I have been working my RF45 (Zay variety) mill fairly hard over the last few weeks. I am finding it is coming up a bit short on fly cutting capabilities. I have been trying to face some mild steel. Mainly removing the scale from it and squaring it up. I am running one of these little Tormach SuperFly fly cutters with a 45degree carbide insert held by an ER20 collet. The issue is when I run a cut of any depth the gears chatter like hell and the mill head vibrates. It is a 1.5hp, 1600rpm gear drive with 0.01mm run-out on the spindle. Trammed level to 0.005mm across 4 inches+. The vise is also squared to less than 0.01mm. If I run a cut of say 0.2mm deep (diameter is about 8cm or 3 inches) at 1,000rpm (copying the Tormach youtube demo speed) with the fly cutter in steel it really carries on a treat.
I am wondering if my issue is the gear drive and if switching to a ~3hp 4,000rpm belt drive system with a VFD and a couple of pulleys (low and high range) would make the machine more steel capable? The Tormach machine seems to blast through steel with the fly cutter at a much greater depth of cut (I was under the impression the Tormach machine was less rigid than the RF45?). I would not even bother trying their feat as I am sure something would let go given the noise the machine makes. It tends to be mostly at low to 1,000 RPM where the noise is most pronounced. I even spotted the fly cutter momentarily stop (only once!). As a side note I have tried fly cutting steel from 500rpm through to 1,600 rpm without much success. I tend to get streaks and grooves along the axis of travel.
I have not been able to produce any straw colored chips, but many are literally smoking hot. But when cool are either shiny silver color or a darker silver.
Ideas?