Best Modeling Foam Cut Feed Speed Setting?

[cekuhnen]

For yellow modeling foam soft to medium density or even hard what do you suggest as optimal cutting feed speed values?

[Steinwerks]

What is your tooling? For something like a single flute router bit I'd expect about as fast as your spindle can go at .01"/rev or more. But I mostly cut metals with a few plastics.

What is the machine capable of doing?

[LibertyMachine]

And it also matters how you are holding the part in place and what size the material is

[cekuhnen]

We use normal yellow modeling foam

the cnc we bought from a company that custom build it but they are out of business now ;(

we use KMotionCNC as the software

current tool we use is this - I configured it based on the tech data we got for the mill tool tip.

objects we will cut will be like the size of a hair dryer or such so consumer product size

[LibertyMachine]

Fast.

12k spindle? 18k? At any rate, max spindle speed, chipload of .008" per tooth, per rev. So, a 4 flute would be 12k rpm about 384 ipm, or about 9700 mm/min

If the machine is not capable of that, than back off accordingly. Is the spindle a single speed, or is there a speed controller on it? You may need to lower the speed a bit if you also lower the feedrate

[cekuhnen]

@LibertyMachine I would have to ask the woodshop head as he was involved in purchasing

so I do not have all the tech stuff.

it was not a cheap CNS as far as I know few 5K grands I think it was around 15 to 20 K if I am not mistaken.

[LibertyMachine]

And that would be "perfect world" awesome rigidity and all that good stuff. Chances are, your machine will have serious issues trying to be pushed that hard and you might just end up around the 70-100 ipm (1700-2500 mm/min) range, in which case, it is what it is and you will have to cut back on the spindle a bit, perhaps down to 7-8k rpm

My 140k mill does not handle 3d milling at those speeds, even with smoothing turned on. Granted, there is a lot more mass being thrown around

Lastly, most material manufacturers often offer up cutting recommendations, you just need to know where to look. What is the brand of choice in your area?

[cekuhnen]

I have to verify the data but as far as I know we can go with 15000 spindel speed for contour passes and 2500 for adaptive

cutting we do at 5000 rmp

you pointed out something interested

cut slower in general to get better results even with smooth turned on?

we only will CNC foam models so nothing that goes into manufacturing or will be used otherwise.

[LibertyMachine]

Sorry, my machine (Mori-Seiki mill) has it's own version of smoothing, it reads the next several hundred lines of code and it preemptively adjusts the accel/decel of the servos. Wasn't speaking of the smoothing built into Fusion

In all reality, even though the numbers work out into such a large territory, you are going to end up in the 70-90 ipm range for roughing and maybe the 150ish range for finishing. Why? Safety and health of the machine tool. Unless it's a beefy solidly constructed commercial unit, chances are the bearings, drive screws and motors aren't built well enough to handle such a large mass as a gantry being driven back and forth at such speed

[LibertyMachine]

This manufacturer has some starting guidelines for their product. It's right in line with what I've read and used on generic brand modeling foam

https://www.freemansupply.com/tables/renshapemachining.htm