2017.03.28 - Setting up the Lathe
The intention today was to get one thing done but when I went out to the workshop I ended up doing something else! Firstly, however, the fore hatch was given a last coat of varnish. The other items were still slightly tacky so they can wait until tomorrow.
This is the task the ended up being done, the lining of the chain locker with glass fibre matt and epoxy. Now I hate using glass fibre as a lot of the time I end up with hands that itch for days where small pieces of glass get stuck in my skin, so I've been putting this task off for some while. Months, in fact. But it is holding up the completion of the Sampson post, the installation of the hawse pipe and the fitting of the cleat for the bobstay line. So, with hands encased in protective gloves I cut the matt in five pieces, roughly fitting each of the five sides of the box, then mixed up some epoxy and got to work. As you can see the result came out quite well. The lighter areas that look like they might be bubbles of air under the matt are not. They are lumps of dried epoxy from constructing the box.
My hands survived the experience and I put that down to changing the protective gloves frequently.
Once the chain locker had been set aside to cure I started on the task I was going to start with, the setting up of the lathe. As you can see here, the lathe has been turned so that it points down the workshop and one of the planks has been clamped to the lathe bed. One plank will be long enough for the three spar made so far but will need to ne extended when I get to turning the mast.
The "free" end has been carefully propped up so that it is level with the lathe bed. Having a long, heavy rotating spar that is not lined up properly will not be a good idea. It could end up flailing around and breaking things, so getting the free end lined up correctly is quite important.
The lathe end of the arrangement is fairly sturdy although I think I may put another set of cramps in the middle of the ones already there, just to be on the safe side.
The next part is to assemble the wheels that will hold the free end of the spar steady.
Not a difficult job but the bearings did need a little oil.
The end of the bowsprit was cut off so that it will mate properly with the chuck on the lathe...
...and a centre finder used to locate the centre of the spar. Conveniently it is also at the centre of the joins although that was by no means certain given my clodhopper planing!
Now I have to design a bracket that will hold the wheels in the correct position. But, and this is the important bit, they must be adjustable. The free end of the bowsprit is 2", the free end of the gaff is between 2" and 3" (64mm) and the free end of the boom is 3". When I get that far the free end of the mast will be 3" as well.
It will not be a good idea to fix the lower two wheels in the bracket and instead they will have to move in and out as required but still be solid enough to support the spars whilst they are being turned at 500 rpm.
So I stopped at this point and returned to the house to start scribbling with pencil and paper to design a simple, yet robust, adjustable support.