Choosing propellers for my setup

[vispaaja]

Hey,


I've been using APC slowfly props for years but balancing them takes a lot of time. Especially SF Pushers seem to be a lot worse than normal SF's. I'd like to switch to well balanced CF props to avoid balancing and would like to hear opinions on brand and size. My setup is the following:

Hexa frame
6x AXI 2814/22 765kv
2x 4s 4000 batteries
Flying weight with camera: 6075g (13.4 lbs)

I currenctly fly with APC SF 12 x 3.8 props but e-calc suggests they are too small for my setup. I have had nice results with them so far and there seems to be more power reserve than e-calc says there should be. I'm wondering if I should switch to 13 or 14 inch props to have better flight time and efficiency? For example these:

http://flyduino.net/Tiger-1344-Carbon-Fiber-Propeller-CW-CCW-V2_1

E calc shows decreased hovering amp draw (see attached image). What are your opinions on T-Props? Anyone with similar setup, which props have you found to be most efficient and well balanced?


Thanks

 

[vispaaja]

Any opinions?

What hover throttle should I be looking for in e calc? 60-70%?


Thanks

 

[kloner]

the tiger cf props are really nice.... i'd be shooting for 50% hover for performance, 40% for efficiency.... the tigers appear to have less bite than traditional props so you can probably go a tad on the bigger side. Most important is that the prop size doesn't make that motor draw more amps than it's rated for and that the esc's can handle

 

[vispaaja]

the tiger cf props are really nice.... i'd be shooting for 50% hover for performance, 40% for efficiency.... the tigers appear to have less bite than traditional props so you can probably go a tad on the bigger side. Most important is that the prop size doesn't make that motor draw more amps than it's rated for and that the esc's can handle

Thanks for your reply! How do normal ESC's handle 40% throttle? Will they heat more? I'm using 6x Maytech 40A SimonK

 

[Hexacrafter]

Vispaaja,
I will offer an opinion, based on our product testing and prolonged flight experiences. Some may offer opposing opinions.
We design out aircraft to hover at 50% throttle. Some like to push this to 60-70%, but our experiences indicate that the aircraft then lacks the required reserve power to deal with wind and turbulance.
I personally feel you are way too heavy for the motors and props you are indicating. Are the motors/ ESC coming down HOT? Are you experiencing shorter flight times?
You do not indicate the diameter of you frame, but do indicate that you can spin 13" or 14" props. Can you fit 15"?
For a similar HexaCrafter aircraft with 6100 gram AUW we would be suggesting Avroto 3515, 14-15" props & 6S.
At that weight, we would be a 6S machine.
Is this configuration a manufacturer recommended set-up for this weight?

These are just a few comments and opinions.
The T-motor CF props are "top of the line"........ again just an opinion.

Respectfully,
Andrew

 

[kloner]

you generally get a little less stable, you could see some heat but more the innability of the motor to ramp up as fast as say one at 50%.... like leaving a stop light in second gear, FC asks for an increase in power and the craft wobbles then straightens kinda deal.....

2814 usually limit out at 12" but i don't know about axi...

 

[vispaaja]

Vispaaja,
I personally feel you are way too heavy for the motors and props you are indicating. Are the motors/ ESC coming down HOT? Are you experiencing shorter flight times? You do not indicate the diameter of you frame, but do indicate that you can spin 13" or 14" props. Can you fit 15"?
For a similar HexaCrafter aircraft with 6100 gram AUW we would be suggesting Avroto 3515, 14-15" props & 6S.
At that weight, we would be a 6S machine. Is this configuration a manufacturer recommended set-up for this weight?

Thanks for your reply Hexacrafter!

Motors and ESC's are warm after flight but not hot. I have a custom frame that can fit 15 inch props. I did some calculations with ecalc that suggest that my motors are really too small for my setup and cannot handle bigger than 13 inch at that flying weight. Otherwise peak amperage goes way over the 25A limit at max power. Trying 13" could bring slight increase in efficiency but really it seems that the best option would be to swap to bigger motors, props and 6s.

The setup you recommended on 6S seems to be ideal with quite a big increase in flight time. It's a shame I didn't know ecalc exists when I started to build my hexa. These new KDE motors would probably be quite similar to Avroto 3515? I've heard they have some incombatibility issues with SimonK so would need to get new ESC's as well.. Have you had sync loss problems with Avroto?

http://www.kdedirect.com/KDE3520XF400.html

you generally get a little less stable, you could see some heat but more the innability of the motor to ramp up as fast as say one at 50%.... like leaving a stop light in second gear, FC asks for an increase in power and the craft wobbles then straightens kinda deal.....

Okay, good to know!

 

[Hexacrafter]

vispaaja,
The Avroto 3515 and 3520 series motors were tested with Maytech 45a Simon k HK series esc by Avroto. This is a manufacturer recommended pairing. We have increased our recommened ESC to the 60a. Maytech HK series as we tend to "overdesign" and wish to ensure long durability and cool temperatures.
We have hundreds of flights with these combinations without issues.
At this time, we have not tested any KDE motors. They are new to the Multicopter line and we cannot recommend any motors/esc to our clients until they have been tested and proven.
I hope this helps.

Andrew

 

[vispaaja]

Nice to know, I've had some low pole count motors that just didn't work with SimonK, so it seems to be very critical to hear test results before buying anything .

I'll try the 13x4.4 T-Props with my AXI's and try to get a good deal of either Avrotos or KDE's when we hear more test results about them.

 

[vispaaja]

Hi!

Just ordered KDE 4012XF-400kv motors and KDE 55A ESC's for my hexa . Need to try them on 6s and 15" props.

Until they arrive, I was thinking if I should replace the Axi 2814/22 765kv's with Plettenberg 15-20 motors that I have left from my latest build. They are 755kv, 4-5s and should have more power.

Do you think this could work?