NEW U7 motor tmotor

Discussion in 'Cinestar 8' started by kjetil t√łnnesen, Nov 22, 2013.

  1. Ryan McMaster

    Ryan McMaster Active Member

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    GH4, A7s and BM4k are all much safer and the 4k with the new Canon 24mm pancake will be a real winner in my book.
     
  2. Guilherme Barbosa

    Guilherme Barbosa Distributor

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    Everybody here put a lot of supposition' well nobody say what temperature you are flying' we fly in Brasil sometimes deep in Amazon forest where temps in the shadow can get up to 40 C- we used 3515 but it just couldn't stand' not using x8 with m10 red epic and a cp pl' so we moved to U7' the escs do get hotter than what I would like' and the way we got around was using PC coolers and 2small 24v fans' fly with 2 16a bats' and I can tell wouldn't change a thing'
     
  3. Kari Ylitalo

    Kari Ylitalo Member

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    That's true. There's definitely huge difference if we are flying most of time around -5C to +10C compared to your +30 to +40C. Which escs do you use by the way? For me Castle esc have been good success with U7.

    Kari
     
  4. Kim Hoogervorst

    Kim Hoogervorst New Member

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    IMG_20141205_122954.jpg IMG_20141205_123018.jpg A mod to the standard cinestar frame to prepare it for the u7 motors, it uses a extra X underneath the centerplate. The center is fixed with carbon epoxy. Makes it really strong (up down) with just a little extra weight. Used the cinestar legs to make the frame stiff left to right...
    Frame now has mt3515 motors but they tend to get hot when flying in high temps....

    Kim
     
  5. Rory Hinds

    Rory Hinds Member

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    what's the consensus regarding flying different prop sizes on a X8 config with say 17" on the top and 18" on the bottom?
    Is this a better practice than flying all the same size props?
     
  6. Steve Maller

    Steve Maller UAV Grief Counselor

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    Most folks (myself included) are flying the same size props, but with slightly different mixer settings. But you'll find things all over the map. For my part, I measured a few different configurations, and that worked best for me. It also simplifies the number of spares I need to have. There are so many variables with these machines (prop size being just one) that I find keeping things as simple as possible helps me stay in the air.
     
  7. Loris Coniglio

    Loris Coniglio New Member

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    Recently I tested U7 490 with 18" prop and Tmotor 80A esc .
    Reached 6Kg of thrust, 1600w, about 60A but the problem are the cable from motor to esc.
    After 2 minute I stopped the test because The three motor cable become very hot and SMOKE !!!!
    How Tmotor do their test for the chart on their site for the 100% throttle?
     
  8. Gary McCready

    Gary McCready Active Member

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    I thought the wires were too small on my Tiger MN4014-400 motors too??
    U7 spec: Max Continuous current(A)180S....44A Was 60A your peak or continuous?
    And
    Max Continuous Power(W)180S....1180W, so 1600 is way above spec???

    You would think they could handle a 60A ESC and a 18" prop....they are in the chart Specs for 25v.
    http://www.rctigermotor.com/html/2013/Power-Type_0928/92.html
     
  9. Yann Kibongui

    Yann Kibongui New Member

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  10. Tim Gould

    Tim Gould New Member

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    Yann,

    Are you trying to run the 490kv motor on 8s for additional power over say 6s or are you trying to gain efficiency by going to higher voltage? I don't think the 490kv motor is particularly well suited to 8s, but that is just my opinion. A lower KV motor would be better suited to 8s or higher.

    It seems like the T-motor FLAME 80a ESCs are the way to go.
     
  11. Yann Kibongui

    Yann Kibongui New Member

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    It was to try gaining efficiency...
    Flame 80a are made for U8/U10, so it's better to stay on the t80A with heat sink
     
  12. Tim Gould

    Tim Gould New Member

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    My opinion is that there is very little gain by going to 8S on this motor and more on the negative side like potential ESC problems. I would stick with 6S on the 490kv motor. Real gains in efficiency come from running higher voltage on a lower KV motor running a larger diameter propeller that spins slower. Spinning the same propeller using the same motor on 6S vs. 8S will be almost exactly the same wattage consumption.
     
  13. Yann Kibongui

    Yann Kibongui New Member

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    Hum ok, thanks for the advices.
     
  14. Yann Kibongui

    Yann Kibongui New Member

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    I finally bought a T-motor T80A to test and be sure it's ok with my U7 490
    I've tested the esc and the motor loose sync betwin 60 to 80% throttle and then run normally at the top of the throttle.
    Well the motor smell after test is not good at all too...

    Anybody experienced this kind of thing ?
    Did you changed esc settings ?
     
  15. Yann Kibongui

    Yann Kibongui New Member

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    Here is the problem in video.
    Tested flyfyn 80A, fentium 80A (the worst) and T80A
    Even T80A loose sync... Is there anybody here who use U7 490 ?
    What esc are you using ?
    I'm a bit lost right now...
     
  16. Yann Kibongui

    Yann Kibongui New Member

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    Some news !
    So I had timing issues with my T-motor U7 490kv even with T-motor T80A and hobbywing flyfun whixh are the same.

    At the top of the throttle the motor was loosing sync.
    It seemed to be a bit better with wookong-m in manual mode but the motor still loose sync on a part of the throttle range.

    Now I'm testing HobbyWing Xrotor Pro 80A HV and it seems to be perfect !
    Just a throttle calibration problem when connected directly to the receiver but work perfectly through wookong-m on manual mode.

    So for me, only these esc works.

     
  17. Ozkan Erden

    Ozkan Erden Distributor

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    Thanks for sharing Yann. I have heard very good results with Xrotor Pro ESCs. I'm also willing to try these one of my copters. They are also reasonably priced.
     
  18. Yann Kibongui

    Yann Kibongui New Member

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    You are welcome !
    150$ for dual pack and less on alibaba ^^

    They are sooooo much cooler than T80A, very happy to have found the right esc's for these motors. Now I can finish my project !
     
  19. Mike Reid

    Mike Reid Member

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    Just FYI to anyone using these with T80A ESC's, I have been using them the together for a little over a year and last week I decided to revamp my whole setup and make it a little more streamlined.

    I decided to solder my ESC's directly onto the FF power distribution and switch from 3 bullet connectors on the motor wires and the motor side of the ESC's into MT60 connectors.

    When I cut all of the shrink wrap off of the T80A's I found that one of them did not have the 35v 470mA capacitors on it. I should have noticed before, but somehow missed it when I was installing them new. They were definitely missing straight from the factory, three of four pads where they solder on didn't even have solder on them. The ESC worked fine, but I ma probably lucky that I didnt run into any issues.
     
  20. Fabien Deregel

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    Hi,

    U7 490 KV work better with 16x 5 inches props, on 17 / 18 they get hot pretty easy and so do the ESc's.. If you want to use 17 / 18 inches props, best match would be the 420 KV ones. People using X8 configurations are most of the time not so happy with the 490 Kv's U7, but once you have them well you got to use them.. So going to smaller props helps a lot to reduce heat and ESC " torture".

    Unfortunatly, these motors have " ancient age" specs (the 490 Kv ones) and very few ESC's are able to run the correctly with 17 inches and more props diameters...

    But if your booms are long enough to support 17 inches props, you can give a try to the DJi E1200 combo. You will be surprised by the performances of the combo ( 25mm boom all support with motor and ESC inside). Even at full RPM current drain is very low.

    And if you want a safe but affordable value, U5 / 400 KV with 15 inches props are a very good choice, all depends of your payload weight..
    Best regards,
    Fabien
     

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