dw_crash

My Feedback: (6)

Gents,

I have a Yellow Aircraft Spitfire IX. I have a sliding canopy on it. It uses a plastic sliding rail set to allow the canopy to open.

Problem is, when the engine starts, the vibration and was eventually wiggles it open. Then, the wash blew it off.....

What do people use to hold these plastic canopies closed?

Thanks,
Dave

wphilb

My Feedback: (10)

I cheated and used a 2-56 alloy allen head bolt through the rail in one spot that holds the canopy closed for flight. It's at the rear edge of one side of the canopy and is barely visible. I know folks have used magnets and velcro but I've seen too many depart the A/C in flight!

Also, consider next time used a mechanical means of holding the canopy to the rails, I've seen small screws used to good effect, or pins as rivets etc. But #1 is preventing wind from being able to get under the edge, I made a lip of fiberglass to go over the front rim of the fixed portion and extending back so that in the closed position there is an overhang of 1/32" or a bit more facing to the rear. That way the canopy can't buldge out in one direction or the other and allow the airstream to puff into the cockpit and overpressurize it and rip the thing off.

Sorry, no good pics, it's in storage right now!

Whit

dw_crash

My Feedback: (6)

thanks for the ideas.

I do have a lip. It is on the underside of the sliding section. You say it should be on the top makes more sense. Never thought of it.

Dave

Laird SS

It seems I've also heard of people using a section of square tubing with a slot cut in one side for something like the head of a screw to travel in. You might also try making the sliding action controlled by a small servo so that there is resistance to motion provided by the gears in the servo. Just a thought.

wphilb

My Feedback: (10)

Here are a few pics of my canopy install, I hope they help, I found them in my backup drive

I think you can see where I added material to the top and sides of the stock canopy. I did this by putting plastic wrap on the stock f-glass canopy and building up several layers of fiberglass and resin, allowing to cure and removing it and fairing it into the stock canopy forming a lip all around the front edge where the sliding portion meets the fixed portion. You can find it if you look but it's not evident unless you are looking for it.

Whit

dw_crash

My Feedback: (6)

Thanks Whit. I get the idea.

My canopy is plastic, not glass. But the idea may still work.

Dave

wphilb

My Feedback: (10)

Dave, 

BobH

My Feedback: (2)

Older YA kits didnt come with the fiberglass frame.

Another option is to put a small "stop" on the canopy slider.

dw_crash

My Feedback: (6)

Whit,

Mine is the older kit. So, no frame.

Dave

wphilb

My Feedback: (10)

Would it be possible to retrofit your plane with the new canopy and frame? Build up the overlapping lip at that time.  Better than losing it again when airborne!

dw_crash

My Feedback: (6)

Whit,

I have to check if the parts are available and fit.

Dave

wphilb

My Feedback: (10)

Good luck! I liked the Fiberglass canopy frame. It did fit my kit and I think I had an older kit and bought the new frame and canopy as an add on. Would not swear to it though. Sorry, I had waffles for breakfast, or was it cereal? 

dw_crash

My Feedback: (6)

he he he....funny Whit!