Starting over on doors

I just got back from a wonderfully trip to Oshkosh and now have about 50 hours on the Hobbs. On the flight home I determined that I need to do something about the doors and would like to seek the general wisdom of the group to discuss options.

Here are my issues, yours may be different so please chime in:
1) Flex in the doors during flight is causing
a) gaps between fuselage and door edge. This is noticeable to me because I have not determined the best gap seal (Van's, Master Carr, etc) to use for my installation and so don't have any installed yet. The issue is that the doors flex a great deal, leading to pins pulling out and losing doors in flight. The seals cover up how much flex is actually occurring.
b) The window to door finish is cracking at several corners. Fiberglass tape around the windows did not prevent this (although they may have been sanded too thin.)

My thoughts are that the system does not have enough locking/engagement points along the outside perimeter and that the addition of one "safety latch" at the bottom center is not a solution to the real problem. The doors will flex and therefore making them stiffer (rebuilding with carbon fiber layers?) is another band-aid solution.

I keep thinking of how the Glass-Star doors have multiple points of locking/engagement and how simple that system is on "their" doors. Other thoughts, although not necessarily practical solutions are:
- Changing the hinge points to the front of the doors like the Cirrus. A potentially challenging solution but it adds a measure of safety to the design should other points fail.
- Having fixed engagement points along the top edge between the hinges that would automatically engage as the door is closed.
- Adding locking points along the sides and bottom as the handle engages.

Is anyone working on any of these or other approaches? What other considerations am I missing? I'm hoping to (re)start a discussion on this issue, find the best potential options, while identifying what others are trying or have tried. Your thoughts?

I don't have an answer to your questions.

My observation with numerous RV-10s with McMaster-Carr seals and with the doors locked, the doors don't move. I'm not flying yet, but I have to exert a little force to get the doors latched. I suspect the seals will develop a memory after being compressed after awhile.

Sean's safety latch also helps tremdously in closing the doors tighly. I think you are discounting Sean's work pre-maturely.

I'm sure that there are better ways to do the doors, but not without significant re-engineering.

bob

I thought the doors were a little flimsy after I installed mine so I did a few things:
McMaster seals, lengthened the pins and machined longer/thicker Delrin pin blocks/guides, made a center door cam lock similar to Sean's, then drilled a few strategically located 3/16" holes through the inside half of the door shell and injected mixed up pour foam to expand and fill a few of the cavities of the door while it was locked in place and allowed to expand and cure overnight. I cleaned up and plugged the holes afterwards with a little flox.

Nick the RV-10 door pins with the planearound center latch works very good.
Putting multiple pins around the door as you are describing is not the solution.
Adding some carbon between the doors will help especially up top where the hinges are. The main cause I feel for door flex in the RV-10 is because the doors are not properly bonded together at the start. I feel that many of these doors do not get the proper 3D glass bond between the inside and outside panels. Also many bonds on the outer edges are not prepped properly and these doors halves can be pulled apart very easily if there is a little gap. Your windows could be cracking because your door is flexing so bad because there is no seal. Also the doors will separate if twisted with a bad bond. The mcmaster carr seal is superior to all others I have seen. When installed properly using the aluminum pin guides and the Planearound center latch it is a very good system that works. Having no seals could be hurting your doors.

If your airplane is not painted yet I would do the Mcmaster carr seals with the planearound saftey latch and would also consider reworking the doors. If it is painted I would still consider the Mcmaster seals but also look at the seals that ATP sells or a variation of that with the Planearound saftey latch and aluminum pins.

FWIW

Geoff
320hrs N829GW

Geoff, I think that we are right when it comes to properly bonding the two halves together. Had I to do it over again, I would have added a layer of carbon fiber where able and paid more attention to the bonding. I recall that the instructions seemed to be fairly casual about just slapping it together. I would also look at how I might make the window recess a little deeper. My hind-sight has improved dramatically.

The doors have been painted and I have the flush door handles but not the third latch, which I will seriously look at adding. I still have to figure out what to do around the windows.

doors

With allot of TLC the doors will work, but can something better be designed? I?m sure it can, and for such a great aircraft, I would like to see a better door design some day.
Sorry I don?t have any solutions, only allot of elbow grease with marginal results.

Ditto what Geoff posted above

I have no problems with this setup.

Yep, my paint is cracking around the windows due to different coefficients of expansion. My house and car has cracked paint too. Military aircraft have cracked paint. In order to not have cracked paint one must leave an unpainted gap around all windows. Possibly filling with a flexible sealant only. Mine is not a show plane but it sure hauls the family and camping gear just fine.

After I complete my build I am going to order another set of door halves to experiment with. While my finish and fit on the windows looks great today , I know that a year from now they will have a crack around the perimeter. I unfortunately started down the line of using a gap filler and a black mask on the window. I really could not get it to work, and I went back to the standard install with a single layer of 6 oz glass. I used the Sika adhesive, which I now know, expands with heat, so it's just a matter of time
My plan is to modify the new door so the window installs from the inside with a bezel around the glass. This way it can be sealed with a simple silicon based adhesive, like many production planes. It can also be replaced very easily. There are several other improvements that I want to make in the latch mechanism that I have seen in various construction logs.

I am finally satisfied with my door operations. I installed the PlaneAround 180? mod and I have the McMaster seals. I can now let the passenger close his own door. I still watch, but there is no way the aft pin is outside if the PlaneAround cam is properly seated - which I can see.
John

More door questions......

I am creeping up on bonding my doors together. There have been numerous posts regarding the doors being too flexible. I have read some recommending carbon fiber in the hinge area, some using pour foam, some extra flox.

1- Has anyone made a door stiffening mod that they are happy with and would like to share?

2- If so, could you provide some detail? For instance, I cannot figure out where in the hinge area reinforcement would be best if placed.

I do have the PlaneAround 180 kit with third latch.

3-Any strong opinions on pre/post installation of the kit prior to bonding the door halves?

Could not have made it this far without all the help on this forum. Thanks to everyone who has posted advice in the past.

-Cliff

I am just ahead of you. My Doors are done. What would I do differently? The plans duck tape over the top is not good enough. I would drill #30 holes all around the upper part and install clecos. You can then fill the holes later. I have to do some filling of the canopy where there was some variance in the curve so the door matches. I did the planearound cam and am very happy with it. The number of hours spent on these doors is amazing. Did not use the VANS gasket bought a very similar gasket from macmaster with peel and stick backing. The glue and pop rivet vans gasket seemed like to much work. I cut the door frame back to much in a couple places so I put making tape on the door and applied a heavy coat of butcher block wax to it then shut the door and filled the gaps with epoxy and flox. Sand Sand Sand. Have fun you can fix mistakes in fiberglass a lot easier than aluminum.

Cleco sounds good to me....

Tom, thanks for the reply. I too thought about clecoing the top of the door to the fuselage. This gives me the courage to do it.

Will keep you posted!

Cliff, this has been hashed over before, but the "problems" with the doors is not with the design, but the execution of the design. My doors are stock, with the exception that I added Sean's center latch and used the McMaster Carr seals. Rock Solid, no flex. They also fall into place and close easily. My advice is to focus on building it right - good craftsmanship and attention to detail. As to adding Sean's latch before or after bonding the halves together, I did it after, and am not sure it would work out if you tried to do it before. Good luck and have fun with it.

before or after

I installed my Planearound center latch before I bonded the doors halves together. It worked out just fine

awmuhs said:

I installed my Planearound center latch before I bonded the doors halves together. It worked out just fine

Click to expand...

In hindsight, I think this is a great idea. I wish I'd thought of it. Fiddling around with all of that stuff inside the doors is tedious...

Here I go.....

Thanks for all the responses. I think given Tom and Alan's experience I will go with the clecos and try assembling the latch prior to bonding. I actually tried the clecos last night and they worked much better than any other weird taping or weighting scenario I had tried.

If I am nervous about the latch I can always remove prior to bonding, but it does sound easier to install prior to epoxy.

Will report on my success and failure. Hopefully the former, and hopefully soon.

Pukauma said:

Thanks for all the responses. I think given Tom and Alan's experience I will go with the clecos and try assembling the latch prior to bonding. I actually tried the clecos last night and they worked much better than any other weird taping or weighting scenario I had tried.

If I am nervous about the latch I can always remove prior to bonding, but it does sound easier to install prior to epoxy.

Will report on my success and failure. Hopefully the former, and hopefully soon.

Click to expand...

Anxiously awaiting your report, Cliff.