Adjusting throttle sensitivity.
 

By the time the throttle stick is at about 1/3 of it travel my engine is at approx 85% full power, making the throttle near idle very sensitive to even the smallest of movements. Other than adding some negative expo to the throttle is there any other way of reducing the throttle sensitivity.

Karol

RE: Adjusting throttle sensitivity.
 

Larger prop. longer throtle arm, set the servo arm so that at idle it is pointed almost strait back.

RE: Adjusting throttle sensitivity.
 

If you don't have a multi-point mix free, and you can't mix THRO>THRO with expo.... the easiest is to mechanically introduce expo by having the lowest part of the throttle stick movement move the servo at the most extreme end of it's rotation, with the arm offset at least one "spline", or maybe two, in the direction of "low throttle". Adjust pushrod length as needed, so that as you're coming up off idle the servo is moving through it's maximum ARC of the radius; this is the least amount of linear movement you'll get.

RE: Adjusting throttle sensitivity.
 

Put a larger throttle arm on the carb and a smaller one on the servo. You should make it so your atv or end points are atleast 100% this gives you good resolution and full stick movement. Personally if you can get it to 120 or 140 then you are doing very well.

RE: Adjusting throttle sensitivity.
 

My Futaba radio has expo function availability on the throttle but I would much prefer to keep it deactivated and reduce throttle sensitivity by a mechanical adjustment, so I will certaintly give your suggestion a try and see how it works out.

Karol

RE: Adjusting throttle sensitivity.
 

WHY??????? You paid to have those features/capabilities, and expo can be easily changed. Mechanical settings are difficult to tweak, and can't be done easily while engine is running. Expo can be tweaked while the engine is running, making it much easier to get it like you want it..... but.... to each his own. ;)

RE: Adjusting throttle sensitivity.
 

I guess when one looks at it in that light you are dead right.....another true example of the saying " two heads are better than one ". Will use the expo to soften up the throttle. Thanks guys.

Karol

RE: Adjusting throttle sensitivity.
 

on my 9c -30% expo is a great starting point

RE: Adjusting throttle sensitivity.
 

Will see how 30% feels for starters on my 8UAF.

Karol

RE: Adjusting throttle sensitivity.
 

Yup, I run my gassers at -40% on my 9c.

RE: Adjusting throttle sensitivity.
 

Expo will soften up your idle to 1/4 + throttle... but ultimately from 1/3 or 1/2 + you will still be hyper sensitive. It depends what your ultimate goal is. You would get closer to a true response by leaving the arms the same length and adjusting both end points and using just a touch of expo.

The only way to get a true throttle curve with an accurate response to get full resolution.

I always try to get atleast 100 / 100 on my end points for throttle and might use 5-10 expo at best but usually its not needed at that point. Sometimes a little bit does help though...

RE: Adjusting throttle sensitivity.
 

My end points are at 120 both ways and the carb arm is longer than the servo arm. I think my problem lies in positioning the servo arm correctly on the output shaft. I already had -20 expo dialled into the throttle and was still having a problem when I started this thread. This is the first time I'm having such a difficult time in getting it right.

Karol

RE: Adjusting throttle sensitivity.
 

Karolh

Set the servo arm in line with the throttle push rod at idle, that way you get very little movement up the begining of the arc at low throttle and more movement as the servo gets towards the top of the arc, the correct way is to take a tach reading at idle and at WOT then set your carb and servo to give half the difference at mid stick, setting up either on the Tx or mechanically, I do both.

Mike

RE: Adjusting throttle sensitivity.
 

Sounds to me like it's not set up good. When you did this, was the engine closed and the throttle and trim switch down completely on the tx and servo closed with no mixing when you attached it?

RE: Adjusting throttle sensitivity.
 

I did all of the above with the exception that I had 20% of expo dialled in on the throttle. Positioning the servo arm/pushrod as Sinergy suggested and with a bit of expo added solved the problem and now I am good to go. Funny how sometimes the little things can be the most baffleing.....thanks all.

Karol

RE: Adjusting throttle sensitivity.
 

be sure you are using - expo,+ expo will speed up the low side throttle

RE: Adjusting throttle sensitivity.
 

That little sucker caught me once. Sure can laugh about it now, but it was no fun back then especially when you are in the air and it's on the elevator :)

Karol