(January 17, 2000 was my first carving day.)
05-20-17 Saturday
Low at 82, high at 88. The sky was mostly blue with some puffs, and a good breeze. there is some humidity but not like it will be in the summer. This weather report is brought to you by the City Of Pompano Beach department of Tourism.
THURSDAY
We had a wood turning club meeting. Because we meet at a school, the school will be closed for the next three months and we will not be able to meet there. The club will look into meeting at another site during the summer, but that is not likely to happen. There is a WOOD WORKING club and we have been invited to their meetings during this time, but I am not sure I will be able to go to those meetings.
Our instant gallery had just a few items. I could not get something together to bring to the club meeting. One of the items on display was a home made chuck designed to hold a bowl backwards so you can finish the bottom.
It is basically two sheets of plywood cut into a circle. One has slots cut straight toward the center, and the other has slots cut to the spiral. There are twenty holes around the outside on one, and nineteen holes around the outside on the other. These holes are in line with themselves.
Wing nuts and bolts are in each slot stuck in where they intersect and there is a rubber bumper on each. When the two sheets are turned opposite each other, the bolts move up and down in the straight slots. The two sheets are connected in the center. One of the sheets has a tenon attached so it can be held in the lathe chuck. The piece is placed up against the sheet and one sheet is turned until the bumpers all the way around hold the bowl in place. The wing nuts are tightened.
Because of the difference in numbers of holes, the holes around the outside has different gaps when looking through them. You simply choose one with just a slit space between them and stick a screw driver into it and apply pressure to tighten the bumpers against the bowl and then tighten the bolts to their final tension.
Run the lathe on a very low speed and carefully clean and finish the bottom of the bowl.
In the DOODAD MOMENT, one guy showed a gnarling tool, used to add texture to the work. He said it comes with different teeth for different effects. He also showed that he gets really good results on polishing the insides of vases and bowls using a small buffing wheel on his drill.
The demonstration was on the many ways of holding work on the lathe.
Wood is basically fibers glued together. Some woods have strong glue, some have short fibers, some have long fibers and some have weak glue. Also the hardness of the fibers changes between woods Cedar is long fibers and weak glue. Most fruit wood is really strong fibers. Basswood has fibers and glue about the same strength. Oak has really strong long fibers and fairly strong glue.
Picture wood as a bunch of straws glued together. When you stick an edge into the straws from the end, the ends move around the edge. When you stick an edge into the side, it resists digging in if it is across the straws, but cuts in easily if stuck in line with the straws. This will help you picture some of the description of how some methods of holding wood works.
The demonstrator started with different kinds of drive spurs and the techniques of using them. One thing I did not know was that the four tooth spur is used on end grain, while the two tooth spur is used on side grain. Mainly because the teeth going opposite the grain seldom gets a bite on side grain. Another thing is that you NEVER pound on the end of a spur to give it bite. That ruins the end of the spur, making it, eventually where they will not hold within the shaft of the lathe. The pounding deforms the end.
He pointed to the WOOD WORM screw. It is a screw that generally comes with your lathe. You drill a hole in the work, as specified by the manufacturer’s instruction,, and then fit the head of the screw in your chuck. These screws have really large, sharp edges to eat into the wood. These are at their best with side grain rather than end grain. The teeth slide sort of between the fiber of the side grain wood. End grain requires the screws to actually cut the fibers to dig in and hold. It can pull out easier.
He covered many kinds of face plates which are simply plates with holes in them that fit on the drive head of your lathe. The plate is set in the center of the work and many screws are driven in. Face plates can be manufactured to precise machining specifications, or can be home made. Generally, it is best to allow for waste wood where the screws go in. Sometimes you might glue a wood block to the work and use that as the waste wood. One simply turns away the excess wood until you have the finished bottom.
A Pin Chuck is a small plate that fits into the lathe and has two or four pointed screws. These are used when the initial surface is not quite square to the center of the work. One puts the work to the plate, in line, and then turn the screws in until the points dig in. I made one years ago, and used drywall screws. The screws bent and the work went flying. I needed to get better screws but never used it since. Don’t use drywall screws. They are made of the wrong metal.
He went through different kinds of chucks, He had a three jaw machine chuck and thought it would be great, then realized that the jaws have only a tiny bit of surface to hold into the wood, and they are designed for round stock, not square or irregular stock. I have one that the jaws are adjusted individually, rather than turning a ring. My chuck can be used to work off-center for special effects.
The scroll chucks, work like the plywood chuck mentioned about above. A spiral plate moves the jaws up and down in a slot. You can get many different jaws for the chucks. The diameter of the chuck dictates the size of work one can hold. Because of the way chuck jaws are designed, they hold best at about a mid point range of open and closed. Some chucks use a key that you turn, others use rods to lever the ring around. With mine, it takes two rods, and you rotate the ring until it locks on then you apply pressure to fix it in place.
He explained that a big mistake beginners make is to measure the depth of the chuck and make the tenon that long. He emphasized that at no time should the tenon bottom out on the inside of the chuck. Everything should be in contact and held by the edges of the jaws. There are different designs of jaws for chucks. Some have a dovetail shape, some have just a single edge, and some have multiple edges on the inside. One creates the edge of the tenon to match the type of chuck you are using. He says that with the single tooth design, many beginners will cut a groove for the tooth to fit into on the tenon. One must not do that. The tooth digs into the wood to hold it. The face of the chuck must contact the bottom of the work.
He showed specialty chucks, for finishing the bottoms of the bowls. Some are commercially made like the COLE chuck. Others are home made like the chuck described above or a “donut” chuck someone demonstrated a few months ago. The demonstrator said he never needs these chucks. He uses a jam chuck or something else described later with his tail stock, to hold the work on the lathe and finishes it until there is a nub. He removes the work and finishes it off with a chisel and sand paper. Vacuum chucks are among these bottom of bowl chucks, their only purpose is to finish the bottom. Break the suction and the piece goes flying. Have the suction too high and the piece will collapse. With all these specialty chucks, they have to be used at a slow turning rate. Many can only go 600 rpm.
There are many versions of what is called a jam chuck. They can be simply some junk wood that you shape into a cone with a tenon on the other end, and stick it into the mouth of the lathe, with the tail stock on the other end. These are great as you can design them to fit your needs. If you are doing one of many of one design, the chuck can be made to fit exactly. With small projects, many turners will use a jam chuck that is fitted for a “suction fit” where it takes a little force to remove it.
One jam chuck I like and should make, is a log rod with a pad at the far end, and a stepped ring that slides along it and can be locked down with an Alan screw. The rod applies pressure to the bottom of the bowl, pushing it against the tail stock. The sliding ring fits into the mouth of the work and holds it center. There is no pressure on the mouth of the work so it will not break. The ring simply centers it.
It is hard to remember all he covered as he mostly touched on many things rather than going in great depth on them. I did learn a lot from them and have some ideas.
SATURDAY
I stopped at four yard sales, getting a salad spinner at one. I don’t fix salads but about four times a year, I wished I had one for something. At this second, I cannot remember what. The price was good and this was one of the better designed ones. It has a pump in the middle of the top, you push it down and it spins the basket. Fairly good mechanism. It has a rubber covered button to act as a brake. There was a switch next to the pump and we tried to figure out what it was for. At first we thought it might activate a gear to change the speed. On a lark, I pushed the pump to the bottom and the switch slide to lock the pump in place for storage. It is fun figuring things out.
I also found a book called BUILD IT BETTER. my brother glanced through it quickly, lots of interesting things. Nothing that would pass our local building departments, but someone on a farm could use it no problem.
There were three yard sales that had nothing that I bothered to even stop for(clothing or they always have the same things), and several signs for sales I could not find. One nicely made yard sale sign had lots of information but did not tell where it was. I am interested on where it is and that it is a sale, not WHAT is on sale.. I will find out what they have when I get there.
When I got back, I took a very short hap, then went over and helped Mom with getting some data she needed off the web. A relation came over for lunch. Talking with him killed the rest of the day. It was too late to do anything.
I hope to do some wood working tomorrow.
Year 17, Week 19, Day two (week 905)
(January 17, 2000 was my first carving day.)
05-21-17 Sunday
The day started out at 79 and soared up to 84. I was never sure whether to wear my jacket or my swim suit........ It was mostly clear with some puff off and on. A nice breeze helped carry the heat away. This weather report is brought to you by the City Of Pompano Beach department of Tourism.
I saw one yard sale on the way to mom’s. I had stopped there yesterday. It dawned on me that this was the one that wordy sign was for. What tipped me off was that they had a couple golf carts there and that was mentioned on the sign. They got rid of a lot of stuff yesterday. They had a box of tiny wooden mallets, ones for children or something on that. I forced myself not to show any interest in them. If I want a bunch of them laying around, in the way, I will make them myself.......(if I ever got around to it)
I went out back, and cut the knotted section off a Mango branch. I had shown pictures of it to one of the experts at the club and he gave me an idea of how to turn it. I cut the trunk a little short, but will work with that anyway. This just changes where the center is located.
I had another piece I was going to make into a "banana bowl" where it is long and narrow. I saw there were shrinkage cracks in it so I decided to split it. I keep forgetting that Mango is a fruit wood, and all fruit woods are very hard and strong. It was a lot of work but I finally split it. It was an epic battle. Me using the wrong tools and it was only pretending to have a crack in it. This might get split up a lot more for crochet hooks and such. Anything that is small and needs to be strong.
Next week, I have a long weekend. If I can’t make some sawdust next weekend, I might never get any done ever.
2383
salad spinner
the tree branch before I had trimmed it last week. this was the view he said to turn it on.
No comments:
Post a Comment