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Users => Vehicles - MultiRotors => Topic started by: cato on November 05, 2015, 11:51:33 am

Title: Cinetank MKII
Post by: cato on November 05, 2015, 11:51:33 am
Payed loads of taxes and customs today, and got a few very thrilling packages :)

My next project: It's a Flying Cinema Cinetank MKII. First step will be to get it fly with CC3D or Revo (if my Revo clone works). There will be no Gimbal or FPV at that stage, which will be added later. Plan is to add some more features, like OSD and maybe some Frsky sensors. I like the voltage sensor very much and want to try the altitude/velocity sensor.

Controller will be my Revo Clone (provided it works), maybe later a Sparky2. Motors are Elite 2216, ESCs are Afro. Bought 4s batteries and later found out that the Elite are specified for 3s, bummer, but I may try 4s anyway ;)

I have a wish list for far future, which I have not thought through so far:
- get I2C mag working. Cliff did a lot work on that already, so I am sure this will work
- Get S-Port sensor data (Frsky Sensors) into the Revo and OSD. No idea if that is possible.
- OSD with HUD information like artificial horizon, throttle position, velocity and altitude and all that kinda stuff.
Title: Re: Cinetank MKII
Post by: ArnhemAnt on November 05, 2015, 01:56:25 pm
Very excited for you.

I have a CineTank MK1 that I am currently building. Progress has been halted for a little while due to work/family and general life just getting in the way. Mine is a customised build with extended landing gear and custom plates to hang a 3-axis gimbal. Definitely going to be using either a Revo (which I already have) or maybe even a Sparky. My build is purely for aerial video and I just want a solid, dependable platform.

I'll be keeping an eye on the progress of your build man - sounds interesting. And, of course, if Cliff has done some work on testing, etc, then you are well on your way. He knows his stuff and is keen to help others as much as he can.
Title: Re: Cinetank MKII
Post by: cato on November 06, 2015, 08:06:49 pm
That is interesting to hear, ArnhemAnt. I don't know the differences between MKI and MKII, but would like to see how your's looks, especially with the custom 3 axis gimbal. I have a 2 axis gimbal ready, but need a gimbal controller, still.

So far I like the frame very much, it is very light and well thought through. There is loads and loads of space for your stuff, so I attached an X8R receiver with FrSky Voltage sensor and Variometer via the X8R Smart Port.

The controller is the Revo Clone which I bought at Amazon, with M8N GPS and I2C magnetical compass.
Title: Re: Cinetank MKII
Post by: ArnhemAnt on November 07, 2015, 10:32:08 pm
I'm away from home at the moment, but will post up some pics of my build when I get back next weekend. From what I understand, the MK11 is a slightly lighter frame.
Title: Re: Cinetank MKII
Post by: cato on November 07, 2015, 10:45:58 pm
I enjoyed a happy Saturday, finishing the basic setup. This afternoon my Cinetank took off first time in it's existence, and of course I did a little video of it. I had done a basic calibration with the revo outside the frame before, so it was not perfectly balanced, and I think the cloud default tuning for cinetank is a bit on the safe side, but otherwise everything worked out perfectly.

If someone wonders about the golde hubs: My motor set contained 3 CCW and 1 CW hub :( So I went to the local do-it-yourself shop and bought a few M6 hub nuts, which fortunately fit :)

Tomorrow first extended test, currently conditioning the new batteries :)

https://www.youtube.com/watch?v=mGv8nyzz2zM
Title: Re: Cinetank MKII
Post by: cato on November 08, 2015, 10:35:41 pm
Oh well,

first flight kinda successful. Had lots of obstacles, for example the Taranis catched moisture and did not work properly for a while, the revo clone does not work properly in EKF, and well, I had bought crapy rotors, which lead to a bad crash which broke one of the arms. So now waiting for a new revo, a set of spare arms and proper carbon propellers ... but still had lots of fun, mostly with my little one, and the Nighthawk will get proper carbon propellers now as well.

Next step will be to use the Mobius as FPV cam. The quad is not so speedy as a 250, so the Mobius should be ok for now.
Title: Re: Cinetank MKII
Post by: cato on November 20, 2015, 07:09:49 pm
My Cinetank is now almost ready to fly, but it's raining cats and dogs. So I thought I'd show you what Andreas from the German RC dealer pitchpump does with his Cinetank MK I:

https://player.vimeo.com/video/89319760

how do I embed vimeo here?
Title: Re: Cinetank MKII
Post by: ArnhemAnt on November 20, 2015, 10:55:21 pm

how do I embed vimeo here?

Good question. I just tried and got the same result as you. Regardless, that dude can sure throw that frame around in the air. That sort of flying is usually done with a much smaller frame.

My building (CineTank MK1) has been halted due to work commitments. I hope to start again in a few more weeks.
Title: Re: Cinetank MKII
Post by: cato on November 21, 2015, 03:37:33 pm
First stage of my Cinetank is finished now. It is now equiped with a Revo Clone from Ebay and a fixed holder for the Mobius cam. As propellers I decided for a relatively expensive brand, Auro-Naut Cam Light carbon-nylone mix. They have excellent flying characteristics, reduced noise and longer flights. First flight tests are positive, if weather allows I will do intensive testing tomorrow.

Cables now braided in the arms, and more cleanly setup. Only the ESCs need a bit cleaning up, still. The quad is not well balanced at the moment, as it is thought to carry a gimbal at the front end. This will need to wait a while, some parts for the gimbal are still missing, and I need to create a holder for the Moius Gimbal from Hobbyking, as I don't plan to buy GoPro stuff at the moment.

Title: Re: Cinetank MKII
Post by: mazevx on November 21, 2015, 06:59:16 pm
As I read about your problems with the props I thought I recommend the aeronaut cam carbon light to you, but you already choose them ;-)
To my opinion its the best you can buy at the moment.
Title: Re: Cinetank MKII
Post by: cato on November 21, 2015, 11:52:07 pm
As I read about your problems with the props I thought I recommend the aeronaut cam carbon light to you, but you already choose them ;-)
To my opinion its the best you can buy at the moment.

I did a short test flight, and the props seem to keep their promise :)
Tomorrow I will switch on the video camera and see if there is some jello. The GCS cinetank default btw did not work too well for me, for one there is a typo in it ;), but worse is an expo of -4 for yaw, which made mine very twitchy. Changed it to +5 and got a nice smooth rotation. That's what you want for a video quad. Guess I will go through all details of the tuning soon :)
Title: Re: Cinetank MKII
Post by: mazevx on November 22, 2015, 02:50:50 am
I had some serious yaw problems on my black snapper with graupner e prop, tried tuning everything but still jumps and wobbles with every yaw Input... Then changed to aeronaut cam carbon... Problem solved!  Why? I dont know... think the profile of the blade is simply good!
Title: Re: Cinetank MKII
Post by: cato on November 22, 2015, 12:41:45 pm
I think that propellers need more attention than I put in them before. The frame I know best now is the Nighthawk 250. I flew it with 5040 Gemfans first. Those fly very nice, but they break at the first slight touch, which is really annoying, as even a slight ground touch during land will damage the prop so much that you have to replace it. Basically I had to change one or two props for every flight. So I changed to 6045 nylon Gemfans. They are far more endurable, but they produce a strong jello on the videos. 6045 Carbon are better, but still produced jello. My next try will be 6030 Carbon-Nylon mix. I have one more variable, as one of the motor axis has a bit dalliance, which I would guess may increase vibrations, too.

I tested the Cinetank with 9045 Nylon props. They fly ok, but not really nice, and they produce a lot vibrations, and a jello in the Mobius. So I looked for props which are recommended for DJI phantom (as my motors have Phanto style shanks) or TBS Discovery. All reviews found the Aero-Naut CAM light to be the best of all. I will test them today :)
Title: Re: Cinetank MKII
Post by: cato on November 22, 2015, 10:41:40 pm
OK, test flight was brillant. Unfortunately weather was very bad, so I could only take a few minutes of very unpleasant weather, and due to the dim light and so far no light set on the cinetank, I had difficulties to see it's orientation even at 15m distance. In this video I am testing more how it reacts and video quality is only second. https://www.dropbox.com/home/public?preview=cinetank%2Baeronout-testflight.mp4

unfortunately due to a last minute change the sensor callibration was off, and the flying is a bit strange. But it's very good to see that there is no jello at all. Motors and propellers produce lots of power, with the current setup it reacts prompt and precise. Only change to the cloud setup is expo, which does clearly not fit my setup. Instead of 10/10/-4 p/r/y I use 5/5/5. The standard setup feels as someone would expect from those values, twitchy on yaw while a bit sluggish on pitch and roll. I like the slight expo though, as it will make smooth turns more easy.
Title: Re: Cinetank MKII
Post by: hburke on November 24, 2015, 08:48:34 pm
great looking build cato! this has me interested in this frame now  ;D

i have never had tube type arms though. do you like those see any differences? they seem like they might be stronger and be more aerodynamic. im not sure i have any motors that i can spare though. time to ask the wife for more money! , LOL  ;D

harold
Title: Re: Cinetank MKII
Post by: cato on November 24, 2015, 11:51:26 pm
great looking build cato! this has me interested in this frame now  ;D

i have never had tube type arms though. do you like those see any differences? they seem like they might be stronger and be more aerodynamic. im not sure i have any motors that i can spare though. time to ask the wife for more money! , LOL  ;D

harold

Thanks Harold,

I really like the cinetank. I cannot tell you if there is a difference regarding the arms, means the cinetank is very agile and quick, but because of it's size, flying it smooth for video is much easier than with my Nighthawk. The only comparision I have, is a friend's TBS Discovery with Naza controller, and although it's a nice quad, it seems no match to the Cinetank. Basically I never saw any 450 doing things like Andreas does with his Cinetank.

The arms are certainly much more rigid compared to the TBS' plastic arms, but also much lighter, as tubes can be of thinner material than flat arms. They are rigid, but there are limits, one of my arms did not survive a 25m drop right onto that arm. Besides rigidity and aerodynamics a big advantage is, that they hide and protect the cables. The price is double the price of the TBS arms ($12 vs $6). As they will hold much longer the caculation will be more on favor of the cinetank.

As soon as I can fly it FPV (one part still in mail), I will do a few videos, but I won't do Acro so easily, my first tests will be control and speed, lift and camera. So far I can say, with Nylon props you don't do it good and may even get jello, with the carbon mix propellers which I am using the flying and  video are very nice (Aero-Naut CAM Carbon light) !
Title: Re: Cinetank MKII
Post by: cato on December 09, 2015, 04:39:09 pm
OK,

the first stage of the build is now complete and tested. It's equipped with a fixed Mobius V3, which is connected as FPV camera. Here a photo of the current stage of the build.



Next step will be a Gimbal for the Mobius, together with a fixed FPV camera and video switch.
Today I did a flight test to see how the camera does. Weather was really bad, as it was dark and raining, but still good enough to see the camera quality.

Currently I still have problems with internal mag, so I am back to complementary mode, but this time chose the experimental complementary+mag+gps mode.
Title: Re: Cinetank MKII
Post by: cato on December 12, 2015, 11:31:37 am
Another flight test with the cinetank: It flies nice in attitude already, but in rate you see lots of jello at low throttle. The default setup makes heavy use of Thrust scaling, so for now I swtiched that off and configured easy tune. Looks like I have to fully retune the quad for optimal video results.

https://www.youtube.com/watch?v=V8ESH8Qielo
Title: Re: Cinetank MKII
Post by: cato on January 05, 2016, 11:30:33 am
I did some tuning meanwhile, but had no chance to test it in detail, because of weather, work and holiday :)

Yesterday I got the Cinetank Gopro Gimbal from Flying Cinema. It seems very well thought through: there is a standard setup, but you can put it together in different ways. I could even attach the fixed camera plate beneath the gimbal. That gives the option to add a second, fixed video camera beneath the Gimbal, but the gimbal is blocking it's view for sure, so the planned fixed video camera will need a different place. One option would be a FPV camera holder on the top frame.

My main problem was that I am fan of the Mobius cam, and don't intend to buy a Gopro soon, so I had to modify the Gimbal to use a Mobius. For that I attached the camera holder of the Hobbyking, which fits perfectly, as both gimbals have exactly the same dimensions. You can see the result in the photo below.

What's missing still is the gimbal controller. Currently I am looking for a decent controller which works well with a Revo and/or sparky2.

Attached two possible setups, with two positions of the camera:
Title: Re: Cinetank MKII
Post by: cato on April 14, 2016, 02:25:38 pm
ok, due to winter the project got a bit stuck. But anyway, I had to decide for a second camera, so I bought a xiaomi Yi instead of a Gopro or Mobius. This way I can use the original gimbal with no modification. I also bought an 8bit Alexmos Gimbal controller.

It turned out that Hobbyking gimbal motors have a wide range of quality: one of the motors just couldn't manage to rotate the pitch axis. I noticed that the roll axis motor felt a lot "stronger", so after swapping the motors (which should be identical), the gimbal started to work nicely. Only issue with the 8bit Alexmos is that it doesn't handle angles around 90° well, so a 32 Bit Alexmos is on the shopping list for next month :)

Here a photo of my current setup. Currently FPV transmission and rx connection of the gimbal controller are still missing, and everything is still a bit messy.

Title: Re: Cinetank MKII
Post by: ArnhemAnt on April 14, 2016, 11:55:24 pm
Looking good.

My MK1 is on hold. Turns out the weight of the 3-axis gimbal hanging off the top plate was too much. I've ordered some 163mm legs and David (from Flying Cinema) is currently designing a custom plate so that I can mount my gimbal from the top of the dirty section. This will enable me to mount the gimbal on a part of the frame that has a lot more support and is far less likely to move about.
Title: Re: Cinetank MKII
Post by: cato on April 15, 2016, 12:54:49 am
that sounds pretty complicated :)
I would like to see a photo of the final setup, sounds like it will be quite impressive.

My cinetank was on hold for quite a while, too, one for work, second because I did some testing with both quads, and third because for a while I did not know what to do about the gimbal problem (which turned out to be a motor problem). Now, next will be the rx channel setup: I need 12 channels, but as I need the flexi port for GPS, I need to use PWM or PPM on the Receiver Port. My receiver supports pwm or S-Bus, so I decided to use a S-Bus-to-ppm converter and connect the FC with PPM, while using PWM for the Gimbal, lost plane alarm a.s.o.

Next I need to get a new fixed position FPV camera, as the one I had spare doesn't work with the setup for some reason. Finding a nice place for it, where view is not blocked by the gimbal may also be a challenge.

But first will be a flight test with gimbal and the completely new PID tuning, as soon as weather allows. Looking forward to that, as especially the new tuning felt a lot nicer than the stock version.
Title: Re: Cinetank MKII
Post by: ArnhemAnt on April 15, 2016, 10:02:15 am
For my Rx, I went with the FrSKY TFRSP. It is a very impressive unit and allows me to run both PPM and PWM as the gimbal board needs PWM.
Title: Re: Cinetank MKII
Post by: cato on April 15, 2016, 12:11:04 pm
thanks, @arnhemant. I will definitely take a look at that rx soon. Unfortunately for this month I already used up my toys bugdet, again ...

BTW, I see you are communicating a lot with the flying cinema guys. Seems they are very open for suggestions, isn't it?
Currently I am wondering how to mount a fixed FPV cam for FPV sessions using the flying cinema gimbal (with option to switch both video streams during flight). I am still waiting for a new FPV cam, so I mounted my Mobius on top,  but it's sight gets totally blocked by the gimbal on steep turns. I think mounting it beneath the front extension might be a good start, and I guess I'll end up with gear and FPV cam and vtx antenna mounted on the bottom part.

My focus today is tuning: as I said I got a reasonable basic tuning for the gimbal now. But after some intensive flying I thought that the stock PID tuning of cinetank may  not be so good, it felt pretty sluggish and strange. So I went for a fresh, manual tuning session, starting with a bench tuning (really scary experience), going to flying session, and finally now I am testing Easytune to get reasonable values. With Easytune I could eliminate most of the artifacts I had got in only one short session, while maintaining a very responsive cinetank in rate mode. It actually feels VERY close to my Nighthawk 250 at the moment, which means it is a bit scary for it's power and size :)

I think in the end I will come up with one pid bench for sharp flying and one using some expo to achieve smooth transitions in rate. I am amazed how aggressive you can tune the cinetank before it starts to misbehave ...

This will certainly need a while and a lot more testing and experience, but it's fun. Now a final session for today, and then some FTT job to do this afternoon :)
Title: Re: Cinetank MKII
Post by: cato on April 16, 2016, 11:01:12 pm
I got one step further:

Now the cinetank has a fixed position FPV cam. This is a Runcam TVL 600 mini. The case could easily be mounted to the front of the top section and it's view gets only slightly blocked when the gimbal turns steep to the left. Almost perfect position. Also the size seems like everything was designed for this: the camera does not touch ground on even surface. I might try the cinetank FPV cam case to protect the camera, later, though.

The third cam, the Mobius is just for fun, and because the video switch has three inputs. It will be removed.

The gimbal can now be rotated using the potentiometers on the tx, the video input to the goggles can be switched. The gimbal is now nicely tuned, but the copter needs a fresh tuning, for which I went back to stock tuning and had already one Easytune session.
Title: Re: Cinetank MKII
Post by: hwh on April 16, 2016, 11:18:02 pm
...The third cam, the Mobius is just for fun, and because the video switch has three inputs. It will be removed....

You could turn it around and have a rear view camera.  :)
Title: Re: Cinetank MKII
Post by: cato on April 17, 2016, 12:04:31 am

You could turn it around and have a rear view camera.  :)

That sounds like a great idea :)
Title: Re: Cinetank MKII
Post by: Tongala on August 15, 2016, 09:24:01 am
Hi it's been a while since you posted. Just wondering how you are enjoying your Cinetank?
The reason I ask is I have just pulled the trigger and ordered one with L arms. Will be a couple of weeks to get here in Australia.
Have been flying 250's but not really for me.
So any feedback/advice would be welcome.
Thanks
Title: Re: Cinetank MKII
Post by: cato on August 15, 2016, 08:19:15 pm
Hi,

my cinetank is very fine. Camera and gimbal working quite well, and it also flies very nicely. Unfortunately my work commitments did not allow me to do any much flying recently. That's also the reason why I'm so quiet here. Hope you enjoy your cinetank as much as I do :)

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