Fly cutter fab...before I jump in.

[BaronJ]

Hi Terry,

Bottom line is that regardless of design, ANY fly cutter should be constructed in such a way that the cutting tip only engages the work piece once per revolution. A properly constructed Type 1 or Type 2 will accomplish that.

If you think about it, The single cutting edge of any rotating tool has to be absolutely perfectly parallel to the work surface in order not to make a second cut. Since this is almost impossible to achieve, particularly on a hobby machine, there will always be two cuts 180 degrees apart unless the machine head is canted, ie out of tram.


If you look at the cutter path at the bottom, the red line shows the path the cutter takes if the mill head is out of tram. The cutter will clear the work when moving one way and take a second cut when moving the other way.

This applies to any rotating tool.

 

[NEL957]

Baron
You know it is your tool. This tool is shaped like a thumb nail and is the best finish possible. There is one advantage to a machine trammed off center will not produce the crosshatch marking.
Very nice cutters
Nelson

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This one was a 20 mm diameter shaft, a 75 mm by 20 mm thick disc. using a piece of 6 mm square HSS M42, held by a single grubscrew. The shaft is a press fit into the disc.

Less than an hour to make.

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[GunsOfNavarone]

Well, I'm glad I asked. There is a wealth of good information here. Sometimes its better to just jump in as i would have knocked SOMETHING out, but probably learned quickly what i need to do differently. At least I have some ideas now of where to start.
Cheers!

 

[BaronJ]

Hi Nelson,

Thank you very much for your kind words.
I've learned a lot from the members of this and other forums ! I hope that I can give a little back.