Anybody used the new APC Multirotor props?

Discussion in 'Cinestar Misc' started by Matt Barker, Jul 22, 2013.

  1. Matt Barker

    Matt Barker Member

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  2. Gary Haynes

    Gary Haynes Administrator
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    Matt most folks using APC are using the Slow Flyers. Not sure what the difference is other than the shape.

    Haven't heard of them before. No phone number or address on the site and the return policy points to the T&C's with nothing about returns.
     
  3. Matt Barker

    Matt Barker Member

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    To me the center hub looks beefer than the Slow flyers. Kinda like the beefy hub of the xoars. Maybe more ridgid/less flex?
     
  4. Gary Haynes

    Gary Haynes Administrator
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    Test fly some and let us know.
     
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  5. Matt Barker

    Matt Barker Member

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    I just ordered a set for less than a pair of xoars. :)

    Stay tuned for a very non-scientific analysis.
     
  6. Matt Barker

    Matt Barker Member

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    xoar 14x5 19grams
    apc 14x5.5MR 29grams

    First impressions:
    More rigid than slow flyers.
    Flys well.
    Looks like a plastic knock off of my xoars.
     
  7. Steve Maller

    Steve Maller UAV Grief Counselor

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    Interesting. Do you have GPX files before/after to evaluate power consumption, etc.?
     
  8. Matt Barker

    Matt Barker Member

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    Right now i'm flying Naza2 until my MK comes back from Germany. :/

    I dont know of a way to data log/meter draw on my naza.
     
  9. Steve Maller

    Steve Maller UAV Grief Counselor

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    How about just flight times? Or handling characteristics?
     
  10. Matt Barker

    Matt Barker Member

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    Flight times seem similar to ACP SFs. Feels more planted/crisp than the SFs.

    Also seems quieter.
     
  11. Sebastian Meredith

    Sebastian Meredith Active Member

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    Hey Matt, Just wondering how have the new APC props have held up? Reccommend them over the SlowFly APC's ?
     
  12. Matt Barker

    Matt Barker Member

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    My $0.02:

    They seem to fly great. They are more rigid than the SFs. They appear to be plastic Xoars. Not as ridgid as the Xoars, but the Xoars are expensive and fragile.

    So far they are I give them the best performance per dollar award.

    Im planning to put the 16 inch MRs on my heavy lifter.
     
  13. Sebastian Meredith

    Sebastian Meredith Active Member

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    Excellent ... thanks for the prompt feedback Matt!

    Quick questions, the inserts required for the MR props .... same as the APC SF? or did you need to purchase new ones?
     
  14. Gary Haynes

    Gary Haynes Administrator
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    Matt how was the balance on them?
     
  15. Steve Maller

    Steve Maller UAV Grief Counselor

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    Just bought a set. Will test tomorrow. They're quite a bit skinnier and a little longer.
    image.jpg image.jpg
     
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  16. Sebastian Meredith

    Sebastian Meredith Active Member

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    Looking forward to some feedback on performance etc.
     
  17. Jason Herring

    Jason Herring Member

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    Do you get the same flight times? And how do they do in the wind?
     
  18. Steve Maller

    Steve Maller UAV Grief Counselor

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    OK, ladies and gents, here's some data.
    First, an explanation.
    I tried to make this as scientific as possible (at least for a lazy Saturday morning). :cool:
    My flight profile was as close to identical as I could manage. About a 3 minute flight with ambient air temp of about 62°F, no wind to speak of, and effectively at about 10m above sea level. Took off, flew about 50 meters away at 10m or so, engaged AH (I have ACC 2.2), and climbed as slowly as I could straight up to about 65-70m altitude. I then leveled off, and tried to slowly descend in the same general area to about 10-15m. I then disengaged AH and flew gently back home. As you can see from the GPX summaries below, the flight profiles are similar. Of note is I did not balance the MR props, so if they're at all out of balance, their performance may improve.
    My observations, both subjective and reading the data:
    • handling was nearly identical, with maybe a slight increase in stability with the MR props. But as I said, I did very little maneuvering
    • I did notice a little less shuddering on descent
    • the MR props might be slightly louder, but I did not measure the sound
    • based on the data, efficiency is slightly improved (lower current draw) even though I climbed a bit higher with the MR props than I did with the SF props
    • ESC temps are a bit lower. It took me about 25 minutes to swap all the props, so everything had a chance to cool down.
    Here are the summaries. The SF props are first, followed by the MR props. And both GPX files are attached. 13082401.GPX is the SF props and 13082402.GPX is the MR props.
    SF Props
    MK Version: FC HW:2.2 SW:2.0a + NC HW:2.0 SW:2.0a
    Flight date: 8/24/2013 8:36:24 AM
    Flight time: 8:36:24 AM - 8:40:01 AM (217 secs, 00:03:37)
    Batt. time : 240 secs, 00:04:00
    Elevation(GPS) : 0 34.11 62.795 m (min/avg/max)
    Altitude(Barom.): -2.3 38.24 68.35 m
    Vertical speed : -2.81 -0.01 1.69 m/s
    Max speed : 15.8 km/h
    Max target dist.: 3.2 m
    Sats : 14 14 15
    Voltage : min. 14.8, max. 16 V
    Current : 0.5 63 91 A
    Wattage : 8 985 1346.8 W
    Capacity: 4264 mAh
    Motor1: 0.0 7.5 12.0 A Temp: 34 60 71 °C
    Motor2: 0.0 8.4 13.4 A Temp: 36 64 76 °C
    Motor3: 0.0 6.2 8.5 A Temp: 36 54 70 °C
    Motor4: 0.0 7.7 13.3 A Temp: 37 58 76 °C
    Motor5: 0.1 7.3 10.8 A Temp: 35 64 85 °C
    Motor6: 0.0 8.4 12.4 A Temp: 37 65 79 °C
    Motor7: 0.1 8.1 11.7 A Temp: 34 67 81 °C
    Motor8: 0.0 8.3 12.3 A Temp: 36 68 83 °C

    MR Props
    MK Version: FC HW:2.2 SW:2.0a + NC HW:2.0 SW:2.0a

    Flight date: 8/24/2013 8:58:40 AM
    Flight time: 8:58:40 AM - 9:02:02 AM (202 secs, 00:03:22)
    Batt. time : 201 secs, 00:03:21

    Elevation(GPS) : 0 33.76 69.478 m (min/avg/max)
    Altitude(Barom.): -0.95 34.69 70.65 m
    Vertical speed : -1.54 -0.02 1.69 m/s
    Max speed : 14.4 km/h
    Max target dist.: 0 m

    Sats : 14 13 15

    Voltage : min. 14.6, max. 15.8 V
    Current : 0.5 63 85.4 A
    Wattage : 8 945 1298.08 W
    Capacity: 3627 mAh

    Motor1: 0.2 7.7 11.9 A Temp: 22 53 66 °C
    Motor2: 0.0 8.6 13.3 A Temp: 25 58 69 °C
    Motor3: 0.0 6.4 9.9 A Temp: 26 49 61 °C
    Motor4: 0.0 8.0 14.1 A Temp: 26 53 65 °C
    Motor5: 0.0 6.7 10.3 A Temp: 21 55 76 °C
    Motor6: 0.0 8.0 13.7 A Temp: 20 56 73 °C
    Motor7: 0.0 7.3 10.1 A Temp: 18 54 65 °C
    Motor8: 0.2 8.6 12.8 A Temp: 20 61 79 °C
     

    Attached Files:

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  19. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I've been quietly working on a motor test station for the past couple of months using some sensors from vernier.com. I have only just started getting some preliminary data, so take the following with a grain of salt -- the first rule of being a so-called expert is to always have a valid reason for being wrong...and I may well need to invoke that.

    I'm planning to publish the data in the form of a Rather Good Guide® in the near future, but with Steve's testing, I thought I would share what I had in the hope that it might be helpful.

    Anyway, the chart below shows a scatter plot of thrust in kilograms (see later note on this) compared with RPM for three props: APC 14x4.7, APC 14x47 MR, and Xoar 14x5.

    Just by way of an overview, I'm using an Arduino Mega 2560 board programmed to emit PWM and driving a FF PDB/ESC (I could never get the MK BL Ctrl to respond properly to PPM even though it's supposed to).

    Thanks to some nimble programming by my son, Niels, the Arduino sweeps the PWM signal elongating the pulse to increase the throttle steadily until the QC3328 motor starts and goes to about 2,000 RPM, and increases it up to about 6,000 RPM and pulls about 20 Amps (bear in mind to hover a Cinestar the QC3328 normally pulls about 9 Amps) -- so it's covering quite a wide range of power settings. At 20 Amps per motor, that would (as you can calculate) on a Cinestar 8, be pulling a total 160 Amps out of the battery. (I'm sitting behind a polycarb shield when this test is running!)

    The chart speaks for itself, but I'm not quite sure what it is saying yet! :)
    At first glance it would seem to say that for a given RPM, the ranking for most thrust is:

    1) APC 14 x 4.7
    2) APC 14 x 4.7 MR
    3) Xoar 14 x 5

    That's not quite what I was expecting so I'm going to be re-running the tests in the next few days.

    In the following graph the thrust is shown in Kilograms -- I calibrated the load cell by using a couple of 0.5 Kg and one 1 Kg weights, so I side-stepped the issue of working in Newtons. I'm using a photogate where a beam is interrupted by prop blades -- in this initial test there are one or two instances where a blade transitions was missed and that's causing outliers in the data. I'll work on correcting that if I can.

    Bear in mind it's a limited sample of data and there are other considerations such as the responsiveness of the motor/prop combination to small changes in throttle -- these will manifest in more stable flight. There are also considerations of how much power is required to spin the motor to achieve the RPM shown below (e.g. Watts compared to Thrust). I'll be working on analyzing the data for that too.

    Anyone, just wanted you guys to see this.

    Andy

    Thrust cf RPM APC, APC MR, Xoar 1-03 2013-08-24.png
     
  20. Steve Maller

    Steve Maller UAV Grief Counselor

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    Very interesting, Andy. My first thought when I saw the new MR props was "they're so skinny compared to the SF props" and I was concerned about their capability to drive enough air. I think it might be interesting to evaluate the thrust as a function of watts, not of RPM, as I think the efficiency of the MRs is being more aerodynamic, resulting in higher speeds. But maybe I'm al wrong, too.
     

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