Agree w/
Scifan.. - there are various 'levels' of protection that could be used, i.e. from just port protectors (shown in the first pic below), to plastic or better yet glass protectors for the screen and bevel, and finally full device protectors, as already mentioned; there are even 'waterproof' cases as shown in the last image that could be considered.
Now I'm an amateur woodworker also, and my first consideration would be to reduced the amount of dust in the shop (forgive me if you're already there and beyond) - first, collection @ the source (I use a standard DC attached to my table saw - can be changed over to the bandsaw or the thickness planer) - have an older DC at the other end of my basement shop connected to my jointer and large belt sander, as needed. Second, I also use an ambient air cleaner w/ high grade filters - this hangs from the ceiling.
My only other comment is that I'm not sure having my iPad near my woodworking tools would make me comfortable - could so easily be damage - I'd probably look for some type of pivoted holder (use one in the kitchen - just a plastic removable holder that keeps the iPad off the counter). Of course, what I would more likely do is to simply printout the plans and leave the iPad upstairs?
Dave
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