New Products Flash Sale
Thread Tools
Old Aug 06, 2015, 10:41 PM
FunN4Lo is online now
Find More Posts by FunN4Lo
Free fall is not free
FunN4Lo's Avatar
United States, LA, Baton Rouge
Joined Aug 2014
1,377 Posts
Quote:
Originally Posted by ovni View Post
Hello all,

I posted this earlier in the FAQ thread which I guess was the wrong spot. Let me try this again!

I just started using the Tarot 2D Gimbal with a GoPro Hero4 Black on the 3D Robotics DIY Quadcopter kit and overall I am very pleased with the setup. I have not changed any of the settings and it seems to be working well out of the box.

The one thing I noticed however is that the horizon is not always straight. Sometimes it will be rotated slightly clockwise (less than two degrees) and sometimes it will be rotated slightly counter-clockwise. Other times it will be perfect. This seems to happen mostly after I rotate the quadcopter (yaw). Even after I stop rotating though and just hover in place, the horizon will remain slightly off.

After looking at the FAQ I learned about the little balancing screw, so I tried putting that back in (I removed it because it seemed to serve no purpose at first!) but that didn't seem to make any difference. Does this sound like a familiar problem? Any suggestions?

Thanks!

-ovni
The yaw/horizon issue plagues nearly every gimbal to some extent. You will probably not cure it at this price point. But great static balance will make it better.

There is also a guy that posted a vid some pages back where he calibrated the gimbal tilted slightly back instead of completely level that he said solved the horizon issue. (I don't remember enough to link it, and I never tried it)
FunN4Lo is online now Find More Posts by FunN4Lo
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 07, 2015, 06:03 AM
ST_Bob is offline
Find More Posts by ST_Bob
Registered User
ST_Bob's Avatar
United States, MA, Worcester
Joined Feb 2013
1,348 Posts
Position of the camera/gimbal during the calibration is critical. You're telling the controller to remember what "up" is. If you do it with the camera even slightly tilted either fore/aft or side to side it will remember that you wanted "up" to be tilted in that direction. Recalibrate properly next time.
ST_Bob is offline Find More Posts by ST_Bob
Reply With Quote
Old Aug 07, 2015, 06:22 AM
modea2 is offline
Find More Posts by modea2
Inspector Gadget
United Kingdom, Blackpool
Joined Aug 2011
196 Posts
HobbyKing Tarot 2D For Mobius

[350QX Mk1]
I have this gimbal with the updated firmware (1.5) which is sold specially for the Mobius camera. It is very nearly there for good stabilised video providing that wind conditions are damn near still. However, when trying to film when moving against the slightest of breezes I get lots of "juddering" [props are balanced]. A mate of mine has the DJI Phantom Vision 2 + and I noticed that when his motors are not powered that the gimbal is completely loose and will move freely with the slightest touch and maintain position at any angle to a resolution of say 0.01deg! Mine however will only rest at say 1 or 2 deg "steps" which makes it damn near impossible to balance such a light camera as a Mobius. Since I got mine from HobbyKing, does anyone think that the motors supplied with the kit are not proper Tarot ones and that that could be the problem. If so, can the "proper" motors be ordered separately from Tarot?
modea2 is offline Find More Posts by modea2
Reply With Quote
Old Aug 07, 2015, 12:11 PM
ovni is offline
Find More Posts by ovni
Registered User
Joined Jan 2009
48 Posts
Quote:
Originally Posted by FunN4Lo View Post
The yaw/horizon issue plagues nearly every gimbal to some extent. You will probably not cure it at this price point. But great static balance will make it better.

There is also a guy that posted a vid some pages back where he calibrated the gimbal tilted slightly back instead of completely level that he said solved the horizon issue. (I don't remember enough to link it, and I never tried it)
Alright, thanks for the insight. Is it unusual for the offset to "stick" though? I can see that during the yaw motion maybe the inertial sensors get confused, but after I return to a hover I would expect things to level out.
ovni is offline Find More Posts by ovni
Reply With Quote
Old Aug 07, 2015, 02:42 PM
clonedkorl is online now
Find More Posts by clonedkorl
A&P Diddy
Midlothian, Tx
Joined Oct 2008
577 Posts
I finally recorded some video from my GP4 last weekend and to me it looked great.... So I am confused as to why there is so much setup conversation on this unit as I have done nothing to it as far as calibration or settings.
clonedkorl is online now Find More Posts by clonedkorl
Reply With Quote
Old Aug 08, 2015, 01:02 AM
ovni is offline
Find More Posts by ovni
Registered User
Joined Jan 2009
48 Posts
New question: Would it be a bad idea to use the same 500 mAh 3s lipo for both the Tarot Gimbal and my ImmersionRC 600mW 5.8 GHz VTx wired in parallel?

Thanks guys!
ovni is offline Find More Posts by ovni
Reply With Quote
Old Aug 08, 2015, 03:25 AM
monterx7 is offline
Find More Posts by monterx7
Registered User
United States, GA, Lakeland
Joined Jul 2013
141 Posts
Quote:
Originally Posted by clonedkorl View Post
I finally recorded some video from my GP4 last weekend and to me it looked great.... So I am confused as to why there is so much setup conversation on this unit as I have done nothing to it as far as calibration or settings.

Will you be posting your videos?
monterx7 is offline Find More Posts by monterx7
Reply With Quote
Old Aug 08, 2015, 03:55 AM
ukbren is offline
Find More Posts by ukbren
Registered User
ukbren's Avatar
United Kingdom, Derbyshire
Joined Aug 2011
1,176 Posts
Quote:
Originally Posted by ovni View Post
New question: Would it be a bad idea to use the same 500 mAh 3s lipo for both the Tarot Gimbal and my ImmersionRC 600mW 5.8 GHz VTx wired in parallel?

Thanks guys!
i would have thought you'd be ok, although you'd probably save a little heat if you could power the vtx with 7V (as anything above that is downconverted resulting in extra heat).

I live dangerously and power everything off my f4S flight battery, via a PDB with built-in 12V and variable (set at 7V in my case) BECs.
ukbren is offline Find More Posts by ukbren
Reply With Quote
Old Aug 08, 2015, 04:49 AM
ST_Bob is offline
Find More Posts by ST_Bob
Registered User
ST_Bob's Avatar
United States, MA, Worcester
Joined Feb 2013
1,348 Posts
The issue with powering the gimbal and the VTX off the same power supply is possible electrical interference. Neither of these devices cause much interference on their own but when powering one from the other or both from a single source you increase their coupling and can end up with problems sometimes. When using a 3S (11.1 - 12.6 volts) power source, the device must dump several volts to obtain the nominal 3.3 to 6 volts used internally. The closer the original battery voltage is to the actual internal operating voltage, the less waste energy is converted to heat with conventional linear regulators.

If it were my setup, I'd try powering the camera and VTX from its internal power supply using a 7.4 volt 2S battery and power the gimbal from either another 2S battery with the negative wire tied to the VTX battery or from a separate switching BEC set to 7 volts. The goal, of course, is to eliminate wasted electrical load which shortens the flying time of the flight battery and also provides redundancy on the video link portion so you won't risk losing FPV video in flight. Efficiency is the watch-word. SBEC's are much better at efficiency than regular linear ones.

A 500ma camera/vtx load on a 5 volt BEC provides 5 volts at 500ma or 2.5 Watts of 5 volt power using 6.3 Watts off the 3S battery. So to obtain 2.5 Watts of usable power by the VTX/camera you must waste 3.8 Watts as heat in the BEC. So you draw 500ma from the battery even though you only WANT to use up 198ma at 12.6 volts. A switching BEC (SBEC) will do this for you. It chops-up the incoming 12.6 volts, runs it through a transformer and smooths the resulting output to 5 volts. This reduces the waste in the system and (can) provides a cleaner output voltage in most cases.

The gimbal can also benefit from lowering the input voltage to 7-8 volts before the onboard voltage regulator gets it. Once again, use a SBEC to do this.

In the grand scheme of things a 500ma draw off the flight battery will only slightly shorten your flight times but reducing this to around 200ma without sacrificing the ability to run the camera/vtx/gimbal will get you back a lot of that flight time at the cost of a few dollars and few grams of SBEC weight. Make sure you keep all your negative power leads tied together but be cautious - some BECs and SBECs don't regulate the positive lead.... If they regulate the negative lead you cannot connect them together and you will have ground loops that can cause all sorts of other problems. Select your hardware carefully and make voltage measurements while running to verify that they can all be interconnected without problems.
ST_Bob is offline Find More Posts by ST_Bob
Reply With Quote
Old Aug 08, 2015, 10:21 AM
clonedkorl is online now
Find More Posts by clonedkorl
A&P Diddy
Midlothian, Tx
Joined Oct 2008
577 Posts
Quote:
Originally Posted by monterx7 View Post
Will you be posting your videos?
I can for sure, let me work on it.
clonedkorl is online now Find More Posts by clonedkorl
Reply With Quote
Old Aug 08, 2015, 03:11 PM
FunN4Lo is online now
Find More Posts by FunN4Lo
Free fall is not free
FunN4Lo's Avatar
United States, LA, Baton Rouge
Joined Aug 2014
1,377 Posts
Quote:
Originally Posted by ovni View Post
New question: Would it be a bad idea to use the same 500 mAh 3s lipo for both the Tarot Gimbal and my ImmersionRC 600mW 5.8 GHz VTx wired in parallel?

Thanks guys!
As long as the Immersion works on 12v (I don't own one) you should be good. I power my gimbal and 600mw Boscam from my 4s flight batt through the same 12v bec
FunN4Lo is online now Find More Posts by FunN4Lo
Reply With Quote
Old Aug 27, 2015, 05:40 AM
pafmonteiro is offline
Find More Posts by pafmonteiro
Registered User
Joined Dec 2007
1 Posts
Hi Rob

I have a tarot 680 pro with a t-2d gimbal, but i have minimal jitter on my videos. Can you send me your tarot t-2d gains?

Best regards,

Paulo
pafmonteiro is offline Find More Posts by pafmonteiro
Reply With Quote
Old Aug 27, 2015, 09:41 AM
clonedkorl is online now
Find More Posts by clonedkorl
A&P Diddy
Midlothian, Tx
Joined Oct 2008
577 Posts
Quote:
Originally Posted by monterx7 View Post
Will you be posting your videos?
I posted my video in the wrong gimbal thread weeks ago!
clonedkorl is online now Find More Posts by clonedkorl
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log GoPro Hero 3 Brushless Gimbal (Plywood) Skewp Multirotor Talk 20 Feb 21, 2015 06:57 AM
For Sale TAROT ARTF Brushless motor Gimbal by TACOTOY for DJI PHANTOM GOPRO 3 rctaco Aircraft - Electric - Multirotor (FS/W) 28 Jan 23, 2015 04:16 PM
Sold Brushless ready gimbal for gopro hero 3 hdworld Aircraft - Electric - Multirotor (FS/W) 29 Jul 13, 2013 03:32 AM
For Sale Brushless ready gimbal for gopro hero 3 hdworld Aircraft - Electric - Multirotor (FS/W) 15 May 06, 2013 07:42 AM
Sold Complete Brushless Gimbal Setup for GoPro Hero 2 crd FPV Equipment (FS/W) 2 Apr 28, 2013 10:14 PM