Peppermill Construction
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Segmented Ring Peppermill Construction

This is a brief description of how I construct peppermills such as the one shown in this photo. This is a 12" tall peppermill, constructed of 158 separate pieces of wood. The techniques can easily be modified to other sized peppermills.

The mechanical parts that I use require a 1 1/16" diameter recess in the base of the mill to accommodate the grinding mechanism. I also add a 2" diameter recess about 1/2" deep in the base to allow for clearance of the grinder mechanism. I sign and number the piece inside this recess.

The top knob has a spigot about 1/4" long and 1" in diameter, that fits into a corresponding 1" diameter hole in the top of the mill body. The rest of the body is drilled out to 3/4". (The whole body could be drilled out at 1" or even 1 1/16" to simplify construction, but I like the extra  wood thickness at the narrow point of the neck.)

The mechanical parts I use measure 11 7/8" from the base to the top of the threaded shaft, with 5/8" of threading on the shaft. The total height from the 2" recess in the base to the top of the knob has to be around 11 1/2". My design gets close to this by construction, then I adjust the final height when I turn to knob by adjusting the thickness of the solid piece at the base of the knob.

I use Titebond carpenters glue for all my work. It's easy to work with, inexpensive, cleans up with water, and sets relatively quickly.

 

Constructing the Rings

 I start by milling the wood I will be using to a standard width and thickness. I plane the wood to just under 1" thick - about 15/16". This thickness has evolved primarily because I tend to use 1" rough lumber which is sometimes hard to keep at 1" when planeing. I use two widths - 1 1/4" for the 5 lower rings, and 3/4" for the upper rings. This again has evolved - the smaller rings in the upper neck can allow me to make more efficient use of the lumber.

For the 12" mill, I use 6 small rings - about 2" in diameter, 6 wide rings - about 3 1/4" diameter, a 3/8" thick 'starburst' top ring, and two solid pieces of wood for the base and bottom of the knob.

I cut the segments for each ring on a table saw with the jig shown here. The jig has been carefully calibrated to cut at exactly 15 degrees so that when assembled, the rings have no gaps.

(As an aside, I always use the tablesaw with the blade at 90 degrees - never tilted. I build jigs that tilt the lumber when necessary. I use an accurate square to set the blade at 90, and leave it locked. If the cut is slightly off 90, the rings will not go together correctly.)

 

The rings are then glued together. I always clamp the rings with metal hose clamps to squeeze all the glue I can out of the joints. The best setup is actually to use two shorter clamps linked end-to-end. This gives you two screws to tighten with.  
Here are some examples of assembled rings. The two thicker rings are used for the body of the peppermill, the thinner ones are for the 'starburst' top I put on many of the mills. The starburst is created by inserting pieces of veneer between the segments that make up the ring. These rings are a bit trickier to glue up - they have more pieces to glue, and the center hole has to be less than 1/4". I usually first glue a strip of veneer to each segments, then glue the segments together. (Hint - unless you require solid wood right to the center, always leave at least a small hole in the center. The gluing and clamping is a lot easier!)

Sanding and Drilling

Once I've glued all the rings, I give them a quick sanding on a disk sander to get rid of any small imperfections. My disk sander is a shop-built disk that mounts onto one of my lathes. I use a 12" disk of fairly coarse sandpaper - 100 - 150 grit. It is mounted on an MDF disk that's attached to a faceplate.I have a make-shift hood that goes over the whole thing to try and pick up as much dust as possible - it generates plenty! The photo on the right shows the disk.

There are two tricky parts to sanding the rings. #1 - avoid sanding your fingers! #2 - avoid sanding the ring more on one side than the other.  Normally one holds the ring between the edge and middle of the sanding disk. Since the outer sanding area is moving faster, it sands more off of that side of the ring. I find that it helps to rotate the ring as you're holding it against the sanding disk, so that any inconsistencies are balanced out.

Next I drill out the center of each ring. I use a drill press to drill the centers out to 7/8", then drill the ring for the top of the neck to 1" diameter to a depth of about 1/2". The ring to go on the bottom of the mill is drilled to 1 1/16"diameter about 5/8" (the depth of the grinder mechanism.) Actually, this ring will be second-to-bottom, as a solid ring is added later (see below).

Gluing the Peppermill Body

Once the individual rings have been drilled, I assemble the body section. I use a piece of 3/4" dowel wrapped in a layer of waxed paper as a spindle to keep all the rings precisely aligned. When the 10 rings that form the body of the mill are all glued and correctly aligned, I clamp the whole assembly down to a workbench surface to ensure tight glue joints between the layers. Once the assembly is clamped to the table I pull the dowel out of the center. (Note - the topmost ring in the photo is not actually part of the mill - it's a clamping block I use for this step. Really just an spare ring that I use for the job, with an extra large hole drilled in it. )

Solid Base

The final piece is the solid base section. At this point I usually check the overall height of the body of the peppermill and the amount of wood available on the top knob assembly (allowing for 1/8"-1/4" spigot on the knob which goes into the peppermill body). The base piece is adjusted in thickness to get the correct total height for the peppermill mechanism. I try to get the base section about 10" tall, which allows some final adjustment on the 2" knob so that everything falls within the tolerances of the mechanical parts.

I have a small faceplate with a waste glue block attached to it. I glue a 3 1/4" diameter piece of 3/4"-1" wood to this with a layer of paper between the waste block and the wood. (A quick sanding with the disk sander will ensure that the wood is flat before gluing).  When this is dry, I turn the base piece, adjusting it's thickness to match the accumulated size of all the rings. I bore a 2" diameter hole about 1/2" into the base block, then bore at 1 1/16" the rest of the way through. (This final hole matches the 1 1/16" hole that was pre-drilled in the bottom ring). At this point I sand the sides of the 2" hole - since it will not be accessible in later steps. This piece can be easily removed from the glue block with a mallet and chisel, lightly sanded to remove the paper and glue, then glued to the base.  

Top Knob

The top knob is glued up with the starburst piece on top, and a solid piece below. This too is clamped to the workbench until the glue sets. I usually use a 1" thick solid piece, so the resulting assembly is about 2 3/8" top-to-bottom. The mechanical parts can now be test-installed into the base in order to measure exactly how tall the knob should be. An additional 3/16"-1/4" spigot is also required, which gets inserted into the neck of the peppermill body.

 

Ready for Turning

This photo shows the completed base and knob assemblies ready for final turning and assembly.

Turning the Peppermill Body

I do all the turning by mounting the body assembly between centers. I Have a custom built spigot chuck mounted on a small faceplate. This allows me to drive the assembly with a 7/8" dowel inserted into the top (neck) of the peppermill body. Some tweaking of the diameters and tapering of this 'drive' (including some masking tape wrapped around the dowel) enables it to slide into the 1" diameter hole in the top of the assembly, but stop where the 7/8" inner hole begins. The beauty of this drive arrangement is that I can get tools and sandpaper at the top of the neck. 

I use a standard tapered tailstock into the base. This rests nicely in the 1 1/16" hole in the center of the base, and again, allows me to turn and sand the base rim.

Turning the body shape is a matter of personal taste and preference. I like to keep the lower part between 2 3/4" and 3" in diameter, and bring the neck down to 1 1/2" or maybe a bit less. Two critical areas are the ends - the top of the neck and base. I have a 1/4" beading tool that I use to clean up both of these. I taper the base slightly towards the center so that the mill will rest on the outermost rim only (for stability).  At the neck I do the same thing. I also aim for a neck rim width of 1/8"-3/16". This has to later be matched to the base of the top knob.

Turning the Top Knob

I turn the knob by first mounting the assembly in a scroll chuck (I have a oneway). I hold onto the starburst assembly. The middle segmented ring is slightly larger than the starburst, so there's a convenient shoulder to rest in the chuck against. I can then turn the lower half of the knob, adjust the height, create the spigot, and drill the center hole. (I drill the spigot end out to about 5/16", and the hole through the very top to 1/4".) Once this is done and sanded, I reverse the knob, holding it by the spigot in the small jaws of a oneway chuck.  Since this is a bit precarious, I bring up the tailstock to hold things securely. (There's now a hole in the top so it's easy to align everything.) The top is turned and sanded.

Now all that's left to do is apply a finish to the pieces and assemble the mechanical parts.

 

 

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