3 replies to this topic

[Bob Riebe]

https://www.enginela...ry-ofria-story/

 

 

No CNC routines for old iron. Here’s a before/after port modification of a cast iron head. Ofria still practices the art of hand-porting cylinder heads and has done so many in over the decades he could probably do them blindfolded.

[desmo]

Does anyone use CNC milling on iron/steel? Sounds like a good way to wear out a gazillion dollars worth of tools. Works great on soft Al alloys though. Al is really easy compared to steel.

[Greg Locock]

Well yes, up until recently there were several high precision tool makers in Australia with massive CNC machines for making the tools for stamping body panels and injection molds for large plastic parts. The one I used preferred working with TiAl6V4, even with a UT stress not far short of 80 ksi, because its chip formation was good, compared with tool steels. But their routine stock was great big lumps of tool steel, which had to be ordered 18 months in advance.

[gruntguru]

CNC can use the same tooling as manual mills and lathes (ie not more expensive) and tool life is generally better since feeds and speeds are more accurately controlled and often adjusted on the fly e.g. a CNC lathe will increase speed as the tool moves to a smaller radius on the workpiece to keep cutting speed constant.

Edited by gruntguru, 02 March 2024 - 02:28.