Jan 2013 Engineering Change - Aluminum Door Formers and Sills

[John Bickham]

I'm working on my door formers and sills. I decided to give the aluminum a try for the corrosion reasons stated and maybe save a few ounces. It takes more time to do it this way welding on the tabs first. There are also little details with attaching stringer tabs, door hinge locations and such. I have had the luxury of following the lead of Russ, Eric, Paul M, Wayne M (Kitlog sites) and others on steps they have taken in building. I haven't seen any other builders use the aluminum formers yet. I think this is standard on the LSA but not sure.

Just curious. Anyone done this yet? I'm guessing the Avipro kits are still using the steel formers.

[whee]

I did it. It sucked and if I was doing it again I'd use steel formers. In fact, I'm going back and replacing all but the baggage door sill with steel. However, I did raise the front sills for Seaplane doors; if I had not done that I'd probably leave those sills AL also.

Thought I should add a couple things. My dad and I are not expert sheet metal workers. If we were I'd for sure keep the AL formers/sills because they weigh about half as much as the steel. The trouble we were having is we couldn't make some of the bends in our modified sills without cracking the 6061. We also didn't like how the 5052 formers came out that had sharp bends. "Quality First" and we just didn't feel like we could produce high enough quality AL formers/sills. Welding all those tabs is the part that really sucked.

[Mark Moyle]

Have done the right and left door formers in aluminum.


Sent from my iPad using Tapatalk

[Mark Moyle]

Don't know as I would do this again. I'm rebuilding a PA20 and have replaced all the door formers due to a service bulletin....with Univar parts....sure was easier than this aluminum stuff.


Sent from my iPad using Tapatalk

[John Bickham]

Thanks for the info.

Appreciate the input on your efforts Jon (right?).
There is a lot to admire in those photos Mark. It looks like you both raised the thresholds. The work is something to behold. The tools and machines in the background are even more impressive.

I've gone OTR (off the reservation) a little on these formers. I've added a little to the tabs for extra support, especially in the widest widths. I also wanted to have a flush face on the cargo door forward post.

The one part I'm struggling with is supporting the aft bottom corner of the cargo door where both the vertical and threshold former taper to 3/4" tubing. Not seeing that being strong enough. Steel can be welded here.

Alum Door Formers (21).JPG Alum Door Formers (26).JPG

[Mark Moyle]

Raised threshold...yes. Seaplane doors. I made rear lower door threshold supports just like the bracket that support the control stick assembly..... Then welded on steel formers.. No aluminum for the rear door.


Sent from my iPad using Tapatalk