This is a mini-instructable for a couple of Dremel/Minicraft guide jigs made from scrap.
The first is a guide for cutting freehand straight lines with the cut-off discs. It's designed to give you something to firmly hold the tool down to, to prevent it getting away.
The second is a guide to maintain a fixed depth into the work, for thinning, engraving, milling. It's like a router base for the tool. It also provides greater stability, and allows finer movements for small detail work.
Step 1: Straight Line Jig
I made this guide from a scrap metal plate, two offcuts of plywood, a piece of scrap steel bar, two large nuts and a piece of paxolin (copper clad printed circuit board material)
The two nuts are sized to fit on the steel bar as a sliding fit. You could use non-threaded spacers here too.
They are spaced apart, and yet held together, by the paxolin piece. The spacing is adjust to be a good fit to the narrowed neck of the tool, so it rests comfortably in there.
The steel bar is spaced upward so that the nuts, with the paxolin spacer under, can slide side to side freely without there being too much slack space.
Everything is held together with superglue!
To use it, place the tool in the nut-rest, as shown. Hold the tool firmly down on this rest, and then you can move it left to right along a very straight line. Angling the tool up and down allows you to cut shallow, or deeper, into the material.
Wear goggles, and try and keep your face out of the plane of rotation. These discs shatter and disappear in an instant when they fail.
Sometimes you might even find all the pieces.
Step 2: Depth Control Jig
This guide was made from scrap MDF offcuts, plywood, some large bolts, and a couple of plastic plumbing pieces.
I needed a way to hold the minicraft tool body firmly, vertically, on a support board. I noticed a 32mm push-fit plumbing fitting (black) was a slack fit on the tool, but that cutting a small piece of plastic waste pipe (grey) allowed for a key-piece that could be forced in to grip it tightly.
Start with a full circle of pipe, split it down, and then keep trimming it into a C shape until it fits tightly between the drill and the black piece.
Then I put a hole into the scrap plywood, which is very slightly conical to match the end of the drill, and araldited the plumbing piece in place.
The two end blocks are scrap MDF, glued and screwed to the end. The height was chosen to allow the shortest of tools, when fully in the drill chuck, to touch the flat table the tool was placed on.
Height adjustment is made with four large bolts. These have an internal hex-head, so an Allen key is needed to adjust them. This allows for very fine adjustment of the cutting depth by raising and lowering the jig. There's about 1 inch of travel, at most.
The bolts "tap" into the MDF -- the holes were drilled oversize, and with two additional "wings" holes either side (as marked in the picture). Then hot Polymorph plastic put down the sides of the holes and the bolt screwed in to create threads. It helps to drop the bolts in hot water too, to prevent the polymorph setting on contact with cold metal.
To use it: Insert the drill fully into the black plumbing piece, clip the grey "key" piece onto the drill, and force it home.
Then you can adjust the height of a drill/milling/flat sanding tool as needed, so you can cut partial depth into e.g. a piece of veneer (see step 10)