Unimat Problem

[thehomeengineer]

Hi
I am not sure what the slowest speed on the Unimat lathe is?
Generally, speeds on smaller lathes tend to be on the higher side even in the lower range, as the diameter work is normally of a smaller diameter so higher speeds are needed.
In a perfect world to find the cutting speed the formula is:
RPM = cutting speed of material x 1000/π x Diameter of material/tool (mm).
RPM = cutting speed of material x 12/π x Diameter of material/tool (inch).
Cutting speed of a few materials in m/min and feet/min when using High Speed Steel (HSS):
Mild steel: 20 -30 m/min 60’-90’/min
Aluminium: 70-90 m/min 210’–270’/min
Stainless steel: 10-15 m/min 30’-45’/min
Therefore, a 50mm diameter piece of steel (2”) would be:
Metric 20 x 1000/3x50 = RPM - 20000/150 = 133 RPM
Imperial 60 x 12/3x2 = rpm – 720/6 = 120 RPM
I also agree with the other comments made by Paul and Marv, a nice sharp HSS tool and a suitable feed rate
0,05mm/Rev or 0.001”/Rev
Also remember as the diameter is reduced the speed can be increased
Hope this helps
The Home Engineer