Alright, this should be a simple task, but somehow I managed to screw it up: I am building a 4*-sixty, and when drilling holes in the wing & wing holding blocks, I managed to get them missaligned [:@].

In short, the holes that I made on the wing do not line up with those I made on the wing holding blocks. Long story, but while I was enlarging the holes in the wing holding blocks to install inserts (these ones: http://www3.towerhobbies.com/cgi-bin...?&I=LXE068&P=7) the holes got way out of alignment, so I have had to enlarge the holes on the wing to allow the nylon screws to line up with the inserts. The holes in the wing are now about twice the diameter (kinda oval shaped), and as a result, unless the screws are really tight - which I do not intent to do with nylon bolts - the wing can move a little side to side which is not good.

What is the best way of fixing this? I was going to glue washers with a 1/4" hole on top of the larger holes to lign up the screws to the blocks. Is there a better way of doing this?

Thanks!

You are going to have to fill in the holes and redrill

Drill out the holes to fit an larger size dowel that will completely fill the miss drilled holes. One can go to either Lowes or Home Depot and find hardwood dowel relatively cheap. Once the holes are filled then redrill the holes to match the ones that were drilled in the wing.

Can we see a picture of that cheese?[sm=bananahead.gif]

That's pretty much what I was going to suggest.
Big dowel (you know how big it will need to be).
drill hole up centre. Preferably on lathe.
Cut thin washers from end or find washers of same size.
Position wing accurately and screw down using washers.
Mark wing with pencil around washers.
Remove wing, cut out holes to diameter of dowel.
Test fit dowels and cut to required length and taper.
Epoxy in place with wing correctly aligned and screws only gently tightened.
make fair.
Go fly.

I actually do this "before" I make a cxck up! it provides a firm and durable screwing point.

psguru,

Thanks for the step-by-step explanation. I was wondering how to line up the dowel, this is a great idea!

I am guessing you are all talking about puttng this dowl in the fusalage and not the wing. It will be very hard to line up where to redrill though the wing when you can't see the mounting blocks in the fusalage. Then it will be very difficult to install those inserts into a hardwood dowel. I have been working on a Four Star 120 and have decided to use the kits original set up as I have seen it work in the past and saw no need to modify it other than I will be ussing metal bolts instead of nylon since the nylon bolts felt like they were going to break just screwing them in. Concider removing the mounting blocks in the fusalage and starting over, redrilling through the existing holes in the wing to ensure they are aligned.

ppkk:

Check this:

http://www.airfieldmodels.com/inform...ruction/11.htm

Mr67Stang - I did it a darn good job making the block solid to ensure the wing doesn't fly off (with traingle stock and fibreglass cloth. No worries, the rest of the plane is built fairly light!) so the blocks aren't coming off unless I cut a whole section off the fuselage . With regards to the installation of the dowells, I had the same question and I have to admit, I had to read psguru's posting a few times to fully understand what he is proposing. If I got it right, what he is suggesting is to line up the dowel first (taper and everything), and then make the holes in the wing to put them in. I don't see any other way than making a holes just a bit larger in the wing to allow some movement of the dowel after inesertion, and then filling the gaps with epoxy or Gorilla Glue when everything is mounted.

Inewqban - Thanks. My dowels are perfectly fine, the problem is the holding blocks. What Airfieldmodel explains is the correct procedre, but I have already messed up the holes so it's a little too late. My original holes were perfectly aligned, but when I enlarged the holes in the holding blocks to put in the inserts I messed things up. I think the issue is that I went from a #7 drill to a much larger size at once and that messed things up - lesson learned (I think next time I'll just harden and tap the hard wood instead of putting in the inserts. I was listening to advice from someone in our field, but it seems most poeple don't bother with inserts and they don't have any problems.)

No.
iWAS writing about putting it in the wing.
And yes, it is a fiddle, that's why there's all that blurb about marking out round washers.

Of course, the next time there's a wing screw to be fitted, the holes will be drilled with the fuselage open, so you can mark through the captive nuts, won't it?

I don't do it this way but was trying to picture the steps anyway... at this point..
Mark wing with pencil around washers.
Remove wing, cut out holes to diameter of dowel.

How is the wing held in place is you have a big hole the diameter of the dowl in it. I know I'm not picutring this properly in my head.

You are welcome, ppkk.
That is exactly what happened, the big drill bit changed the centerline of the original orifice, that is very common, and even more in soft materials.
One way to avoid it is to fix the fuse under a pressdrill and make diameters bigger for the same hole while keeping the same position.

I've assumed throughout that the wing is of foam core construction, otherwise it'd just be a matter of putting another piece of wood in place........

Note, skill is required for this exercise!

I don't know the size of the holes that are already there, but they will need to be of a size and location to allow the screws to go through the wing into the captive nuts.
So, the wing should be positioned and held in place by means other than the screws. Elastic bands are good.
The washers are placed over the holes and the screws put through The washers and then the wing. The screws are gently tightened down onto the wing. The holes in the washers should be just a clearance for the screws.
Mark around the washers.
Remove everything and then carefully cut out the hole for the dowels to slide through the wing.
Push the dowel into the hole that has been made and re-fit the wing. I prefer to leave the end of the dowels sqared off so that the heads of the nylon screws are not stressed by being tilted to the side by the slope of the aerofoil.
When you are satisfied that the wing fits squarely with the screws in place, glue it all up and let it set with the wing firmly held in place and the screws <u>gently</u> tightened.