12V Linear Actuators

[kmacht]

I've flown lots of Cessnas with electric flaps, and not one had a manual over-ride.

Yes but that Cessna had an engineered and tested system built based on decades of experience and by degreed design engineers. The airplanes were also tested for controlability during certification should the flaps fail at any range between full up and full down. People here are buying and using linear actuators from all sorts of different sources and just connecting them to a switch without thinking through the what ifs or testing those what ifs. What if the switch or linear actuators shorts or jams and the flaps come down on their own or what if they won’t come back up during an attempted go around? It’s experimental aircraft and people are free to try anything they want. It’s the second or third owner or the passenger who doesn’t necessarily understand or know the risks they are taking on that worries me. Go build, try things, and experiment but please try to fully think through what could go wrong when deviating from the plans and don’t just assume that because it worked in the certified world that it will work on a sonex.

[Skippydiesel]

To All,

The linear actuator I wish to use, is for operating a small cowl flap. Failing down or up, will not endanger the aircraft. DOWN may add some drage and overcool the engine. UP may result in high temperature in Climb Out , this can be managed, by reducing power, increasing speed (lowering the nose) for an uneventful, circuit to landing.

[BRS]

"Cowl Flap" Now that bit of information helps a lot. Have you seen these?

https://antisplataero.com/product/ez-cool-cowl-flap/

[gammaxy]

The actuator on that cowl flap looks a lot like an Actuonix one: https://www.actuonix.com/

I mentored a FIRST robotics team that used a couple L16-R actuators that operate off 6v and a PWM signal. Not sure what exactly you're trying to do, but I think the L16-R I used or a smaller variant would be fine for cowl flaps, but not for wing flaps :-) They do have a big selection that I assume includes some faster ones with more torque.

[Onex107]

I was a student in a C-150 with my instructor practicing touch and goes at a grass strip 25 miles from our home field (and a mechanic) when the flaps failed down. It took some gentil altitude control, and a lot of time, to get back home.

[Skippydiesel]

"Cowl Flap" Now that bit of information helps a lot. Have you seen these?

https://antisplataero.com/product/ez-cool-cowl-flap/

The LA looks like an offering from eBay or CaryMart.

[quote="gammaxy"]The actuator on that cowl flap looks a lot like an Actuonix one: https://www.actuonix.com/

Could be but for some reason Actuonix do not have a viable offering below 50 mm extension - I need 20-25mm

Having investigated quite a large number of suppliers (in Australia/Canada/USA), it seems most, if not all source their small LA's from China.

So far I have purchased two LA's from CarryMart (Chinese) both have failed in the full extension position.

[Skippydiesel]

WARNING!
CaryMart appear to offer a 3 month warranty on their LA's.
Two unanswered emails down the track, I have a strong feeling that the warranty is bogus.
Should this situaton change, I will be only too happy to inform you.

[Jester504]

My Jabiru Sonex will easily climb with two people and 2/3 flaps. Haven't tried it with full flaps, though.

[BRS]

Weather was nice yesterday and warmed up (briefly) to above 40 deg. So I flooded my engine (R2300) and finally took to the skies. Note to self, stop over priming. At 3500', 70 mph, full-Flaps, full-throttle (85HP), 200#pilot 7gal fuel, the ship climbed at 600 fpm. Didn't try other speeds as the attitude felt about right and ~70 is what I want on final and would likely be close to that if I ever had to go-around with failed flaps.

Nice exercise, glad I did it, glad it works.

[Skippydiesel]

Weather was nice yesterday and warmed up (briefly) to above 40 deg. So I flooded my engine (R2300) and finally took to the skies. Note to self, stop over priming. At 3500', 70 mph, full-Flaps, full-throttle (85HP), 200#pilot 7gal fuel, the ship climbed at 600 fpm. Didn't try other speeds as the attitude felt about right and ~70 is what I want on final and would likely be close to that if I ever had to go-around with failed flaps.

Nice exercise, glad I did it, glad it works.

Linear Actuators?????????