MT portable drill - a Q for the engineers?

[ivan]

I was recently given an old (what I think used to be called) blacksmith's portable electric drill; about 300 rpm / Morse 2 taper / 2 big side handles, and in good condition. There was something similar 40 yrs back at our village forge (long gone), used sometimes in agricultural machinery repairs.

I have a small range of suitable twist drills as the bench machine takes M2 taper, but to be honest the bench machine doesn't really like it as the whole structure isn't really man enough, so the drills are prone to chatter in mild steel. My first trial with the portable (14mm) proved I wasn't man enough either and the resulting breakthrough jam bent the tang before the motor stopped...

Anyone know the secret of drilling mild steel with such a beast?

 

[jasonB]

I have always known them as "gut busters" as thats what happens when youy get a jam :shock:

14mm with a hand held is not easy in one go, try 6, 10, 12 & 14

Jason

 

[AndyT]

It's a bit off-topic but I think you are describing something like the drill described by Neal Stephenson in his classic essay on operating systems In the Beginning Was the Command Line.

"The Hole Hawg is a drill made by the Milwaukee Tool Company. If you look in a typical hardware store you may find smaller Milwaukee drills but not the Hole Hawg, which is too powerful and too expensive for homeowners. The Hole Hawg does not have the pistol-like design of a cheap homeowner's drill. It is a cube of solid metal with a handle sticking out of one face and a chuck mounted in another. The cube contains a disconcertingly potent electric motor. You can hold the handle and operate the trigger with your index finger, but unless you are exceptionally strong you cannot control the weight of the Hole Hawg with one hand; it is a two-hander all the way. In order to fight off the counter-torque of the Hole Hawg you use a separate handle (provided), which you screw into one side of the iron cube or the other depending on whether you are using your left or right hand to operate the trigger. This handle is not a sleek, ergonomically designed item as it would be in a homeowner's drill. It is simply a foot-long chunk of regular galvanized pipe, threaded on one end, with a black rubber handle on the other. If you lose it, you just go to the local plumbing supply store and buy another chunk of pipe."

It's a fascinating essay for anyone interested in IT - available at

http://www.cryptonomicon.com/beginning.html

Andy

 

[Grinding One]

You were using a slow speed and cutting oil weren`t you??The oil is to keep your bit cool and prevent binding...