How do you guys make those smooth, rounded, fuzz-free holes in your ribs?  Mine look like they are carved with a hatchet. 

I use a sharpened piece of brass tubing.I sharpen it by pulling a Xacto blade on the inside of the tubing. Sometimes I will cut a few teeth in the sharpened edge to let it cut faster. Does a really good job on cutting clean holes. I also use a template rib to center the cut in the same place on each rib. Otherwise you need some way to define the center of the hole.

Yep.

I also have an old golf club shaft that I cut off right below the first step down fromthe top..  That steel is VERY thin and will sharpen right up!

I use brass tubing and water pipe copper tubing.

Something I accidentally discovered is step drills will drill holes in balsa and aircraft ply without the tendency to tear like a standard bit will. They were very expensive but Harbor Freight has a 3 piece set on sale.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91616

I use a "Forrester" bit. They come in different sizes and make nice holes, and if you want that perfessional look back drill them.
Larry 

Or, you could get a set of Ebay item number: 270005397243 (I am in no way affiliated with the seller, just a cool way to do it)

EricV

  I've tried this technique, and it works pretty good.  I pirated a set of cork borers from the lab I work at.  They make a pretty clean cut, and it was easier than running down various bits of tubing to sharpen.....

Steve

I have been using the brass tube with wood handles that TY described for years, I have also added other sizes when needed.

Of, course, now I use laser cut parts in most cases.

To be fair to Steve Fitton, I had a little fun at his expense.    There's nothing new about making holes with brass tubing, we all do it for tank plumbing and such. He was doing the exhaust holes in his Avanti and was describing the pain of doing it with a Dremel and getting them round. Well, I finished an Avanti also recently, and told him I used brass tubing for even those large holes, went right through the plywood doublers fine, and I had the rings from the back end of the brass tubing in the palms of my hands to prove it! It was Steve that then had the the epiphany to use his Lab Rat knowledge and come up with the Cork Borers like I pointed out in the Ebay add. The handels on the Cork Borers make it a little easier on your palms too. So, kudo's to Steve on those.

And, just to add a little more to the discussion, I've used brass tubing in my drill before also, with a dowel shoved in the back where I chuck it in the drill to keep it from crushing the tube, with very good results. If you need really aggressive cutting, you can even nick up the brass tubing to get a serrated edge to cut faster, though not quite as clean of a cut. The tubing is soft, so use short lengths, only enough to drill the depth you need, and don't lean on the drill to hard.

Have fun boring holes in balsa & the sky!
EricV