rise when switched from man to atti. mine are quads

just from the description you have there at 2800 grams, your missing some power with the dji motors to swing the perfect prop. a 2810-2814 size motor would do you much better
 


kloner

kloner

Aerial DP
the 845 are easy enough for her to spin, if you need more power step up to the next size like a 9x5. The 10" add alot of watt draw to the setup, in atti it'll keep it from leaning very far forward or back cause they just run out of power, hard to adjust the gains when there like that to a stable look.

theres another prop, 3 blade gws that's available in 9x5x3, decent prop for the money, but alot of em came to me where tweeked pretty bad
 



T

Totallycommitted

Member
Ok so now ya got me interested in this prop question....

I,ve got a flame wheel 550 with pulso 760kv motors and 40amp fun fly esc's and gps naza, using APC 1045 props and a nano tech 4s 5000mah bat, and she flies awesome, I am using the outer shell of a av200 for skids and a locked off cam mount, as I have stripped the Av200 of servos etc......she flies incredibly well. 8 mins no cam with a 550d canon 5 min on 1 battery.

But, my main concern is my OCTO which has axi 2814/22 motors may tech 40 amp esc's a droidworks heavy lift frame and a cinestar 360 cam gimbal still using the above batteries and 12.38 slowly APC props. I am still dialling her in but she is flying very well.

IN TERMS OF PROPS SHOULD I BE LOOKING AT SLIGHTLY SMALLER SIZE ? GRAPNER 11.5 ?

Any suggestions for an optimum setup in terms of props here ?

Thanks for any advice

Matt
 

kloner

kloner

Aerial DP
do you have an osd or logger? that's the best way to tell by looking at your amperage draws/watts
 

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