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+--- Thread: How To Make A Flat Bottom Hole (/thread-1070.html)
RE: How To Make A Flat Bottom Hole - EdK - 12-13-2012
(12-13-2012, 05:52 PM)TomG Wrote: I have a full set of flat ground drills for just such an occasion. Just drill the hole nearly to depth with a standard drill and finish to full depth with the flat bottom drill. They are super easy to make. Just grind them square on the belt sander and relieve them on the bench grinder.
Tom
Ah yes, the belt sander. That's one item on my project list that is working its way to the top. Actually, the one I plan on making is more properly called a belt grinder, I think.
Ed
RE: How To Make A Flat Bottom Hole - Mayhem - 12-13-2012
I need to do something similar myself, so this is good, useful information.
RE: How To Make A Flat Bottom Hole - PixMan - 12-13-2012
I've made flat-bottom drills from standard jobber length drills by hand many times. It takes me all of about 2 minutes with 1/4" drill because I have a Norton seeded gel wheel on the bench grinder. It's been on there for over two years now and I haven't ever had to dress the wheel. It still looks new even after some pretty heavy grinding. I'd picked up a couple of them for $5 at the annual Norton Company "yard sale" they run as a United Way fundraiser.
Far faster than any belt grinder! The 3x36" Norton zirconium coated belt on my dad's belt sander is all clogged up with wood anyhow. ;)
RE: How To Make A Flat Bottom Hole - the penguin - 12-14-2012
(12-13-2012, 05:52 PM)TomG Wrote: I have a full set of flat ground drills for just such an occasion. Just drill the hole nearly to depth with a standard drill and finish to full depth with the flat bottom drill. They are super easy to make. Just grind them square on the belt sander and relieve them on the bench grinder.
Tom
I've made a few flat bottom drills, using a belt grinder, having various results, probably due to haste on my part.
I have one of the Australian designed (maybe built) Jancy RadiusMasters, a 2" x 48" belt grinder, a vary versatile machine.
RE: How To Make A Flat Bottom Hole - EdK - 12-14-2012
(12-13-2012, 10:59 PM)PixMan Wrote: I've made flat-bottom drills from standard jobber length drills by hand many times. It takes me all of about 2 minutes with 1/4" drill because I have a Norton seeded gel wheel on the bench grinder. It's been on there for over two years now and I haven't ever had to dress the wheel. It still looks new even after some pretty heavy grinding. I'd picked up a couple of them for $5 at the annual Norton Company "yard sale" they run as a United Way fundraiser.
Far faster than any belt grinder! The 3x36" Norton zirconium coated belt on my dad's belt sander is all clogged up with wood anyhow. ;)
Ken,
What the heck is "a Norton seeded gel wheel"?
Ed
RE: How To Make A Flat Bottom Hole - PixMan - 12-14-2012
(12-14-2012, 06:55 AM)EdK Wrote: Ken,
What the heck is "a Norton seeded gel wheel"?
Ed
Ed,
The seeded gel ceramic wheels are something introduced by Norton Company around 1990, and have been steadily growing in popularity. They cut so much faster than standard vitrified grinding wheels that they're in a different league. You have to push harder than normal to see the benefit (they generally cost two to three times a regular wheel) but when you do you're greeted by cool cutting and low wheel erosion.
This is what they look like:
http://www.trinitymilltool.com/p-46-7-8-diameter-wheels.aspx
RE: How To Make A Flat Bottom Hole - petertha - 12-14-2012
Because you mentioned vice stop, Ill attach a pic of one I made recently just for other ideas. But if I had to make it again, I would extend the slit past the 1/4" rod hole. Because... the steel is from 5/8" stock & I have to torque the two 8-32 capscrews pretty good to lock the rod down (ie a lot of strength/resistance from the steel itself).
RE: How To Make A Flat Bottom Hole - EdK - 12-14-2012
(12-14-2012, 05:00 AM)the penguin Wrote: I've made a few flat bottom drills, using a belt grinder, having various results, probably due to haste on my part.
I have one of the Australian designed (maybe built) Jancy RadiusMasters, a 2" x 48" belt grinder, a vary versatile machine.
Jack,
That's a very nice belt grinder.
Ed
RE: How To Make A Flat Bottom Hole - sasquatch - 12-14-2012
Petertha, nice work,, and yup impressive belt sander Jack!!
RE: How To Make A Flat Bottom Hole - TomG - 12-14-2012
(12-14-2012, 05:00 AM)the penguin Wrote: I have one of the Australian designed (maybe built) Jancy RadiusMasters, a 2" x 48" belt grinder, a vary versatile machine.
So Jack, what's the theory behind your sander? Is one section of the belt backed like a normal sander and one section left unbacked for freehand work? It looks like a well made machine.
Tom