Home Forums Everything about the Mini Tricopter LitterBug's RCExplorer Mini Tricopter Build thread

This topic contains 59 replies, has 5 voices, and was last updated by  punong_bisyonaryo 2 months, 1 week ago.

Viewing 15 posts - 16 through 30 (of 60 total)
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  • #40453

    Kevin_Erik
    Moderator

    You may want to opt for the 35A ESC’s David currently carries. They have a burst current of 45A which should prove usefull with 6S.

    #40461

    LitterBug
    Participant

    Biggest reason to go with 6S is efficiency and lower current. Higher voltage, lower current, on low KV motors for the same thrust. So you are less likely to experience battery sag, and puffing as well.

    4S = 16v
    6S = 24V

    Watts = Volts x Current.

    So for the same power (watts) at a higher Voltage (S), it takes less current (amps)

    So say you are running 20 amps on 4S. that’s 20Ax16V = 320watts.
    If you switch to 6S, your amps drop. 320watts / 24V = 13.3 AMPs

    Lower current = lower losses due to heat.

    In theory, I should be dropping from 2300kv to 1600kv. Only dropping to 1900kv on 6S is like bumping up to 2850kv on 4S. So I’ll be gaining more potential power…

    LB

    #57159

    LitterBug
    Participant

    After the recent dRonin firmware Wired release, @jihlein has rebased and added the triflight routines to his MyDronin branch. This also adds hardware support for the RCExplorer F3FC flight controllers. Managed to build it on my dev box and test it on two frames tonight at an indoor fly. Servo Feedback on the DTFc which I use on my Mini Tri is handled on the LED out pin since there is no RSSI or other analog inputs available.

    6″ Mini Tri DTFc: http://dronin.org/tunes#?key=ahFzfmRyb25pbi1hdXRvdG93bnIYCxILVHVuZVJlc3VsdHMYgICAmNzmmAoM
    Did this as an upgrade from the previous Stock Neat release. All flights were LOS in leveling/horizon except during in-flight Tailtune. Did an autotune and flew on stock dRonin without triflight routines enabled. Punch outs and throttle chops had quite a bit of uncommanded yaw. Roll axis was responsive with no yaw coupling. Pitch axis had noticeable yaw coupling. After enabling triflight, Servo feedback, doing ground tailtune, and inflight tailtune, it flew noticeably better. My buddy who didn’t know what changes I was making even commented on how much better it looked. Almost no yaw coupling on punch outs or throttle chops, and no noticeable yaw coupling on pitch. I did not adjust the dynamic yaw min/max or Yawboost. Left those at default value 1. I think those are better left for adjustment out at the field where there is more room to fly FPV.

    Have not yet switched arms out with the F80 motors. Still running F40 2300kv at this point.

    Cheers!
    LitterBug

    #57164

    Kevin_Erik
    Moderator

    I am seeing some posts here that appear to be duplicates or posted by the wrong individual. Guessing that the files had to be scrubbed after that last bot attack.

    #57167

    LitterBug
    Participant

    Hmm. this is not a dup…. I tested two tris last friday. Posted the results for my Mini Tri in this thread, and posted the results for my Baby tri in that thread… Similar, but different Tricopters, and in the correct threads…

    LB

    #57213

    LitterBug
    Participant

    Simple Horizon mode testing of the Mini Tri at an indoor fly… (dRonin based TriFlight)

    Cheers!
    LitterBug

    EDIT: Prop FAIL! 😉

    #57253

    LitterBug
    Participant

    So as it turns out, all the components on my current Mini-Tri build are 6S rated (except possibly the F40 2300kv motors if you are paranoid). FC/PDB= DTFc 2-6S, ESCs= DYS XS30A 3-6S, Servo UBEC= RMRC 6V/3A 2-6S. Mind you, the motors were originally tested and charted at 4S for given props, but if you limit the max current in some way to keep max power the same with the higher voltage, everything should work just fine. (Watts= Volts*Amps)

    I’ve been playing around with 6S on an F550 hexcopter with oldish “3S” 2212 980kv motors and have noticed some gain in efficiency. Mind you, I’m NOT going full throttle with the ESCs on 6S. I have adjusted max PWM on the FC to be 66% of max, so I have equivalent to 4S power without worrying about burning up the motors by running too much power through them, adjusting anything on my TX, or limiting myself to 66% on the throttle stick…

    Figure I’ll try the same with my current Mini Tri build before switching to the F80 1900kv motors. (which I won’t limit to 66% power because they are rated for higher watts…)

    Cheers!
    LitterBug

    #57255

    Kevin_Erik
    Moderator

    You can set current limits on those ESC’s and use those F40-2300KV motors safely @ 6S.
    Depending on the Series of F40 you have they’re good for the following wattages…

    Note: (P/V=I)

    F40 270W, 270 / 25.2v = 10.71 Max Amps. I’d not try 6S on these unless you want a sparkler.
    F40-II 520W, 520 / 25.2v = 20.64 Max Amps, set your ESC limit for 80% of that.
    F40-III 560W, 560 / 25.2v = 22.23 Max Amps, set your ESC limit for 80% of that.

    Note: With the F40’s @ 6S your RPMs could max out @ 57,000 if not limited by the propeller. (38,640rpms @ 4S) Conversely, the F80-1900KV motors can hit 47,880 RPM’s @ 6S.

    That being said, the Emax LS2207-1900kv is a good motor for our Tri’s. Can handle 6S and weighs about 10 grams less than the F80-1900KV. It’s what I am current using on the 6S Baby Tri.

    Kevin

    #57256

    LitterBug
    Participant

    Kevin,
    @Kevin_Eric wrote “F40 270W, 270 / 25.2v = 10.71 Max Amps. I’d not try 6S on these unless you want a sparkler.”

    You are missing the point… Max watts is the limit, not Max Volts.

    Cheers!
    LitterBug

    #57259

    Kevin_Erik
    Moderator

    Yeah i realize but in the BlHeli ESC app your going to see current limits.

    #57260

    LitterBug
    Participant

    Uh no, you have not paid attention…. re-read and comprehend. I am NOT adjusting the ESC.

    LB

    #57262

    Kevin_Erik
    Moderator

    No i suggested this as protection. There is a current limit feature thats part of the BlHeli esc’s.

    #57279

    LitterBug
    Participant

    Just got done doing an autotune on my Mini Tri with F40v1 2300KV motors on 6S. Motors came down stone cold (less Amps = less heat), no sparks, everything running smooth. Got a few packs on the charger to head out to the field to get some FPV on it and on one of my Baby Tricopters.

    Cheers!
    LitterBug

    #57281

    Kevin_Erik
    Moderator

    Sweet !

    So how is the torque and flight times?

    I have a set of LS2207-2550kv that inhave been reconsidering. Once the crappy weather breaks and i have the innitial flight done i may opt to swap the baby back.

    #57283

    LitterBug
    Participant

    Had it out to the field today and got a couple packs in. Mostly just playing around validating 4S motors do not blow up on 6S if you limit max power. They actually came down stone cold where they usually run warm on 4S.
    Mini Tri on 6S

    Cheers!
    LitterBug

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