Hey all,

I have a 4 star .40 and am planning on cutting one rib off the wings. I was wondering how you round the wing tips? I like to look of it and would like to give it a try.

Alladin,
On a plane with a built up wing such as the 4-star rounded wing tips are usually made by shaping and sanding a block of balsa to the shape of the wing tip. Then that piece is glued onto the wing tip.

Ken

What Ken said and with final sanding done when the tip is attached to the wing. Best if an easy to sand glue is used such as a wood glue like Tite Bond II or Elmers (Aliphatic Resins) and not CA or epoxy. Apply glue and clamp in place until dry. You can even glue the balsa block in place and then rough out the shape with razor plane before starting to sand.
http://www2.towerhobbies.com/cgi-bin...&I=LXAA64&P=ML
Very handy tool for a builder, and inexpensive.

Ahh ok, I thought there was more to it like bracing and things like that. I'll give it a try after I clip the wings. Thanks alot for your responses.

If you want to just use a piece of sheeting to make the tip shape then it would take braces or fillets. We were discussing gluing on blocks and carving/sanding them to shape. It can be done either way.
Are you wanting tips more like shown here:
http://image.rcuniverse.com/forum/up...64/Rx96142.jpg

I've also just taken a thick piece (1/4 in or more) of balsa and cut it to roughly the shape of the end rib, glued it on and sanded it to the rib profile with a minimum of rounding. That also works fine.

When I carve a wing tip out of balsa I will usually take a router bit on my Dremel and hollow out as much of the inside of the block that I can. I do this to cut down on weight. Try to make sure that the weight of both wing tips is close so it doesn't throw the lateral balance of the plane off too much.

Ken

No bruce88123. I wanted to round them with a piece in the middle of the wing when looking at it from the side. Now I understand what you all are talking about starting with a piece of balsa and sanding it down.

Use bruce method but mount the piece in the middle and brace it with balsa gussets top and bottom. Be very carefull to get both ends of wings the same height. If you don't want the gussets to show thru the covering, undercut the gussets.