HOW TO : Differential Thrust | Flite Test

[@muninmatt]

I am gong to describe a very interesting problem I had/have using HKing ESC's and a Turnigy reciever, that i think is worth sharing in case anyone else runs into it. I set up differential thrust essentially the same way you did, but one or more of my motors would continue spinning even at zero throttle following rudder inputs. As long as I didn't enable the rudder mix, both motors would start and stop at the same time. If I enable rudder mixing and move the rudder back and forth a bit, many times one or more of the motors would continue spinning at low speed even though the rudder is moved neutral and the throttle moved all the way down. After doing some troubleshooting/meditating on the issue, I came up with a possible explanation. Before you ask, I did all the obvious stuff, ESC calibration, small tweaks to trim and mix settings, and the like. The total travel of the sticks on my radio is limited mechanically by the chassis of the transmitter itself. If I were to take off the front faceplate of my radio, my sticks would have a small amount of extra movement. At some level, the sticks themselves have to return to the computer in the radio a numerical value indicating their position. For my example, I will say that with the faceplate on, my radio delivers a numerical range of -95 to +95, and with the faceplate off, perhaps it delivers a maximum of -105 to +105. When the sticks on the radio are calibrated, the radio knows that when the throttle reads back "-95" indicating the throttle is all the way down. The radio sends a "-100%" signal to the throttle channel, and the ESC's are calibrated to exactly this signal. What I think happens to cause my problem, is that when i'm at 25% throttle, and I throw the rudder hard to the left, the right ESC somehow gets sent a signal that is "lower" than -95. This somehow causes the ESC to think "oh no, I must have been miscalibrated before because I'm getting a new lowest possible reading on the throttle." The ESC seems to on-the-fly recalibrate itself to this new value for "zero throttle," thus when I move the stick all the way down, one or more of my motors continues to turn. My workaround for this problem was to disable subtractive mixing all together. Rudder inputs only add signal, they never subtract it. Since making this change, my motors always stop when I kill the throttle. A more robust solution would probably be to install better firmware for my radio.

[@sailorjohn2224]

I recently programed my spectrum 6(black) for differential thrust, watching every video I could find. It took two full days. The roller is now hard to use due to wear. Result was a switch was activated in a menu 3 levels into the programing FROM THE FACTORY that prevented success . After all that work I found that flying two motors on one battery (2200 mha 35c) drew so much current (40 amps)that it swelled a battery with each flight. The plane I built was able to carry two batteries in parallel and cured the problem . You really have to want a twin! I wish josh would put a wattmeter on their recommended setup.

[@Propnut48]

I noticed the radio you are using is very similar to my Tactic TTX 650. I will try the same set up in it. Thanks

[@Propnut48]

It worked perfectly

[@freemarlochip]

The amount of mixes required for this function can vary depending on your transmitter's programming capailities/functions. One very IMPORTANT thing to have when doing this sort of setup is to make sure you have a receiver that has the proper FAILSAFE functions for the secondary throttle as some receiver will simply HOLD LAST COMMAND which would be very bad with this setup in the event signal was lost.You would get the esc/motor on throttle channel go to low throttle position while the other secondary esc/motor would simply stay running at what ever RPM/throttle you had it moments before losing signal...

[@skagerstrom]

Aren't you supposed to dissconnect one of the ESC's power leads from the cables when running dual? Not sure if the Futaba ones have some sort of smart power management, but I'm pretty sure you could fry a cheaper reciver if booth ESC's feed power to it.

[@NETBotic]

I would, but it really depends on the BEC.

[@outabody381]

Love you guys and the show. without you guys I would probably be out of the hobby. building is what kept me in it

[@nathonbrown3596]

this is awesome, I think if more videos were out there like this one, not so many people would stop a 4 channels

[@jameseby8207]

Keep up the great work with the videos. You guys got me into the hobby. One suggestion I think you guys should make a video on another day along with a video on Monday and Wednesday.

[@glenaw]

Watching videos, 737-800 NGX, I've seen the engine throttles at slightly off positions of each other to off set what I believe to be two problems of flight. One being to off set cross winds and the other to compensate for engine torque. Are there any problems in flight were you would intentionally use a off set in engine thrust for RC Model Planes?

[@grim4this]

Bugga me, I have ben wondering if proportional throttle was an effect of the circuit board/rx or the transmitter, out of the blue you answered my question ( you popped up in recommended video for you section on youtube ), either you or youtube have phychic powers :), thanks mate this video is awesome. I have bought ( and broken ) enough planes for a lifetime, and am know looking at building flying things with my scraps/parts, if it wasnt for your channel i think i would of thrown them away ages ago.If you ever get bored ( lol ) do one for a spektrum dx6i ( if its possible to program that to do the same thing ). Good job tho guys. One weird thing i noticed about your videos, and its you guys yourselves, even when im watching one that doesnt concern me ( liike im never going to build a star destroyer big enough to launch from a truck, but you guys did ) i find that i still end up watching it as you all seem to have personallities that make great tv. If any one of you move to England could you please apply to host the new Top Gear, the show needs you.

[@jonathanmchugh1391]

You should make a compilation of your crashes :D great job as always

[@NightFlyyer]

Great demo and good info. Thanks.

[@MichaelBender-Riker]

Very nice and simple video. This is probably a hack you don't read in a official manual. 👍😃😃

[@glend.spicer8204]

Really enjoy you info videos, I learn a lot from them. THANKS

[@joeteichert6821]

Thanks so much, this video was so helpful!

[@FPVTeamLegit]

Love the Flags At the end :) cool video

[@ryank3601]

Really nice tutorial. Keep up the great work guys.

[@elexoflyer9363]

Please do a challenge where you fly a plane ONLY on the switches on a transmitter. No sliders or sticks.

[@boy6named6zoen6]

interesting. i would like to see that one too.

[@beechcraft12]

eww no

[@jadenjohnson71]

You guys use to be all spectrum. I miss that.

[@boy6named6zoen6]

spektrum is overrated. I use a frsky taranis and have a dsm2/X orange module on it for the smaller blade bnf helicopters 450 size is the biggest i fly with dsmx . for the bigger heli's like my 600 and 700 i use frsky receivers. better range and for the functions on the taranis you would pay big time on a spektrum transmitter. taranis is budget friendly and has so much to work with.

[@Metallica4Life1995]

Lol Spektrum, they're just the apple of the rc world. I use FrSky FlySky and Walkera and never had problems with any, plus I'm saving a ton of money in the long run.

[@boy6named6zoen6]

+Metallica4Life1995 that's a good one.

[@Metallica4Life1995]

I would honestly use FlySky's protocol over Spektrum. I've used spektrum multiple times and ended with up frustration and constant signal drop outs, while the FlySky receiver (Which mind you is a fraction of the price of spektrum) has gone out to 2-2.5 km range with no hiccups whatsoever

[@everythingcustom4034]

Yea definitely is

[@rockjano]

God it is very complicated. I know these Graupners are great expensive radios but man these are quite complicated beasts. I did it with my cheap and great FS-i6 which only has 3 mixes and it works!!!!! I used all of the mixing possibilities (it would be nice to have more) but it is just doing what it should, and I only used 5 channels (delta mix + diff. thrust + front steering wheel on the place of the rudder) I still have one more channel for some bomb dropping :-)

[@Moethebro123]

Na, it's just the old people in Germany who fly mode 1. I think the reason why it is default on Graupner, is because it's the first mode. I have the mx20 and I love it!

[@nigelkelseycouzens8266]

this is very helpful, and like you said works on most tx,s as I am using turnigy 9xr and 9xr pro would you say this is possible with these tx,s or not if I wanted to use this idea???

[@nbkblood]

Gonna set this up soon on a Bloody wonder twin using Deviation on my 12s ...But have a question on the twin baron what size motors are you using? Looks like a pair of 2204s ?

[@djDTOUR]

I needed this for my mini kraken!

[@seppilin351]

if you're at 100% throttle, is there any throttle "travel" left to go in either direction? Or are you subtracting throttle then? If so, can you only turn in one direction?

[@Chretze]

Quick question: Instead of using channels 5 and 6, can't I use channel 5 and original throttle? Because then I'd have one channel left for a servo to open cargo doors and what not.

[@alvinaufar3513]

why am i watching this, i don't even have rc

[@grim4this]

Cause these guys rock :)

[@trentpierce7656]

Me too

[@ryanm.191]

Because they are awesome. Also yt recommendations are messed up right now.

[@bill1595]

well alvin it is time you did get rc. It's a blast my friend, find a club or someone near you and get started!

[@davonizdashit]

step up your game and buy a drone man! Thats the future

[@SteevyTable]

Now try this with an idle up on a twin variable prop plane. That should make some tight flatspins. If I'm counting the channels up properly, it should only take 7, leaving one free for lights, or gear, or something.

[@sparrowlt]

1- Isnt better to remove one of the red wires in the ESCs so only 1 bec is providing power to avoid conflicts? 2- Its as simple as use 2 separated channels for motors and mix rudder with each one of them (in the desired direction) and each mix use a switch to enable/disable.. you can play with how much.. a 100% mix would do one motor stop and the other go full whrn using full rudder

[@veganautfpv1237]

EXCESSIVELY LOW THROTTLE! Okay, so maybe I missed a post about this, but: I have a Spektrum DX8G2 and I followed this setup. I am flying the FT Sea Duck with the Power Pack C (Emaxx GT2215/09 motors). I tried running a 2200mah 50c 3s battery and it was a pain to just keep the plane from stalling. I tried my 3200mah 30c 3s battery and it was pretty much the same thing. I notice that when I am full throttle and use the diff thrust, one motor cuts down and the other one still revs up quite a bit. This tells me that my issue is the radio setup, not my hardware. How do I set it up so that my throttle is actually 100% when I set it at 100%?

[@mramazing643]

hi flite test, can you make a p38 swappable/foamie?

[@nbkblood]

Does it matter which motor is mounted on which side of the wing? I know to run one cc and one ccw motor to counter the torque roll but does it matter which side they should go? CW on left or right ect...

[@route66flyer29]

Wish you'd do some videos on the FS-i6 for us poor folks that can't afford high end gear. Why do you think we're avid Flitetest viewers and foam builders? I think there's a number here that can't afford the "good stuff". I'll admit it, I'm retired and poor..

[@rockjano]

I did it with my cheap and great FS-i6 which only has 3 mixes and it works!!!!!

[@rowannadon7668]

agreed! I have the fs-i6 and u would like some videos on it

[@rockjano]

I don't do video but if you are interested I can write it down how to do it.. by far not as complicated

[@route66flyer29]

I don't have a twin to do it with yet, wanted to know for future builds, thank you for the offer Banati.

[@killaclownmcl1]

Bánáti János hope you see this, would the set up you described work the same on the fs th9x?

[@Topgear60]

Richard .UK. Please could you show mixing on a Graupner MZ12 Pro. I am using the boat model section none the less it seems to be different to your good illustration ? I have downloaded the manual but it seems to me you need a dgree in physics to understand the instructions.

[@soumyadastidar8732]

This is a super late comment but i had to say it because im curious. So i just watched this so i can do diff thrust on my bushmule. However i already have a 7 channel receiver and tenecally i need 8 for the reverse. But i dont see why you guys aren't just mixing throttle to aux 1 then rudder to throttle and rudder to aux 1 its the same thing really just easier in my opinion and 1 less mix and the best still able to use aux 2 for flaps or gear or whatever you need.

[@klauschristensen5845]

Just a thought... ... could you use differential thrust to make a four motor plane, without any flaps at all?

[@elizabethedelweiss]

God, you guys really need to make an me262 kit using this type of thrust

[@hitechpoint7276]

Damn buddy do i have some news for ya

[@NotGyra]

Nice one! Can you guys do a review of flysky Fs-T6 ? Really really appreciate that😁😁😁😁

[@nate5609]

I have had one of those radios for years now it is really good I never have problems with it, but there is another model that can give you more programming options if you want to do things like this.

[@retrogaming3772]

Hi Flite Test, I was in ohio the other day so i ran hover to your HQ and no one was there, so i left something with a note on it asking for you (Josh, and anybody else available) to sign it and send it back, and i was wondering if you got it?

[@TastyManShark]

Can you guys make more videos with Spectrum controllers and reservers?

[@jtunheimr8657]

@FliteTest What lipo should i use if i fly 2 Motors? I have two 2S brushless motors should i use then 4S and 3S ESC's????

[@Stubby0266]

How about showing for a Hitech Aurora 9 or HT 7 pro?

[@Ev0ltion]

I think about getting that radio(newer version). What can you tell me about gimballs how much worse to these feel compared to frsky taranis?

[@bradyputney9076]

Almost half a million subs

[@nicos1097]

Can you guys please do a review on the new 1.2m spitfire by horizon hobby?

[@ZuNunchaku]

Do we still need vertical stabilizer if using differential thrust?

[@maxsurfer26]

Is this possible with the cheap fs-i6 TX, if the model is a wing (no rudder), but with retracts. Or do I need more channels?

[@gabehaarberg5251]

Are you guys ever going to bring up the USA Today drone again? You said you would. 😑

[@justinwantz211]

What would be a good transmitter with the 4 mixing options. I wanted the fs-t6 but I think that only has 3.

[@phsavatage8681]

Do i have to cut/pop off one of the + leads for the esc before I connect it to Rx?

[@hermandenissen9399]

Hi guys, I have a problem. I want to do this differential thrust on a resque boat (2 motors, no rudder). Only my Graupner mx16 hott has only 3 free mixes. Can you solve this? Forward and backward. Thanks Herman from the Netherlands

[@robbutler19777]

Who has this radio? Can you do it for the 2 common radios? FR Sky or spectrum?

[@chaoticgaming4464]

If I have a 10 channel and I bus then would i be able to have flaps, landing gear, etc. also can I do differential thrust on the tgy i10?

[@CDNRCFlyer]

Hi Guys I have a Futaba T8FG I have looked the mixing program and I am confussed Can you help Thanks

[@tomzeleznik6793]

Hi I got the same issue. Debating trying to set up a v tail mixer... I’ll have to figure out how to reassign the elevator though...

[@outabody381]

Not many people have this radio. nice to know how to do it if I get one though

[@jameseby8207]

Is there going to be a Flitefest west

[@willjameson63]

i bought a devo 7 receiver, it doesn't have numbers but it already has names by each port i.e. elev aile thro rudd it only however has one port for the throttle, are these just guides and can i overall these guides, or have i messed up. Kind Regards

[@jorionray7624]

can you do this with a spektrum dx6i - we need it for the sea duck

[@edwardyu965]

can you fly a plane with differential thrust but with no ailerons or rudder

[@AliSot2000]

Could you build a 3 propellered airplane with a decent size with differential thrust ?

[@wdave6944]

Yeah - Like the German tri-motor used in "Where Eagles Dare". Same winter camo too. That'd be cool.

[@jericbatayon6403]

I have 2xBATTERY and 2xESC... can i connect the battery to each esc?

[@jonas2431]

Are the motors spinning the same way

[@sapropbuster1]

Why don't you show us how to program the old Spektrum DX7 for this??? Please??

[@dtsmychnl]

What about removing the power line from one of ESCs?!

[@or3442]

Can differential thrust be done with the flysky i6

[@berespisti]

Is this transmitter good for an fpv miniquad?

[@Drukranos]

Does ESC with BEC damage the reciever wenn i plug bot in ?

[@wdave6944]

The Graupner MZ-12, eh. Guess I gotta buy the White Album all over again ;-)

[@jameseby8207]

Would you guys ever consider vlogingOr filming everyday in the office

[@kabturek]

What about throttle cut ? without it my fingers feel endangered.

[@reefer2917]

you've got 2 power supply's going into your Rx possible damage to Rx ???

[@Ultrazaubererger]

the Rx doesn't care but the becs might. just remove one of the positive leads and tape it.

[@TheMuddatrucker]

Can this be done on the new Orange tx6i?

[@fahrvergnuugen]

For anyone using a flight controller (like the eagle tree vector) that doesn't support differential thrust, I wrote this arduino sketch which does the mixing: github.com/fahrvergnuugen/rc-differential-thrust-mixer

[@Dbestc1]

Josh how to differentiate my fs i6 right joy stick thrust

[@naritpodhipak687]

When is this plane gonna be out??

[@joshuasturm7495]

Make a quad that you fly around FPV and catch Pokemon with.

[@AerialAdventuresFPV]

can u do a tutorial on tuning a quadcopter with naze32?

[@arsalkhurram4960]

I'm pretty sure they already have a tutorial

[@marcajo111]

My radio is hitec flash 7. Its possible with this radio?

[@stefanvujic3102]

How do you reset the mixes to neutral?

[@rockjano]

OK So How I did it with FlySky FS-i6??? Ch1 - AILERON Ch2 - ELEVON Ch3 - MOTOR 1 Ch4 - RUDDER (I put here the steering front wheel as well) CH5 - MOTOR 2 CH6 is FREE (can be used for anything else) We have 3 mixes Mix 1 (we connect the two motors so both works parallel) Mix is ON Master Ch3 Slave Ch5 Pos. mix 100% Neg, mix 100% Offset 0% Mix 2 (we change the MOTOR power as we move the rudder for MOTOR 1) Mix is ON Master Ch4 Slave Ch3 Pos. mix 20% (can be anything from 0-100%) Neg, mix 20% (can be anything from 0-100%) Offset 0% Mix 3 (we change the MOTOR power as we move the rudder for MOTOR 2) Mix is ON Master Ch4 Slave Ch5 Pos. mix -20% (can be anything from 0-100%) (I don't really know why NEGATIVE 20% but it works like that) Neg, mix -20% (can be anything from 0-100%) (I don't really know why NEGATIVE 20% but it works like that) Offset 0% THAT IS IT It works like a charm!!! Enjoy!!!

[@cloroxbleach7386]

There is a bixler3 in the hobbyking store!!!!!!😆

[@maxxiang8746]

Can I use a kk2 board instead

[@serenity6988]

What is the easy proper formula to app lie for weight of plane to proper KV Size of brush less motor Size..So if I have a 8 lbs plane, what size kv do I need. Keep in mind that I have watched 100s of videos. Ive been searching every where. Why is this information not easily available to all the rc hobbest in the world. Brian. I dont need a treasure hunt! I need an exact answer please. Thanks

[@ShaunHusain]

I imagine there are lots of variables including the air frame itself and lift generated by it moving through the air. I built a few quadcopters recently but just looked at models of the same size and what kinds of components they use. Answers to questions like this or ones about battery life have too many factors not accounted for to really answer.

[@ShaunHusain]

Also kV just tells you how many revolutions per minute per volt applied. So depending on the voltage you'll get different speeds having a larger radius motor will give it more torque some brushed motors are also taller than others and have variable quality in the windings for the motors magnets and adhesives used for the magnets think it's really a matter of just seeing what's out there and experimenting with your particular air frame.

[@didierneeferc]

What motors and escs are that?

[@elefanteist]

I want to buy the radio sends to Brazil?

[@jellyman1735]

Does this work with a DX6i?

[@matthewvanprooyen259]

last video until flite fest

[@peterafong4600]

very informative viedo but i am trying to do this setup on my taranis to fly my super bee that i built

[@wdave6944]

Well guys, I'm sorry. I didn't get a Graupner. I opted for the FS-I6S... but it'll be just as good once I put the go-fast stipes on. Oh, I know... I've got a vinyl sticker from Summit Racing - I'll put *that* on it - HA! Graupner doesn't come with a Summit sticker does it. (oh - I gotta grow up - maybe tomorrow ;-)

[@Migueldeservantes]

Mennnnn.... so far they haven't one of those tutorials fo every radio but for futaba, there is none

[@mauryasteeltraders6178]

How to throttle calibrate 4 esc's at a same time using flysky fs i6 transmitter if anybody knows about it then please reply me

[@Lan1ine]

Hey y'all should put out the vtol Guinea pig

[@route66flyer29]

Can you do this mix on a FS-i6?

[@rockjano]

YES you can ( a lot more easier) I did it...

[@route66flyer29]

Thanks Banati

[@rockjano]

Look my post I wrote it down...

[@FPVCustomsDE]

almost no one in germany actually flyes in mode 1 ;)

[@DaynHolz]

That´s what I tought.

[@eliasrenner555]

I'm using mode 4 for planes and mode 2 for quads :D

[@DaynHolz]

You are 100% crazy! :D

[@boy6named6zoen6]

the old plane guys do i think. from the 3 instructors at my Heli club 2 of them fly mode 1 and that are the older guys. the third one is my age and flies mode 2. they teach you how to fly helicopters with a cable method and have different options from mode 1 to 4 but most of the new guys prefer mode 2.

[@boy6named6zoen6]

the old plane guys do i think. from the 3 instructors at my Heli club 2 of them fly mode 1 and that are the older guys. the third one is my age and flies mode 2. they teach you how to fly helicopters with a cable method and have different options from mode 1 to 4 but most of the new guys prefer mode 2.

[@andrewsrc7717]

Is Chad still with you guys?

[@totalminer2002doesMC]

I want a triangle plane, like the circle plane but a triangle!

[@jonathanamparo1792]

too bad im using old futaba 6ex, anybody knows how to do this.........thanx in advance for your help

[@kammelryder]

you can get a mechanical differential thrust using a V-tail mixer between the rudder and throttle.

[@dekutree64]

Thank you! I've been wanting to try differential thrust, but didn't think it was possible without an expensive transmitter. Never heard of a V-tail mixer before now.

[@jonathanamparo1792]

Master Kammelryder thanx for the reply. i think i will try that. I just dont know exactly how to program in the radio, and the exact throws. I will be trying this for my FT Sea duck. thanx once again

[@loganlewis8123]

finish the shinden plz

[@Damastel1]

Bring back the vigen

[@Lanzbik]

Yea

[@RCFlightReviews]

the viggen in still for sale. i doubt they will do another video though as it is so old. it was just rereleased in waterproof foam though!

[@Lanzbik]

+RCFlightReviews omfg yessssss I can finically fly it in the snow!!!

[@sajivshah5502]

can u do a video talking about your tein bloody baron. Like if u want to see this

[@sajivshah5502]

twin engine bloody bsron