Thanks for your reply Phil. It is very unusual to make 2 propellers the same. We make 2-3 a week and business is growing. I design the propellers mathematically then I draw them using Rhino. Then I pass the 3D drawing and the lump of wood to the machinists. I have looked over the shoulder of the company doing my machining and the CAM software doesn't look that complicated, the sort of thing I'm sure I can learn. At the moment I am spending about £25K a year on machining, it certainly makes commercial sense to gain such capabilities as it is a major part of our manufacturing process.

I'll be happy with a tolerance of 0.2 mm.

At the moment they are being made on a large 3-axis Thermwood, which seems to do the job well but the job is taking about 6 hours per prop including programming. I believe the machining time can be speeded up considerably with better tooling and fixtures. The loads on the cutter are quite high and the tool has to be extended from the holder by about 150 mm in some cases to gain clearance from the work. I'm supposing that a 3-axis machine will have better rigidity at the spindle, for such big heavy cuts when roughing out, on a pretty hard wood. I'm looking for a 20 mm tool holder, again to help minimise resonance.

How do you think a 4th axis will help the job?

Keen to enter discussions with anyone with track record building large-ish machines who can take on this project.....

-Prop Man


Quote Originally Posted by M250cnc View Post
Prop Man,

Are all the propellers the same, who currently does the cad/cam

Just learning the software can take a long time, you would need 4 axis and the software would cost around £5K +

What is the tolerance on the props, how many do you need to make.

When/if you make them yourself and you screw up YOU PAY.

I'm sure a lot of peeps on here could make this, me included but don't know a dedicated company that makes them.

Phil