What's the best technique for enlarging already drilled holes?
For example, the holes for the center hinge bracket on the HS need to be enlarged to #12. I progressively stepped up the size but still got some "chatter" when starting the #12 hole.
Also, what makes the bit get stuck in these situations? I'm really not pushing hard, but when it hits the aluminum of the spar doubler it wants to bind and get stuck...
Thomas
Enlarging holes
The correct answer would be to use a reaming bit to enlarge the hole to the desired size. I've never even seen a reaming bit. I just used regular old drill bits. You might try a little lubrication on your drill bit and make sure they are sharp. Don't skimp on them. Buy enough to change out periodically. That's what I did for what it's worth.
Re: Enlarging holes
A reamer produces a higher quality hole than is possible with a drill bit. This is generally a non-issue when the hole will be filled with a solid rivet. However, in the case of bolts and especially close tolerance bolts, it is considered good practice to always use a reamer for the final pass through the hole in which a bolt will occupy. Additionally, to prolong the life of the reamer and enhance the quality of the finished hole you should use a lubricant such as Boelube or paraffin wax and make the final pass with a low RPM. Reamers are available in every possible size and the more common nominal diameters can be found at any good tool supplier.TShort wrote:What's the best technique for enlarging already drilled holes?
For example, the holes for the center hinge bracket on the HS need to be enlarged to #12. I progressively stepped up the size but still got some "chatter" when starting the #12 hole.
Also, what makes the bit get stuck in these situations? I'm really not pushing hard, but when it hits the aluminum of the spar doubler it wants to bind and get stuck...
Thomas
Rick
Rick Galati RV-6A
N307R "Darla"
N307R "Darla"