Drill flute styles

[extropic]

ranging from 5/32 to 7/32

Those are small enough diameters that you should be able to handle.
I suspect that major factors are less-than-sharp drill bits so you're advancing them with too much pressure.
Too much pressure results in the break-through happening with too much metal left to cut. In other words, as soon as the web breaks through, the cutting edges spiral through.

To test my theory, get some new, top quality bits, use a good lubricant (I like dark cutting oil as used in pipe threading), and let the bit cut. Don't 'push' the bit through. As was previously mentioned, it's key for you to develop a 'feel' and reduce your feed pressure as the web breaks through.

Obviously, it's good advice to rigidly secure your vise/work-piece but I understand the practicality of what you're trying to do. How about this? Bolt your DP vise to a base plate that extends beyond the back of the vise far enough to bear against the DP column (anti-torque). Additionally, tighten a collar around the column with just enough clearance to let the base plate slide between the table top and the collar (anti-lift). Many ways to skin that cat.

 

[matthewsx]

Another tip is getting a foot-switch for your drillpress.

Amazon.com

I've had one for years and it makes holding stuff while drilling much easier, also you can stop the drill in an instant without letting go of your work.

Also get a heavier vise



Stuff catching while you're drilling is just something that you learn how to avoid more than changing bit styles IMHO. It only takes a couple of times getting your fingers whacked to decide to put some effort into making sure it doesn't happen.

John

 

[RJSakowski]

Parabolic drills are used for better chip extraction in deep holes.

I caqn appreciate the part to part variation of a hand forged piece can make it difficult to securely clamp. If I were drilling a multitude of holes, I would invest the effort in making a hold down clamp. Toggle clamps can be quickly and easily operated. A piece of flat stock with an appropriate hole on one end and the other end fastened to a backing plate which is clamped to the table will hold the part and the toggle clamp to hold the flat stock.
To use, insert the part and start the hole, then activate the toggle clamp and finish the hole.

McMaster Carr is a good source for the clamps and clamping forces of over a ton can be achieved.

 

[extropic]

Is the bottom of the work-piece essentially flat and perpendicular to the DP spindle? If the drill bit doesn't break through a normal surface it can be a significant factor.

 

[natewi]

Had trouble adding this text. Anyway, I had same problem you are describing. I put one bolt on just one corner of my vise and used a t-nut which slides in the slot. I steady vise with one hand while drilling. By using just one bolt.... it’s quick since I don’t have to tighten the vise down and I can swing vise back and forth to line the bit to the hole needed on work. Also...little bit of loctite on the T-nut keeps vibration from loosening bolt.
Also.... I use a small machinist vise quite often. Just clamp it in the bigger pictured vise above.

Great idea. Thanks!!

 

[natewi]

Is the bottom of the work-piece essentially flat and perpendicular to the DP spindle? If the drill bit doesn't break through a normal surface it can be a significant factor.

No it's curved, I think you nailed it. Since it's not flat when it breaks through it snags on the thicker side.

 

[Illinoyance]

Learn to recognize when the drill is about to break through then reduce your feed. A drill press is a very basic tool. In spite of that some finesse on the part of the operator is needed.

 

[homebrewed]

Work trying to climb up your drill bit is commonly encountered when you're drilling some plastics and brass, or anything else that tends to grab as the bit breaks through the other side of the hole. This can be addressed by "dubbing" your drill bits to reduce the rake of the cutting flutes. I did this to dedicate bits for drilling brass, using a 600-grit diamond stone. Run the stone across the flutes, keeping it parallel to the axis of the bit. It only took a few passes to change a nasty drilling job into a no-excitement procedure.