West Midlands Woodturners

Transcription

1 Chairman s Comments West Midlands Woodturners Secretary: Brian Goodall Telephone: briangoodall@gmail.com JUNE 2013 Stuart Mortimer at our June Demo Day didn t disappoint my anticipation that we would see a real master of his craft. His demo style, technique and banter kept us entertained and well instructed throughout the day. His Gallery of Work was stunning as those of us who managed to be there can testify. Stuart was complimentary to us as a Club paying tribute to the pieces on our Display Table & he concluded the day by making the generous offer to be available at the end of the phone to anyone who wanted to share a problem or ask for advice. As a testament and inspiration from his Signature Spiral Technique I set this month s Chairman s Challenge Project based on the basic set up :- see further on for picture and description. PROGRAMME st July: Hands on day 9th-11th August: AWGB International Seminar. Loughborough. August TBC: Hatton Weekend 18th August: Demo day with Steve Heeley Reminder: We are now half way through 2013 and I shall be standing down at our next AGM. Please give some thought to the future and what you can offer WMWT. See you in July at our Hands On Brian. Chairman s Challenge: (Sponsored by Earlswood Interiors and Crafts) A Piece of Spiral work from Basic Layout as shown in picture of Stuarts 1st. Demo piece. Your own piece from Basic blank preparation, marking out, spiral cutting. Taking the technique as far as you are able to include a Spiral Feature in a finished piece. Challenge yourself & have a go! Next Page

2 Page 2 WEST MIDLANDS WOODTURNERS Report on demonstration by Stuart Mortimer. (by John Hooper) Stuart is no stranger to WMWT having last visited us in February This visit included twisted forms, nesting (or coring) and a box with finial and was a packed and informative session. At the beginning, Stuart informed us that he had made many of his own tools, some of which were to be used in the demonstrations and also spalted his own timber. There was some discussion concerning roughing tools with Stuart stating that he rarely used a roughing gouge, preferring to use a skew with a "softened" heel. Used in both directions, this method should give continuous cuts, positioning the skew at "10.30" for bead and cove forming and as close as possible to "12.00" for plane cuts. Stuart demonstrated his method for using a gouge for end grain holes, starting by creating a countersink larger in diameter than the hole required and then pushing the gouge in at the centre, "wobbling" the gouge as necessary to achieve depth. This method should avoid the creation of the nipple at the base, and the last cut should be a pivot cut to give a good finish. Twisted form marking out: The basis of the twisted form is the diameter of the cylinder, and Stuart commenced with start lines on the cylinder at intervals equal to the cylinder diameter. These sections were then sub-divided into smaller but equal sections. Using the chuck and tool rest, longitudinal lines (4) were drawn to create a grid on the cylinder. Diagonals were then drawn across the segments to create the twist, or spiral, pattern. Using a saw, small cuts were made along the diagonals to act as guides for either hand cutting, with a gouge, or power cutting with an angle grinder. The resulting spiral was improved using a hand rasp and sandpaper. Since a hole had been formed into the centre of the cylinder, deepening the spiral cuts creates the "bines" which produces the open spiral again finished with rasps and sandpaper. This marking out technique formed the basis of Stuart's work later in the day. Next Page

3 WEST MIDLANDS WOODTURNERS Page 3 Twisted Egg in Yew: The piece of Yew was highly figured and when roughing down, Stuart placed the blank off centre (between centres) so that the best features were retained, as far as possible. Chucking spigots were added at both ends, and the egg profile was cut with a gouge. A parting tool was used to create the centre line, slightly tapered to allow a good fit, and a thin tool was used to cut down to about 6 mm. The two halves were separated by twisting off. After filling the shakes (splits and gaps) with copious amounts of superglue (Stuart's fingers seemed to be resistant to the adhesive effects!) the diameter of the lid spigot was marked on the base section which was then hollowed out using a gouge and then a scraper (held in the 7 o'clock position to achieve fine cuts). Several trail fits were necessary until Stuart was satisfied. The interior was sanded and finished, using more superglue to fill shakes revealed during hollowing. The top section was re-chucked and a shear cut was run across the face to avoid skipping when hollowing, which would ruin the piece as the edge of the spigot could be damaged. This section was hollowed out to the same thickness as the base section, superglued as necessary, and finished with a scraper and sandpaper. The base was re-chucked and the top and bottom sections brought together and the top spigot was reduced. It was then necessary to re-finish the centre part of the egg, at the join, where the profile changed due to parting off, to give a continuous curve. The spigots were reduced, and the egg was sanded and finished. The egg was marked for spiralling in the same way as the first demonstration. In this case 16 lines around the egg and 8 lines along the egg were drawn, ensuring that the centre section was clearly marked. The guide lines were drawn, and shallow cuts with a rasp were made at the centre. Using a small angle grinder and a power rasp, the bines for the bottom section were formed. The bines were sanded, ensuring that sufficient material was left in the centre sections and at the bases to avoid breakage. The process should be repeated for the top section. Stuart commented that this was where glued bines can be acceptable particularly where they appear as part of a knot or feature. Next Page

4 WEST MIDLANDS WOODTURNERS Nesting: The next part of the day was a demonstration of how to nest, or take cores, from a large blank. Stuart has fabricated his own coring tools from steel bar with carbide cutting points brazed on to the tip, but started by demonstrating coring using a "strong" parting tool. For this he used a piece of Sweet Chestnut, orientated to produce natural edge bowls. After marking the two cut positions on the face with the parting tool, wide cuts were started, and some depth of cut was achieved. Stuart then switched to his "homemade" tool and increased the depth until it was possible to rock the core by hand. The centre core was removed, using the coring tool as a lever to break the remaining timber. The second core was removed in the same way, producing two bowl blanks and a solid centre core. The second coring demonstration was on a larger diameter piece of Spalted Silver Birch. After roughing to a cylinder a bowl profile was created and two cut positions marked with the coring tool. After the centre was removed the blank was supported with the tailstock, and the second core was cut. Unfortunately, the club lathe used was not powerful enough to enable completion, despite strenuous efforts, and Stuart decided to stop, and remove the core back at his workshop. Pigtail Twist: For this demonstration, a cylinder was cut with a taper. The taper length should be twice the diameter of the cylinder. The marking out was a little more complex with 8 sections on the cylinder, to allow the cutting of one full spiral. The sections on the taper were unequal, with the first one being a half pitch (i.e. half cylinder diameter) along the taper and the second section being a full pitch (i.e. cylinder diameter) towards the taper point.

5 WEST MIDLANDS WOODTURNERS Page 5 Stuart marked the spiral on the cylinder to create one full spiral, and then continued onto the taper, drawing the pigtail and marking the waste areas to be cut away. Using the angle grinder, the cuts were made and the piece sanded and finished. Egg shaped box with finial: Having mounted a cylinder in the chuck, Stuart then cut the egg shape, leaving enough of the cylinder at one side to allow for the finial, and at the other side, to form the base. The separation point was marked on the egg, divided roughly two-thirds and one-third (an approximation to the Golden Ratio), and parted off. The egg was hollowed out with a gouge and a scraper for the finishing cut. The other half of the egg was re-chucked and hollowed out, forming a slightly tapered rim to fit. Several trial fits were required to ensure a tight fit between the two halves. The inside of the egg was sanded and finished with wax polish. The tight fit was necessary so that the lid did not spin when remounted on the lathe. The finial post was formed with a taper leading to a "thistle" top. A freehand twist was cut, using small a hand rasp and the pitch was determined at 3 diameters for each spiral rotation. The finial was sanded and finished. The final stage was to cut the foot for the base, forming small beads and coves (with skews and "skewchigouges" made from masonry nails) and reducing the diameter of the foot. the base was parted off, and instead of making a jam chuck, Stuart wound 6 layers of masking tape on the egg and remounted directly into the chuck, applying only enough pressure to hold the egg without crushing the thin wall. The bottom of the foot was flattened and finished.

6 Small open spiral finial: WEST MIDLANDS WOODTURNERS The final project of the day was a small finial cut from pine. The cylinder was roughed from a 1½" square x 6" blank with a dimple point at one end to accept the tailstock centre. The top and centre sections were shaped as a teardrop and pear respectively. The pear section was marked up with 4 horizontal lines and 3 concentrics to form a 2 x 4 grid. The spiral lines added such that 4 bines would result. The bines were cut using a power rasp, and the point of the rasp was used to cut into the centre, taking the middle out. The finial was sanded with narrow strips of cloth-backed sandpaper and with the tailstock removed, a simple pointed cone was formed at the top. This was a very full and informative day, with many techniques and approaches used. Perhaps the most useful element was the way in which Stuart marked out for twists and spirals, working with medium sized and very small pieces. Stuart's work is of the highest standard, and quite a lot of practice will be necessary (for me, at any rate) to emulate it.

7 WEST MIDLANDS WOODTURNERS Chairman s Challenge Results for June: Page 7 Premier Group - 2 entries 1st - Dave Nash 2nd - Ted Gill Basic Group - 6 entries 1st - Brian Bateman 2nd - Kris Cietak 3rd - Dave Howgate Display Table:

8 Page 8 This message may be of interest to members: WEST MIDLANDS WOODTURNERS My name is Jim Preston and I work in the export sales department for BriMarc Tools and Machinery, we supply woodturning products to the UK, Europe and around the world. We have a stockist in Palma de Mallorca who are very passionate about woodturning, they have produced the enclosed poster to promote Mallorca, it highlights that there are facilities for UK woodturners to meet likeminded people and exercise their woodturning passion whilst enjoying a break on this beautiful Island. I visited them earlier this year, they are lovely people and very hospitable, have a good workshop, a working use of the English Language and most importantly a real passion for woodturning. You can find more information at their website view their YouTube Channel info@tornyfusta.com<mailto:info@tornyfusta.com>, or contact me if you have any questions. I hope that this is interesting for you and your club members, I would be very grateful if you could please display the attached poster, if you would like to receive an original poster please let me know and I will send you one. Next Page