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Feb 04, 2020, 05:44 PM
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OMPHobby T720 with DSM2 Rx ( Maiden )


OMPHobby T720 with DSM2 Rx (12 min 49 sec)


Chalk and Cheese

The difference between using a Taranis Q x7 and the OMP factory transmitter is like night and day !
Fly in stability mode the T720 is snooze town . It is almost boring .

I was flying with 100% rates and 50% Expo on the elevator and ailerons .
Turning off the stability mode and the T720 flew really nice . On the factory Tx the T720 was a challenge , especially at the slow speed I was flying at and the dead zone on the factory transmitter left you with little to no fine control . On the Taranis it was just gravy .

DSM2/x Satellite Rx

As mentioned , would bind to the Tx in DSMx , but did not work with the T720 control board .
When I tried DSM2_22 everything worked just fine .

Zippy 350 ..

For this flight I was using the slightly larger heavier Zippy 350 2s .. This be the old blue pack which apparently you can no longer buy . I did order a new yellow Zippy 350 ( larger and heavier again ) . That zippy ( yellow ) 350 just arrived .
The blue one gave some 11.30 minutes of flight time around 50% throttle and when I came home the battery tester reported some 40% battery left .
Kiss my beehive right ? I landed when I did because I was getting worried , I did not really notice any power sag but I was sure I was close to 10 minutes flight time ( over in hind sight ) .

T720 Hunts the ground

It does ever so gently hunt the ground . I have done a little elevator offset in the Tx , will see if that cures it . If not I may need to re calibrate the gyro .
If it did not hunt the ground the ( this one ) T720 would be an amazing trainer on the Taranis Tx .

Conclusion

A) The factory Tx is junk ( my humble opinion )
B) The zippy 350 seems to have moved the CG enough
C) On the Taranis the T720 is so freaky good

If I can cure the mild ground hunting , the T720 would be a perfect 10 out of 10 and amazingly Noob friendly .
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Jul 29, 2020, 03:39 PM
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Hi, I just discovered your post regarding the OMPHobby T720. Would you mind sharing where did you purchase that DSM2/x Satellite RX? Did you get it thru the manufacturer's site or is it just a normal RX? thanks, Alwin
Jul 29, 2020, 06:14 PM
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https://www.ebay.com.au/itm/DSM2-DSM...8AAOSw~hBZ3lfF

THis one I think ! Got it quite some time ago .. Ebay

Wont bind DSMx , but did bind DSM2
Aug 04, 2020, 06:06 PM
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Hi there,
I just got a HobbyMate Satellite RX and got it connected and to bind to my OMPHobby T720 and my Jumper T8SG transmitter in DSM2 protocol. So that work perfectly following your binding instructions in this forum.

Now for setup of dual rates an Expo on the transmitter and to assign a 3 way switch what do you recommend? Also does the T720 use channel 5 default for the gyro settings?
And the most important , how do you program Sport or Normal modes?

Thanks,
Alwin
Last edited by Antiguatech; Aug 04, 2020 at 06:19 PM. Reason: more info
Aug 05, 2020, 02:18 AM
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Ch5 is for Gyro , best to use a 2 position switch for that .

Rates as needed and expo again to suit you .

CG is a little rearward with the OMP , so maybe start with 50% rates on the elevator .
Expo might be 50% to start .
The T720 is so stable , you may wish to mix in some rudder in full stability mode to get it to turn tighter if needed .

Dual rates ? Probably not needed .
Stability and less stability ( gyro ) should be enough .
Aug 05, 2020, 02:17 PM
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I used a 3 position switch for the gyro, so I will re-assign channel 5 to a 2-position instead.
Also the 50% Expo on the elevator makes sense.

Again, thanks
Alwin
Aug 05, 2020, 07:00 PM
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Fly it on the Good Tx ..
Mine is so stable and predictable ( after re calibrating the gyro ) that it is almost boring to fly .
I would feel confident handing it over to a Noob after taking it up to say 10 meters and handing the transmitter over . Maybe the perfect buddy box plane ?

Also FPV , being so stable ...
Aug 06, 2020, 10:53 AM
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Yes, definitely no more stock TX.

By the way, you mentioned re calibrating the gyro, how do you calibrate this plane with a non-stock or different TX like the T8SG or in your case a Spektrum?
I think I tried the same procedure like from the original TX, but it didn't work.
Aug 06, 2020, 06:46 PM
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Hmmm , worked for me with the Taranis ..

If mem serves , stay in Stability mode ..
and you then lay the plane flat or maybe , a few deg of nose up - wings level .
And pull both sticks bottom left was it ..
Keep an eye on the control board doing this ..
Hold both sticks while the control board starts flashing quickly .
When the control board stops flashing , it is re calibrated and you can let go the gimbals .

At least thats the way I did it .
Aug 06, 2020, 08:18 PM
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I think it worked, I used this sequence:

Controller on first, then plane in a level position.
Move both joysticks down and out at same time.
Rapid flashing for a few seconds and then release.

Also I noticed when switch for the gyro is on (offset 100), the red and blue lights on the plane are solid.
On Sport mode (switch position off, offset -100), it still has some gyro but more sensitive to controls, the blue light on plane flashes on and off when active.

I will test fly again tomorrow and see how it works.
Thanks
Nov 24, 2020, 06:51 PM
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i watched the video and would like to add an s-bus receiver into the other spare port of the plane.
is there a suitable FlySky satellite receiver that i could use ?
Nov 24, 2020, 08:16 PM
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Not that I could vouch for ...
I had a Sbus Flysky Rx that just refused to work , I tossed it in the rubbish .
Life is too short for stuff that does not work .
Nov 25, 2020, 08:04 AM
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Quote:
Originally Posted by old4570
Not that I could vouch for ...
I had a Sbus Flysky Rx that just refused to work , I tossed it in the rubbish .
Life is too short for stuff that does not work .
so the DSM2 satellite receiver you bought on ebay - did it come with the plug that connects straight into the T720 ?
And what is the range you can get with that receiver (i'm assuming it gives more range than the stock receiver - perhaps that is not correct?)

i have a jumper t8sg that i want to use to control the plane so i am flexible. sadly the Deviation team are not managing to keep up with the OpenTX team as they have managed to find the protocol that OMPhobby are using and have added it to their latest firmware.
regards
Nov 25, 2020, 07:21 PM
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Yes , DSM2 is better than stock ..
Yes came with a cable ..

But if you plan to fly any distance , then maybe a long range Rx
Nov 28, 2020, 01:31 PM
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Quote:
Originally Posted by old4570
Yes , DSM2 is better than stock ..
Yes came with a cable ..

But if you plan to fly any distance , then maybe a long range Rx
thanks for your reply. what is a good budget long-range Rx ?
i would like a range of 1-2 km.


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