How about too much?
One thing to consider is unintentional damage that is a machine crash.However, thanks for your concern, both questions (material strength and thermal stability) are to be considered, and I'm discussing them with Corian's technical staff atm.
WRT strength, the purpose (and expectations) of the machine is crucial :
But still, I want to run some simulation to confirm that everything is right as my intuition says, especially at dowel nuts assembly points.
One gotcha with thermal issues is that it can be very localized especially if the material doesn't conduct heat well. The end result is expansion in one place resisted by cool parts else where. So you get twisting and binding as thing move out of alignment. This can by the way be a problem on any type of machine built in any manner. If you get enough expansion in one part of the frame you will either have your linear rails bind or the expansion will cause them to attempt to rock on the corian mounting surfaces. So yeah thermal isolation of hot parts would be a requirement. My general experience here has been on high precision lathes that never saw a piece of Corian, however that doens't mean that it wasn't a problem.There are multiple things to consider when it comes to thermal expansion : dimensional precision and geometry (squareness/parallelism)
Here is some meaningful data I have :
* the mill will be operated in a somewhat thermally stable environment (home shop)
* the thermal expansion factor of Corian is 39*10^-6/L(mm)/°C which builds up to 0.025mm/°C on the longest dimension (Z Axis) or 0.00156mm/°C across the thickness of the material.
* the mass of the mill (Corian parts weights about 90kg) "should" give ''a lot'' of (sorry no data available on conductivity right now) thermal inertia to flatten out transients if any.
* the topology of the mill (open frame) means dimensional precision is essentially a mater of relative movement/positioning of spindle and table. No ATC so tool origin will have to be checked at change and tends to correct error/variation along the machining.
* to hinder geometry the mill would have to be heated in such a way that there would be large temperature gradients across the frame (non uniform expansion) and for that purpose possible heat points (motors) are thermally insulated from the frame besides being mechanically insulated (plum couplers).
That's the state of my research so far ..
What do you think ?
In any event it will be interesting to see this machine in operation. Best of luck with it!