JETLEGEND 1:5 YAK130 TEST VIDEO-----(Single turbine version)
#101
My Feedback: (1)
Thanks Mark,for the glitch it is one servo at a time,i suspect the battery. For the flap,i don't understand because i bind another receiver to try it with only the flap on it and it did the same. But the stange thing is that not only one servo does it but both. Can it be the battery,i use lipo 7.4 pulse tx pack. I have the new spektrum 20 ch receiver with dx18 tx, 2x5000 mha pulse rx lipo 7.4. Powerbox igyro.
thanks
Mike
thanks
Mike
#104
My Feedback: (1)
Hi, i had a answer for my flap servo from jet legend, they said that flap servo have an overload protection on it, after 12 sec they release torque till next command. That scare me because when you put flap you what them to retain their position. Did you encounter problem with your flap servo at all, and can you try appliy some pressure on it to see if they release after 12 sec.
thanks
Mike
thanks
Mike
#112
Hi, i had a answer for my flap servo from jet legend, they said that flap servo have an overload protection on it, after 12 sec they release torque till next command. That scare me because when you put flap you what them to retain their position. Did you encounter problem with your flap servo at all, and can you try appliy some pressure on it to see if they release after 12 sec.
thanks
Mike
thanks
Mike
I have experimented with a spare Spark servo I have here and can report the following.
The correct voltage for these servos is 7.4-8.4v with enough amperage available to hold that voltage under load.
On my first try I used a small 5 cell nim pack at 6v were I did manage to get them to "let go"
To do this I had to apply a "considerable" and constant force on the servo arm.
When the force is released they return to there original position.
I must add I can only get them to "let go" with both considerable force and a poor voltage supply.
This is true of any servo when the voltage is below spec.
On a good 8.4v supply I could "not" get these servo to let go evan after several attempts.
Certainly not at the amount of force I am willing to apply which felt far more than would ever be needed in actual use.
For your servos to "let go" or "relax" they must be under at the very least "some" strain were in fact they should be under no strain at all.
Are they ended out on the linkage?
I would check your voltage under load, in the Yak there are at least eight servos on board that have a total potential of producing 320kg of force!
If you are in communication with Spark It might be worth asking if they have a servo programmer "gizmo" you could purchase.
There then might be the option of setting the holding power, end point, direction etc of these servos to better suit your needs.
I for one feel confidant in these servos and now have them in three or four air frames all of which have performed faultlessly.
On both my Yaks, Cougar and large F16 I use twin Jeti 5200ma Lion packs that have the potential to deliver up to 80 amp each!
Last edited by Mark Vandervelden; 03-02-2017 at 07:01 AM.
#114
Mike
Have you modified the linkage on the flap and aile to give the servo more advantage over the control surface?
Its not 100% necessary on JL PNP with Spark servos as they are powerful and the surfaces are not that big.
The exception are these Yaks flaps which are huge and sit a long way into the breeze.
I have gone from using less than 50% servo travel to over 100% on my adjusted setups halving the servo effort needed.
"The Yak flaps only need to go down 25-30 degree for take off and "defiantly" no more than 40-45 deg for landing"
Shown here is my 1/5th Yak and my JL Cougar, but I have done this to all my JL PNP airframes
I reduce the servo arm output from 20 mm to 13 mm or whichever brings the output hole flush to the hatch skin.
I then have to open the servo hatches slot to accommodate a std 3 mm clevises.
You then have to put the clevis on the servo arm first and then put the arm on the servo with the clevis already snapped on.
The hatch skin this way prevents the clevis from ever opening up and slipping off, works a treat and looks very neat.
Last edited by Mark Vandervelden; 03-02-2017 at 01:13 PM.