Tarot T18 Octocopter

By Herrminator117 on Mar 23, 2016

8  3,290  30

EDIT Jan 2020: Hello RotorBuilds!
I'll be honest, forgot I had made this page almost 3.5yrs ago now haha! But, as many of you know the T18 frame and Octo's in general are not common and finding any info on them is wonderful. So I am going to try to update a little bit on it! It flies wonderfully and I flew a lot while I was in college, especially for promotional events, nothing attracts people like a flying lawnmower. The FAA rules have changed so much and I have yet to do the Part 107. I am nearly to my PPL so I am just trying to figure what will be the best path. ANYWAYS, enough about my life.

What people care most about are the battery mounting plates. They are completely custom and made by me for this frame. I don't have the STLs out in the public, but do sell the mounts or can sell GCode for you to print your own. I have multiple versions of the battery plates. A clean version that doesn't have the mounting plates for the legs, and one with. (I will post some photos of the mounts in the gallery) I also take commission to edit the file if you wanted a different landing assembly to attach to them. You can direct message me here, leave a comment or find me on Reddit at r/Expensive-Hobbyist and dm me. Reddit may be the easiest way.

Lessons learned on this copter.
1) Buy the best batteries you can afford. These batteries do NOT have a high enough C rating to keep up with how quickly this beast drains them. I have puffed all 6 of my original batteries and they are the reason I have spent the most time on the ground.
2) Don't autotine your PIDs: I have seen plenty of people struggle with this. I haven't seen a controller that autotunes large octos perfectly yet, and typically they introduce more issues than they fix. There are an immense amount of Youtube tutorials on how to manually calibrate your PIDs. It is a lot more work and time, but much more worth it.
3) Keep a good wiring diagram and be as NEAT as possible when wiring. If you ever have to do maintenance, not knowing where your wires are going is a nightmare. Label all your wires and to which arm they go.
4) Buy the best FC you can afford. The OG pixhawk is fine, but is not nearly robust enough for my liking. I want to update to a full DJI kit with triple GPS, but I don't have that kind of money.
5) TAKE. THINGS. SLOW. Realisitcally this copter is a 12-15lbs flying death machine that will cost you anywhere from $2k to $5k. Be smart. Don't yank it off the ground in the first day. Figure out its ticks and its problem areas. With its weight, it does not fly like a sub 2 pound quad. It'll twist and turn if your PIDs are off. Be a skilled pilot and practice on other frames first. I realize this was my first copter, but I do NOT recommend it. It was a terrifying thing to learn on.

There was a lot of other equipment that was added to the copter after the main flight components. So if there are any other questions please feel free to reach out. Good luck and happy flying!

Original post below:

So I just got air worthy two weeks ago and have flown about four times. Its currently grounded due to not having a charger with the ability to charge my 10,000mAh batteries.

But a little background, Ive never built a drone of any type, or even something RC. I do have a small RTF racing drone that I taught myself to fly on first before I attempted this. And I spent the better part of two years doing a lot or research and saving my money.
When I started out with my research, so many people are quick to shoot people down who want to start with an octo, with good reason! But I don't like being told what I can't do, so here we are!

In the future I am working with a friend who is in college for Cinematography and we are making a company to do aerial footage. (Yes I am aware of the 333 Exception and being a pilot and such) Our primary camera/gimbal will be a Ronin M w/ a Lumix GH4 and we may get an opportunity in late summer to fly with a Red Epic Scarlet! But I have a lot of testing before we get there!
Comments, suggestions, and questions are always welcome. Thanks for looking!

Frame: Tarot T18
Flight Controller: 3DR Pixhawk w/ UBlox GPS
Motors: Tarot 5008 340kv
ESC's: Hobbywing 40a
Props: Quanum 18x5.5 CF
Batteries: 4x Multistar 10.0A 6s Lipo
-2x Zippy Flightmax 5.0A 6s Lipo
Retracts: ARRIS x5
Tx: Taranis+

Max Flt Time: TBD (~20min no payload, ecalc)
Max AUW: TBD (~6783g, ecalc)
Max Payload: TBD (~11228g, ecalc)



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mariamobied   10 days ago  

Hello! this post is really helpful! I'm also planning on building a tarot T18 for a project and I have some questions, I am confused about the PDB connections and how is it connected to both the pixhawk and the batteries, and why are you using 2 batteries instead of one.
I would really appreciate the help and thank you so much!

carrottop432   Oct 16, 2020  

Awesome job on the build, especially those custom plates! I have a T18 that I've been working on for a couple years now. Flew it some, crashed it once (my fault). Work has kept me too busy to do much with it, but I've had a little time to work on it more lately. I may throw a build up on here about it. I'm looking forward to future updates on your build!

bentheboss   May 13, 2020  

what connectors did you use for the batteries?

Beeup   Apr 30, 2020  

I have a T18 that I completed a couple of years ago, I am interested in your battery mounts. Please send info. Thanks

bentheboss   Apr 23, 2020  

Hello can you please send me the battery mounts STL FILES? And yes I have a 3d printer...

Herrminator117   Apr 23, 2020 

I don't put my STL's out in public anymore as a few of my designs have already been ripped off and claimed as others work. Specifically with these battery mounts I have hours of prototyping and revisions made to them and keep them close to the chest, so I apologize.

I will message you with specifics on how I can help you going forward.

bentheboss   Apr 23, 2020 

I'm willing to paypal you? I'm 14 years old building this project with my dad :) I have no intention of ripping you off...

bentheboss   Apr 22, 2020  

Thank you for all the great information. I ordered the parts and now all I need to do is order the lipo battery! I was thinking of a 6s 22,000 MAH 25c TATTU smart battery (https://www.getfpv.com/tattu-plus-22000mah-22-2v-25c-6s-lipo-smart-battery-pack.html) Would this work?

Herrminator117   Apr 22, 2020 

It definitely should! It also has a great weight-to-capacity ratio compared to what I used to run.

My only concern with single large batteries are how do you mount it. I don't know what your main use for the T18 is, but with a large pack like that you're pretty much forced to sling that guy center underneath the main plate where a gimbal would go. Now if you're not using this for a camera and don't need to worry about a large gimbal then that isn't an issue!

I went with two larger packs and then balanced them out on the arms for weight distribution, because I had no other place to put those bricks!

RickyT   Aug 06, 2016  

I am starting a T18 build, I pretty much have all the parts and electronics. I noticed your retract/battery mount you made, how did they perform?

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RickyT   Sep 21, 2016 

Are you selling these mounts or is there an .stl file available? Tks

steckrca   Jan 17, 2020 

Did anyone ever find these mounts? I've been searching for a while and have come up with nothing.

Herrminator117   Apr 21, 2020 

Hey Steckrca, sorry I missed this! I updated the page and forgot to reply to you. I still have and sell the original mounts, you can read about it in the "About"

bentheboss   Apr 16, 2020  

Hello I'm planning on building this octocopter and I was wondering what all the upgraded components are?

Herrminator117   Apr 21, 2020 

Overall upgrades were the retracts which were :
ARRIS servoless retracts
Custom battery plaforms (which the retracts were attached to and both were removed when collapsed).
I acquired my HAM radio license and upgraded to a 1.3GHz video system

Pretty much everthing is as stated here. Lots of little odds and ends were custom from my 3D printer. Such as how I mounted things: pixhawk anti-vibration mount, vx and tx mounts were all custom. Gimbal mount was all custom. However, you will run into any of those when you are building your own drone.

bentheboss   Apr 21, 2020  

Please what battery are you using now?

Herrminator117   Apr 21, 2020 

I unfortunately have not been able to fly with this guy in some time! I am active duty Air Force and by nature live near airports. I used the 10,000mAh batteries listed until they died on me (need a much higher C) The T18 has been wrapped in packaging for the better part of two years (you can see it in the photo with the PDB)

I was looking for new batteries a little bit ago. I would suggest getting two 10000mAh 6s 25C (MINIMUM) like these: https://www.genstattu.com/tattu-10000mah-22-2v-25c-6s1p-lipo-battery-pack-with-as150-plug.html

bentheboss   Apr 17, 2020  

What PDB did you use?

Herrminator117   Apr 21, 2020 

Funny enough I actually utilized the built in PDB that the T18 had. The Male and Female bannana plugs with the revolver holes for soldering in the wires. I soldered in all my wires into the fram and then I purchased a secondary spare and inverted it, 3D printed a cover and then soldered in XT90 plugs for my batteries and a XT60 to power the Pixhawk.

In hindsight I would add a switch somewhere in this system, because it regularly arcs on connection/disconnection which is bad for the LiPo's. But it works.

juissi88   Jul 06, 2019  

Hi. where you buy battery mounting plates?
what is your pid settings?
This is my project and battery is too close from pixhawk

bentheboss   Jan 05, 2020 

up and running?

Herrminator117   Jan 20, 2020 

Hey there! Sorry on the delay, the battery mounts were custom. 3D modeled and printed by me. I have sold them in the past to people who have DM'd me if that is something you are still interested in. I have since added a couple of renderings of what the parts look like, along with some better photos of them on the copter.

bentheboss   Jan 05, 2020  

still running?

Micky6934   Feb 25, 2018  

Hi Mate i have just built a Tarot T18 with pixhawk board just wondering what your PID settings are as my Pixhawk board is not getting a good autotune and it is gettings wobbles after a autotune.

Whiffles   Sep 21, 2016  

What sort of flight time do you get with those batteries? That's a lot of milliamp hours!

Herrminator117   Sep 21, 2016 

Yeah 20,000mAh is a lot haha. But it will get me about 20-25min of flight w/o payload, and 10-15min flight w/ payload. (Payload being a Lumix GH4 and a DJI Ronin MX)

Whiffles   Sep 21, 2016 

Do you have any footage online from this? I'd love to see how it turns out.

Whiffles   Mar 23, 2016  

Very cool! I think that's the largest build on the site. How well does it fold up? I imagine that's going to take the whole trunk!

Herrminator117   Mar 23, 2016 

It honestly fold quite well! Ill add a photo tomorrow, but with blades on its dimensions are 70in long and 12in wide and 5in tall, folded up that is. So we use an suv and fold the seats up!

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