Reaming vs Drilling

[dicel87]

I was recently out surfing sites and found a builder talking about "reaming" the prepunched holes as opposed to drilling them.

Is this just a different bit? Or is it different method of drilling?

Thanks
Scott

[captain_john]

You know Scott, I heard something to that effect as well. I seem to recall the reason for doing so was to achieve a "rounder" hole. The drill bits leave a triangular hole when used at the wrong speed.

Now, the next time I use a reamer will be the first time. That being said, I chose to continue drilling my prepunched holes in lieu of reaming them. My reason for doing so was, I feared the side cutting could be more prone to error. Essentially, the reamer could oblong the hole if used incorrectly.

I am using drill bits and getting good results. I ain't changin'!

Maybe I am all wet, but I just like using tools for what they were designed... unless of course it is my brother's!

CJ

[jim_geo]

From what I've seen from reamers they actually do give a rounder hole. They can also give you an over size hole pretty easily though. My two cents.

[nightflyer]

Reamers are available in very finely graduated steps, and when used properly, produce a close tolerance hole with a smooth surface finish. These are important considerations when you're making a precision hole in a machined part or other heavily-loaded structure; improves fatigue life, etc. THEY OFFER NO ADVANTAGE when you're drilling the vast majority of the parts in Van's aircraft, which are relatively thin aluminum. Using them won't do any harm; it's just a waste of time and effort, when a simple twist drill of the correct diameter will give you the size and quality of hole you need. Trust Van's engineering! If a hole needs to be reamed for precision, it'll be called out on the drawing or in the manual. Besides, reamersare expensive!

[arffguy]

I mentioned that on Dec 6. Nightflyer, you are absolutely right about "time and effort." The theory goes that drill bits are designed to drill into undrilled materials and enlarging a hole uses the side flutes of the bit and thus makes the holes less than perfect. I have heard this from other sources but primarily from the guy at Clear Air Tool. Of course he has reamers and drill bits to sell also. He seems to be a good guy. I have bought several tools from him including a pneumatic squeeezer and have gotten fine service. I won't bother with a reamer simply because of the cost and time to do 14,000 holes in an airplane. Heck, the RV already has twice the rivets (spacing wise) of a Cessna 182 anyway and it's a smaller airframe. If Van thought it was necessary to use the reamers he would have us do it that way. You are more likely to crash doing something stupid (like running out of gas or buzzing someone) than from an airframe failure anyway. It's amazing the little things you sweat when starting these projects and then after awhile it becomes second nature.