Throttle expo
 

Can anyone give me some numbers/tips for what amount of expo gives a nice linear response when using a Futaba/ ZDZ(40) setup. So far Im using like +50% and the response is still heavily biased towards the first half of stick movement. I have my servo and throttle arm running parellel to each other.... I also notice that it appears the last 25% of actual throttle movement does little to increase RPM... and yet Im using a inner servo arm hole so that the servo is travelling approximately 100%.
Anyone thought of mixing the throttle to itself(perhaps using a negative percent of travel to help this- Ive done that(with a +%) to double travel on elevators and it worked well) Thanks in advance:D

RE: Throttle expo
 

I use the 13pt curve. Then I can adjust it to where I really need to smooth it out. For instance I can really squew the bottom of the curve and leave the top alone. It's a lot of trial and error, but I think it works better.
RickP

RE: Throttle expo
 

Hi,

I'm not sure if your doing this already based on the quote, but if not, try this for a problem with the low end being more sensitive.

Install the arm on the servo in such a way that at wide open throttle the arm is close to perpendicular to the pushrod and at idle the arm swings back to almost parallel with the pushrod. This gives you much greater resolution at idle based on the fact that the standard servo's output isn't linear to begin with. It might need expo, it might not.

This is just one way to fix the problem mechanically instead of using a multi-point mix, but it is worth a try ;)

Later,

Willem

RE: Throttle expo
 

the first Thing you must do is take out any expo you might have put in.
Next run the motor and pay close attention to the throttle curve.
If the motor has most of the rpm below let say half throttle then start adding
negative expo (futaba) or pos expo (jr) to get the trottle responce that you want.
I use about -25% for my 3w qs106 and about -15% with my toc 100. Every motor will be different
depending on many different variables. Ie needle settings, Air flow around carb,norm running temp and so on.

good luck. Ihope this helps

RE: Throttle expo
 

Thanks for the ideas.. and sorry I must be geezing.. I'm having this problem despite running -64% expo not the + 50 I said... maybe a few more will weight in on this problem... Im using a Futaba 8U radio

RE: Throttle expo
 

Either take the expo up to -90% or use a point mix with Master and slave being the throttle.

RE: Throttle expo
 

Thanks Geistware, for being clear about the point mix- I tried the point mix last night but it seemed to me that only affected the first half of stick movement- maybe Ill try again tonight- meanwhile Im flying with a bunch of expo as suggested and might try Williembad's suggestion on linkage alignment

RE: Throttle expo
 

WIth master and slave being throttle
Try doing the following:
1=-80
2=-50
3=-30
4=-10
5=0
I think that this will give you the idea.