Civil Engineering Reference
In-Depth Information
Fig. 4.5. Small three-flute cutters, called FC3s, are useful for cutting small slots and
keyways. They usually have a 6mm or
1
⁄
4
in shank although 8mm, 10mm and even
12mm diameter shanks are available. The FC3 cutter is normally regarded as a
throwaway cutter in industry, but it is possible to resharpen them in the home work-
shop. I find FC3 cutters are not normally sharp enough for use on profiling plastic
components.
Roughing cutters
Roughingcuttersareusedtoremovelargeamountsofmaterialintheshortest
possible time. The edge of a roughing cutter is most often of a sinusoidal
shape although straight edge roughing cutters are available. These are sim-
ilar to normal cutters but they have a series of staggered nicks all round to
break the chips into smaller lengths.
IbelievetheoriginalroughingcutterwastheRippacuttermadebyClarkson
with a very coarse pitch. If you imagine a cutter with a coarse sinusoidal
thread along it with flutes, you can see it will remove a lot of material in a
short space of time. Over the years, the Rippa cutter has been refined by oth-
er makers, and various pitches of roughing cutters - fine, medium and coarse
pitch - are now readily available.
