beefy servo to retract 22" wheels

[Dave Krall CFII]

Been searching google, etc. with no luck. Need strong electric servo with 8-12" travel that can hold two 22" main gear on 2' legs during rough surface landings, under 1400# plane. Any sources?

 

[Dave Krall CFII]

Been searching google, etc. with no luck. Need strong electric servo with 8-12" travel that can hold two 22" main gear on 2' legs during rough surface landings, under 1400# plane. Any sources?

Well I finally made some real progress on my own when I started calling the mechanism by its right name, "linear actuator"! There's some 8 to 18# units out there by TracMaster that look like the ticket for $300 to $400, that can move 250-500#. That's the ticket, with pins to lock the gear in up & down positions.

 

[SCCutler]

Dave:

I would be concerned about having a pin system which was robust enough to take the stress of landing while remaining reliable to engage and disengage. How are you planning on handling that?

 

[Dave Krall CFII]

Dave:

I would be concerned about having a pin system which was robust enough to take the stress of landing while remaining reliable to engage and disengage. How are you planning on handling that?

Big and well lubricated.

 

[SCCutler]

Big and well lubricated.

...hmmm...

 

[Dave Krall CFII]

...hmmm...

The pins' cross section should be thick enough steel or titanium to withstand 40,000# of shearing force I figure. They can be smoothly placed or retracted from their placement via SS cables connected to limiters on the linear actuator.

The pins isolate any real landing shock forces from the actuator.

 

[Jim in NC]

The pins' cross section should be thick enough steel or titanium to withstand 40,000# of shearing force I figure. They can be smoothly placed or retracted from their placement via SS cables connected to limiters on the linear actuator.

The pins isolate any real landing shock forces from the actuator.

I would think you would want to look at some landing gear designs that utilize an "over center" feature to the mechanism. That way, the load is not transfered to the actuatior, or pins, but instead by the linkages of the gear, itself.