Evolution of design

Due to the shape I want to achieve and the limitations of using the lathe I would have to create two halves of the design and then mount them together. In order to do this I used the same technique as in the previous post but create two smaller domes. Again starting with a piece of Jelutong i cut a block, marked the size of circle required and roughly cut the shape out.

Again this was shaped into a dome so it could be cut away from the main body of the shape.

This was repeated a second time making sure that the diameter of the body remained constant. During the construction of the second dome i had to discard a piece of wood due to imperfections in the wood

In order to cut the domes from the main body of the wood i created a 90 degree jig. This would allow the wood to be mounted and secured while cutting the piece. 

The angles of the jig were cut at 90 degrees and checked with a tri-square making sure that the front and rear face of the jig were parallel. This allowed the jig and dome to pass through the band saw and cut a perfectly straight line through the back of the shape creating a dome with a flat surface parallel to the apex of the dome.

 





after cutting the first dome the second dome was mounted onto the same jig. The diameter of the dome was measured using a pair of large calipers, this measurement was then transferred to the second shape and the jig was aligned to allow a couple of millimeters for error.

Again this dome was cut from the main block of wood, to produce the following shapes.

Moving forward.

Well its been about a month since my last blog so it's time for an update.
The model is starting to take shape. I have machined an oversize prototype and started to construct my final piece.


PROTOTYPE

I have used a piece of Jelutong to construct the main body of the piece. This has been cut into a block, marked into a circle and roughly cut before being mounted onto a flat lathe plate. i also cut a small wooden washer to stop the plat over tightening on the thread. This was then machined to produce the desired ellipse shape. Once the rough shape was achieved the shape was sanded with progressively finer grades of sandpaper in order to achieve a smooth and uniformed finish.