Drilling errors and solutions

[magicniner]

I can't drill for diddly by hand. I find that I simply can't figure out how to drill perpendicular to the workpiece no matter how hard I try.

Get a small piece of mirror or mirror finish stainless with a hole in the middle, with the mirror on the surface you're drilling and your drill through the hole, the drill is perpendicular when the drill bit and it's reflection appear to be one straight bit - simples! ;-)

 

[spumco]

Get a small piece of mirror or mirror finish stainless with a hole in the middle, with the mirror on the surface you're drilling and your drill through the hole, the drill is perpendicular when the drill bit and it's reflection appear to be one straight bit - simples! ;-)

Great idea, but if I'm drilling by hand, I'm probably just making a butcher hole somewhere in the target vicinity. Think spade bit in wood. And I'm usually drilling at some odd angle and would need a 3rd hand to hold a guide.

If I need it precise, I use the mill.

 

[TakeDeadAim]

There was a great vid by Jon on his NYCNC YouTube about accurately laying out. Even though for the last 10yrs of my wage slave tour was metal fabrication, this laying out then drilling holes was my nemesis.

What Jon showed was how using a trisquare and the scribe to lay out your line accurately, then using an auto punch by feeling the scores made with the scribe. I could now get the absolute center of my scribe lines, then like has been mentioned come back with a good sharp center punch. The other thing was using a two step 1/4" drill to start the hole. But all of this is moot if you are not at least using a drill press because it's impossible to stay totally straight by hand. YMMV.

Ive seen Jons video and that technique works great to make one or two accurate parts. However; this poster is looking for a solution to production drilling. As suggested by many a fixture with drill bushings is the answer. No need for layout or measuring each piece once the fixtures are made you simply insert the part and drill. They last a long time, can often be used for multiple designs and have better repeatability