Ragz

Here are a few pics of my Da100 install. And here are my questions:

Pic 1,2,3,4 shows the choke lever from both sides of the carb. As you can see in the pic 1 and 2 the lever moves in a manner that necessiates the use of a bellcrank. Pics 3 and 4 show the same from the other side. Can someone show me how they rig up their bellcranks? How are others doing the choke lever, in case they DONT use a bell crank. Do you use a servo? where? how? The entire position is slightly odd and if I use a push rod to move the lever, it will be pointing vertically downwards, in line with the muffler exhaust.

Pics 5 and 6 show my "poorly" cut spinner. Is the gap between blade and metal too much? Will it cause problems in engine efficiency?

Pics 7 and 8 show the throttle servo. Is this a safe place to have a servo? What about vibrations? The servo is a hitec 225mg...good choice? any reco?

This is my second gasser, the first being a DA50 based plane that was much simpler to rig. Hence these questions.

DKjens

My Feedback: (50)

DKjens

Geistware

My Feedback: (16)

I would not use a bellcrank for the choke.
I would glue a servo arm to the choke arm and use it to extend the lever arm of the choke.
That is what I do on my BME engine.

The gap is good. So long as the spinner doesn't touch the blade, you are OK.
Make sure your servo mount for your throttle is strong enough not to break lose during vibrations.
I have seen this happen then you can't land until the fuel runs out

Ragz

DKJens, Does the 4-40 choke push rod exend vertically downwards? If so, wont it vibrate through the tiny cowl hole? I used to use this method on the needle of some large 4 stroke glow engines..and those push rods woud really vibrate throught the cowling. Can you provide me a pic of your installation?

Geistware, can I see how you glue the servo arm on the choke lever?

Geistware

My Feedback: (16)

This is the only picture that shows the choke arm.
I have to take my cowl apart and get my wifes camera to take another one.
On this I used a brass shim, JB welded to the choke arm.

pcm

My Feedback: (13)

You can take the choke arm off your DA and flip it over making it hang down. It will leave plenty of room for a 4-40 ball link and they fit perfect on the choke arm. Put the 4-40 ball link on the outside in the large hole on the choke arm. A small washer on the other side and bolt it together with the 4-40 bolt that comes with it. It will center itself on the arm.

I mount all my servos inside the plane. I don't like seeing fuel residue on my radio gear.

As far as the spinner goes I don't see anything wrong but cosmetics.

Aerohead

My Feedback: (37)

As far as the choke arm, use a piece of fuel tubing or a rubber grommet to cushion the rod where it comes through the cowl.

sillyness

My Feedback: (25)

Here's the wicked easy solution for a servo operated choke... been using this for several years now:

1) Go to LHS
2) Get a pack of dubro metal landing gear straps and star washers/short bolts/nuts sized to fit the landing gear strap
3) Bolt 1 landing gear strap to the choke arm (same side as throttle) with a star washer between the strap and the choke arm... use red locktite also. The strap should be set 90 degrees off the choke arm axis.
4) Now, when you push the strap forward and back the choke will open and close... bolt up a little ball link and some nyrod and you are set (use a long threaded rod in the end of the nyrod... you don’t want the plastic between the mufflers).
5) If using nyrod for throttle, use Precision rod instead... my throttle trim never changes.

Here are some pics... hope they help:

P.S.- On your setup, make sure your servo mounting bracket is really secure!!!
P.S.S.- As it works out with my method, if the motor comes loose and pulls forward, the choke closes.
P.S.S.- The last pic is there so you can see where my throttle and choke servos are located.

Ragz

Nice ideas...let me see how mine turns out...

lyka

perfect idea, sillyness . Congratulations !!!!!
I will install this system in my DA 100.
SO much thanks