yetti831

Hi again,


I wanted to switch out the TX and RX that came with my Nitro F-35 to a Skyport T4VF. When I did so, I needed to reverse the throttle as when the stick was all the way down it flew to WOT. I also needed to put the throttle trim all the way up instead of all the way down. So I did just that. Next I noticed that there was no gradual increase in throttle. The first few clicks were empty followed by what seemed to be 50% and then with the throttle all the way up, about 90%. It seemed like it wasn't @ 100%. I really want to use this TX/RX, but it's just incredibly annoying not having more throttle control. What the heck is wrong? Thank you!


-Yetti

CGRetired

My Feedback: (1)

Because the Skysport does not have end points (not a computer radio I believe) you have to do all this mechanically. The stick movement relates to 100% servo movement. So, you have to work with the mechanical settings of the "levers and bell-crank" action of the servo arm and the thrlttle arm.

First, zero the servo. You can only do this using one of the other channels with trim set to the mid point or at zero (no plus or no minus trim, just set it to the mid point on the TX). Connect the servo to that channel (rudder, elevator, aileron... whatever, but not the throttle). This will set the mid point of the servo. If the servo arm is not 90 degrees to the side of the servo, then remove the servo arm and rotate it 90 degrees. Each arm is offset somewhat to enable you to find the ONE of the four arms that are the correctly centerd ones for that servo. If you do not have a four arm servo, get one.

Next, center the throttle on the TX and again, center the trim. Then, once you have the servo centered and the correct servo arm selected, then you can cut the other arms off... or not, your choice. Install the servo, or if installed, plug it into the throttle port on the RX. If it does not "rotate" correctly, then use the throttle reverse switch on the TX and get it right. The throttle arm on the servo should now be centered. Do not touch anything on the TX. Set it aside, yeah, leave it on.

Open the throttle on the engine to what you think is mid throttle setting. Set the trim to fully closed (all the way in) Now, use the hole on the servo that is the furthest away from the center and the same on the engine throttle arm. Adjust your linkage so that they match up. Lengthen or shorten as necessary. Connect the throttle linkage. Now, slowly move the throttle until you go to full open. IF no bind, then go to full closed. If no bind, then you are ok. If it binds, then re-center it, chooose a next hole on the serov that is closer to the center. Leave the one alone on the engine. Re-check for binds and that the throttle opens and closes fully with no binds. If no binds then you are ok. If it binds, then more adjustment is necessary. Continue to adjust as necessary until you are happy that it opens fully and closes fully wiht no binds. NOw, you should have correct adjustment and trim settings so that you can close the throttle with the trim to shutdown the engine when finished.

RCKen

My Feedback: (9)

CGRetired is right on the money. Follow his advice to mechanically adjust the throw on your throttle.

Ken

opjose

Guys this is an EDF JET... no servo arms nor throttle servo.


Yetti:

The ESC "learns" the throttle range.

What you need to do is to power up the TX and move the throttle up to full power.

Then power up the plane ( retain it just in case it takes off on you! ).

Then after the first beep, bring the throttle down.

The ESC will remember the throttle range and should now work properly.

You may also have to try again at Mid, FULL, Idle positions in that order.

The ESC will "learn" the new range after a few attempts.

yetti831

Interesting. Let me try this. Thanks again.

Also, should I switch the throttle back from reversed to normal?

opjose

No don't switch it back.

If high stick produced a higher throttle, you have the direction right on the TX.

Now you need to get the ESC to accept the new throttle range.

Most ESC's "learn" this...

Typically the arming sequence "teaches" the ESC the throttle range.

However the exact sequence varies a lot.

I have some planes that you need to first bring the throttle to idle then back to full throttle to get the ESC to arm AND learn the range, then you bring it back down to turn on the motor.

On others you need to start with the throttle all the way up, then bring it down to arm the plane.

And I have one or two where you have to go from mid stick, to full, and back to idle to arm the ESC...

yetti831

Got it, thanks.


Another question. I picked up another 2500kv for my wild hawk, but I am using the same prop. When I get near 3/4 throttle, the prop begins to whistle very loudly. Too many rpms for the prop? I'm not sure what size it is. It came with the Wild hawk.

opjose

Sorry but I'm not familiar with the Wild Hawk...

Link?

yetti831

[link=http://www.nitroplanes.com/rtfwiha54el3.html]Wild Hawk[/link]

opjose

Oh, yeah you are overdriving that prop effectively stalling it, which is why it whisles!

That's too high of a KV rating for that prop.

That 2500Kv motor is more suited to a gear drive motor or to an EDF.

The included motor produces around 950Kv or less, so you could have used something in the 950-1250kv range instead.

yetti831

Heh. Figures I would do something so dumb. Well, in the meantime I can keep the throttle below that point and fly, right? [:-]

goirish

WOW!! what a nice lesson on how to set up the servo for the throttle control Sometimes we get lazy when using a computer TX. Nice Job.

opjose

Maybe, but it will be very inefficient.

I wouldn't be suprised if your flight times are reduced greatly.

It's akin to spinning your car wheels in snow at full throttle, while your car inches to a destiniation only 50 yards away.

If the original ESC can handle it ( check to see if it has a jumper on it, or a place where a jumper COULD have been installed ) LiPo's you might have been better off merely throwing a LiPo pack into the plane.

The higher voltage would give it MUCH more power.

The motor would wear faster, but I suspect that the plane will give out long before that brushed motor will.

yetti831

But, if I keep the throttle below the point at which the prop stalls, then wouldn't I be getting sufficient traction to move through the snow without spinning the tires? The point at which the prop stalls is the point at which the tires loses traction?

As for the brushed motor included with the Wild Hawk, it was acting very strange. From 50-100% throttle, the prop would slow momentarily, if only for a second, and then return to its normal speed. Is this from an improper break-in?

opjose

Re: Prop

Yes in a way, but what you are doing is flying with a very short throttle range.

At low throttle the plane is not producing the thrust the motor is capable of.

At higher throttle you get a lot of pitch speed but low thrust.

It may work but it will be very inefficient which you will see in greatly reduced flight times.

You may or may not notice more power while in flight.

Re: 50%

No that is not from improper break in.

On a standard brushless setup, I would normally say that this sounds like a timing issue.

I wonder if it would manifest in flight though?

Did you check it out while the plane is flying?

CGRetired

My Feedback: (1)

Somehow, I read "NITRO" which means, to me, most likely glow powered. EDF Jet, eh? Ok. Whatever. At least he knows how to set up his glow throttle. After all, this is a beginners forum.

Thanks, Ken and Irish. I appreciate the cudo's.

CGr.

opjose

Understandable and what I would have assumed as well.

Yetti831

This is why I suggested keeping your questions together in one thread, to avoid things like this.

Due to our exchanges I'm familiar with what you have, but others are not.

goirish

Gotta get them glasses changed.

CGRetired

My Feedback: (1)

yetti831

I'll post in my old thread back over @ the nitro planes support page . I posted here because I didn't think it fair to expect you to answer all of my questions.

opjose

Not really a problem since I own this plane too.