This will be a collection of some simple tips and techniques that I have learned over the years and use regularly.
Quick way to make a radius grooving tool - 27-03-2017
Grinding external radius lathe tools - 20-03-2017
Regrinding carbide inserts for special operations - 03-02-2017
Using a ball bearing to hold rough and non parallel parts in a vice - 03-02-2017
Centering work on the rotary table - 03-02-2017
The finished toolshank with the 2,4mm Hss blank:
The Hss blank got hard silver soldered into the shank (Hss does not loose its hardness when silver soldered) and then ground sharp on the surface grinder (It could also done on the benchgrinder):
The 5° tilted round Hss blank alters the actual radius that the tool creates slightly, but in this case, the error is only 5/1000mm on the radius. It is quite easy to check this in a Cad program
The tool in use to machine a radius groove into titanium - The tool will only plungecut but not cut to the side, as there is no clearance to the side built into it:
When doing this, I prefer to run the rotary tool quite slow to be able to press it tightly into the radius I want to form. Using a permanent marker on the surfaces to be ground shows you the progress.
I did also not want to come back with a second tool for finishing, as I had to make a bunch of them.
I decided that a normal CCMT06 finishing insert with a 0,2mm nose radius is a good starting point, but I ground a substancial back- and side rake to the top of the insert.
That way I was able to rough and finish with two cuts - First cut took it down to 4mm in diameter, second cut finished it to 3,9mm +-0,01mm.
The way the insert was ground is very primitive: I grab them with a needle nose vice grip.
Then the the top face of the insert is held freehand against a diamond wheel, eyeballing the angles - I tipped the top surface about 5° back and to the right, to create a nice, positive cutting action with very little cutting pressure. As the insert has already a nose radius of 0,2mm, it is also a very durable tool.