Piston spring for seaplane door

**pa12pete** · 07-03-2021, 09:44 PM

Hi all,

I have a PA-12 with a seaplane door and want to put a piston spring on the door. I’m tired of getting bonked on the head when I inadvertently release the latch that is currently installed.

Anybody done this? Any advice on piston selection?

Thanks,
Pete

**stewartb** · 07-03-2021, 10:12 PM

Read this thread. https://www.supercub.org/forum/showt...vice-amp-ideas

**cubdriver2** · 07-03-2021, 10:14 PM

You just want it to stay up on the ground or do you want to fly with it open? Most don't stay open all the way in flight, added a latch to hold mine fully open in flight

Glenn

**skukum12** · 07-03-2021, 11:58 PM

HaHa, I suppose bonking the head qualifies for medical matters.

**KJC** · 07-04-2021, 06:58 AM

This is the rod you need. Note the part number. Order the ball sockets with the rod. You need to fabricate the brackets out of stainless. Make sure you install the gas piston at the top. It easily keeps the door open in flight or on the ground. Be sure to space it so the gas piston fully extends and don’t allow the door handle to contact the bottom of the wing. TIG the lower bracket neatly to the door frame so you don’t have to drill holes in tubes.

Click image for larger version.

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Click image for larger version.

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**cubdriver2** · 07-04-2021, 08:23 AM

Originally Posted by KJC

This is the rod you need. Note the part number. Order the ball sockets with the rod. You need to fabricate the brackets out of stainless. Make sure you install the gas piston at the top. It easily keeps the door open in flight or on the ground. Be sure to space it so the gas piston fully extends and don’t allow the door handle to contact the bottom of the wing. TIG the lower bracket neatly to the door frame so you don’t have to drill holes in tubes.

My doors are a lot lighter then yours, 1/2x1/2" x .029 wall tube. I tried a heavier strut but my door would have folded in half when trying to close it. Good luck in your search

Glenn

**KJC** · 07-05-2021, 08:24 AM

I have no idea what you mean. The above photos are of a stock door with a Lexan cover. That gas piston works perfectly.

**WindOnHisNose** · 07-05-2021, 08:34 AM

Originally Posted by skukum12

HaHa, I suppose bonking the head qualifies for medical matters.

Having bonked my head on the door (and about each and every part of the wing) this thread may belong in Medical Matters. Pete texted me and asked me to move this thread, so it is now moved.

Hope your 4th was a great one. Always nice to celebrate the Birth of our Nation!

Randy

**pa12pete** · 07-05-2021, 12:35 PM

Thanks guys.
Thanks for the great details, KJC. Where did you get that piston and ball joints?
Here’s to minimizing the head bonking…!
Pete

**stewartb** · 07-05-2021, 01:49 PM

My Cub uses gas springs and this time I used Guden. Stainless isn’t important unless you like the look. Mine are all black nitrided and they work great. All gas springs I’ve used had to be ordered with the proper ends. There’s a link for connector options on the website. https://www.guden.com/itemDisplay/st...al-gas-springs

Here’s the current link for SPD gas springs, now know as AS Raymond. https://www.asraymond.com/struts.html

**MT12** · 07-05-2021, 08:00 PM

Here's a couple shots of mine. I had a hard time trying to do the math, so I just went down to the local Carquest and bought one that felt right, as I recall it's a 25 pounder. I welded up the brackets and attached via vise grips to fit. It worked but it felt weak so I put a bracket on the other side, again it worked great until I bought a second identical shock and mounted them both up. The door wouldn't fully close, it was an angle thing I guess. Thus the second 'lightening hole's in the one photo.