We are back at the college for the second time this year and Rob set up the camera and audio equipment for the zoom broadcast, for members who were unable to attend the college for the demonstration.
We were using the new cables that the club has purchased were used for the first time this evening to enhance the picture display and cut down on the interference for the viewers.
Final after a very long time we were able to have a professional turner demonstration to the club.
A number of members join the demo via Zoom, whilst we had 24 members in total within the club room.
The demonstrator for this evening is Paul Hannaby.
He will be demonstrating the use of a ring hollowing tool whilst carrying out the development of two projects.
Project one – Natural edge Cherry bowl
Paul explained how he decided where the centres were to be mounted on the log blank. He was very good in his explanations throughout the evening and answered the questions when requested.
The Cherry wood was mounted on the lathe in spindle orientation, the speed was increased until the lathe started to vibrate and then backed the speed off ready for turning. The Cherry blank was turned down and a tenon was cut on one end ready to be mounted in gripper jaws.
The blank is cut down into a taper with the edge of the bark still on at the opening part of the bowl, The lathe was complaining a bit with the number of cuts that were coming off, he explained that this was due to the lathe being at its limit due to that length between the bearings and the overhang of the blank. After the basic shape had been set the cup part needed to be addressed and a straight cut was put directly across the blank.
Next, the centre hole was hollowed out using a spindle gouge, used as a type of drill until the required depth was achieved, this was then opened out to about one inch. Paul also demonstrated the Richard Raffan cut where the tool is used upside down and towards the opposite side.
At this point, Paul started to demonstrate the use of a ring tool with the tool rest moved further away from the blank so the tool clears the rest whilst removing the waste. The ring tool is used at about the seven o’clock position within the blank and can be used to remove a good amount of wood.
Paul demonstrated how the ring tool can be sharpened with a diamond file by rubbing against the bevel and moving it in a circular motion.
The top inner edge of the bowl was refined by using a spindle gouge until the required shape was achieved and then the remainder of the waste wood was removed from the inner part of the bowl. After the hollowing out was completed the outer edge was defined whilst leaving the bark on the rim, the outer shape is now looked at and a ball is produced prior to the base being turned and then cut off.
To make the bowl more stable whilst getting thinner Paul used polystyrene balls which were mounted into the opening and then the tailstock advanced up to hold the ball in place, these helped stop the vibration from the lathe and held the project more secure. Polystyrene balls can be obtained from Hobbycraft.
Project two – Goblet with a Barley twist stem
The goblet was made from a Sycamore blank 75mm x 75mm x 200mm, it was started off the same way as the previous project, to get the blank round and have a tenon created on one end for the gripper jaws.
Always working back towards the headstock, as previously a hole was bored down the centre and widened out so as to take the ring tool to hollow out the bowl part of the goblet. A chamfer was included to the top of the goblet and was taken back to a level area but not to a sharp point. The outer shape of the goblet is then formed, and as this is being developed the size of the stem needed to be formed and sized (3/8 or 10mm). As the stem was being formed a length of approximately 100mm was left ready for the twist to be applied.
Between the bowl of the goblet and the stem a feature was included to differentiate between the two areas both at the top of the stem and the bottom, this was produced by using the skew chisel. The size of the foot is about the same diameter as the opening of the goblet.
Paul was able to carry on a running commentary as he worked through the projects and passed on a lot of information in addition to answering the questions aimed at him.
Cutting the twist in the stem, Paul used standard engineering files:
6in Rough Cut Round – 8in Rough cut round – 8in 2nd cut
Microplanes can also be used.
No measurement was used, it was estimated by sight, the file was applied at a 45-degree angle to the stem and started to file whilst turning the lathe by hand. when the first twist was cut a second one was then cut between both ready to form the twist, this was produced by using the 6in file and then followed up with the 8in rough file to give greater depth. The file is now placed across the groove at 90 degrees to the stem and removed additional waste wood, the file was then placed at about 22.50 coming back towards the base.
The twist is then finished off by the use of abrasive sheets at about 400rpm on the lathe and additional grits added for a smooth finish, the base was then parted off.
The demonstration went well throughout the evening with all questions answered by Paul. The club would like to thank Paul for an informative and expertly delivered demo.
Report by Barrie Fisher and edited by Steve Hackett