That's interesting, which model do you have? My original question related to the entry-level DML250 and yes, I'd used a vac fitted with a crevice nozzle, aided and abetted by a selection of paint brushes but still found I wasn't clearing all the dust away. However, yesterday I picked up a DML320. That doesn't have the thin metal plate you speak of but nor does the motor housing have the dust-trapping fins of the DML250, using instead a smooth surfaced cylinder. No doubt dust won't just slip right off but should be easier to brush off. I say "should"...
It's a DML 305, sort of bigger 250. Attached photos, I took it out so you can see the construction, should be a doddle to make one, all you need is a bit of aluminium or similar, you might even be able to use beer or sardine cans. Take a rectangular flat piece of whatever, at the half way mark cut 1/3 in from each side, cut to adjacent corners out, fold a bathtub shape for one half (sits at the headstock end) and leave the rest flat but bent down a little. On mine there is a cross piece in the casting and a single setscrew to locate it, but gravity would do the job just as well. Interesting that is wasn't mentioned in the assembly instruction or diagrams so maybe a recent modification. I've not 'cleaned up' for the photos and I was mid job so you can see it does a pretty good job of keeping shavings off the fins.
All engineering design is a compromise - I guess the 3 people on Apollo 11 wished it was made of thicker stuff but it had to be light enough to lob it up into space. The DML range is designed to be compact and self contained, so you can fit one on a conventional workbench and move it about if you have to. Putting the motor where it is helps achieve that compactness at sensible cost. I doubt they set out to do a bad design job. I've not seen any complaints about motor failures.
