Would someone please show me with a picture or two how to install nylon wing bolts. I need to see both how the bolts screw into the nuts in the fuselage and what modifications or reinforcements are done to the wing for the bolts. Here is the plane I'm working on. Thanks.

I don't have a picture for you, but there is usually some 1/4" plywood blocks, maybe about 1" square, which are epoxied to the fuselage sides with some tri stock reinforcement underneath. The plywood blocks are drilled and tapped for 1/4-20 threads, and then the threads are hardened with thin CA. I like to run the tap through again after the CA dries, to clean up the threads. Make sure that the blocks do not conflict with your torque rods.

On the wing, there should be a thin (~1/16" ) plywood plate that covers the bolt area of the wing, and you drill holes large enough for the 1/4-20 bolts to pass through cleanly.

Here's a picture of the mount for my Bel Air 40. You'll notice on this one that there is a single plywood block which spans the fuselage, rather than two short blocks. On this plane, it worked out, but on my Four Star, a solid block would interfere with the aileron torque rods.

Of course, you also need a dowel or two in the leading edge of the wing, with matching holes in the fuselage former to accept the dowels. You can see these holes on the left side of the picture, in former F-2.

I won't argue with mclina - that's what I would do... but unless I can be shown the forward bulkhead from another angle it looks like there isn't a place for the front dowl.

As it sits, it looks like this is a trainer that was meant to have elastics holding the wing in place and there aren't any signs of a method to secure the leading edge by either a dowl into a bulkhead or a cross dowl to secure elastics.

Can we have some more photos? []

may be its easier to have rubber bands to hold the wing.....
can the wing accomodate rubber bands?
that is what i would do. (the rubber bands)

anyway added some pics of nylon bolts

Aug, my question is this:

Is this plane designed to use wing bolts, or is this a modification you're doing?

Instead of threading a plywood block I prefer to install 1/4" x20 blind nuts.

You also have to reinforce the wing to accept the hold down bolts and dowels. If the wing was originally built for bolts then this is not an issue, but if not, you’ll have to modify it. Generally a plywood plate over the trailing edge will be sufficient for the bolts, but for the dowels you’ll have to open the wing and put some 1/8� – 1/4� plywood in for the dowels to go into. These normally attach to the spar, but if you have a dihedral brace then you need to add 1/4� plywood onto the dihedral brace to reinforce it where you’ll drill a hole through it. You also need to reinforce the leading edge with some balsa blocks for additional support where the dowels will penetrate it.

If the plane was built for rubberbands, just leave it that way - they work fine and are time tested.

Hogflyer

Thank you all for your help. The plane is a trainer originally designed for rubber bands. I just wanted to use a design on the wing that would be obscured by the rubber bands. I see the two dowel holes in your picture. I see the plywood strip you are talking about. I have one in the front and the rear. Can I use four nylon bolts, two in the front and two in the back or that would cause excessive damage should I have a bad landing?





This is the front of the fuselage wing saddle.

You may be able to use four bolts, but it will involve some structural work on the wing. It looks like the plywood mounts you have in your fuse could be used for bolts. You'll want to make sure they have tri-stock reinforcement underneath.

On the trailing edge of your wing, the thinner part, a 1/6" plywood plate would probably suffice for reinforcement, but on the thick, leading edge, you would want to be concerned about crushing the wing with the bolts. You would need to do something to strengthen through the thickness of the wing.

AUG,

If what’s bothering you is cosmetics then I’ll tell you that the most important view of the plane is the bottom (flying).

There are reasons for using rubber bands on trainer wing:
In case of hard landings I’ve seen rubber bands tear, nylon bolts never brake, the wing and fuse do.

Wing with bolts has a wood dowel in the leading edge to hold it in place and more important it has reinforced structure of glue and wood around it inside the wing.
Also the back of the wing with bolts designed for bolts, pushrods wise etc’

If I could I would use rubber bands in every plane I have over nylon bolts.

If you are missing a nylon bolt you are not flying, while rubber bands are endless.

There are a lot more reasons to use rubber bands over nylon bolts.

Just my 2 cents.

Alex

Thank you Alex. You've convinced me to use rubber bands on this model. I'll save that design idea for when I get more proficient, maybe on my next model. At least I did learn a lot from you all about the subject. You guys are great and it is appreciated.

Good choice. Alex is absolutely right. Buy a big bag of #64 rubber bands from Staples, and forget about the nylon bolts.

After you get used to looking at your plane with rubber bands, they become invisible.

Just in case you are interested; this article may assist you in making your decision.

http://www.masportaviator.com/ah.asp?ID=106&index=2

Regards,

Clay

As far as cosmetics. Some guys at the field I fly at have colored rubber bands in a variety of colors. I don't know where they came from but you can look around.

All rubber bands are not equal. Usually those from stationary supply store such as Stapeles or Office Depot are very poor for our use. Not very elastic and definately weak. Go to your local hobby shop and get some Sig bands, you will see a big difference in quality. You can also get different sizes, the #64's are a little short for some planes, any with a chord of over 10 inches.

A few years ago I converted an Ugly Stik to use bolts instead of bands. It was actually a lot more work than I thought it would be, but it came out OK. It was a 60 size plane so I felt the wing needed extra reinforcing. The hardest part was getting the wing dowel aligned with a hole in the bulkhead. I did it by drilling a small hole in the wing leading edge, inserting a piece of pencil lead, and using that to make a mark on the bulkhead. I used a wing bolt kit made by Du-bro. It included the bolts and two plastic pre-threaded blocks that could be bolted to the fuselage sides. Was it worth the effort? I guess... Well, anyway you all have to look at the drawing I worked so hard on...

Nice! I'm saving this for future reference. Thanks.