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Turning #4MT drills down to #3MT...Possible?
- Thread starter PaulH
- Start date
Like most things, worrying about Murphy's Law is worse than just doing the job. After some experimentation, I chucked the used 1 7/16 Cleveland drill by making a home built 118 deg female cone adapter on the drill point driven by a dog screw with the tang center in the tailstock live center. Got it to run within a thou. Plain ol' HSS cutting tool had no problem taking the 4MT down to 3MT. Taper shank seems to be relatively soft. Will make the finish pass in the morning, and grind the smaller tang. But, I did order a 4x3 adapter from MSC, 41 bucks delivered. That way I can keep the drills #4, which happens to be the size of my South Bend spindle. Next project is to build an old school drill pad for the tailstock. Thanks for all the help fellas.
Sounds like you found a workable solution.
Post some pictures of your setup
Post some pictures of your setup
I'm in the process of learning a new computer and operating system, photos are problematic. . I am a man of the previous century and it is not going well at all. Jumping from windows 7 to google chrome may be a bridge too far.
Imagine a piece of scrap steel with 1: a concave divot exactly matching the drill point to be modified, 2: with a 1/2" pin protruding slightly to engage the flute of the drill, as a driving dog...the assembly chucked in the headstock. On the tang end, the center drilling used in the manufacture of the drill is engaged with a live center in the tailstock, and loaded somewhat heavy to ensure rigidity. Very secure, I was able to take heavy cuts with confidence.
Imagine a piece of scrap steel with 1: a concave divot exactly matching the drill point to be modified, 2: with a 1/2" pin protruding slightly to engage the flute of the drill, as a driving dog...the assembly chucked in the headstock. On the tang end, the center drilling used in the manufacture of the drill is engaged with a live center in the tailstock, and loaded somewhat heavy to ensure rigidity. Very secure, I was able to take heavy cuts with confidence.
Ahh, I get how the headstock end works now.
I have half a dozen drills that were slightly bent when I bought them.
I may be able to clean them up by grinding them to the next size down using a similar process.
Still going to have some challenges I reckon.
Good luck with your OS migration
I have half a dozen drills that were slightly bent when I bought them.
I may be able to clean them up by grinding them to the next size down using a similar process.
Still going to have some challenges I reckon.
Good luck with your OS migration