The spindle of my Sherline Mill has a maximum speed of 2800 rpm, and that is probably not fast enough to run tiny engraving bits. I have a Dremel 395 hand tool (35000 rpm), so I made a mount for it.
This mount is made of aluminum and UMHW. The tool threads into the front block, and the rear block acts like a band clamp. Here you see it fastened to a Sherline riser block.
For successful engraving, you need to be able to make a uniform groove. Here I have mounted the tool to my Sherline mill for a test on scrap aluminum.
The cutting bit is a Dremel 105, which has a 1/32 inch diameter ball tip. Dremel warns that the ball tip bits do not cut very well when held perpendicular to the workpiece, so I have tilted the tool. Dremel provides both .094 and .125 diameter collets, so I could use also use small end mills.
This is the groove produced by freehand X and Y motion of the mill, and angular motion of the rotary table. The grooves represent both directions of travel in the X and Y directions. I judge the groove to be uniform enough for my purposes.
To do useful work, I have to make some more tooling:
1. I would like to be able to engrave identifying letters on my reel feet or bearing caps. For this I need a pantograph. Making the four bars of the linkage should be easy. Also I need a lettering template that will guide a stylus, perhaps a template from an old Leroy lettering set. The difficult part will be control of the Z axis.
2. For decoration of end plates, I may make a rose engine. My plan for this is to mount the Dremel tool on my lathe cross slide, and replace the headstock of the lathe with a rose mechanism. I have already explored the geometry of this mechanism, see post of 13 July 2011, “Engine Turning”.
Is it silly to engrave the end plates of a reel? I don’t know of any classic reels where this was done. But everyone finds 19th century pocket watches to be attractive.