Countersink Technique

Reheat · Post by **Reheat** » Fri Feb 18, 2005 10:21 am

Maybe I'm slow and everyone else already knows about this....
BUT, I got tired of having the countersink get away from me and buggering up my work. Initially I went to the portable elec drill to use a slower speed. However, it seemed unless the work piece was wide and flat, I had a hard time getting the Microstop to work consistenly. Anyway, I noticed that the countersink would fit into the deburring tool handle and I just stuck it in there without the microstop and now, whenever space allows, I have complete control over this monster. Its a little slower, but for a hamfisted guy like me, its worth it! I just twirl it a little and check it with a long rivet, twirl some more if need be ... you get the picture. Like I said, it's a little slow, but consistent. You might try it if you are having problems like I was.

Post by **Spike** » Fri Feb 18, 2005 10:45 am

Reheat, I had major issues with countersinking and ended up trashing one of my HS spars. There is a whole thread about it in the Screwup Chronicles forum. It basically came down to bad technique. I encourage you to practice using the cage with a power tool and some scrap until you get comfy doing it. Otherwise it will take FOREVER to build the plane.

You can also check out my builder's log and see how I screwed up and how I fixed it. There is an "OOPS" category and more information on the second page of the Tail category. Here are some pictures to show how I kept the cage from tearing up the metal on my second go around.

-- Spike

Reheat · Post by **Reheat** » Fri Feb 18, 2005 1:45 pm

Hey! putting the wood beneath the work to keep the C/S from drifting looks like a great technique.

I'm finishing up the fus now and there are a lot of places on the QB that you can't put any backing. I just finished C/S the fwd upper skin/under structure and used the deburring tool on at least 60 - 70 holes. Took maybe 1/2 hour. When the surface is curved is where I really had a hard time using the cage as a little angle one way or the other produced a lopsided C/S. Could be my gyros are starting to precess at my age.

Thanks for the input. I'll give your method a try!
Cheers.