Comment

Comment by Normand Lambert on July 19, 2010 at 11:23am

Hi john,

Nice if it works out ! Mine will be very low tech. I've seen this on certified float planes...Mirrors set on the wing permitting view to the wheels... Effective if the mirrors aren't foggy. For the struts, it's in Montreal. I can get you the info to phone in. Let me know.

Also, I've done the switch from air operated actuators to electrics...WORKS real good. I can provide pictures.
I used the old Zenair amphib floats and modified the mecanism slightly. Easy to do.

Norm

Comment by Ron D Leclerc on April 30, 2010 at 5:09pm

Hey John

Whose floats do you have... I'm interested in the setup.
I have a few questions about the floats and also your redrive... can you e-mail me?
imfow@mts.net
Ron

Comment by Jake Reyna on November 8, 2009 at 6:48am

John, I'm putting this information into my mental toolbox should the opportunity arise to use a linear actuator. The first entry will be, Ask John ;-)

Jake

Comment by John Ellis on November 7, 2009 at 2:17pm

Flaps - yes many folks already use the electric linear actuators to run thier flaps. You don't really need to add any limit switches since the actuator has an internal resistor that indicates position. All you need to do is connect a rocker switch for extend/retract and have a indicator similar to my LG one above, or the fuel gauge you mentioned.

John

John

Comment by Jake Reyna on November 6, 2009 at 7:58am

John, I went down a similar path developing a Flap position indicator. I modified a VW fuel sender used in the Zodiacs to act as a Flap position sender, the float rod is attached to the actuator rod and then modified an inexpensive Fuel gauge to show the range of motion, instead of Empty and Full, I show Up and Down with a couple of intermediate marks for 1/3 and 2/3 flaps. Total cost, $50.

I had never thought of linear actuators, it made me pause and wonder, where can I use one of those? So, it's in my experiMental tool box. It could be used as a Flap motor, you would need to add a couple of micro limit switches for intermediate stops, this is something I've seen in RV's. Here's a some info and the link in case you need more ideas.

"Flap motion is accomplished by an electrical linear actuator the switch for which is located in the center bottom of the instrument panel. Flap deployment is encoded by a cam attached to the torque tube which successively closed up to four micro-switches. The number of closed micro switches is shown by light emitting diodes (LED)on the enunciator display above the radio stack, none for fully retracted flaps and four for fully deployed flaps. Flap angle is roughly 10 degrees per illuminated LED."

RV site

Jake

Comment by John Ellis on November 5, 2009 at 3:02pm

Jake - Thanks for the question...

Position indicator - The linear actuators typically have internal limit switches that are not accessible. This makes it good in one sense that they automatically stop at the limits but you can't use the switch to indicate the full travel position. They do however have potentiometer output that can be used to sense position. I could use two voltage comparators to determine if the actuator is at its limits but this would actually be slightly more complicated then the bar graph which only needs four components as compared to seven per wheel.

I took a look at the Ray Allen product. It needs switches rather than the pot that the linear actuators have. Plus the parts for my project will run me less than 1/2 the cost of the RA product but I do have to do a bit of machining to make the indicator body.

Thanks again for the question it gave me an idea to make this a bit better. The RA product you pointed out has blue top lights for seaplanes. I should go blue too…

John

Comment by Jake Reyna on November 5, 2009 at 1:57pm

I'm sure you know that Ray Allen offers a Gear Indicator, but will only indicated Up or Down, unlike trim indicators. My question is, what is the advantage to having a position indicator? If your gear isn't all up or down, does it matter since neither is good?

On the other hand, it's experimental and that's the only reason you need to build a better indicator.

Jake