I find this absolutely fascinating... I would LOVE to test some CNC props vs labbed product on either of my Donzi's...

I am very curious about a couple things,,,, okay maybe 3 or 4 things

1) what happens to the hydro laminar flow across the blade with the machining troughs? is it faster?? meaning the prop turns easier or just the opposite??

2) CNC products make it extremely easy for copycat vendors later on copying your work and repackaging their product, and you've done the homework... how do you protect yourself from your innovations, and proprietary designs??

3) is it safe to assume that balancing is an issue of the past?

4) as Brett stated, i'm still not sure why the blades couldn't be manually tweaked for minor corrections??

Jim

More great questions Buizilla.

Are you only doing #6 props or are Bravo XR applications available?

BUIZILLA, Questions lead to more questions. In your second question you mentioned coping cnc props being easy. Well what came first the original program or the copy program? Kind of like the chicken or the egg.
Jim

doesn't matter if it's a chicken, or the egg.... new CNC needle scribers can copy ANYTHING they want.... it would be great to see proprietary stuff not copied, but it's gonna happen... just look at the new 7 axis scribers doing hull flips

Good questions. As far as water flow over the surface. Let's say our Bravo and outboard props have been the fastest on many boats. Deep V cats just set a very nice Kilo with our CNC props.

Not worried about the props being copied. The technical aspects of machining a complex 3D 5 axis part is not something to be undertaken by the machine shop down the street. Then there would be the problem of making different pitches and diameters, changing pitch progression, cup profile, blade chord length, blade thickness, etc. So if you just copied one prop you would have a very limited product line. If you are making props and know nothing about the propeller characteristics you wouldn't be able to service or modify the model for the application. Not to mention you would have to make a mold for a casting first before you could even start machining, that's not nearly as easy as it sounds.

Balancing is not a thing of the past. The props are checked for balance and adjusted as necessary. What is very consistent is the moment. Even if a prop is statically balanced if the moment is far out it can still vibrate or won't be smooth.

As far as getting a cast prop as true as a CNC prop. It's possible. But to get it as close to a CNC prop would take so much time it would cost you more than a CNC prop. Even that, take 10 CNC props cut with the same program and they will run within 0-15 rpm of each other. Then take 10 lab finished props made from the same person for the same application and the rpm difference will be much greater than that.

I love the Smart Craft system in the newer boats. It's a great sales aid. When testing I point out to the customer the rpm between the motors. Typically it's within 0-15 rpm. You won't see that with lab finished propellers very often.

2112,
They do have props for XR applications.

We currently have Sterndrive Semi-Cleavers, Outboard Cleavers and now our newsest propellers in the line-up,
SSM #6's.

The 5B RH #6 propeller is machining today. We will be testing with an OEM in the next week or so and then with some Offshore Teams as well. I will post the data as it becomes available!

As promised here is the RH being machined!

throttleup,
You should post a video of 5 axis machining of a prop. I am a CNC machine shop that does 3 and 4 axis work, I am still amazed by it. Probably very few people here understand the process ....you wouldn't be giving away any secrets, just educating......

Randy