Originally Posted by T3beatz

Yakman what do you think about the servos?

FROM YOUR REPORT ... I BELIEVE THAT FOR THE PRICE AND FOR THE CAPABILITY OF THE SERVO IS HANDS DOWN WINNER....I WILL BUY ...THE 4116 AND 4120 (NOT THE 4020) THAT IS HV ... THE PRICES FROM THEM IS 28 US DOLLARS ... IF YOU WANT BETTER PERFORMANCE FROM THAT YOU HAVE TO GO TO HITEC THAT HAVE 90 US DOLLARS... THAT HAVE ALSO THESE FUTURES AND PERSONALLY I BELIEVE THAT YOU HAVE VERY PROFESIONAL PILOT TO UNDERSTAND THE DIFFERANCE OF QUALITY ...IN A 3D ENVIROMENT ...WHEN YOU ARE IN THAT LEVEL ... ITS NORMAL TO PAY ,,,90 -150 US FOR A SERVO ... BUT FOR NORMAL PEOPLE THAT HAVE FUN .. AND MAKING 3D FOR FUN ... ITS TOP ...FROM MY POINT OF VIEW....
THANKS FOR YOUR REVIEW!!!!!

No problem, anytime... If the XQ-Power company keep it up they will be just fine in this hobby. In my opinion as it sits now Its a great servo, this weekend I am going to get some flight test to see if it will stand up to the vibrations and torture of the rudder.

I also am going to order some of the 4120's to test soon. I all I have to do is press the button, but I didn't want to do it unless the 4020 checked out good.

Originally Posted by Ara Tidwell

How about a resolution test? If you set your radio to one trip step per trim click, is every step actuated?

ie jr's test
YouTube - JR Comparison Test

Yes the JR servo moves with every click... but the budget digital servo moves about the same amount when it does move... So as far as precision would that make a difference? Go into your A9 or JR radio and change the trim step to 6 and your good to go, same precision movements.

The XQ power servos on my Hitec A9 got down to 5ms before it would not move every time... The default for the A9 is 12ms.

Originally Posted by T3beatz

Yes the JR servo moves with every click... but the budget digital servo moves about the same amount when it does move... So as far as precision would that make a difference? Go into your A9 or JR radio and change the trim step to 6 and your good to go, same precision movements.

The XQ power servos on my Hitec A9 got down to 5ms before it would not move every time... The default for the A9 is 12ms.

I am not sure what you are trying to say here, it makes no sense. When I ran Spektrum A6000 servos that required 6-trim steps before they would move, I could see the difference with my eyes and the airplane was difficult to properly trim in the air. I am never going to make that mistake again!

what I'm saying is although the JR servo moves with every click of the trim the movements are not super fine at all...

the budget servos movements may not have moved with every click, but when it did move the movements were on par with the JR's servo movements.

Basically the video does not show how precise the servo its it just shows that the servo has better programing involved. (I'm not an expert electronic engineer so I can't really explain the details of the digital pulses coming from the servos controllers).

This video shows good dead band... but resolution and deadband are totally different things. But they do go hand and hand when needing a very precise servo for helis are precision planes.

They should do a slow sweep of the both servos and get close up and let us see which one is smoother. or how many moves does it take for each servo to sweep 60* (although the JR servo will probably win, but who knows).

It's funny that they call that servo an inexpensive digital... when the XQ servo cost less and has way better specs... Just not the JR name.

T3 this still makes little sense to me. A servo that only takes 1-trim step to move and does this consistantly is going to be higher resolution than one that takes more than 1-trim steps to move, especially if it is like the A6000 that takes 6-trim steps. 6-trim steps is a lot and with 3d throws you will have trouble getting your plane in trim.

ok, let me put it a different way...

If I had a servo that moved 1 step for every trim click, and it took 30 steps to move it 60* VS a servo that took 6 trim clicks to move 1 step and it took 30steps to move 60*.... which servo has better resolution?

I'm not saying the JR servo sucks, it has very low dead band.

T3, what you need to look for is that a servo will move every time you give it 1-trim step of movement consecutivly. the math you gave me does not add up here.

-edit it does if you mean 30-trim steps and 5 steps of movement over 60 degrees

The math does add up... look it over again... both servos took 30 steps to move 60* (not clicks of trim). That would mean they both have the same resolution.

If a JR DS821 takes 1-trim step consistantly to actuate the servo, and a Spektrum A6000 takes an average of 6-trim steps to actuate the servo, the resolution of the DS821 would be about 6 times greater. With 3d control surfaces the a6000 was visibily "blocky" when you made fine movements with the stick and near impossible to trim correctly.

No, the Deadband would be about 6 times greater, not resolution... so if you moved the sticks with the JR the servo would move from center faster than with the Spektrum A6000.

I understand the way you are describing it, but in actual flight the JR servo if moved so much it would need more expo...
and the budget servo would need less to match the performance.

Example... If both servos are centered and I moved the stick full left and both servos go 90* to the left and end at the same point. How could this happen?

Originally Posted by T3beatz

No, the Deadband would be about 6 times greater, not resolution... so if you moved the sticks with the JR the servo would move from center faster than with the Spektrum A6000.

I understand the way you are describing it, but in actual flight the JR servo if moved so much it would need more expo...
and the budget servo would need less to match the performance.

Example... If both servos are centered and I moved the stick full left and both servos go 90* to the left and end at the same point. How could this happen?

JR DS821 will move 60 degrees in MANY fine steps, at a very high resolution
Spektrum A6000 will move 60 degrees in 6x-FEWER bulky steps at what I call low resultion.

The JR servo would not need any more expo than the other servo, since the steps it moves in are 6-times finer than the A6000.

I personally cannot comment on the spektrum A6000 servo because I don't own one... I'll take your word for it on that one. But the servo shown in the video moved about the same as the JR servo (when it did move)...

but what I am thinking is that once a servo starts to move the motor is constantly getting pulses from the servo controller until it stops again or is pushed from its neutral position.

so when you trim the servo with one click at a time the process starts all over again with every click. thats what makes the dead band evident, not while the servo is in transit.

T3, dude, no sense in debating it with him. Too be honest, it's my opinion and only my opinion that he's got you on the hook and the best thing to do with it is to spit it out. Look at all the other threads this guy has posted in. Just trolling I tell ya. You won't be able to convince him by debating it in a thread and you'll just perpetuate it. Doesn't matter if you're correct or not.

Just saying.................

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