Hi Guys,

I need a large hatch (about 8") on the top of my plane. It will be opened after every flight.

Ideally, it would be hinged at the front, (or side) and held down in the back with a quick release, like the one from Hobby Lobby that is spring loaded.

Does anyone have any experience with holding down your hatch with magnets? I would like it to be as "tool-less" as possible.

I have several ideas, but I would rather use (copy, steal?) an already tested design from one of you guys. ;-) 

Does any one out there have any ideas? .... Pictures would be greatly appreciated. 

TIA for any help on this. 

I usually use a screw in hatch, but it's not 8".

Rudy

I have used both the spring load latch ... from BVM models, they were originally used on jets and they work well. Springs are a bit strong and you need a good hard fingernail to deal with them constantly. I am using one on the top hatch of my electric smoothie.

I have also used the magnets. They will be what I use anytime I am building the structure rather than dealing with a premade structure (smoothie arc). I have used the small ones, about 5 mm from hobby shop, about $10 a pair. They work very well. You can get larger ones, about 3/8 inch at Jo Ann's fabrics. They are alot cheaper. The comment of good structure is true. They hold very well. Put some kind of a hold down at the front of your hatch, like a dowl or a tongue in groove, and two magnets at the back and the hatch is going no where and will require a good grab to remove. I am using them now on all the cowlings of my RC planes and will be on all future stunters as well. A good idea though is to have lateral guidance on our cowl so the magnets are only retaining downwards, not laterally at all. I have seen some that guide laterally well, they have a dimple on one magnet and a protrusion on the other that locks lateral guidance really well but most do not have that. They came on my Brio-10 rc electric pattern plane but have not seen those in a hobby shop as yet.

I always liked the quarter turn latches Bob and Rolland McDonald showed me how to make years ago and used them in all my planes since I returned to stunt last year, but after using magnets last fall and winter in RC ships, they are the direction to go. Oh, the jet guys are switching over too.

Bob Branch

Thanks for all the info. guys. :-)

I ordered some magnets and will try them. My R/C ships all have bolt down hatches, but the magnets sound like a good choice for our CL size planes. I'm glad to hear they hold so well. I will try to secure them well, and make some form of finger hold to lift the hatch. .... I'll try to get some pictures posted when I am done.

Thanks again for all your help.