Bespoke CNC

[M250cnc]

Prop Man,

4th axis means a rotational axis, and it would seem to be impossible to do this without a rotary ?

Heavy cutting means potential for movement/deflection of the prop

Are they doing this with one cutter setup, this is where expensive software can cut down machining time as well

Maybe post a sample file to show the size/shape of what you are after

Phil

[Prop Man]

Phil,

Do you mean rotation of the work for the 4th axis? If so, the work is turned over manually. The propeller blades do suffer from resonance when the finishing cut is being performed on the second side as there is little material left. The work is held in the centre and at each end by the parent material, which is cut away once the process is finished. In addition, wooden wedges are jammed between the bed and the work, about half-way down the blade for the final cut on the second side to add rigidity and improve the finish.

I have some good ideas of how to build a much improved fixture system which allows the work to be well supported and rotated manually along it's long axis to machine the second side. Fixture building is something I will do as I have the capabilities and experience to do this.

They are roughing it with a 25 mm braised tipped square cutter and finishing with a replaceable HSS bladed cutter with a radius on the corners.

I'll try to work out how to put some pictures up. Propellers range from around 50" long to 95" long. The blank starts off as a square section and most of the material is removed during machining.

Prop Man

[Prop Man]

Pictures of the Thermwood cutting a propeller in the 'galery - albums' section.
-Prop Man.