Disabling the mixer

01-04-2010, 04:22 PM

Robehouse | Disabling the mixer

Any suggestions, pro's & con's about disabling the mixer. Also, for max cruise, anyone have performance numbers regarding the ailerons setting '0' to -10? Thanks JR

01-05-2010, 11:59 AM

Mike | Default

There is a bit of information under "Flight Controls" on the old board that has not been brought over here yet. You might want to get in touch with Jack for more info. I don't have the mixer connected in my bird however the parts are there. I don't believe the mixer installation and minor lower stall speeds outweighs the squirrely safety issues at slow speeds. I remember reading somewhere, someone, doing some testing...mabe on the old board.

Go to the main page in this forum, goto the bottom, and click on the old board. The link will take you to the old board.

01-05-2010, 03:30 PM

Robehouse | Disabling the mixer

Thanks Mike. I appreciate the help. I’ve been through the info at the old site, Jack is next on my list.

JR

01-19-2010, 10:49 AM

Jack Ardoyno | Mixer Disabling

Hi Jerry,

I have been an advocate for disabling the mixer for almost ten years now. I'll try to distill my thoughts on the subject:

The principle is good in that the lowering of the ailerons along with the flaps should accomplish two beneficial effects: lower stall speed and lowering of the nose attitude for a given speed. After testing and flying many of the Seawinds now flying my conclusions are: the stall speed is lowered by one or two knots at water touchdown speed - 60 KIAS. The lowering of the nose is on the order of two or three degrees. These positive effects are considerably outweighed, in my opinion, by two negative effects, in most planes: loss of aileron effectiveness at landing speed and considerable increase in adverse yaw, sometimes to the extent of making the plane almost unlandeable for some pilots. I made an inflexible rule for myself in testing new aircraft: I would not make a first flight without disabling the mixer, because the negative effects varied so widely from plane to plane.

Although I spent six weeks building my mixer table and installing it, I have subsequently removed it from the aircraft, which is what I ultimately recommend for everyone. It may be disabled as follows: remove the actuating arms from the sliding table to the flap horns; set the table at optimum position for aileron angle (usually about 1/2 inch from the forward limit) and secure the table in one of two ways: using appropriate lengths of either reinforced gasoline tubing or 3003 aluminum tubing around the 3/8" ss table shafts and clamping in place with hose clamps. The tubing should be slit for ease of installation.

I would be happy to go into more detail if you like. My cell is 612 940-6425.

Jack

01-19-2010, 11:31 AM

Robehouse | Mixer

Jack, thank you for you input. I did disable the mixer last week using 'tube & clamp' and during some flight-testing was able to 'feel' the increase in aileron authority at slow speed and unable to realize any appreciable differince in stall speed. My ailerons are set at –5 to 6 degrees with no noticeable loss (or gain) cruise speed. Time will tell as I gain experience with the new configuration but so far, it appears that disabling the mixer is ‘the way to go’. Thanks again.

JR

01-20-2010, 10:27 AM

Mike | Default

JR, what are the flaps set to....?

I do notice a speed difference when the flaps are set neutral to -10*

01-20-2010, 11:18 AM

Robehouse | Mixer

Hi Mike, It seems that a -5 to -7 degrees (as opposed to -10), MAY yield a knott or two increase in cruise speed however, I need to do further flight test to confirm. I'll keep you posted. JR