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Setting up in the lathe it is best to be able to do all these next operations without taking it out of the lathe. I used a collet chuck instead of going between centers or using a 4 jaw. This collet chuck I use is really accurate and with a tail-stock center for good support everything works nice and runs true.
Putting the curve in the fusee barrel. The trick here is figuring out the radius and setting up for that. Once the radius is figured I was able to use the center of my compound post for the measurement. By setting a square to the barrel and moving the cross slide out to a predetermine measurement, be very careful not to change or bump the handle on the cross slide. Now we have a accurately measured radius that can be cut by swinging the compound on its axis. This ends up being more of a arch than a proper fusee curve. In the future of the build we will take torque measurements and adjust this arch to the actual mainsprings power being used at each rotation of the fusee barrel.
Setting up the tool post I had moved it close to the center of the compound mounting surface. By pulling the cutting tool up to the surface of the barrel and moving the saddle to the left until the apex of the cutter is on the edge of the barrel all we need to do is feed into the work until a arch is made all the way from one end of the barrel to the other. Really the tool post can be set anywhere on there, the idea being that at the apex of the swing of the cutter lining up with the edge of the brass blank, if you havent moved from the original measurement you will get the arch you want. For measurements of diameter of the fusee I am not remembering that the book had any in there so all I did was make sure the larger end was the right size to fit the larger boss on great wheel we just made.
Now here is a goofy idea. 🙄 While turning the compound by hand I was noticing the swinging action to be jerky and a bit difficult. By adding this wood clamp to the compound it gave me alot more leverage and I was able to stabilize the swinging action for a smoother and cleaner cut.
And WHALLA, 😯 a curved piece of brass….now what???
Well…we need to cut the groove into this brass arch at 12 threads per inch. The trick here is to feed into the work piece while traveling from the right to the left of it. I suppose there are many ways to go about this BUT…I had a idea 🙄 here we go again…I had a spring loaded retractable cutter head from a old New Hermes Gravograph. It had just enough travel to cut down to the smaller diameter. By calculating out the size of the nose of the cutter and allowing for a raised shoulder so the cable would not slip out at 12 threads per inch (the book did not have this cutter size) I ground out a piece of HSS round stock. Made a brass collar with a set screw to fit the cutter and ground away one side of it. This collar acted as a depth stop. I hope it will help when I make the final curve adjustments.
With the threading dial, a very slow speed, a light touch and set up a stop on the right hand side of the saddle so each return to the right was at the same spot. Simply watch the threading dial, engage the leadscrew at the proper time and push in on the cutter all at the same time….SIMPLE…RIGHT??? I was so excited I forgot to take pictures
Over at the smaller lathe and milling machine the arbor was taken down to proper sizes, winding square with 2 degree taper milled. Final work on the grooves was done at a later time using a fine file to a polishing stick with polish. If your using cable the grooves are round, if your using a chain then you would make them flat.
Here I am crossing out the great wheel. I had decided to cross out the wheels with a bit of a different designed crossing. In the next post or 2 I will show how I used the pantograph for crossing out the wheels with the design I came up with. Marking out, drilling plenty of holes to make it easier on the scroll saw, and filing with the die filer. Alot of hand filing after most material was removed.
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I had a little trouble figuring out the dimensions for a template to use on the pantograph. The issue was when I reduced down to my smallest wheel crossing I was milling away the spokes, or they became way too thin. So I thought I would first make a actual wheel by hand at the smallest size I wanted. I then laid it in the printer, scanned it to the computer and increased the size to fit a sheet of paper and make my template at that increased size ratio. That worked well and now I can do any size reduction I want for any sized wheel and it will turn out properly.
Here is a You-tube video I did on crossing out the wheels for this clock. Have fun
If you have not been to http://learntimeonline.com/ ….check it out. More good information about clock and watch repair.[youtube:ffus0d5s]5w2ERIuu63I[/youtube:ffus0d5s]
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