Bernd
Well-Known Member
I tried the counter sink I made yesterday after I filed the relief on the back side of the cutting edge. The copper color you see is from something I made by using sulfuric acid and some copper. As you can see by the some what bleary picture the land of the cutting edge is a bit narrower than in the thread I first presented this tool.
I gave the cutter a try on the first hole. It worked but not to my satisfaction. So I made a fourth cutter. This time I was going to do it right. I turned up a blank, put it in the fixture and setup the cutter properly this time instead of just eyeing it in. The blank is 3/8" in dia. So I touched the side of the cutter up to the blank using a piece of paper that will tell me when I'm close by pulling the paper out of my hand. I measured the paper as being .004" thick. So now I move in half the blank size plus a bit for the paper thickness, which is .1875. And I'm close to the center.
Next I do the same for the z-axis. Then move the cutter down .1875". This brings the cutter close to the center of the blank.
Once the cutter is in position it should look something like this. The cutting edge should be very close to the pointed end of the blank, both in the y-axis and the z-axis. Now your ready to cut the first cutting edge. Then turn the blank 2 positions on the hex and cut the second and then the third.
And here is the result. Notice I cut further up the blank this time. Plus I used the full length of the rod this time.
I cut it to a usable length for the Sherline mill and turned a 5/16" dia. pilot to fit in the collect chuck of the mill. I used the cutter but it didn't work to good because the top land was to wide. So I took my Dremel tool with a cut off disk and ground back the top land to a very narrow edge. NOTE: Make sure to wear safety glasses when using a grinder such as this. My wheel exploded on the second tooth. I thank the Gods above that I was wearing safety glasses because a piece did hit the glasses.
Here's the end result after 3 days and 4 cutters. A nice counter sunk hole.
Why did it take 3 days and 4 cutters to come up with some thing the was usable. Simple, no patience. Had I done it right the first time I would have saved myself some aggravation and been further ahead. What did I learn? I learned a lot about how not to make a good cutter. ;D
Bernd
I gave the cutter a try on the first hole. It worked but not to my satisfaction. So I made a fourth cutter. This time I was going to do it right. I turned up a blank, put it in the fixture and setup the cutter properly this time instead of just eyeing it in. The blank is 3/8" in dia. So I touched the side of the cutter up to the blank using a piece of paper that will tell me when I'm close by pulling the paper out of my hand. I measured the paper as being .004" thick. So now I move in half the blank size plus a bit for the paper thickness, which is .1875. And I'm close to the center.
Next I do the same for the z-axis. Then move the cutter down .1875". This brings the cutter close to the center of the blank.
Once the cutter is in position it should look something like this. The cutting edge should be very close to the pointed end of the blank, both in the y-axis and the z-axis. Now your ready to cut the first cutting edge. Then turn the blank 2 positions on the hex and cut the second and then the third.
And here is the result. Notice I cut further up the blank this time. Plus I used the full length of the rod this time.
I cut it to a usable length for the Sherline mill and turned a 5/16" dia. pilot to fit in the collect chuck of the mill. I used the cutter but it didn't work to good because the top land was to wide. So I took my Dremel tool with a cut off disk and ground back the top land to a very narrow edge. NOTE: Make sure to wear safety glasses when using a grinder such as this. My wheel exploded on the second tooth. I thank the Gods above that I was wearing safety glasses because a piece did hit the glasses.
Here's the end result after 3 days and 4 cutters. A nice counter sunk hole.
Why did it take 3 days and 4 cutters to come up with some thing the was usable. Simple, no patience. Had I done it right the first time I would have saved myself some aggravation and been further ahead. What did I learn? I learned a lot about how not to make a good cutter. ;D
Bernd
