Weekend Projects - Three-legged Bowl archive

Friday 1 May 2015

Tracy Owen turns this unusual three-legged bowl using English maple and ebony timbers

Gallery

This project has been made using two timbers: English maple (Acer saccharum) and ebony (Diospyros spp.). The ebony provides a contrast with the pale coloured wood and I think it has worked well in this project. If I had been making this for myself, I would have used my vacuum chuck so that I did not have any sort of chucking recess in the piece, and I would probably have made the underside a different shape. Instead, I decided to use an ebony insert to cover up the chucking recess, which is quite a good way to cover up the recess left at this stage. A good alternative to using ebony would be an ebonising lacquer or stain to mimic the appearance of ebony. Another idea I came up with was making the three legs all different lengths so that the bowl would stand on its legs at an angle. For this project however, I decided to make the legs all the same height, so the bowl sits evenly. Which method you choose to use, however, is entirely up to you.

Tools used

32mm round-nose scraper

32mm shear scraper

32mm spindle roughing gouge

10mm bowl gouge

12mm bowl gouge

10mm spindle gouge

20mm skew chisel

Diamond parting tool

STEP 1

To mount the blank, which measures 280 x 75mm on the lathe, use a faceplate ring. This is a quick and efficient way of mounting a blank. Using these rings enables the chuck to be left on the lathe

STEP 2

Firstly, cut the underside of the blank to a rough shape using a 12mm bowl gouge. Take fairly heavy cuts with lathe speed at around 700rpm

STEP 2

This is the shape that would be produced if a vacuum chuck was used. The finished item using an ebony insert will end up similar in shape

STEP 4

Use small gripper jaws in expansion mode and cut a straight sided aperture of about 38mm in diameter using a 10mm bowl gouge

STEP 5

Use a 20mm skew chisel with the side of the chisel flat on the toolrest to clean up and cut a nice straight side to this aperture

STEP 6

It is now onto the final shaping of the underside. Start in the centre of the blank working outwards using bevel contact. As you can see here the cut is producing a very fine shaving. Lathe speed is around 900rpm

STEP 7

Further refine the previous cut still using the same 12mm bowl gouge, but this time with a shearing cut. This will allow no bevel contact and the wood will come straight into contact with the edge of the tool, once again producing a very fine shaving

STEP 8

Continue to further refine - this should produce a surface that requires less sanding, this time using a shear scraper. This tool has been ground so that there is quite a heavy burr on its top edge. The tool is used at about 45° to the wood, working from the middle outwards. For this procedure I normally slow the lathe down to about 600rpm

STEP 9

The underside now needs finishing and the surface requires power sanding using 120, 180, 240, 320 and 400 grit with the lathe speed at about 500rpm

STEP 10

Before removing the faceplate ring after sanding, mount the blank into the jaws of the chuck. This is done to remove any marking from the underside of the piece. If it is held firmly on the lathe with the spindle lock, it will leave two hands free to remove the ring and screws. Secondly, if for any reason the mounting point was not cut correctly or the blank was not running true with the ring in place, it could be swapped back so that further work could be done to correct it

STEP 11

Go back to shaping the rim and the inside of the bowl using a 12mm bowl gouge. The bowl will have a wide rim and will be slightly undercut going into the bowl form. Lathe speed is about 1000rpm

STEP 12

Keep an eye on the wall thickness using double-ended callipers. Remember that this needs to be thick enough to have holes drilled to take the legs at a later stage

STEP 13

Make the last few cuts with the 12mm bowl gouge to remove the wood left in the middle. Leave the centre of the bowl thicker while working on the rim and outer part of the bowl. This form helps to keep things more stable and gives less vibration

STEP 14

For the final finishing to the surface use a round-nose shear scraper. As with the straight-nosed scraper, this is used on the outside at about 45° to the wood. Shear scrape the inside of the bowl and the rim with this tool. Once again, reduce lathe speed to about 600rpm. Once complete, power sand the inside and rim using 120, 180, 240, 320 and 400 grits

STEP 15

This is the first of the four pieces of ebony to turn. This one will be used to make the decorative insert that will be used to disguise the chucking recess. Turn this using a 38mm spindle roughing gouge with the lathe speed at 1,000rpm

STEP 16

Use a parting tool and a set of Vernier callipers to cut the tenon to fit the chucking recess in the bottom of the bowl

STEP 17

Contraction mode to grip onto the tenon just cut. Use a 10mm spindle gouge to do the appropriate shaping. Once the tool work is finished sand with 240, 320, 400 and 600 grits

STEP 18

This ebony leg, which measures 63 x 20mm has already been turned to a cylinder with a spindle roughing gouge. Turn a tenon down to 10mm - this will be the drill size used to drill the holes

STEP 19

Before you mount this leg into the chuck for final turning, cut a small chamfer with lathe speed at around 1,000rpm. If this was not done at this stage you would end up working too close to the jaws of the chuck

STEP 20

With the leg mounted into the jaws of your chuck, set about doing the final shaping using a 10mm bowl gouge. The action of this tool is a pulling cut working away from the chuck using the bottom wing of the gouge cutting well above centre. The other two legs will be made in the same way

STEP 21

Now mark where the holes will be drilled. These could have been done earlier while the piece was still mounted on the lathe, but I think this is an easier way to mark the holes. Use a pair of compasses working from the centre of the aperture to mark three lines roughly a third apart. These pencil lines can be sanded away once the holes have been drilled

STEP 22

Having drawn the pencil lines to mark the holes, find three points using a set of dividers until the distance measures equal. These three points are marked with a further pencil line and then the holes are drilled taking care not to go too deep or go through the bowl

STEP 23

Here you can see the three legs and the centre insert which have been glued into place using a few drops of thick cyanoacrylate glue on each. All that is required now is two or three coats of oil to finish

STEP 24

Here is the finished piece having its first coat of Osmo Oil, applied with a tissue. Once it has been completely covered it will be buffed to a finish using a soft cotton cloth. Repeat until you are happy with the finish

STEP 25

Here is the finished three-legged bowl


Woodworkers Institute

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Tracy Owen , Weekend Projects


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