Advice on Proper Operations for 3D Object

[george]

I started a project and got some great modeling advice and help over in the other forum. My project can be downloaded from this thread.

My first thought are that this is going to be mounted on a flat shelf so the bottom side could just be flat to help simplify the setup. I've looked at the 2D Adaptive, Parallel, and Spiral operations and they all seem to do a good job in the simulation but I know that the machining time is going to be long before I see the final product so I'm hoping to try and get it at least close to right on the first try.

I've got multiple flat end mills and a 1/16" tapered ball-nose bit. I thought I'd start with a 1/4" flat end nose and leave some stock, then finish with the 1/16" ball-nose. Assumming that the correct plan of attack what operations would you use?

My next problem is how can I get the outline shape to be cutout? My thought is if I can get the shape that is viewed from the top to be cutout through the stock I can then manually sand the edges to soften it.

Any thoughts?

Thanks,

George

[Laurens-3DTechDraw]

Sounds like a decent plan.

[george]

Hi Laurens,

Any thoughts on what I can do to get the shape outline cutout? How much stock would you leave with the flat mill operation and what kind of stepover for the ball-nose operation? I was thinking of leaving 0.020" of stock and then ~0.006-0.010" stepovers for the ball-nose.

Thanks,

George

[Steinwerks]

With a 1/16" ball nose your cusps are going to be a bit big on .01" stepover. I'd recommend .006" at a maximum, but it depends on what sort of finishing you'll be doing post-machining, too.

[skrubol]

What are you planning on using for stock?  If it's wood or MDF, you could probably get away with .012 (d/5) and just spend a few minutes with some sandpaper.  If it's metal, .006" at the most.  For material to leave, .02" is probably fine for wood, leaves enough to allow for a little bit of tear out.  If metal, .005" is probably enough.