|Dremel Sherline Headstock|
Making a Dremel rotary tool headstock for Sherline mills and lathe. The Dremel
rotary tool is a very verstile tool that has a speed of 30,000 rpm for
driling, griding, cutting, and many other applications. The Dremel rotary tool headstock can be mounted
on Sherline mini-mills and mini-lathes for some light-duty precision
milling, cutting and grinding small workpieces. This headstock can
be used as a milling table rotary tool holder, it provides four mounting moles for
mounting on the T-slots of milling table and
lathe cross-slide. It can be use for high speed machining on woodworkings and some soft metals.
This rotary headstock is made for mounting Dremel rotary tool models of 100 and 200. The model 100 is a single speed version that has 0 and 30,000 rpm only. The model 200 is a variable speed version adjustable from 0 to 30,000 rpm.
The Dremel rotary tool is a precision tool primarily applied to woodworking. It is designed as a light, versatile duty power tool. The model 100 and 200 are the two very early models. The latest rotary models do not fit into this headstock holder because of the different body dimensions. The nose housing cap thread is 3/4"-12 TPI (standard thread size for all models). This will be compatible with all others optional adapters.
The Dermel rotary tool bits provide a larger variety of applications, it is not limited for woodworking. Various applications include: metal cutting, grinding, and even ceramic tile cutting. It provides a lot of cutting bits in large areas of applications.
This dremel rotary tool headstock can be mounted on the models 100 and 200, as shown in the picture of the Dremel model 100 (single speed) - and the Sears Craftsman model # 572-243502, which is same as the Dremel 200 variable speed version (the Craftsman rotary tools is OEM made by Dremel). Both ot them can provide 0 to 30,000 rpm high speed operation.
The rotary tool holder is mounted on the Sherline mini-milling machine for milling and drilling operations. The pictures show the holder mounted on the lathe tables. When it is mounted on the lathe cross slide table, the spacer block will be use for raising up the lathe headstock to align the spindle center and the rotary tool. It is very useful for grinding and cutting small diameter round stocks.
In this picture, the holder is mounted with the variable speed rotary tool (Dremel model 200). The variable speed is needed for working with different materials, like plastics, which requires slower speeds to avoid melting the piece.
The rotary tool nose house cap is threaded with 3/4"-12 TPI. For mounting the rotary tool, the original nose housing cap is
replaced by an aluminum taper nose nut. The nose thread is mounted on the
nose mounting plate secured by the nose nut. The rotary tool is
plastic so the nose nut must be hand-tied.
The 3/4"-12 TPI tap is not a common size, it can be purchased from KBC tools, www.kbctools.com.
The Sherline headstock locking screw is a 5/16"-18 TPI cone point set screw. It is available and can be ordered as Sherline, P/N 40540.
It can be made by modifying an offshelf 3/4" x 5/16"-18 set screw grinding the tip at a 90 degree angle.
Checking the dremel bearing runout, it has 0.0015" measuring on the collet mounting nose. When a 1/8" shaft cutter is mounted with collet and measuring the total runouts on the shaft of the cutter, it has almost 0.004". The amount of runout is slightly different when different collets and the drill chuncks are tested.
When the Dremel rotary tool is used on metal, there is no problem in handling aluminum alloy, copper alloy type and other type soft materials for milling operations. But for ferrous and other hard materials, the Dremel should only be used for grinding, engravings and cutoff-type of jobs. The rotary tool does not provide a lot of power for milling and cutting hard materials and is not suitable for this kind of job.
Drilling printed circuit board is my primary Dremel application in this project. It provides precise drilling. The picture shows drillings of 0.032" holes with a solid carbide drill bit.
The 1/8" shaft 1/16" carbide end mills is used for cutting PCBs, it nicely cuts slot holes on the PCB.