Hi,

some points:

1. Spindle:

-How did you get to the conclusion that you need ER32 collet? You say ice is soft and easy to route. 2.2KW SPINDLE WILL LOWER THE COST OF THE BUILD CONSIDERABLY. Furthermore there are on the market many Carbide bits that have the cutting area much bigger than the shank. these will be perfect for rough 3d jobs with rapid removal

-Water cooled is a must, just run normal antifreeze.

-Bearing grease will not be a problem. -5C is not a big deal. Just run the spindle slower to faster some minutes every time, so it can heat a bit. You will need to do also the following things: make additional bracket and fit a seal on the spindle shaft, best would be if you change the grease with salt water resistant grease/ Mitchel, etc./ , the one they use in fishing. it is a very fast grease, so no worries there. For sure its better than the original one :-)

2. Frame

it should be at least bi component industrial coating marine epoxy painted or you would be sorry very soon. Best would be inox and then epoxy painted. Yeah, inox rusts too

3. Rails must be inox, Hiwin has inox rails and carriages.



I see your biggest problem with "chip and dust removal and damage" , cause your chips would be water. hence water will go all the time where it should not. Ok, electrical connections could be dipped in polyurethane/ via hot melt gun and polyurethane glue bars/ but never the less all steppers have shafts, so those shafts have to have additional seals.

I see it working if you plan use it in a room where is -5C. I see that you looked at the machine i am making. Following a similar design is easy to protect all ball screws.

But if you plan only an enclosure where is -5C, i see it very difficult-aluminum also f***s in moisture , so more or less every metal part left visible-shafts, plates, bolts, ball screw supports, ball screw nuts etc., should be sealed or painted over. Same goes with the cables, their ends and connections must be dipped in polyurethane.