THROTTLE set up dle 20
 

help
i am having trouble setting up the throttle throw on this motor i had to do the EPA to low for it to trim out is there a way to set up a throttle control ,thanks

Go to the sticky titled "gas engines for newbies" at the top of this forum and follow the directions there. Basic set up is to set your endpoints at 100% both ends, trim in the middle and then measure the distance between servo arm and throttle arm at both ends low to high throttle and then make your rod length the difference between the 2 measurements. use the hole closest in on the servo arm and about 3/4" out from center on the throttle arm. Make final adjustments using end points. The trottle on the DLE is really at full with the arm only pulled back 3/4 of the way so it takes some adjusting to get it close to being linear. My throttle stick is right around the 3/4 point when the engine is at full, a throttle curve set up on the radio would help if you have that feature.

Here you go, I took it from the thread. But I would suggest you still read it if you're new to gas. 37. Throttle Linkage, Trim, and Adjustment - Our carbs are really intended to be nearly "full on" a majority of time...not to be continually varying them in the middle range which is our main usage. So, to get things "right", it's important (maybe VITAL) to properly setup the mechanical *and* electrical setups of the throttle and carb arms. Here's what I suggest:

Method A - Basic Approach

Full DOWN throttle trim is "cutoff", closing the carb completely. This is the full ATV adjusted on the bottom end. I set this by fine tuning the ATV so the control rod isn't binding the servo, but the throttle plate is completely closed.

Middle "detent" throttle trim is the "landing" and "taxi" trim setting. That is determined by a couple of things that inter-relate. First, in the System setup screen, set the Throttle trim authority to 50%. It is far too sensitive otherwise, for a gasser. Then, assuming that you've set the carb arm length to be slightly more than the servo control arm take off length, the 'half trim' should be where the plane will sit motionless when engine is fully warmed up. Finally, set the Throttle Curve function ONLY if you cannot get the low end sensitivity/linearity mechanically. Reason I suggest that is that the mechanical rotational and linear geometry of the arms can go a long way toward getting it "right".

Finally, the "full" trim is the "hot restart" setting, because my carbs tend to be leaner on the low end, so a hot restart needs just a bit more travel.

Method B - The Real Deal

Now - the "real deal" is to get the correct pushrod length. There are, again, many opinions on these mechanical setups, but I'll just describe mine, as it is consistent, repeatable, and reliable.

Use a Servo arm where the "take off" or "ball link attach" point is about 5/8" from center of shaft. Purpose of that distance is to ensure that you'll be close to needing 100% ATV on both ends of the throttle channel, making the "clicks" of throttle less profound. You don't want big differences per click, and a longer arm will be too much. Shorter arm requires too much ATV diddling, and introduces mechanical expo which may not be in the "correct" direction.

On the Carb, use an arm with the ball link take off point at 3/4" from shaft center. This permits more rotation of the arm, and helps solve sensitivity issues mechanically at the carb. Walbro carbs are HORRIFICALLY non linear and overly sensitive...


Now, with both arms installed, set your ATV to about 90% on both extremes. Open the carb arm to "FULL THROTTLE" (where it hits the mechanical full throttle stop), and move throttle stick to FULL throttle. Measure the straight line distance between the centers of the ball link attachment points. Now, go to full CUTOFF low throttle and low trim, and rotate the carb arm to FULL CUTOFF. Measure that straight line difference. If not the same as the full throttle length, take the average. Create a Carbon fiber, or stiff metal pushrod of EXACTLY that length.

Install. You will be very close to "perfect". Tweak the ATV end points as needed, you perhaps will need to adjust the Throttle trim authority again, but you will be very close to a good linear setup. If it isn't like you want it, THEN setup the Throttle curve function, but not until after all the mechanical stuff has been taken care of.

DLE throttle set up
 

Love your approach to this. I hate to sound stupid, but what is "ATV"? I'm using a Taranis X9D plus and that has no meaning to me.

ATV = adjustable travel volume
Also, EPA (End Point Adjustment)
End Points
Travel

Whatever your radio calls the way to adjust the throw or end points on a given channel, no idea on a Taranis but that should give you an idea of what to look for

A lot of guys make the mistake of setting the end point too far open at wide open throttle. That has a tendency to burn up servos (happens all the time!), especially digital servos. Instead, leave a very noticeable amount of throttle travel at wide open unused. There will be no loss of power, even if you were to leave 10% of the throttle travel unused.