I've always agreed with the guy (was it Tony Bingelis?) who said the proper way to sharpen a drill bit is to cup it in the index and middle fingers, with the thumb resting lightly on top ... and then pitch it underhanded into the nearest trash bin. Bits are relatively cheap.

Sorry, that was sideways to your question. You can guess that I have absolutely no experience with an electric sharpener of any make.
 
I use a Drill Doctor in my machine shop and it works pretty good. I have no experience with the Harbor Freight model. Anything under 1/4 inch is really not worth messing with in my opinion. I bet I haven't used 6 or 8 of the #40 and #30 drills used for riveting in my whole RV-9 build.
 
No, no, nooo

Instructions that came with the Harbor Freight sharpener did not help in understanding how to make it sharpen a drill bit (wear goggles, don't run with scissors, etc.). Never did figure out how to make it sharpen but did dull quite a few. Save your money, buy new bits.
 
118 deg or 135 deg??
suitable for split-point?
Save your money and buy more drills from Avery, or Cleaveland or some other reputable aircraft tool dealer.
Just my opinion.
 
drills

Small drills go in the trash. Five years in a machine shop I am reasonably good at sharpening the larger bits, lets say 3/16 and larger, freehand on a bench grinder, finish with fine grit wheel. The secret to the larger bits is a trial run on a scrap of thick aluminum to see if they cut evenly on both flutes. If not regrind and try again. Mark the side thats cutting and take a tiny bit off that side.
 
Drill DR

Purchased the middle of the line Drill Dr (about $150) a few years ago. Found that it was a waste of my cash - works ok on bits 3/8" and larger but not very well on the size of bit that we use on aircraft.

My opinion - don't waste your money on drill sharpeners.:mad:
 
Drill Doctor

Works great but you have to develop a 'feel' for using it. It's fine for polishing up some tips that don't cut like new. The cobalt drill bits will last until you lose them. It's all about the pressure and feed of the material. They all cut steel for a long time. even stainless. if you use a little oil.
 
You must log in or register to reply here.