Getting A Straight Hole With Drill Press?

dontrinko

Registered
Registered
Joined
Aug 18, 2011
Messages
89
Sometimes when I drill a hole using my drill press the hole is not perfectly straight? i have checked with a square and the platform is perpendicular to the drill chuck. My drill vice has a "V" in it to hold round stock straight. i have checked this also. What am I doing wrong? Thanks; don

P.S. when I need a perfectly straight precise hole i use a lathe but i would think The drill press would be straight also
 
I have had pretty poor luck with hole sureness with a drill press, mill is a lot better. both are better then a hand drill for me.
 
The table on my DP tilts relative to the column slopes down from the middle toward the front and back about an 3/16 of an inch.
Make sure your quill is 90degee to the table.
If the table is 90degrees, does the vise hold things square to the column & quill?

Note: I cobbled this table together from 36inch tall I beams (legs) from a torn down bridge and left over 12" channel (top) from the same demolition.
All was twisted, bent and free. Works well for putting holes in stuff. Not so well if you want precision.
Come spring this table is being reassigned as an outside welding table and I bringing in a barn find gang table.
The reason I'm elaborating is that we don't necessarily need to spend huge money to make things work.
Question becomes what is the application and what are the tolerances.
What are the reconciliation options?

Having a good time in the shop and doing good work doesn't necessarily mandate spending huge $.

Daryl
MN
 
First what model drill press? Second most drill presses aren't precision machines. And I said most.
 
How did you check square?
Consider chucking a drill rod, or other known straight rod.
Then check square.

How far is it off?

Daryl
MN
 
Your problem could be more about the grind on your drill bit than the machine itself. Drills aren't real precise under the best of circumstances but if the bit isn't perfect it's pretty tough to get a straight hole that's on size. You might try pecking at it.
 
You might also try a center drill or spot drill to establish a better start to the hole. If your holes still wander as your drill deeper, then, as has bee suggested, look at the grinding of the point.
 
+1 to all the above.

Another possible cause of crooked holes is trying to use too much downward force on the drill bit. This is most likely with smaller diameter bits. They can flex if pushed too hard. It's also natural to bear down harder if a dull drill bit isn't cutting as fast as you think it should (don't ask how I know). So be sure your drill bit is sharp, and use cutting oil.
 
are you talking about keeping a hole straight when drilled into a round piece of stock? If that is the issue, then it could be your drill bit tip is walking as it tries to start the hole. For these situations I use a hardened drill bushing as a guide to keep the drill bit running true. You can make some pretty simple jigs to hold different size drill bushings == Jack
 
Back
Top