Oh snap!

[AlexPeterson]

Originally Posted by Draker

"Pull" rather than push sounds interesting but how would that work when the tool will not yet pass through the holes? For example, prior to reaming, I believe the -7A gear weldments come from Vans drilled to 9/32".

Reamer shanks are smaller than the flutes. Put it through backwards, connect to drill. One would have to inspect the reamer to be sure the flutes have appropriately sharpened/formed features on the shaft end. Some sort of bushing on the non-flute end would be necessary to get the initial alignment coaxial.

[fixnflyguy]

Welcome to reamer 101! At my day job, we run reamers well over 2" diameter all day long. Reamers are very brittle due to hardness,and will not handle even the slightest of side loading well. The only part of the reamer that "cuts" is the beveled edge on the front of the reamer, and typically, it will be custom ordered with a short pilot section that is cut down to the starting hole size.The flutes merely keep the reamer going straight through the hole. If you are using a "straight" (unpiloted) reamer that is .311, you will rely solely on a steady hand to keep it straight through the hole, and it should be run slowly with moderate pressure and well lubricated. "Pulling" a reamer can only be done with one made to do so, typically called a shell reamer that is slid over a boring bar and run with specialized device you wouldn't need for an RV project. When I run a reamer through an object, I will often pull it out using only hand rotation of the drill motor to remove it, thus preventing any additional material damage from the back edge of the flutes. Good luck!

[Draker]

Thanks for all the tips. It sounds like it would be always preferable to use a drill press to work the reamer when possible, rather than a hand drill, in order to prevent the possibility of side load and hand wobblyness. Live and learn.

[sblack]

The reamer should only be removing that last little bit to bring it to size. Don't try to remove 1/16" with it. 10 thou maybe? Alignment is also critical. Not easy to do.

In shop class back in university a guy was hauling on a 5/8" reamer in a huge radial drill. The flutes were packed full. It sounded like a 357 magnum when it went. Scared the **** out of 20 people in the shop.