Several people have commented on the radius arm for my ball turner and asked what the engraving bits are. I call them “D” bits as they are a half-round in cross-section. They are also called “V” bits based on the profile. You can buy them in lots of different angles and coatings. I tend to buy the cheap bits from ebay or Amazon in packs of 10. However, specialist milling tools suppliers have parts costing £10s each.
For the lines on the brass ruler I used the following parameters:
- 60° carbide D bit
- 1/8″ diameter bit
- 0.25mm single cut depth
- 2000rpm (maximum speed on the Sieg SX2.7)
- Feedrate ~ 20mm/minute
As I say, it is best buying a box of 10 of these bits as they easily chip.
You can buy them from places like:
- Amazon, search for: cnc v engraving bits
- Sainsmart – selection of engraving tools
- Rennie Tool Company – higher quality parts, UK supplier. Available in different angles, tip size and shank diameter
- Eternal Tools – tip diameter and angle selection
A free hand and ball turning tool designed to work on the Warco WM240B lathe. I’ve done some free hand turning before and although it was ok, I used a wood working technique and this is a bit dangerous with metal. With the need to turn the curve on the smokebox door of the Burrell traction engine I also need a ball turner.