The EDF Tricopter !

Welcome into my new project,

You can directly watch the video here :

or

See here below the detail and the steps I had to go through and watch the video later (you'll find it after everything).

The choise is yours !

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Alright ! Time for some fun !

The aim                              .

eum... Put an EDF ? On a tricopter ? I'll use my "old" tricopter I named the "Zombie" /you want to know why Zombie ? it was dead, crashed. But it came back from the dark, creepy and gloomy world of the crashed copter and is still flying\  based on the RCExplorer.se tricopter scratch builded in this FliteTest video. The EDF I'll be using on 4s is a 64mm 3500kv EDF with a 35A ESC (kit from HobbyKing).

Nice, isn't it ?

Mounting the EDF                              .

I first take some mesurement to have a fairly idea of the dimensions I'll be using later to make the plans.

Then I make the plans for the mounting stand.

I next pin the plans on some 5mm plywood and trace them out.

/I know the wood plates are dirty. It's because those are the one I use to drill holes, solder stuff and cut everything :)\

Just a little test fit before adding a small slot with a little saw so the EDF can slide in.

As I don't have access to a lazer cutter or a better tool, I cut it with my Dremel. For the inward parts I use a special /special because I don't know the name of it !\drill bit to "trace" over the line I had to cut again and again till it is cut /and it's long !\.

I also use a Hobby knife to carefully clean all the slots.

I said CAREFULLY ! Unbelieveble...

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If you do cut yourself, please follow the following steps :

• Do not cry        /Alright, it's okay to cry, even if you try to be manly\
• If the cut is deep /like you can see the bone underneath\ call the 911 if you are in the US /lucky you !\ or 18 if you are in France /like me\ 112 in Europe, or just go to a hospital.
• If the cut isn't too deep, but you are giving a blood bath to your project :
• Clean the wound with 90° alcohol or special bacitricide stuff or even with perfume if you have nothing else.     /no it will not hurt nor sting, trust me\                /It does sting ! How can you trust someone that                                                                                                    said to cut carefully something and still cuts himself ?\
• Apply a bandage. /plaster ? stupe ? I'm using what Google trad is giving me! \
• Check if your vaccin are up to date /you don't want tetanus, trust me on this one\
• If you can, just call : "MOOOOOOOOOOOOOOOM !"

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 "This medical interlude was brought to you by 2ma inc.   2ma pharmaceutic, for a better world "

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Ok, back to the serious work !

After a test fit with all the pieces all together and the EDF unti in it, I just check how it will look like on the tricopter, if the dimentions are ok and if there is enough place between the back of the EDF and the top of the box.

And I looks greaaaat.

Mounting the EDF ESC                             .

I want to place the ESC neatly but this one is huge next to the ESCs I usually use. As you can see there is a little space in between the two plates, underneath the EDF. /What a coincidence !\ and it's just the perfect dimention to fit the ESC in /The truth is that it's for real a coincidence\.

It fit perfectly in, I just have to add some holes to let the air flow pass and cool down the ESC and glue with CA all the pieces together.

Mounting everything on the tricopter                               .

To add the EDF superchargerofthesuperspeed on the tricopter, I chose to use the screws holding the front of the camera tray and the one that stop and hold the arms in place. Unfortunatly I completly misjudge the holes position for the back screws /those which hold the arms in place\ so I have to redo it but this time I directly drill it using the holes of the plates.

 Now that everything is in place, I just need to :

• solder a XT60 for the EDF ESC
• connect the ESC servo lead on my receiver /I'll use the 6th channel\
• glue the EDF unit into the stand before I forget to do so /Please, remember it to me before I do forget !\
• programm the taranis
• fly the crap out of that thing /might be easier to say than to do...\

Programming the Taranis                              .

    This is the part I was the most afraid of. Thank to the Painless360 youtube channel and his playlist on the Taranis (I have to adress him big thank you /THANK YOU !!!\ because without his videos I couldn't have made it), I managed to program my radio as I intended to.

    Some other build I've seen where using complicated mixing /it's complicated for me !\ to have the copter in auto-level mode and use the throttle to control the EDF. With that mode they are using using the copter like an airplane. /Which is great by the way, I'm not judging. Peace !\ I want to have full control of each channel. As shown on the schema below, I'll be able to fly in two modes :

1. Auto-level mode : The copter is alway horizontal, I control the speed of it with the EDF by the slide on the left side of the Taranis. Turning should be done only using the yaw and if I need to do hard turn I can also add some ailerons. This mode able me to fly fast foward and to control at the same time control the altitude of the copter with the throttle. It means that I can be go fast foward and punch hard on the throttle to rapidly gain altitude, or managed the throttle to do reaaally low fast flying.
2. Accro/crazy/insane/expert mode : No stabilisations ! I mean, I don't really have an idea of what it would looks like. I think it will be great for acrobatics, flips, rolls and great punch foward with the EDF. /Honnestly this is not the mode I'll use first\.

/Lets switch on the Taranis !\

"Welcome to taranis"

My first aim is to program the radio so I can control the EDF using the left slide. As you can see below, in the inputs page, I add a new input called EDFi controled by the LS (left slide) with 35% expo. Then I add on the 6th channel of the mixer page the output comming from the EDFi simply called EDF. The EDF unit is then controled through the 6th channel on the receiver.

I also need a kind of throttle cut for the EDF so I won't activate it by mistake /I did and almost destroyed my mini tricopter and my computer... The EDF is powerfull !\. I'll use the SA switch. If the SA switch is down, I want the EDF to be inactivated. Middle position is EDF activate and the copter in accro mode. Finally, up position is EDF on and the copter in auto-level mode. The auto-level mode is controled on the 5th channel. To program the EDF throttle cut I add in the Special Functions tab a new special function. When the SA switch is down, the function override the channel 6 /which control the EDF\ to -100. It means that whatever I do, the value on 6th channel will stay on -100 and the EDF won't spin. I also add a function play track so I know what is going on.

When the SA switch is in the middle position, I just have a track play and I can control the EDF with the LS.

With the SA switched up, I override the 5th channel so the autolevel is activated on the KK2 board. I also use the SG switch to activate/ desactive the auto-level without touching the EDF so I can fly the tricopter normaly.        /I'm not sure it will happen again !\

I also want to arm/disarm the KK2 board in the Naze32 style using a switch. Unfortunaltely with the KK2, the only way to arm it is no throttle and full right on the rudder /or left. I never remember, let's say full right\.The solution is in fact really simple. I just need to override the throttle and rudder channel using a function.

I use a new function : when the SG switch is in the middle position, nothing happen.

If I flick SG up, I override the throttle (CH1) to -100 (no throttle) and the rudder (CH4) also to -100 (full right). This combination reproduce the arming sequence needed to arm the KK2.

To disarm it's almost the same. I flick SG full down. It still override the throttle to -100 but this time it overrides the rudder to full left (100). 

/I think I can't do anything more here \

Test Flite                    .

/Hahaha ! Test Flite - Flite Test ? Ok I stop there\

This part might be a little boring by just reading my crap english and will surely be more interesting by watching the video. If you click here, you'll directly land on the test flight footage !

/But if you want, you can stay with me ;) \

Alright to test the EDF tricopter I went at my usual place. Unfortunatly I think the field is a little to small to test the max speed of it.

I first discovered that my PID settings were actually not that bad and just for that, I was already really happy /PID tuning is so... I think most of you understand what I mean ! There are people like David Windestal that know how to do it, and people like me, just trying and trying and trying...\ 

The EDF gave a great punch to the copter. The first try was only 10% of max EDF thrust. I mostly flew it at 20-30% max thrust but the acceleration was high enough to fold back the right arm /or maybe the screw weren't tighten enough ?\.

The worst problem was the battery. Each motor can draw maximum 20 A and the EDF unit 35 A. It means that the hardware can draw at the max roughly 95 A. The battery I used was a 20C (30C at burst) 3000mAh. This one can give 60 A and 90 A during the burst. This explain that I discharged the battery in almost one minute with the EDF at 20% max thrust. This is also why when I activated the EDF, the copter tended to loose altitude.

Otherwise the copter flew remarkably well ! I could control it with only the EDF, the throttle for altitude and the yaw to turn.

/I'm loving it !  Tadada da daaaaa ! M\

On the second day I really wanted to fly it FPV and push a little the EDF. Unfortunately, right after giving 70% of thrust, the EDF unit slided off the mount... /I told you to remind me that I had to glue it in place ! I trusted you ! Oh ? it's a revenge for "the 90° alcohol will not sting" ? Alright then, I think we are now even !\

Really pixelized picture. On the left, the EDF unit. On the right, the stand where the EDF should have stayed.

/Bad, bad EDF\

Conclusion                               .

I really like this project. Building it was great and flying it even more. The next step will be to get a better battery so the copter will have better performance and longer flight time. At this point I'll be able to do a speed test flying FPV and hopefully do accrobatics.I'll do another video with the new perfomance and the speed test.

I really hope that you enjoyed reading this article as much as I enjoyed writting it for you ! 

Stay tune for, I hope, more and more project of this kind. If you have ideas for me, subscribe on my youtube channel and leave a comment on the EDF tricopter video. If you think adding an after-burner on it is a great idea, just say it. If you think I should't put my house on fire, please, tell me :D

Again, thank you for reading me !

/I think I did promess you that I'll put the video link here. Enjoy !\