Tarot X8 Octocopter Build Diary

Here's a little section of anybody who manages to find a really odd ball model that doesn't fit into any of the other catergories.

Re: Tarot X8 Octocopter Build Diary

Sponsor

Sponsor
 

Re: Tarot X8 Octocopter Build Diary

Postby Mark » Mon Jun 08, 2015 1:58 pm

Christmas come early :D
Cheers
Mark

If you nose runs and your feet smell, you're upside down !
User avatar
Mark
Site Admin
Site Admin
 
Posts: 15928
Joined: Wed Aug 26, 2009 10:44 pm
Karma: 409

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Mon Jun 08, 2015 6:23 pm

Mark wrote:Christmas come early :D


Indeed it does Mark, indeed it does. :D
Now I know how it feels to have Christmas with mid summer temperatures. =-)
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby casper » Mon Jun 08, 2015 7:21 pm

SDeath wrote:A table full of stuff, let's get building.
Not everything fitted on the table and I haven't received everything yet so I'll see how far I can get but it looks like this week is filled with building.
Great timing as I am off these 5 days. =-)

Image

Nice looking parts SD :mrgreen: a nice week off building
My Honda MP4/4 Build Diary
viewtopic.php?f=80&t=5208
User avatar
casper
General
General
 
Posts: 12889
Joined: Tue Jun 07, 2011 6:23 pm
Location: North Wales
Karma: 366

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Wed Jun 10, 2015 2:40 pm

After a bout 2 days of building (not all the time as some critical parts that haven't arrived yet don't allow me to go very far), but still I am happy with the progress, allows me to take things slow and rethink things before I do them. =-)

These days have mainly be about unscrewing everything they did in the factory and making sure there is loctite of every screw that goes into metal, if you don't they will vibrate their self loose and things will fall off, not good!! I also replace all the screws that cam with the frame with better screws that have a bigger head, the originals looked a bit flimsy, only a few € so no big deal.
The other major task at hand was soldering, the frame comes with coax type cables that you connect to the PDB (Power Distribution Board) and you need to solder these to the ESC (Electronic Speed Controller), as I bought some extra capacitors to make sure the ESC don't get damaged by unclean power, because of the length of the cables, I also need to solder these in between the coax cable and the ESC.

Some pictures with some explanation of what they show, first off (no I am not backing them) a picture of all the ESC soldering and cables ready that go into the arms (almost), the red and black servo extension cable you see is for the LED lights on the end of the arms, I test run a few of them yesterday and forgot how bright these babies are, they will hurt your eyes after a while even in bright daylight.
The black and white twisted cable is the signal cable going to the ESC, this will connect to the flight controller on the other end and will let the ESC know how fast it needs to turn.
The black metal parts are the hinges the arms mounts to, and it will be mounted to the frame, the arms on this UAV can hinge downward for easier transportation.
Image

I still haven't received the heat shrink to go over the ESC's and capacitors, so for now with this I can't go any further, the arms are aluminum so isolation is required against short circuits.

Here you see the ESC and the capacitor array up close, the idea is to solder the capacitors as close to the ESC as you can, but because space is limited in the arms, they need to go in sideways, with some heatshrink this should just fit in, if things rattle I'll add some foam to the ESC to make sure they stay put and don't cause vibrations, as vibrations is most important to minimize these, they interfere with the flight controller.
On the right side of the ESC you see the 3 bullet connectors that the motors connect into.
Image

This is how things look now, first thing I did was mount the landing gear and get that to work so it can stand on it's feet, they go up sideways so this takes up a lot of room.
You can see the 8 arms laying between the landing gear, and 3 of the 8 motors attached, the other motors haven't arrived yet but probably will tomorrow.
The round carbon fiber plate is the lower of the two frame plate's, almost all electronics will be mounted in this area. In the middle you can see a black box with connectors, this is the PDB, this is where the ESC's coax cables plug into, it is connected to the main flight batteries. I also added some stickers with motor numbering and which way they should turn, they need to follow a certain pattern.
In the back on top of the white box you can see the the top frame plate, the red thingies, can turn and lock the arms in the up position for flying, it's a nice system, very solid.
Image

This is the motor mount, the motor screws go in from the bottom through the carbon fiber plate into the motors. In the red pieces you can see holes, this is actually very clever, it diverts some of the propeller downwash into the tube for cooling the ESC, and I've heard this actually works really good.
Image

Here you can see on of the motors mounted to the mount, the carbon fiber plate is sandwitched between two rubber grommits, this is to help dampen motor vibrations.
Image

One thing I have also done is make a bracket to mount one of the camera's, this is under the bottom plate all the way up front. Not sure yet if I will keep it like this, I might point this one down, and add another one on to of the top frame plate facing forward, and then with a video switcher switch between the camera's if I might need to find a good landing place. But for now I will keep things like this.
There will be a OSD (On Screen Display) print added to the video feed as well so having both video feeds switch and both show the OSD information would be something I need to look into further.
Image


So far I really love this build, everything is solid, and made with incredibly tight margins, but still everything works, it is all machined metal pieces, so not casted like our partworks cars, so much better quality.
Everything just fits great, I have not once had the idea I might strip something. The hinges are a tight fit into the arms, but still I was able to press them in by hand, I've read some reviews that others had to use a rubber hammer to pound them in, but I haven't seen this problem, the trick I guess is to properly align the pieces and apply evenly pressure.
I have also tuned in all ESC's, this means letting the ESC learn the throttle range, this is how you do it, you take each of the ESC assemblies you seen in the first picture, then connect this one up to the PDB, the receiver and a motor. Turn on the transmitter and apply full throttle, nothing happens as the receiver is still off, you connect the flight battery to the PDB and this powers on the receiver and ESC, the motor will beep twice to indicate a full throttle position is found on startup, take the throttle on the transmitter to the down position and the motor will beep once more, the throttle range is learned and when you push the throttle leaver upward the motor starts to spin.
!!!!! ALWAYS DO THIS WITH PROPS OFF !!!!!
Take off the main flight battery after you've done some test power ups, and then disconnect the ESC assembly and repeat this with the next assembly until you are done.

I hope you like my update I like to explain how things work, hope you don't mind.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby Mark » Wed Jun 10, 2015 5:17 pm

Great update SDeath. It's going to be a real beast !!

Always interested to hear how things work. I work with motor control systems (amongst other things), so it's interesting to see how the technology is applied in the hi-tech hobby world.

Ducting air from the prop wash for cooling is a brilliant idea !! It really is free cooling. The lift comes from the props interaction with the air (Newtons 3rd law) and what the air does after than has no effect on the lift. It will affect the motion of the 'copter if it's still in ground effect, but that is turbulence, and explains why any sort of helicopter is more stable once it gets well clear of the ground. If I recall, ground effect lasts for the height equivalent to about the diameter of the rotors so will be much less for a quad/octocopter than a traditional helicopter. In fact its probably none existent as you have long u/c legs. I stand to be corrected on that, having never flown a quad copter. Well, not yet anyway !!
Cheers
Mark

If you nose runs and your feet smell, you're upside down !
User avatar
Mark
Site Admin
Site Admin
 
Posts: 15928
Joined: Wed Aug 26, 2009 10:44 pm
Karma: 409

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Wed Jun 10, 2015 6:30 pm

Mark wrote:Great update SDeath. It's going to be a real beast !!

Always interested to hear how things work. I work with motor control systems (amongst other things), so it's interesting to see how the technology is applied in the hi-tech hobby world.

Ducting air from the prop wash for cooling is a brilliant idea !! It really is free cooling. The lift comes from the props interaction with the air (Newtons 3rd law) and what the air does after than has no effect on the lift. It will affect the motion of the 'copter if it's still in ground effect, but that is turbulence, and explains why any sort of helicopter is more stable once it gets well clear of the ground. If I recall, ground effect lasts for the height equivalent to about the diameter of the rotors so will be much less for a quad/octocopter than a traditional helicopter. In fact its probably none existent as you have long u/c legs. I stand to be corrected on that, having never flown a quad copter. Well, not yet anyway !!


Yeah it scales with the helicopter, and I will be long out of the ground effect with this rig. Don't know exactly the height of ground effect, but as I work with real helicopters all day I am not unfamiliar with the term. =-)
Also there is another phenomenon called, settling with power or also known as vortex ring state, this happens when you decent through your own rotor turbulent air, and causes the rotor blades to loose lift and can be a huge problem if you don't have enough room to get out of it. Kind of like a stall as the blades won't have enough air to work in. You'll get a donut of circulating air around the rotor blades.
Also what people mostly don't know is that a propeller or rotor blade don't cushion on air, they are actually pulled up, by the low pressure it creates above the blade/wing.
This can also happen to RC helicopters and multirotors as this applies to all aerodynamics.

A fun thing they did in the past with ground effect is created a boat/airplane that flies above the water about 5 meters or so on the ground effect cushion of air. Really cool and more efficient than boats, less drag.
This is a Russian example: Image
Other examples: https://www.google.nl/search?q=ground+effect+boat&biw=1680&bih=925&tbm=isch&imgil=GTsfi1LAy6me2M%253A%253Ba6bHEYTnzkLnEM%253Bhttp%25253A%25252F%25252Fwww.australianhovercraft.com%25252Fhovercraft_photos.htm&source=iu&pf=m&fir=GTsfi1LAy6me2M%253A%252Ca6bHEYTnzkLnEM%252C_&usg=__H4J685lBzQs-mXxqt5eYESdw82o%3D&ved=0CCoQyjdqFQoTCJnE9a_ThcYCFYSOLAodbq0D9g&ei=3XN4VdnhOYSdsgHu2o6wDw#tbm=isch&q=ground+effect+boat
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Wed Jun 10, 2015 6:37 pm

I like how this frame design houses the ESC's in the arms, really makes for a cleaner build and saves space in the main frame.
Make sure when anybody buys this frame, the ESC's aren't too big to fit the arms. The 50A version of my ESC's include a heatsink that causes it to be too big for the arms to house the ESC's there.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Fri Jun 12, 2015 3:08 pm

Well this week has been great, I've had so much fun building this, it's so nice to put something together that just works. :D

So today's update, yesterday has been all about the arms, as the remaining 6 motors and the heatshrink came in, what a timing that was. EM you can learn from that. ;-)
So to show you a bit of what has been done some pictures.

This picture shows you the ESC with extra capacitors that I soldered a few days back, next to it is the heatshrink, it's a hollow sleeve, although flat in the picture, you put the ESC in and apply heat with a heat gun like a paint gun or hair blower, the paint gun works better, but use it on the lowest setting.
Image

After the heat treatment it looks like this, added a zip-tie to secure the wire in place and this allows me to pull the wires from the end:
Image

All 8 done:
Image

And after that it takes about 30 minutes for each arm to put them together, and loctite all screws and mount the arm to the frame and test functionality and rotation.
What you do is put the wires in the tube on the frame end until the ESC come out at the motor end, push the arm hinge all the way in the tube on the frame end, then mount the motor to the motormount and connect the 3 wires from the motor to the ESC make sure the motors turn the right way if not swap two of the 3 motor wires in the ESC and it will turn the other way.
Then I fix the wires to the motormount and guide them into the arm, I used some foam to secure the ESC inside the arm into place so it can't move/rattle. Secure everything with scvrew and make sure to loctite them all up.
Here you can see the motor on the arm and the wires cover in heatshrink to protect them against chafing:
Image

I mounted on each arm one of the 3W LED's and make them stick out a bit, the rotor downwash will help with cooling these LED's as they might get a bit hot, they are so bright. =-)
I used some double sided heavy duty tape to secure them.
Image

And this is how she looks now:
Image
All arms spread wide, so I had to mount the top plate just for display purposes the locking mechanism for the arms is on the top plate, so I could see and get an idea of how much space I have and think about placement of all electronics.

Didn't do much today, I had to take care of some household things, the wife is away for 2,5 weeks so I had to do some cleaning.
But today I did tidy up some of the wiring that comes from the motors to the PDB, it gives me a better idea of room I have and what to put where, I will have one Video transmitter that I will fix to one of the arms and one telemetry transmitter that will go on the arm on the other side, inside will be 2 BEC (Battery Elimination circuits, basically a voltage regulator), the radio receiver and the voltage regulators for the LED system.
On top of the frame will be the flight controller and the parachute system, and the separate battery for the Parachute system. I'd like to have a backup for almost everything to allow me to deploy the parachute in case of problems, so extra battery and BEC voltage regulators.

Image

The way I tidied up the wires I still have quite some space in 4 sections of the 8 available between all the arms, sections where stickers 1 and 2 and 7 and 8 are is where I have quite a lot of room to place stuff.
i'll have to see how I can place everything most efficiently.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Fri Jun 12, 2015 3:16 pm

ow and from arm tip to arm tip is 113cm. :shock:

With the props, about 30cm will be added to the full width of this beast.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Fri Jun 19, 2015 9:16 pm

Just an update on the build, been working last weekend and a few days this week so I didn't build everyday.

But I am making good progress.
Last few days I have been routing all wires and been busy placing all devices inside the frame, and I had to cover all wires with wire mesh to protect them.
Which is a bit discover and learn, and boy did I learn, not the hard way luckily. Nothing is broken. =-)
So bottom plate is covered with all power related devices for LED lights, backup power, main power, and the receiver for the controls.
On top of the drone is the parachute launcher and the flight controller with GPS and the battery that powers all electronics and parachute.
The motors, the LED lights and the Video transmitter will be powered from the flight batteries.

It took me some time to think about the best way to power it all and provide with as much redundancy as practical.
When the flight batteries die I want to be able to launch the parachute. But there are still things that could cause a potential crash, but those are hard to solve without taking so much extra devices on board, it'll be very impractical.
So I fly two main flight batteries and a smaller electronics battery for redundancy.

It's too dark now to make pictures of the rig itself but I will do so tomorrow, I will have to take the top deck off, which I have done multiple times last few days.

There where few things that I encountered when I put the top frame deck on the bottom one to connect them all up (I installed each deck separate), the LED lights started to blink when I powered everything up. Sp it must be a power issue I thought, so I tried to find the culprit by disconnecting things one by one until both deck where disconnected electrically from eachother still the LED's blinked with both decks powered, eventually I discovered the 433MHz telemetry transmitter being the one to cause the blinking, so it was a wireless interference with the LED drivers. :doh: Took a while before I figured that out.
Today I fixed that problem for 95% by wrapping the LED drivers in anti-static bags, the ones your HDD come in. These bags are coated and actually conduct on the outside of the bags to prevent any static electricity to enter the inside of the bags, so they deflect static electricity. This seems to improve things and only a little bit of blinking can be detected, and I have a new cable coming tomorrow so I can put the transmitter a bit further from the frame on the arm.
Then another problem I found yesterday, the OSD seemed to quite out after a second or so, this eventually was a setting, you can switch between two OSD setups to overlay different info on the video screen, the 2nd screen had no overlay items so that's why it looked like it stopped working, this doesn't look something I will be using so I disabled the switching for now, now I know how it works I can enable it back and setup so it works from the transmitter.
I did make a picture yesterday of the Video screen with OSD overlay:
Image

After fixing all these issues today I had some time to work on the flight controller setup and calibration. All sensors on board need to be calibrated, this means the gyroscopes and the magnetometer in the GPS need to find their offsets. This means setting the frame in certain positions to calibrate the gyroscopes and turn the frame in several patterns to calibrate the magnetometer.
You can do this using the telemetry transceivers, there are two, one of the airframe (the one that interfered with the LED's) and the other connected to my laptop with a USB cable.
The software package to do this with, anything flight controller related, is Mission Planner, this is a screenshot with Live data from the drone:
Image

You can see my house, the one with the solar panels on the front and back, this was inside my house so the GPS isn't very accurate, and I only had contact with a few satellites, but the position is spot on in the screenshot actually, but it wanders all over the place while inside the house.
Mission planner can also be used to plan missions (no **** Sherlock) you can let the drone fly the planned route fully automated if you want and it can land itself.
I also connected the retract landing gear to the flight controller and got that working as well, so I can control them by hand and fully automated bu the flight controller.
I'll make a video tomorrow of the retracts working, and the pictures of the frame as they are now.
Still lot's of small things to do and fix to the frame, lot's of wires to fix up. And eventually I also have to fix the parachute loom to the frame, but this will be about the last thing I will do.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Sun Jun 28, 2015 1:15 pm

A new update of my build, getting ready to do my first test flight tomorrow.
I did a test launch of the parachute system yesterday in my back yard, on the ground and it was successful, see the video on this link: https://www.youtube.com/watch?v=GBw4b9TUGkw

And I also tested the landing gear last week and made a video of it's operation: https://www.youtube.com/watch?v=SPVWtgayVMU
It's now fully routed through the flight controller, meaning it can automatically lower the gear when performing a landing or flying an autorouting. But also manually obviously.
My transmitter is programmed that one switch stops the motors, launches the parachute and lowers the landing gear in case of an emergency.

This is how the final cable mess looks like in the bottom deck:
Image

All cables that could potentially chafe against carbon fiber or metal parts are protected with wire mesh.

And this is the top deck with all equipment mounted on it:
Image

Image

The GPS receiver is on the pilar in the middle and the flight controller is on the vibration dampening mount, the blue round things are the dampeners.
Inside the launch tube you can see the negative end with the fuse looped around it, it goes below the piston to the positive terminal where it is also looped around it, when power is applied to both the terminals the fuse creates a short and will melt, releasing the piston ontop of which the parachute is:

Image

The parachute is connected by 4 paracord wires to 4 of the 8 arms, those 4 cords are tied to a ring in the C of G of the RPAS (Remotely Piloted Aerial System) and the parachute is mounted to that ring. The 4 paracord ropes are taped using some light tape to the side of the launch tube, to keep things from moving into the props. When the parachute is deployed the tape will rip off the tube.

Image

All props are now mounted too:
Image

Image

Tomorrow I will fly this beast for the first time.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby casper » Mon Jun 29, 2015 4:17 pm

good luck with her first flight SD
casp
My Honda MP4/4 Build Diary
viewtopic.php?f=80&t=5208
User avatar
casper
General
General
 
Posts: 12889
Joined: Tue Jun 07, 2011 6:23 pm
Location: North Wales
Karma: 366

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Mon Jun 29, 2015 5:01 pm

casper wrote:good luck with her first flight SD
casp


Thanks Casper,

I have already flown two flights of 10 minutes each and it looks like I can get about 15 minutes of flight time out of each flight pack.
And she flies great, and I still need to do a autotune flight, that means the flight controller will go through a series of movements to find the characteristics of the RPAS and make adjustments accordingly.
In stabilize mode it's very responsive, but there was still some drift to keep it into one place. In the Loiter mode it held position perfectly by using the GPS and barometer, and a more relaxt way of flying. Very gentle and calm.
See this short video we made: https://www.youtube.com/watch?v=eAR6lX7RO5E

I had some minor issues, the front camera vibrated a bit so it moved to point down. Need to make the mounting better.
And the OSD overlay didn't show any data on the 2nd flight so I need to troubleshoot why that happened. It was working but, it showed it was looking for data, but somehow couldn't get the datastream from the flight controller.
But these are minor things not flight critical.
Was a bit afraid/nervous it might flip on first takeoff, but luckily that didn't happen. Nothing fell off so that's good too. =-)

And some pictures of the bird in flight:
Image

Image

And with gear up:
Image

Image
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby Mark » Mon Jun 29, 2015 5:21 pm

Looks great ! You must be very pleased with her :D
Cheers
Mark

If you nose runs and your feet smell, you're upside down !
User avatar
Mark
Site Admin
Site Admin
 
Posts: 15928
Joined: Wed Aug 26, 2009 10:44 pm
Karma: 409

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Mon Jun 29, 2015 6:10 pm

Mark wrote:Looks great ! You must be very pleased with her :D


Yeah I am, it was a great build so far, next up is the gimbal to go below the RPAS. And enjoying more flights and fixing the minor problems I found during todays test flights.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby casper » Tue Jun 30, 2015 7:07 am

excellent project SD :mrgreen:
My Honda MP4/4 Build Diary
viewtopic.php?f=80&t=5208
User avatar
casper
General
General
 
Posts: 12889
Joined: Tue Jun 07, 2011 6:23 pm
Location: North Wales
Karma: 366

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Sun Jul 26, 2015 10:11 am

Small update on the build (turned out to be a big update), I will post some new pictures this week if the weather is good enough to fly.

I have solved the problems I encountered in the first flights and I have done about 10 flights in total now with it.
Flight time without gimbal was indeed about 15 minutes.
I weighed the octocopter and it weighs 7,5kg, without the gimbal an dSLR camera, that will add another 3,4kg to the weight so all up it will be 10,9kg with Nikon D300 dSLR and GoPro camera.
I have fixed the front FPV camera and included a vibration damper to it, now it's image is good enough to be used for FPV (flying through the camera's image).
This is how the FPV camera's image looks like now: https://www.youtube.com/watch?v=bhN9fQ7AUgk
The OSD problem was easily fixed by upgrading the firmware.
I have also performed the first autotune flight, in this flight the flight controller twitches the controls to each side and looks how fast it will respond and change the internal variables accordingly, I will see if I have the video of that flight and upload it tomorrow.

After that I have been working on the gimbal itself, pictures will follow as well tomorrow, it holds a lot of electronics as well so it was like a mini project inside the big project.
I also did a first flight with that, but we encountered some problems with that as well, the gimbal would shutdown after a minute or so in the flight loosing stabalisation of the image and control of the motors.
We where able to reset it a couple of times by landing it so here is a very rough, everything but perfect, example of the image stabalisation done with the GoPro:
https://www.youtube.com/watch?v=TTRTRg3eYCM
The dSLR and the GoPro are on the same gimbal so we can video and take pgotographs at the same time.
The flight time reduces to about 10 minutes with the gimbal attached.
The shutdown problem is hopefully fixed by re-balancing the gimbal and changing the stabalisation controller settings and adding ferrite cores around the sensor cables.

Another small problem was with the gimbal mounting to the battery tray, I used aluminum standoffs, but they stripped easily, so changed those for brass and they work perfect.

I also didn't have enough room for the gimbal below the octocopter, so I had to extend the landing gear struts, I ordered some heavy duty carbon tubing, to make them longer and upgrade to a higher strength carbon tube, the original was on the edge and I think it might have failed at some point in it's life. I extended them from 35cm to 45 cm, giving me enough clearance to land with the lens facing to the ground without damaging anything.
The landing gear system doesn't have a problem with the added weight.

Another major issue we had during this first gimbal flight, almost caused a crash from about 30 meter in the air. The battery tray to which the gimbal is also mounted hangs on a carbon tube that goes through sets of rubber dampers:
Image
Bu the dampers are to easy to be pushed out to the sides, so the problem we had that this came undone during the flight which meant the entire battery tray with batteries and gimbal to be able to move freely for about 15cm to front and back, when this came loose the entire drone shifted and turned obviously so I almost lost control, the flight controller was able to regain the control and keep the craft fairly stable, having to adjust all the time. So I brought it down with my finger on the parachute switch, as I was almost certain I was going to need it, but I managed to bring it down, but while landing there was another shift so the multirotor had some backward drift during the landing causing it to tip over on the back two arms. The propellers stopped in the mud, but it seems like there was no damage at all. Still have to do a post crash test flight without gimbal, but I couldn't find anything damaged, not even the blades or the bearings. So looks like I was lucky.
I fixed this ussue by using 3 zipties around each rubber damper, this seems to work fine, but haven't flight tested it yet.

I also made a rail system for the batteries so I can exchange the flight packs a lot easier.
I used velcro to fix the batteriues together and aluminum L profiles for the rails. I have one set of rails on the batteries and one on the battery tray. Drilled holes to them both and I can fix them together with a few bolts and nyloc nuts:
Image

Image

Image

Image


Tomorrow I will post a video we made from the ground showing the drone flying without the gimbal, so you can see how smooth it flies.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Re: Tarot X8 Octocopter Build Diary

Postby cnarvaez » Sat Nov 14, 2015 12:51 am

Hi, I almost finish my Tarot X8, but I can´t config the landing gear in mission planner, I have power +5v controller and the servo card connected to the AUX3 on the pixhawk, I have an dx7s and config the rc6 but doesn´t works.

Please help me, thank you in advance.
cnarvaez
Cadet
 
Posts: 1
Joined: Sat Nov 14, 2015 12:42 am
Karma: 0

Re: Tarot X8 Octocopter Build Diary

Postby SDeath » Sun Nov 15, 2015 1:12 am

cnarvaez wrote:Hi, I almost finish my Tarot X8, but I can´t config the landing gear in mission planner, I have power +5v controller and the servo card connected to the AUX3 on the pixhawk, I have an dx7s and config the rc6 but doesn´t works.

Please help me, thank you in advance.


Did you update the Mission Planner software to the latest version? Please do so, update to the latest Beta, that made the option available in Mission planner.
Before it also didn't show for that channel as available option in the Initial setup.
If that doesn't help than you can also connect it to the receiver directly and program your remote to that channel. The downside is you can't use the landing gear auto restract/extend feature while planning missions.
User avatar
SDeath
Captain
Captain
 
Posts: 1219
Joined: Fri May 24, 2013 11:00 pm
Location: the Netherlands
Karma: 68

Previous

Return to Miscellaneous Models

Who is online

Users browsing this forum: No registered users and 1 guest