Little is known about this type of turning as very few books on woodturning
even mention it, let alone have information, or the how to, in them.
Quasi.
Just what does "Quasi" mean? Dictionaries vary some-what in the explanation
---"not quite right" ---"similar" ---"the same as,
but different"
Well, quasi turning is all of these. It is REAL flat
turning, BUT not quite.
For this exercise let us make these two candle stick holders. An exact matched
pair because they were both turned at the same time.
To start this
project we must make a reel of just two ends separated by 4 spacers.
The spacers being 10 mm or similar threaded rods.
First and foremost what is the maximum diameter that will
swing over the bed of your lathe?. And don't forget to include the banjo that
will support the tool rest. Just for safety, take a few mills off the
diameter so there is a little clearance .This figure will become the diameter
of the reel to be made. The length is any size that will fit between centres,
maybe even long enough to turn four legs for a chair, all at the same
time
Make up two disks of 25 MM thick craft board or plywood to the
diameter as above. In my case a diameter of 220 MM.
Fit two pieces of steel
30 MM. square x 4 mm thick with a good deep counter
sunk hole to the shape of your live and dead centres, these to be fitted
at the centre on the outside of each disk,. This will take the live centre
at the tail stock end and a dead centre at the head stock end.
Drill
four holes 10 mm diam. as per "A"in Fig 1 Mount
the counter sunk plates with 4 small bolts and then bolt the two disks temporary
together. Fit a face plate on the lathe, a dead centre in the head stock and
a live centre in the tail stock and then mount the disks in the lathe. Mark
through the faceplate a hole to mount a bolt to drive the disks. Remove disks
—drill hole—mount the bolt in the face plate—remount disks, and clean up the
rim of the disks in the usual woodturning method.
Most lathes these
days have an indexing head and this is a very accurate way to mark the circumference
of these disks. 12 marks around the rim will be very nice. If you
don't have an indexing head, that is no trouble, just use a compass, and a little
time, and you will achieve the same results.
At the same time mark a datum
mark on the two disks and plates. This will aid in the assembly later.
Remove the disks from the lathe and prepare to mark out for drilling as in Fig 1
SETTING OUT, DRILLING AND THREADING THE DISKS
Holes A are not threaded, nuts and washers will hold the disks apart to make
the reel straight and true.
Holes B are marked 40 mm from the edge,
drilled and threaded to 5/8 inch Whitworth A
little neat's foot oil to lubricate the tapping thread helps to
make a clean thread in the wood. When assembled, a threaded rod
in the holes "B" will hold the work in place and allow it to
be rotated, four or six times, depending which set of holes are being used
Holes
"C" are drilled and threaded to 5/16 inch Whitworth threads on one
disk only. It is best to use the disk without the drive hole, this will put
the indexing at the tailstock end. Don't do what I did ,drill and tap both ends,
it is a waste of time. These holes are indexing holes and set on a diameter
of 50 mm. Again a threaded rod in the hole will hold the work in place
while one face is turned. The threaded rod is then removed, the work rotated
, and the threaded rod is reinserted in the next hole and the turning
continued, this continues until all faces are complete.
To mark out the indexing
holes, make a template of ply wood or light metal, about 75 mm square. In the
centre mark this spot and measure 25 mm out, mark and drill a hole 1/4
inch diameter. Return to the centre mark and drill a hole
5/8 inch, the size to fit over the 5/8 inch thread.
This template serves two purposes.
1. to lay out all the C indexing holes
accurately on the end plate and,
2. to mark the work pieces, indexing
hole.
With the two end plates still bolted together, mark holes
B and draw the 50 mm diameter circles.
Drill these holes, {B} check
the datum and then, separate the disks.
Using the compass, radial mark
the 6 spots around the two circles. This method is not actuate For a better
method use FIG 2, and for the square indexing , mark at right angles to 1 and
4, and draw a line sq 2 and sq 4.
Method of locating six evenly spaced points
Draw 2 lines ACB & DCE the length of the diameter of
the circle, at 90 deg to each other
With C as the centre draw the required
circle
With A&B as centres and C the radius draw two arcs JF&HG giving
the required points at A,F,G,B,H, and J.
A hint.—This is also the method
to mark out a clock face. Just add 2 extra circles at D&E
Cut 4 pieces of 5/8 inch threaded rod 50 mm long and grind, file, or turn the thread away to make a round 1/2 inch X 15 mm long. Cut a slot in the end, for ease of working.
Screw thread into hole "B" place the template over the thread, now mark and drill all the "C" holes. 16 in all.
TO ASSEMBLE THE REEL
When all the holes are drilled and tapped,
assemble the two disks by using four threaded rods,
each 200 mm long plus the thickness of the two disks nuts and washers.
This
length could be made longer, later, when
you have more feel for quasi turning. Using nuts with
washers on the inside, and the same on the outside
mount the assembly in the lathe via the live and dead centres , it can
now be trued and tightened up.
INDEXING PIN
Make up two, 50 mm long X 5/8 inch
whitworth threads. Remove 15 mm long of the thread to 1/4 inch round by filing
or turning in a lathe and cut a slot in the other end of each so you can use
a screwdriver to insert them in the indexing holes.
That completes the jig assembly. Naturally a simpler reel could be made but this jig can be used time and time again.
In case you have forgotten what this is all about, we are going
to make two identical candle stick holders. Just one of an unlimited
number of possible projects.
Material required
Two
pieces of quality timber 200 mm long X 75 mm square
Six pieces
of scrap soft wood 200 mm long X 40 mm square.
Method.
Mark the centre of each end
(all four ends) then drill a hole 1/2 inch diameter in the centre of each
piece of timber,15 mm deep. The two work pieces will rotate on this centre .
To
drill the index hole place the 1/2 inch part of the threaded rod
in the end hole and using the template you made, place it
over the thread, mark and drill a 1/4 inch hole, this will now become the indexing
hole, and must be very accurate. Twenty mm at the end with the indexing
hole will become waste, so the foot or base will be 20 mm from the end The
hole in the other end will be enlarged later to become the hole for the candle.
The
waste pieces become a template and are not rotated.
MAKING A MATCHED PAIR OF CANDLE STICK HOLDERS
This
is where your skills, knowledge and your imagination, come to the fore.
Start
by turning the two work pieces round in the lathe in the normal way, maybe turn
a neck shape and also a base or foot shape .See photograph. Fig 1 Make sure
to leave 20 mm at the indexing end {foot end} as scrap wood, this is because
of the indexing hole, it will also be used to hold the work in a chuck to finish
the top —a hole for the candle and any other modifications you desire when you
have finished the quasi turning.
Leave the scrap pieces of soft wood in the
square state.
Mount all eight pieces in the reel— drill holes in each end
of the reel as shown in Fig 2 and using wood screws hold the scrap
pieces of timber firmly in place.
Use the large threads to hold the work
timber centre, screw the threads into the hole but don't tighten them
just yet. Now fit the 1/4 inch threads into an
indexing hole and find the index hole in the timber and call this position
one for the two work pieces. Tighten the centre threads just a little, fit
washers and lock nuts and tighten them all .
PREPARING THE LATHE
Fit a live centre in the tail stock and a dead centre
in the head stock Fit a face plate on the nose of the head stock with
a bolt that will go into a hole in the end of the reel, this dog assembly will
drive the reel.
Fit the reel between centres making sure the centres are
firmly in place.
Set the banjo in place, and the tool rest at the correct
height, now
TURN THE LATHE OVER BY
HAND
CHECK EVERY THING CAREFULLY
Set the lathe at a low speed
Now it's up to you
With CARE,
GO
After you have turned the first face, undo the two indexing threads from
the work pieces and move the thread to the next hole {the
one of six in this case} rotate the timber to match the
thread, tighten, do the same to the other work piece. Don't
change the scrap pieces. The shape on these is your template to follow
so all faces will be the same.
Repeat the above five more times to make six
exact faces.
NOTE— The two six indexing holes have two extra holes, these
are for square facing and not for a six face article, so when rotating the work
for either four or six sides, be aware of this, although you might like to use
a combination of both,— interesting.
A little hint here will help. If you
coat the faces of the scrap pieces with a contrasting spirit pen or facsimile
after the first face has been turned, and if you go too deep when turning the
next five faces, this will surly tell you, and don't throw away the scrap pieces,
just rotate them to a new face for your next project.
After finishing
this first project you can go on to many more, the field is almost unlimited.
HAVE FUN
