drill bit

B

Bill S

Senior Member
I have been practicing sharping drill bits by hand. No luck holes are not round. So I was thinking about getting a Drill Doctor. They have the one that does only 118 degree angle and one that does 118 and 135 degrees. How often do you think a bit with an 135 degree would be needed? The cost between the two is about $35.00 more for the one that you can put a 135 degree angle on the bit. I do some projects using bed frames that seem like a harder seel than mild steel.

Thanks
 
I bought the two angle version several years ago and have never regretted it. Now my bits are sharp and you get very quick at setting up for a sharpen.
I could never master the free hand method.
Dave
 
I have the two angle one as well.....I've collected each type of angled bits over the years, and this set up let's sharpen each to its original finish. Like most things for me, there was a learning curve until I got it right, particularly the split point feature!!

Dick.
 
A machinist would say no drilled hole is round until it has been reamed to size.
Drill Dr. works pretty well on bits 1/4 and larger.
 
I use the Uni-Bits (single flute type)to get a rounder hole and to make small holes larger. I used to think that they were a gimmick till I used one. There is nothing else that can drill through plexiglass without cracking it. They will drill well through soft metals too. They're expensive but they last a long time. You need a mill to drill very accurate holes but still should ream them for close tolerance.

I use my Drill Doctor for large bits but I have an 8-inch disk sander wheel that I use to do the smaller ones since its just quicker to do them by hand. I use a small green wheel grinder for my old lathe bits but I mostly just use the carbide tip type now.
 
deuce_roadster said:
A machinist would say no drilled hole is round until it has been reamed to size.
Drill Dr. works pretty well on bits 1/4 and larger.
Click to expand...

Funny as heck.
Reaming will get a hole fairly round. Good enough for a machinist for certain.
A tool maker knows that holes are not round until they have been ground.
 
Kube said:
Funny as heck.
Reaming will get a hole fairly round. Good enough for a machinist for certain.
A tool maker knows that holes are not round until they have been ground.
Click to expand...

As "beauty is in the eye of the beholder" so goes the round hole. It depends on what your tolerance is. I would venture to say that there is no man made hole that is round. Mighty close with the instruments that we measure with, but still not perfect!
 
No Drill Dr here but I'd like one.
A three flute drill is probably closest for a quickly bored hole.
(aluminum or cast iron) Very much a perfect circle.
Reamed holes are just ok as far as being perfectly round and exact.
Honed would be more accurate and water jet is also pretty good.
 
I have the 750 and love it. Basically paid for itself with just a few sharpening's of my 3/4" drill bit.
 
I would guess it goes back to what you want the hole to do.

If you are looking for clearance to hold two parts together, you could use an ice pick and a hammer. Grin.

A little tighter than that and good commercial drill bits will work.

After that, you are into reaming and boring and honing. But, hey, are we building tooling or just clipping stuff together?

On the subject of drill point sharpening:

Back in the late 1950s I was employed, as a high-school student during the summer, by Skil Corperation, when they were located at Elston and Cicero in Chicago. My project was to investigate, by activity, drill-point angles and how they effected power consumption. Skil was looking at battery tools at the time and wanted to know.

1957. Or 8. Don't remember. Been a while. Grin.

Quite by accident I managed to produce a drill-point that used less than 50% of other points.

Unfortunately, for the rest of time, I was unable to reproduce it. The original, for several weeks, always performed. The duplicates, produced on the same tool grinder, by the original tool maker, never did.

Point - Magic? Accident? Unknown factors?
 
Bill,

With some practice you WILL get the hang of sharpening drill bits by hand. The BIG mistake people make is treating the bit like a pencil going into a pencil sharpener and turning it through 360 degrees.

I guess that a search on YOU TUBE will show you how it's done ?
 
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