Optimized Cutting Parameters - Shapeoko 3 XXL

CNC Machines Shapeoko
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I am looking at the XXL to prototype some products out of 3/4" Baltic Birch. My main question is how hard can you push the machine and router continuously(1 Hour)? I have experience with industrial cnc equipment and 3d printers, but nothing in this realm.

The main feature on these pieces would be ~2.5" diameter, .5" deep pockets(circular, hexagonal, etc.) all across the board. Likely held down by a custom fixture, possibly using vacuum. I’m thinking .25" carbide two flute, down cutting end mill. Helix in to d.o.c./stepdown and then adaptive clear out in a spiral pattern, leaving 0.03" on the walls to clean up at the end.

Using this process, what would be the best parameters for this situation? 1/8" d.o.c. with a higher stepover and higher feed rate? 1/4" step down, less step over, slightly less feed rate? Just trying to get some optimized parameters so I can figure out how long the process would take, before I commit to it.

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I like the technique at: https://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm for working up optimal feeds / speeds.

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Yes, you can run it a long time.

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As per the above thread; you you can push the machine hard for 10-20hrs without issue…

The shapeoko 3 is not as rigid as the more industrial-type routers - shopbot/laguna etc, so it can’t take as deep cuts at as high a feedrate, but it will still cut wood at 100-150IPM pretty easily, and compared to other options in this price range it is the most rigid option, certainly beefier than the X-carve.

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Thanks everyone for the replies. Mike, that milling is impressive for the machine.

Does anyone have some parameters that they have achieved in baltic birch plywood?

Stuart, you say it can do 100-150 ipm, but what d.o.c. and step over is that at?

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Jake, first of all I have to put my hand up and say I miscalculated - I have cut around 3200mm/min which is actually closer to 125IPM… I’ve cut at these speeds in softer timbers like pine with a 1/4" flat endmill while doing adaptive toolpaths, with a 2.5mm stepover or “optimal load” and around 5mm DOC (not at my computer so I can’t give exact figures). I also cut around this speed with a 1mm tapered ball mill while doing 3d relief carvings, though the DOC and stepover were more like 1mm and 0.25mm respectively.

pocketing with a 1/4" bit in plywood(I cannot source baltic birch plywood locally) I think 2500mm/min at 3mm DOC and 40% stepover would be pretty achievable. lots of pocketing like that I would definitely be looking at adaptive toolpath strategies, that way you are less limited by the rigidity of the machine

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Just so credit goes where it belongs, @Vince.Fab is the source of that - the guy has made some awesome stuff.

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