Fly cutting

[MalcParticipant @malc]

Having made a fly cutter some time ago I put it to use squaring off the edges of some 5/8” thick mild steel. The cutting edge of the 1/4” round tool soon needed sharpening and it was tricky to grind an effective edge on it. It was then that I found an old 17mm drill which had been butchered at the point and the shank. I cut it short with about a 45 degree angle I then ground a shallower angle and some rake to give a cutting edge. I also cut the shank end short. It looked very crude after this attack with the angle grinder but I thought it was worth a try in the lathe. I was amazed how well it cut, it seemed to have a shearing action rather than chipping the surface like my old fly cutter. I will try to post a picture of my “Tatty tool” and the surface it produced. The lathe was running at approx. 230 rpm and I was taking about a .012” cut, although I did a couple of .020” cuts which went just as well. I am always surprised by the quality of the surface produced by fly cutters anyway, but I was well chuffed with this little bodge up!

[MalcParticipant @malc]

[Thor 🇳🇴Participant @thor]

That's good use of an old drill. Broken HSS drills make useful tooolbits. I made a couple of boring bars that work well, a bit smaller than yours though.

Thor

[Nigel Graham 2Participant @nigelgraham2]

I made a slightly similar arrangement for my EW lathe, which has just a simple tool clamp. The bits are typically ground from 1/4" broken drill-bits, FC3 cutters etc.

The holders are just short pieces of 3/4" X 1/2" b.m.s. bar with drilled (not reamed) holes at each end at angles to give some height adjustment. The bits are simply gripped by grub-screws.

Not quite Dickson finesse but better than fiddly shims under individual tools: if not quick-change then the semi-fast service!

I have an old (Warco?) 4-point face-mill having carbide tips brazed to the body. I've wondered how feasible it would be to remove the worn-out tips (somehow) and convert it to renewable insert form, either carbide or with HSS bits rather as Malc has made. Only it's MT3 and my mill now has an R8 spindle…

[Howard LewisParticipant @howardlewis46836]

Looking at my Warco 3MT face mill, the time is overdue when the tips will meed to be removed and meet the diamond wheel on the Worden. Then will come the task of resetting the four tips to exactly the same height. Lots of time spent with a clock, probably!

Hopefully, it will cut at least as well as when new, maybe even better!

Howard

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