Here is what I’m trying to make.
I drilled the small holes in the ball today and turned the first large one.
The small holes are different this time
I decided to not do the little collar around the holes until after I’m finished with all the other turning. I don’t know how well this will work out, but it’s worth a try. Previously the collars got messed up by the tool holders while turning the inner layers of the large hole, doing a lot of damage. This new procedure is to prevent that from happening. Here’s a photo of it.
What would we do without tape
Before turning the large hole, I decided to put some masking tape over the the small holes, again to prevent damage. I figure this would also protect in between the holes and prevent some scraping/compression problems I had in that area before. Here it is all taped up.This worked very well and I experienced no damage at all this time.
I finally made a plug that fit properly
I was going to use Yuri’s method with a stepped plug and wax seal. After thinking it over a bit, the thought occurred to me that Yuri is probably using different sized drills to make his large holes with. That means the hole walls are straight (90degrees), while my holes are made with a tapered cutter the the hole edges are also tapered. That makes a tapered plug a better fit.
If you recall I was having a lot of problems making a plug that would actually fit the hole. After checking some old plugs closely, I found that for starters the plugs were too short. In addtition to that, I used the bottom diameter suggested in the book, but I found that the actual hole diameters were a bit larger. So now I will make each plug from actual hole measurements (duh) and use the plug turning procedure I showed before. Here it is again in case you didn’t see it.
Getting the plug in is easy, but getting it out again requires rocket surgery
As you can see from the photo I did get a good fit, and all the way to the bottom this time. The plug has good contact with every layer now and hopefully will hold everything in place while I turn the other Holes. After plugging the hole, a small hole is drilled in the center of the plug to accept a small screw which acts as a handle for removal purposes. I just put it in for the pic, but I won’t be using it until completely finished with the ball.
Chinese ball turning requires a wide flat tool rest
The toolrest has to be flat and wide to support the special turning tools at exactly the right height (cutter tip perfectly centered) and therefore requires a special toolrest.
I didn’t want to make a whole new toolrest so I adapted the one I have. The pictures below tell the story pretty well. I did have to drill a couple of mounting holes in my stock toolrest. The rest is just a piece of wood with a thin slice from a counter top. I had to cut a bevel on the wood mount to get the counter top piece level. The counter top bit is held on with carpet tape for easy change out. I do plan to make a new one soon that is wider, but this one works well as long as I remember not to push down on the handle of the turning tool while cutting.
That’s all the minutia I have for today. I hope I get a chance to continue tomorrow, so if I do I will let you know how it’s going. Thanks for reading. Here are the links to the series.
-- Mike, American in Norway The four steps towards competency: 1. unconscious incompetence, 2. conscious incompetence, 3. conscious competence, 4. unconscious competence