Prop Size and Pitch

Discussion in 'CineStar FAQ - Tips and Tricks' started by Josh Lambeth, Sep 1, 2012.

  1. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    Ok so I am looking to switch to some XOAR wooden props but want to know a little more information about Pitch and Size and how it affects flight times and lift capabilities. Im currently flying with the stock 14x4.7 APC's that Quadrocopter supplied. My primary camera is the 5DMKII and at the end of my flights my motors are really hot and so is the battery. Im averaging between 60-70amps during my flights. Any suggestions on a different size or should I stick with the same size just in the wooden prop flavor? Thanks for the info guys.

    Josh
     
  2. Daniel garate

    Daniel garate Member

    Joined:
    Jul 8, 2012
    Messages:
    38
    Likes Received:
    5
    Hi
    i Just finish a 1 month job shooting with my hexcopter, average weather temp. was 104 degrees....Arkansas....
    i was flying my cinestar 6 with BL's / heatsinks in both sides, quadrocopter motors, 14x7 props, carrying a 5D mkII, on a AV200 360 mount....the motors and bls were extremely hot, cause of weather and payload, ....i was doing like 65 amps ,......

    When i changed to the 13 props, Amps went up, but the Bl and motor temps went down....dont know why exactly, but i prefer to have a cooler motor and BL, with more Amps, than a super hot motors and BL's......
    I like how those props work with this setup....

    good luck

    daniel
    www.helicamperu.com
     
  3. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    What was the new pitch for your new props? Also did you notice any flight time differences? Thanks for the info.
     
  4. Tristan Twisselman

    Tristan Twisselman Active Member

    Joined:
    Jun 30, 2012
    Messages:
    416
    Likes Received:
    25
    You sure your props aren't 14x4.7
     
  5. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    Whoops... typo. Yes. 14x4.7. Thanks Twister.

    Josh
     
  6. Marc BRACELET

    Marc BRACELET Active Member

    Joined:
    Jul 10, 2012
    Messages:
    204
    Likes Received:
    27
    For information my motors are at 38 / 40 Degres Celsius after 14 minutes flying a 7D on my CS6, i use 2 Lipo 6S 8000 mah in parallel with 2826-8 motor size KV 550 and 14.5 XOAR props.

    I give you an interesting link if you don' t already know for the exact calcul of a MultiRotor configuration... it' s a must have tool.

    X-Copter Calculator

    Hope this help you...:cool:

    Best.
    Marc.
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Salut, Marc:

    From whom did you get the 8000 batteries, please?

    Also, when you connect them in parallel, is there any risk, if they're at different voltage that you get high current between the batteries until they equilibrate?

    Thanks
    Andy.
     
  8. Marc BRACELET

    Marc BRACELET Active Member

    Joined:
    Jul 10, 2012
    Messages:
    204
    Likes Received:
    27
    Hi Andy,
    my batteries are The Turmigy 8000mA Nano-tech from Hobby King and no, no problem to connect Two of them in parallel, you have just to be sure that they are fully charged (The 2 Batteries) before flying...

    Marc.
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Thanks, Marc.
    Are there any other changes you have to make beyond just putting the two batteries in parallel? Does it "ripple" outwards? As in, new motors, new Bl-Ctrl/ESC, etc. etc.?

    Andy.
     
  10. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    When you run in parallel you are just effectively doubling your total amps of the battery. 2x 6200's mAh = 12,400mAh total when in parallel. If you run the batteries in series thats when you double the voltage which would require new electronics and such.

    So I ran everything through the ecalc deal and I will be able to use the 13x6.5 XOAR but I guess my question still remains... are there benefits? I am not 100% sure what running smaller props will do? I know these are noob questions but I have never really looked into it before until now. Should I just get the wooden versions of the 14x4 props which almost match the APC's I currently fly?

    Thanks!

    Josh
     
  11. Marc BRACELET

    Marc BRACELET Active Member

    Joined:
    Jul 10, 2012
    Messages:
    204
    Likes Received:
    27
    No, no other change, the fact of having two batteries is exactly as if I had one 16000mA alone, I have 2 connectors for batteries and if I want to, I can use a one of these jacks with just one battery 6000mA. This changes nothing for the rest. I stay in 6S no problem.:cool:

    SDC.JPG
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Don't feel bad in the slightest, Josh. I've got the same questions and more, too! I'm curious about the net gain of the two batteries given the increased weight of the second battery.

    Also curious to learn the benefits with today's wooden props vs AFC slow fly. The wisdom out on the net seems to suggest Xoar props lighter (so can change speed faster), more rigid (so more power transmitted to the air mass), and quieter (not quite sure how often this matters). Are wooden props stronger if one has a ground strike?

    Andy.
     
  13. Marc BRACELET

    Marc BRACELET Active Member

    Joined:
    Jul 10, 2012
    Messages:
    204
    Likes Received:
    27
    Using smaller prop have two effect :

    - 1 - You' ll have more stability...!!!

    - 2 - less performance, more power consumption and engine overheating most important, but, but much more stability, it is a difficult choice between autonomy and Efficiency .

    I suggest you the same size of props, with wooden XOAR for the same size you' ll see a big difference of performances...:cool:
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Thanks for the image, Marc. Ouah!!

    I have never, ever, seen shrinkwrap that large. How big is it before you shrink it down? <grin>
    Also thanks for the info that you can go up to 6S without changing anything. That's impressive -- I guess the Recom's are happy with the higher voltages and the Bl-Ctrl/ESCs do not melt either.

    Just to clarify, you have two battery connectors -- one (the top left hand one) connects to the normal place on the Power Distrbution Board, but the other connects somewhere near ESC #5? Sorry for the noob questions, but I'm struggling to see how you wire it up -- and I can see you've moved away from the Deans connectors -- is that just for convenience or current draw?

    Thanks
    Andy
     
  15. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    Ok... So since i already have heat issues down here my best bet would be to switch to a wooden prop of the same size. Thank you for that info!

    Josh
     
  16. Marc BRACELET

    Marc BRACELET Active Member

    Joined:
    Jul 10, 2012
    Messages:
    204
    Likes Received:
    27
    @ Andy
    Sorry for the poor quality of the I-Phone Picture, these may help you to unterstand (EC5 plugs are not well connected because of the DJI beep that will awake all the family).

    IMG_2738.JPG IMG_2737.JPG IMG_2739.JPG
     
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Thanks for the images -- I understand about not wanting to connect the EC5 late at night.

    So, as far as I can tell -- and please correct me if I am wrong as this is data from my study of the images.

    1. You are using the balancing lead for telemetry of the battery voltage, as well as an on-board display (nice display by the way -- who makes that -- a quick Google search didn't reveal anything? You have found all the good toys!)

    2. In JPG.147 : The primary battery looks like it is feeding to the normal connector on the PDB -- it's a little dark under there, but I think I can see the wires heading to the PDB

    3. In JPG.145 I can see the second battery leads (with another one of those cool Lipo monitors).

    4. In JPG.146 I can see the second battery and it's EC5 leads.....but can't quite make out where those leads are connected to on the PDB?

    Also, what's that twisted pair of white whites on the top of the battery? Some other cool toy? ;)

    Thanks
    Andy
     
  18. Marc BRACELET

    Marc BRACELET Active Member

    Joined:
    Jul 10, 2012
    Messages:
    204
    Likes Received:
    27
    You can found all the description of these toys here : FR-SKY TELEMETRIE and buy them from Aloft Hobbies with adaptator and RX for you radio system

    Correct...

    Correct...

    I hope this is for you a good answer...;) No PDB for me but a big Spider.
    SPYDER.jpg

    It' s a Temperature sensor for my batterie pack...

    @Josh
    I' m sorry we have ruin your "Prop size discussio...", In the future, I promise with Andy to stop upsetting topics...:):p:oops:
     
  19. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,313
    Likes Received:
    214
    HAHA no worries guys. Some good info in there!

    Josh
     
  20. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,357
    Likes Received:
    1,161
    Yeah, sorry Josh. I think Marc is way ahead of me in terms of double-battery setup and it certainly is good information and very much appreciated. It never occurred to me to feed the power directly to the BL-Ctrils, but, now you mention it Marc, it seems entirely rational given the current draw. Vous avez raison! (Relax, folks, I didn't call him a raisin. It just means, "you're right.")

    As some of you may already know, I've produced a three and half-hour, two-DVD set called "A Rather Good Guideā„¢ to Building a Cinestar 6 or 8" for QC. The DVDs will be available very soon. The promo video is on this page http://www.quadrocopter.com/Cinestar-6-8-Build-Guide-DVD-Download_p_619.html -- I couldn't have done it without all the great information, freely given, by people on this forum and mikrokopter.us and .de.

    I think there might be a need for a "Heavy Lifter" and/or "Beyond the Standard Cinestar" DVD that pulls together all the how-to knowledge from Katya, Josh, Marc, Tabb, and others who are pioneering this field (all I seem to be doing is pioneering new failure modes! :( ). If there's demand, I'll work on it after I've finished my next production. (See, Adam, I'm stayin' focussed, man....stayin' focussed.... ;) )

    What do you guys think? Feel free to email me at ajohnsonlaird@me.com if you'd like to discuss it or berate me! ;)

    Thanks
    Andy
     

Share This Page