Those are there to provide places to mount various things with cable ties. The only thing that we’ve ever used them (thus far) for is to mount the vibrating motor for the diamond engraving tool. You can see a picture of that use on the product page: http://shop.evilmadscientist.com/productsmenu/partsmenu/297
Hi Windell… Thanks for the info. I had been thinking of using one of the slots as an index/hold-down method for an appastrapus I’m going to try to make, to help hold the pen orthogonal to the distal arm. I actually bought the engraving tool from you, so I should have known, but haven’t opened it yet. 8^( Been having too much fun with the pen and the software.
Speaking of the photos on your product pages, I really want to compliment you on your superb informative photos. And that goes double for your instruction sheets. They are the best, clearest, that I have ever seen!!!