Drill Press Challenge

Now that I own a whopping 3 drill presses, I thought I would see how well they perform in accuracy.  This may be a hotly debated topic, but I think of "runout" when I think of accuracy.  That is, how well centered does a cutting tool travel in relation to the center axis of the quill?  I have a dial indicator, so I can find out.

First up is my most recent acquisition - the Walker Turner drill press with a best estimate date of manufacture in the 1940s:

Find the low spot on a straight and solid shaft, zero the indicator, and then manually rotate the belt to rotate the quill to find the high side.  In this case, I'm showing about 0.0045 (four and a half "thou" as in thousandths of an inch).  Not bad.

Next up is my Atlas drill press given to me by my Uncle in Peoria.  I absolutely love this machine:  It's quiet, and smooth, and it has never let me down.  It also has the speed reduction intermediate pulley set for slowing down rotational speed.  Thus, it is a good metal drilling tool.  I believe this machine is 1950s vintage.

Results for the atlast:  0.0125 - about twelve and a half thou.  This is about 3x worse than the Walker Turner machine.  Hmmm.

Now we go way back in time to the granddaddy:  the "Champion Forge & Blower Company" Post Drill.  This is over a century old by now, and my best guess is this was made 1905-1910.  I have a previous post about restoring this post drill.  Let's the test begin:

This was a bit of a challenge to set up with my indicator.  The table is rather small, and the keyless chuck barely fit my 10mm straight shaft.  (I don't think this manufacturer knew what the metric system was 100 years ago)

Results were a bit crazy.  Runout was 0.170.  The needle on my indicator went all the way around and then alot more!  

I thought it would be cool to put a pencil in the chuck, and rotate it to visualize this runout.  It's easier to see this way.

I've read on some machining forums that the 3 jaw chucks in drill presses can wear after alot of use.  I believe that is the case for the Atlas - things appear to have some wear.  For this last drill press with nearly 3/16 of an inch of runout, I think the chuck itself is not centered in the quill.  I don't use it, so I'm not going to bother repairing it.  It's just a nice show piece.