[Regia-NA] Re: {Regian-NA} a bit on antler and bone working in which Magnus goes a bit nuts.

[rmhowe]

Bill [divers descriptives] wrote:
> The hardest part for me when doing a comb is the planing 
 > of the plates to make them all the same thickness.
 > Since I do most of my work sans electricity, that's a lot
 > of work. Does anyone have a better method?

I should imagine they pushed against a little board stop
pinned or held in a slot to the top of their workbench/beam
and scraped/filed them to thickness. One should do this to
the convex side first, and then the concave, rather the
opposite of how one would plane a board in a jointer/planer
situation. Otherwise you would get tipping side to side
and negate your efforts. [With a cupped board one should
plane the concave side on a jointer before putting it in
a planer.]

The scraping could be done with a file held at an oblique angle
and used with both hands in a method known as draw filing.
We know they had files for certain.
A finer, medium -curved tooth- file used today for body
work would work well, the same kind one would use on
aluminum so it doesn't load the teeth. The period file
survivals I have seen all had larger teeth. Of course finer
teeth are destined to be eaten away by rust. A formica file
for laminates for countertops would also cut well.
File teeth in period were made by driving a short chisel
angles into the bar with carefully measured strokes - a
distinct art.

An old trick using hand planes when you want exact matches
is to put sticks of equal thickness on either side of the
plane bottom. When you hit bottom you hit bottom. This could
be accomplished by using double stick tape [or a water
dissolving glue like ordinary hide/white glue to put the sticks
on with to a metal plane, or little flat head bolts and nuts
through the plane base.] This is very common in
Chinese/Korean/Japanese constructions where they are making
shoji screens or tansu moldings or fretwork screens. I
think http://www.leevalley.com/ has some for sale currently.
I'm pretty sure I saw three different models of Asian
'winged' planes there fairly cheaply.
These have bars sticking out at 90 degrees to the body.
They are usually pulled instead of pushed.
For tiny pieces some people push against a flat head
screw that can be screwed up or down on the worktable.
Set low enough it should avoid your plane with edge-
sticks. For more stability you could use two flat-topped
wood screws placed near each other to push against. The
screw's edge both holds the piece and pushes it down
when planing.

There is a new type of bowyer's scraper that has about
five or six scrapers set into its bottom vertically
at oblique varying angles into a little board. I haven't
tried one, but for fine carving in bone or plastic
I commonly reshape dental tools and scrape with them.

When I was making parts to one thousandth's of an inch
by hand sometimes I would use one little board of exact
thickness at one side of the piece to be worked on
and slide the non-sandpapered end of my stick over the
board while the sandpapered end slid over the workpiece.
[Actually all of these were plastic pieces.]
Of course the board has to be set on some thing like tape
or sandpaper equally glued to it's bottom with double-sided
carpet tape to come by the right thickness for it.
Checking with a dial vernier caliper would tell you when
the workpiece is exactly the right thickness and parallel.
Sometimes you can simply swivel the sanding board as if
on a pivot. On small long things this is very necessary.
You can also stick your spacer to the bottom of your
sanding board. ;) There are many paths to the same end.

I used to make tiny plastic moldings as small as 15 X 20
thousandths' of an inch, often triangular in cross-section
of of off-cuts of plexiglass.

We actually cut many pieces on full sized tablesaws
on the blade's side -away from the fence- that were each
tiny compared to the blade's individual carbide teeth.
In this case the moldings were a bit like strings and we
grabbed ahold of them before they got sucked into the
teeth. The heat from the friction would curve them
away at first. One does this by placing one's hand heel
securely on the tabletop first and then grabbing the
piece with the fingers at a slightly safe distance.
A hand-shake non-located as above and your fingers
could be in the blade.

On precisely cut multiple pieces we would make a
plastic (jig) piece cut through only *part-way* to slide
back and forth against a [machined bar clamped-down]
fence and then glue locating pieces to the top of it
to butt against. The bar or fence was always checked
precisely front and back for parallel to the miterslide
grooves. * Something like this would make parallel pieces
multiply. [A Jig is a moving part for holding pieces
to be machined/worked in some fashion. A Fixture is a non-
moving piece that holds a workpiece to a machine table
that is generally moved under a cutter. These also have
handwork applications.]

We also made certain the saw yokes under the
top were adjusted so the blade would be parallel to
the miter-slide slots. This is done by loosening the
4 bolts under the top that hold the saw trunions and
moving/tightening/checking the same tooth rotated front
and back by measuring the distance back and front from
the miter slide slot.
There can be only one way of accurizing a saw.
It's a pain but you only have to do it once, and you'd
better unless you like inaccurate and burned cuts.

All circular saw blades wobble a bit and we would take
a little wood block and rotate the blade by hand against
it both sides backwards by hand. Then we would mark the
far and near teeth from the fence on it with magic
marker on either side of the blade.  These were referred
to as the 'High Teeth'. They were the ones we measured
from to the fence when we set up.

IN practice the workpiece to be cut into tiny pieces was
then located atop the sliding jig against the glued on
little fences set to the desired angles and as we pushed the
piece across the top of the saw we would hold the tiny
pieces with ice-picks to keep them from flying away.

I am digressing on the topic because you are looking
to get evenly matched pieces.

When I did plastic models or parts the jigs were made
of plastic. I did industrial and architectural models
and at one place we also did Sci-Fi replicas once in
a while for an esoteric collector who would then put
the pieces together himself. The submarine from the
old 60's series for example with the front end a bit
like a manta ray's wings was one of them.

When I did plywood for cabinets or wood parts for
furniture the jigs were made of plywood and had a fairly
exact little stick or two screwed on the bottom that slid
underneath in the miterslide slots. Sometimes there
would be location fences tacked to the top and sometimes
there would be brads driven in the top, clipped off a
1/16th of an inch high and filed sharp to keep the
workpieces from moving when we pushed the jig over the
tablesaw top. The unwanted piece cuts away on the other
side.

On one of these there was no jig side on the other side
of the blade. It was simply a cut off jig and I would
scribe ink lines on the workpiece edges where I
wanted them cut and simply set each of them over the
edge of the sliding jig, then press down to hold the
piece rigid on the pins. Guaranteed a relatively
accurate cut.

One last method for unusual pieces involves cutting
acute angles.  Normally only angles of 45 degrees
may be cut on the tablesaw - unless you make a jig
that moves vertically over the tablesaw fence or
locates with a wider base sliding on the groove
for the miterslide.  If you clamp/cramp your workpiece
to this you can cut up to and including knife-edged
angles.

These are all not commonly known techniques.
If you ever try them on acrylics use CAST and not
extruded acrylic. Extruded melts much more easily
when sawing.

I slab my antler and bone out on a bandsaw, if you want
all even plates you do it between the fence and the blade
once you've gotten past the round outer side curves you use
for the outside plates. This assumes you still have new
teeth for the blade and it's tracking straight. I once
cut a number of antler pieces in the University Crafts
Shop when my tools were in storage to the grateful looks
of all about me. ;) I've done it by hand too and I prefer
saving the muscles these days.

When I am dealing with the calcareous spongy tissue in
bone or antler I have one final trick. Getting rid of
the spongey material is difficult by hand. It's easy
with a bandsaw.

Just as in using a technique with which it is easy
to file with a jeweler's saw blade in small places by
using the side of the blade to rest against the material
while you file delicately with one side of the saw teeth
you can do much the same with a bandsaw by resting the
good part of the bone against the side of the moving
blade and letting the side of the bandsaw teeth nibble
away at the material you don't want.

To do this SAFELY one should cut midway into a board
first and leave the board [clamped/cramped if possible]
on the table. One then uses the board to rest the bone
or antler on. This way there is no danger of the
material dropping into the larger hole of the saw's
throat plate and pulling your fingers closer to the blade.

**I hold the material from -behind- the blade** as it
moves and *I rest the part I want against the side of
the blade behind the teeth. Meanwhile I nibble away at
the parts I don't want with the teeth.* You work from
the middle toward each end essentially if you have a
lot to remove. Doing enough of this is going to wear
away at the set of the teeth so you might want to use
the teeth on both sides alternately. More set on one
side than the other and the blade tracks in the direction
of the most set. Set means the front edge of alternate
teeth (generally) sticks out sideways a bit from the
blade. No set and you cannot cut turns with the workpiece.

Of course in doing any of this using power tools you
want adequate eye and breathing protection. I suggest
a face shield at the minimum for eye protection. I have
wheels on the smaller [Sears] bandsaw so I can roll it
outside for cutting smelly or dusty materials. I have
cups to put under the wheels so they won't otherwise
slide.

I am uncertain of the provenance, but one of the things
I made my wife years ago was the little animorphic comb
depicted in Du Chaillu's The Viking, 1883. That was a
rhomboid one piece carved out of the conjunction of various
antler limbs. I did it entirely by hand from slabbing to
carving the grooves with engraving chisels.
It's quite pretty, but described as possibly foreign in the
book. Only I've never seen this one piece style [attached
to a chain probably hung at the shoulders] anywhere else.
Anne has a full-sized version, it has two opposing
heads and hangs from a silver twisted ring at the top.

The way the Vikings apparently worked antler was to
scratch deep V's lengthwise down the shaft at quarters,
and then drive a large tapered piece into the I assume
*soaked* antler end to split them which didn't always
succeed from the remains of failed pieces -or- by
prying/popping the plates up with a heavy knife or chisel.
This was done after cutting the antler to length generally,
although I know I have seen cuts just deep enough to hit the
calcareous tissue probably in one of MacGregor's books.
I've seen it described both ways in the literature
including a couple of how they were recreated books or
articles.

I have more resources than just MacGregor's books on making
and varieties of combs from different provenances.
A few I am still looking about for. Not all of them I have
had time to put into the computer though for quotations.

I spend a substantial amount of time searching for certain
subjects like bonework on the web and waiting to see which
ones I've ordered I actually get. Right now I am waiting on
six of the Birka books including I, II: 1,2,3, IV and
something ancillary from Sweden and Holland. I believe I
am getting them all this time. III and V I already have.

Tomorrow I should receive a rare 1918 German monograph on
the Ancient Artillery of Castle Saalburg, that's an English
approximation of the German. First I ordered it, then they
called saying it was lost, then they called telling me it
was being sent again the next day. Good for the blood pressure.
I imagined someone had stolen it from the store.
Ridiculous price. Had looked for it and at the only one
listed for six months. One of the prime resources on Roman
siege engine reconstructions. I have ambitions towards
making the little arrow/javelin throwers that accompanied
most legions and which wreaked havoc at Maiden Castle.
(Curiously it's much cheaper than Birka I. This has been
an expensive week but then we aren't going to Pennsic
this year. May go to the coast instead.)

Magnus, just getting to this part. Sorry I'm a bit late.

> Bill