Using Fusion 360, what is the best strategy for milling the picture below.
My current settings have the adaptive clearing taking about an hour and the spiral cleanup also taking an hour. Does that seem about right. I am using a 1/4" ball end mill.
I need to make 10 of these from walnut, so I would like to get the machine time to something a faster.
I don’t mind investing in a specialized bit, if that will speed the process up a bit.
2 hrs feels about right. Adaptive paths can be slower than straight pocket.
I made similar with Fusion 360
I make these egg trays occasionally. They take ~20 minutes to do the 2x3 version. I very intentionally left the cutter marks in the pocket though. That allows me to go a bit quicker.
Editing to mention that’s 20 minutes with a bit change. I use a 1/4 up cut to rough the pocket and do the profile. Then use a 1/4 down cut to finish the pocket.
If you want to really cut down on the machining time, you could remove the bulk of the material with a roughing bit such as this one.
A larger finishing bit could also help. If you’re using a trim router you’ll be power-limited, but I’d expect a 1/2" round nose bit, or even larger if you’re just taking light finishing cuts, to work fine. Whiteside, for one, has a big selection of round nose (aka core box) bits. A larger bit radius should provide a smoother finish in fewer passes.
From your rendering, it doesn’t appear that your pockets have flat bottoms. But if they do, you could use a bowl bit instead of a round-nose bit.
Hey Andy, hey Martin,
what is this good for? Besides not having your stones flying around loose? Is this for a game?
I have a 80mm spindle, so I can use a 1/2" bit.
@ Nick
I like your design better. Do you flatten the bottom a little?
The game is called Mancala or Kalah.
I have a friend who has played the game since he was a child and when he saw some of the other projects I’ve done, asked if I could make a bunch for his family.
He has a bunch of African Black Limba that he wants to use.
Since I am making quite a few, I want to cut the CNC time down a bit.
Thanks!
Hey Martin,
great! I like to learn new things!
Thanks for the explanation!
I actually measured an egg and based the divot off that! It’s not a sphere or a flat bottom.
As others have mentioned, a roughing pass does speed things up. I use a 1/4 up cut bit and follow up with a 1/4 down cut ball nose.
Hello Martin,
You did not say what your speeds and feeds are at the present.
I used to cut things at around 70ipm for roughing and 100ipm for finishing (1/4" cutter in a router). I invested some time in a feed optimization software and wow - what a difference.
I cut a 3/4 size Eames House Bird out of walnut. 3D adaptive clearing roughing at 471ipm (Whiteside RU2100 – 1/4 inch Upcut Spiral- Solid Carbide) 20000rpm. Step down .233" and step over .1"
Finishing at 200ipm (1/4" ball cutter - actually meant for steel since I didn’t have one for wood available) 20000rpm. Step over .03"
It was a big piece of wood I cut down to make these birds. it would be the equivalent of roughing out a 12" x 12" x 1" deep pocket. It took 30 minutes to rough and 40 minutes to finish. And the cutters were like new after it was done. The sound is definitely different when it cuts that fast which may concern you but it did not bog down the router at all.
So what I learned is with wood I can go alot faster than what I expected.
What feeds software do you use?
Pat
GWizard by CNC Cookbook
I did not find it easy to learn but once I understood how to use it I find it very powerful.
Their marketing tactics are a little over the top but the software works well. But I had to watch all their training videos and do a lot of reading to understand it all. Just as in real life there are alot of options and variables when milling and this software seems to account for most of them. It is $79 USD for 1 year for unlimited size machine which converts into a lifetime license when the year is done for hobbyists with under 2HP machines.
I am not at all saying it’s the best - just it’s the one I chose to learn.
I feel a little dumb, I have a 80mm spindle so I can use a 1/2 bit. When I do that, processing time is significantly less.
In Fusion, what option and settings to you use.
I have been playing with both spiral and scallop, I’m not sure which is best.
Martin
I nearly always use scallop to finish 3D shapes since the stepover is more consistant that with spiral. For your shapes in the first post I would use scallop to finish. For roughing those kind of pockets 3D Pocket Roughing may be faster that 3D Adaptive Clearing since there is no tight internal slots or islands to work around. But Adaptive does a better job of keeping the cutting load constant - when there are islands and details to work around.
As for the settings it’s probably easier if you look at my F360 file and find what you want.
Here it is. You will have to un zip it and import it into Fusion.
Apologies if I’m jumping in at the end, but a 3/4" or 1" bowl cutting bit will get you good results with much less work and time. 0.02
-Tom
Its a great game. Very simple to play, no luck factor (dice roll etc), and you have to respond to your players moves (that is, it is difficult to look ahead and plan as the board changes). Another game if this ilk (simple to learn but challenging to win ) is Othello/Reversi.
We use pebbles from places that mean something to us, although i have resorted to aquarium stones, but they be garish). I think it is typically played with seeds/nuts.
Martin.
I’m late to the party (first post here as well) but first thanks for creating the Fusion model of the X35. 
That has helped me already in preparing for the possible purchase of a OneFinity machine.
If I understand correctly you are using a ball end exclusively for each strategy. I’m far from an expert on the best approaches to machining wood but somewhere I must have read about the benefits of clearing with a standard flat bottom upcut bit. This makes sense to me as a flat bottom will to almost all cutting at its OD which, by virtue of higher average cutting edge velocity will allow a higher average material consumption rate.
I don’t do carving but I have done a lot of shaping for contoured front baffles and have always started with the flat bottom for material removal and ended with smoothing using the round nose. Perhaps someone will chime in if there is a reason not to use this approach.
