hi folks,

is any one other than me having problem with main gear doors,i have my UL equiped with kingtech k210 and electron retracts and lineal actuator for 3 doors.the only 2 times i flew full power first time blew one door,so i replaced hinge system for a very strong industrial style steel hinge.the second flight i flew it full power one door fluttered,so i reduced power and landed,aluminum control horn was bended,before anyone asks doors close totally flush and closing is very stiff.
any advice is welcome.

I bet pics would help out tons here.

I agree with Ravill-pictures of your set-up would help! With that said what epoxy did you use on the hinges and did you mount the opener on the front end or the backend of the doors.

There you go....

Sorry but I don't see in any of your pictures where the Comp/Arf supplied textolite piece that gets glued on to the door. Its for the actuator to connect on to. How is your actuator connecting to the door?

as i said before they blew off,attached is how i´m fixing it.

I've hear of using a magnet to help keep the door closed and prevent the airstream from blowing it open.

it’s not the hinges that need beefing up, it’s the actuation horn leverage that needs increasing. Post a picture of the angles you have on the actuator ram please

D

Dave.horn geometry is ok .lever is a little closer to hinge point due actuator is 25mm stroke not 30mm as original.

Sorry poor drawing quality

Change the drive point so that you have more leverage (longer moment arm) in the gear closed position.

You might need more throw from the door motive force (servo, air cylinders, linear actuator) but that is the breaks

.....and here I was hoping someone was posting a really good tip to fix this chronic problem on the Ultra Lightning. I am close to having a tub made to fit under the gear. My theory is to have the gear retrack onto that without gear doors - like on the Ultra Flash. This will seal the wing and not allow air to get inside.

JanR