Bit for large 3d bowl

[bking1836]

Hello everyone,

I have made many, many flat bottomed trays using bowl/tray bits, and I would like to branch out and create a proper bowl/dish using thicker stock. This is new territory for me. There's no fine detail -- just a nice big oval dish cut from 2" stock.

I can handle the basic programming in VCarve Pro 9 (thanks to Vectric's great tutorials). I would love some guidance on this:

1. Should I use both a roughing and a finishing toolpath?
2. Which bit(s) are ideal?
3. Using a radiused end mill isn't a great idea, right?

I have a 1/4" ballnose, but that would take forever for a large dish. So I am willing to invest in the right tooling to do this. I also don't mind a little extra sanding effort after machining since there's no detail to worry about.

I have a PRS Standard 96-48 with the 2.2hp HSD spindle.

Thanks!!

[pro70z28]

Judging by your description, I'd be inclined to use a 1/2" ball nose. I don't always do stuff by the book, more often I use what I already have on the shelf when I can, if it means saving a trip to the tool store.

[bking1836]

Judging by your description, I'd be inclined to use a 1/2" ball nose.

Thank you. Any opinion about cutting height? Looking at Amana tool options, there are 1.25" and 2.125" cutting height options. I guess it depends on the angle of drop as you bowl out the stock, right? Steeper angle would require a longer bit to keep the collet from interfering.

I don't mind going to the tool store since it's usually either Amazon.com or Toolstoday.com :)

[bobmoore]

you should probably be looking at a core box bit rather than a ball nose since you get a deeper cut for larger bowls. I would use a .5 to a .875 diameter bit with a .5 shank for more aggressive cuts then a finish cut with the same bit but a finer stepover to reduce sanding labor. In my experience a smaller ball nose won't help much.