Archiv der Kategorie: englisch

Turning a latticed pendant

OLYMPUS DIGITAL CAMERA

(Die deutsche Version dieses Berichtes gibt es unter http://drechsler-wissen.de/drechseln-eines-schmuckanhaengers/

In this capital I will show the turning of an eccentric-lattice floral pendant.  I used the same blanks and equipment as described it the „http://drechsler-wissen.de/step-by-step-instructions-for-turning-a-latticed-pendant/„.  Since I am not willing to describe the method over and over, I recommend that you read this article prior you start.
Of course you might choose your own method of mounting the blank.

Mount the blank and mark the center.

OLYMPUS DIGITAL CAMERA

Divide the blank by six, leaving sections of a 60 degrees angle and mark the sections on the outer edge, for mounting the blank properly.  Apply two screws in the tool rest as stoppers for the cutting tool.
Cut two spheres.  The larger sphere will be set exactly on center.  The smaller sphere will be a next to it on the right side.

OLYMPUS DIGITAL CAMERA

Now move the blank 60 degrees.  To assure accuracy put a mark on the edge of the chuck, which must be matched with the mark of the outer edge of the blank.

OLYMPUS DIGITAL CAMERA

Again cut two spheres, then move for another 60 degrees, etc.

OLYMPUS DIGITAL CAMERA

This image shows how the front of the pedant should look like.

OLYMPUS DIGITAL CAMERA

Mount the blank with the concentric jaws and turn the back of the blank.

OLYMPUS DIGITAL CAMERA

Start from the center and carefully turn off the material until you reach the grooves of the front side.

OLYMPUS DIGITAL CAMERA

When you reach the grooves, the inner part of the center will fall off.  Leave a ring, which is holding the „separated parts“.  Leave a second ring on the outer edge of the pendant.  But make sure that the outer ring will tightly hold the tips of the star.

OLYMPUS DIGITAL CAMERA

This image shows how it should look like.

Mount the back of the pendant with the groove jaws.

OLYMPUS DIGITAL CAMERA

Move the tool rest to the side and turn off the outer ring of the pendant.  Small chunks will be cut off, therefore make sure you wear eye protection.

OLYMPUS DIGITAL CAMERA

Again this is how it should look like.

OLYMPUS DIGITAL CAMERA

The turned pendant

Now the pendant looks straight and flat, which does not really look attractive.

OLYMPUS DIGITAL CAMERA

Sand the back of the star.  Hold the sand paper in a way that it will not catch.

OLYMPUS DIGITAL CAMERA

Now sand down the front.  I use an electronic miniature angle grinder.

OLYMPUS DIGITAL CAMERA

Sand the outer edge of the star down, so that the tips will become thin.

Be very careful.  Make sure the sander will not catch.

OLYMPUS DIGITAL CAMERA

Also sand the inside of the pendant to a round shape.

OLYMPUS DIGITAL CAMERA

The final sanding will be done by hand with fine grit sandpaper

OLYMPUS DIGITAL CAMERA

The final product.

OLYMPUS DIGITAL CAMERA

The design of the pendant depends, where you position the spheres. On the image above I cut the larger sphere off center.

OLYMPUS DIGITAL CAMERA

The result

OLYMPUS DIGITAL CAMERA

The position and width of the ring holding the „separate parts“, will have an influence on the design of the pendant.

I will determine the position of the ring by measuring the front of the pendant with a caliper and mark the position on the back, by using a divider.

OLYMPUS DIGITAL CAMERA

See the results above

OLYMPUS DIGITAL CAMERA

Again, it is of importance that the tips of the star will sit tight on the outer edge.

OLYMPUS DIGITAL CAMERA

Again, the sanding requires careful attention

OLYMPUS DIGITAL CAMERA

Just leaving a smaller ring on the back, will change the design of the pendant.

OLYMPUS DIGITAL CAMERA

Drill a fine hole on the back ring of the pendant, clue in a pin with an eye, attach to a silver lace or a leather lace and place it in a box.

All three pendants were produced by using the same method.  When turning the one to the left, I only cut one ring instead of two.

By changing numbers and position of the spheres and vary the holding ring, you significantly may change the design of the pendant.

OLYMPUS DIGITAL CAMERA

It is not chiseled in stone that the pendant must have six tips.  You may experiment and vary to change the design of the pendant.

 

How to turn a wooden sphere Step by step

kugel_drechseln_35

Diese Anleitung ist auch in Deutsch verfügbar fahne_deutsch

Making a sphere is said to be the supreme discipline at the lathe. It requires a lot of exercise to master this task. That’s why many wood turners buy a sphere cutting jig to make the task easier. Producing a truly round sphere without any devices and jigs is left to the real masters amongst this discipline.

That is utter nonsense!

Turning a sphere without any additional devices is actually very simple. You really do not have to invest in expensive equipment if you are reasonably skilled with the turning tool.

The following pictures show how I do it. To be honest, I could not find some of the steps which I am proposing in the internet- even after a long search. That makes me wonder. All the hints that I have seen, even in the newest videos from professionals, require much more training and skill.

kugel_drechseln_01

I start with a squared timber – here using Swiss pine 80 x 80 mm.

Of course, you may use a shorter piece. However; if I do it, I do it right and produce some extra blanks.

kugel_drechseln_02

First of all, make it round!

kugel_drechseln_03

Please note: The cylinder must have an even, round shape! Therefore I adjust the slide gauge to 76 mm and spread some dimensionally accurate grooves across the role.

kugel_drechseln_06

Now I turn the cylinder as precisely as possible towards these grooves.

kugel_drechseln_07

That’s how it should look like:

IMG_6326

Now adjust the stop of the circular saw to the diameter of the cylinder.

IMG_6327

After that, I cut the roll in pieces. Their length always corresponds with their diameter.

IMG_6328

That is how it should look like, 6 blanks for 6 even-sized spheres.

ksv_01

Clamp the blank diagonally between the „tips“. Be very precise!

For this task I have designed a special clamping device allowing a positive-locking of the cylinder.

A carrier with a matching counterpart forms the basic framework. Both with Mk2 socket.

Please do not forget the ring shown at the far right in the picture. We will need the ring later on! Otherwise you have to unclamp the work piece again.

ksv_02

Due to the fast rotation of the work piece shadows will appear. You may use these shadows as auxiliary lines.

Here again a more precise picture of the process. It was quite a challenge for the photographer and me.

The shadows show a big sphere, two straight lines which meet at the upper sphere-shell and the upper part of a smaller sphere, which is running into the two straight lines.

ksv_24

To be on the safe side, you need this clamping ring which is momentarily hanging loosely on the tailstock.

ksv_05

Now turn down the blank on the right side, using a parting tool.

ksv_06

That’s how it should look like!

ksv_07

Lock the clamping ring tightly into the turned corner piece. This will prevent the wooden cylinder from coming loose. A second clamping ring on the left side is not needed.

ksv_08

Now the actual turning process may begin.

ksv_04

We now turn the work piece towards the clearly visible inner sphere, respectively the two straight lines.

You do not only see very precisely where adjustments have to be done, you can also hear and feel it.

ksv_09

Actually, you can’t make any mistakes. You can see, hear and feel where some adjustments need to be done.

kugel_drechseln_18

Place a ring on the sphere to detect inaccuracies.

kugel_drechseln_19

I take a piece of S240 abrasive paper, fold and cut it.

kugel_drechseln_20

Fold it the other way around and cut it 3 more times.

kugel_drechseln_21

Using the metal ring, I press the pre-cut abrasive paper on the work piece shaping the sphere segment even more accurate. This will allow precise clamping of the sphere later on.

ksv_10

The sphere now is fixed into the tailstock by a revolving wooden lathe center, which has a slight inner rounding to prevent the work piece from denting.

You can see exactly where adjustments have to be done when the lathe is revolving.

kugel_drechseln_25

Now I turn the work piece towards the clearly visible shape of the sphere.

kugel_drechseln_26

Here again:

It is very simple. You can see, hear and feel where some adjustments have to be done.

kugel_drechseln_27

Now some finishing operations,

kugel_drechseln_30

The S240 abrasive paper will do the rest.

kugel_drechseln_29

You need to turn the sphere a few times in order to sand the work piece evenly.

kugel_drechseln_30

The intensity of the sanding process of course, is up to you.

ksv_25

Here are the tools I have used during this process:

The carrier and the ball bearing mounted counterpart at the tailstock. Both parts clamp the cylinder with high accuracy.

The clamping ring prevents the wooden cylinder from getting out of place.

The device for the ball bearing, coated with a mixture of cork and rubber to press the sphere into the chuck without leaving any dents.

kugel_drechseln_34

I use a metal ring to press the abrasive paper onto the sphere; you may as well use a wooden ring.

You can easily turn it yourself.

kugel_drechseln_35

And here is the result! A Swiss pine sphere with a diameter of 74 mm,

Remeasured: plus – minus two tenth of a millimetre. I can live with that!


And now the steps in the context as a video:


Die Spannvorrichtung gibt es inzwischen bei den Werkzeug – Angeboten


 

Step-by-step instructions for turning a latticed pendant

OLYMPUS DIGITAL CAMERA

Diese Anleitung gibt es hier auch in deutscher Sprache fahne_deutsch

First of all I want to clarify:  Neither the technique nor the pendant are my inventions.  The technique is known since several hundreds of years.  The first time I saw such a pendant made by „Didi“, was in the internet platform „drechseln-und-mehr-forum “ in April 2005.

I attempted to develop simple and safe methods of mounting the work piece, to make the turning of a pendant as smooth as possible and to keep the loss of wood and wear of tools at minimum level.

The wooden blank

Of course you may use any kind of wood which is suitable for turning, however the choice of the proper wood will tremendously reduce the cleaning job of the lattice.
Short grained and burled woods are ideal.
I made good experiences with plum, pear, apple, olive, boxwood, cocobolo, rosewood, lilac, African blackwood, Finnish silver birch, and tulipwood.  However my favorite is brown mallee, which almost does not require any final cleaning work of the lattice.
Note:  This is not a complete list of  recommended woods.

OLYMPUS DIGITAL CAMERA

You may round the blanks by turning them between centers.  However I use a holesaw of which I cut off the drill bit.  I insert the saw blade with the desired diameter.  I then  mount a 2″ wide slat, about 3/8″ to ½“ thick, on the vise of a pillar drill and cut out the blanks.
It is of importance to position the saw in a way, that at least one point of the outer rim of the saw blade is cutting in open space.  The blank still will be round, but with each revolution the saw dust is removed, the saw blade will not get as hot and it will produce a clean cut blank.

Mounting the blank

There are numerous ways to mount the blank, e.g. mount it with hot glue on a piece of scrap wood or make a wooden chuck.  These methods are lavish and time intensive.  Besides that, with these methods I destroyed numerous blanks and some self-made turning tools.  To simplify the process, I designed three sets of chuck jaws, made from aluminum.

OLYMPUS DIGITAL CAMERA

The first set of jaws will hold a blank 1-7/8″ in diameter, 1/6 “ thick, and about 5/8″ off center.  This set will be used to turn the eccentric spheres.

OLYMPUS DIGITAL CAMERA

The second set of jaws will mount the blank concentric.  The picture shows a set made for the Mini Chuck by Jet.

OLYMPUS DIGITAL CAMERA

The „groove jaws“ will grip on the concentric grooves on the back side of the pendant, in such a way that the work piece can be turned from the front and on the edge.

OLYMPUS DIGITAL CAMERA

The turning tool
This is my universal tool for all lattice work.  I made it out of a steel bar with handle, in which I inserted a 1/8″ HSS square, secured with a crub screw.  The tip is ground down to a width of approximately 1/16″ and furnished with a cutting edge.

OLYMPUS DIGITAL CAMERA
OLYMPUS DIGITAL CAMERA

It is of importance that the profile of the tool is shaped in a way, that it fits into the spheres to be turned, which means that the lower edge needs to be shaped conic or round.  The red circle in the image symbolizes a sphere to be turned.  Of course the benchmark for the edge is the diameter of the smallest sphere.

OLYMPUS DIGITAL CAMERA

The tool rest

I use a flat tool rest which is made out of a steel square.  Certainly, any other tool rest will do, but mine has two significant advantages:  The tool rest can be positioned very close to the blank, so there is minimum overhang of the tool.

If you have too much overhang, the 1/8″ square chisel will start vibrating, which is the first indication for a destroyed pedant or turning tool.  Since it is impossible to preclude that pedant or tool will burst, safety goggles are a must.  Also the tool rest serves as stopper for the tool, guaranteeing an equal depth of the grooves on the eccentric side.

OLYMPUS DIGITAL CAMERA

Turning the face of the pendant

Mount the blank with the eccentric jaws.  Make sure that the blank is cross-grained.

OLYMPUS DIGITAL CAMERA

Mark the inner sphere with a pencil.

OLYMPUS DIGITAL CAMERA

Now adjust the tool rest exactly to center heights.

OLYMPUS DIGITAL CAMERA

When using the tool rest as stopper, let the tip of the tool stick out exactly that long, that the hang-over will cut 1/8″ in depth grooves.

OLYMPUS DIGITAL CAMERA

Now finally, start turning the grooves.  Slightly press your left hand against the tool rest to ensure uniform grooves.

OLYMPUS DIGITAL CAMERA

The images shows the finished face of the pedant

The frayed fibers on the edge of the grooves indicate, if the wood is suitable for this kind of work and/or if the tool was properly cutting.  I recommend to sharpen the tool prior cutting the grooves.  This will significantly reduce the final cleaning job.

OLYMPUS DIGITAL CAMERA

Turning of the back side.
Mount the pendant concentric and turn to a slightly convex shape with approximately 3/16″ to ¼“ thickness.

OLYMPUS DIGITAL CAMERA

Start from the outside when cutting the concentric grooves, again use the square tool rest.

OLYMPUS DIGITAL CAMERA

The profile of this pedant shows that is important to cut the most outer sphere at minimum depth (see right bottom on the image).  Since the front is rounded, this is the thinnest part of the pedant.  If cutting too deep, the pedant will be destroyed during the sanding job.

OLYMPUS DIGITAL CAMERA

For the other grooves you have more tolerance.  For the rest of the grooves it is not necessary to work as precisely as you do for the first one.

OLYMPUS DIGITAL CAMERA

Now finish the back side.

OLYMPUS DIGITAL CAMERA

Clear the inside of the grooves with a folded piece of sandpaper.

OLYMPUS DIGITAL CAMERA

Final sand and rounding the edges with a scouring pad.

OLYMPUS DIGITAL CAMERA

The face again

Now mount the blank with the groove jaws, but use sense and be very careful.

Never spread the jaws, because due to the clearance of the chuck more pressure will develop on the outside with increasing speed, which definitely will destroy the extremely fragile pedant.

OLYMPUS DIGITAL CAMERA

This profile shows the proper way of mounting.  The jaws have a full grip on the groove.

OLYMPUS DIGITAL CAMERA

Bring the face to a convex shape by using 120 grit sand paper.  You could turn the face, but pending on the kind of wood, in this state the outer edges of the grooves may burst off.

OLYMPUS DIGITAL CAMERA

Finish the face and the outer edges by hand with a fine coarse sand paper.

OLYMPUS DIGITAL CAMERA

Final sand the grooves and its edges with the lathe turned off.

OLYMPUS DIGITAL CAMERA

Cleaning and coating

Pending on the kind of wood and/or the sharpness of your tools, fibers still might be inside the groove, which needs to be removed.  For this purpose I use a especially shaped carving knife.  When this is done I finish the pendant with a layer of tung oil.

OLYMPUS DIGITAL CAMERA

Suspension

To suspend the pendant I usually use a thin black or natural-in-color leather lace.  Since you put in a lot of effort in turning the pendant, you should rather spend a few cents more and get a pretty ductile lace, which is straightened by the weight of the pendant.

OLYMPUS DIGITAL CAMERA

Placed in a suitable box it will make a perfect gift.

OLYMPUS DIGITAL CAMERA

Variations

Of course you may make the pendant smaller and suspend it on a silver lace.  In the above image the center has been moved.

OLYMPUS DIGITAL CAMERA

OLYMPUS DIGITAL CAMERA

Ear rings made from violet wood and lilac, diameter 1 1/8″.

OLYMPUS DIGITAL CAMERA

This pendant was turned with the same jaws.  You will find detailed instructions how to make it in the 2009 summer issue of the „Drechslermagazin“