The Long-bed lathe's frame assembled
This is my version of the long-bed lathe built by Carlisle Lynch, and featured in a 1986 FWW magazine article. Lynch built his lathe using laminated 2X material to create 3 inch thick stock to create his lathe. That would be pretty inexpensive to duplicate even today. Luckily, I had enough left over 8/4 maple from a previous job to build my lathe. Twenty four-inch long lag bolts and washers and here we are. After thicknessing, my stock ended up 1-7/8 inches thick. The weight and mass of the maple more than makes up for the difference in thickness of material used by Lynch and myself.
I am re-using a tool rest and motor from my Sears lathe. One of the most innovative features on Lynch's design is the use of a sliding wood bar mounted on the front bed rail, which engages the electric on/off switch, to act as an emergency kill switch. When I first read Lynch's article, I misinterpreted the drawing and thought the bar was a routed groove in the bed rail. I spent a lot of time wondering what purpose it served. Having stood beside the 10+ foot long lathe, it is obvious that if I got a sleeve tangled in a turning while working at the lathe, there would be no way to reach the off switch. So one of today's tasks is to make and install this saftey feature.
The belt driven drive shaft is made up from components I have picked up on-line. I purchased one-inch diameter steel pipe from McMaster-Carr. The one-inch bore flange bearings came via Amazon. And the step pulley came from Ebay. All for around $100. I am having a local machine shop drill out a morse tapered seat and cut RH and LH threads on the 18-inch steel tube. The machine shop costs will end up being the largest cost involved in building the lathe.
Lynch specified the use of one-inch diameter steel pipe and components in his article. While searching for a one-inch bore four step pulley all I could find that were commercially available today were pulleys which were of 5/8 or 3/4-inch diameter. No one seems to carry one-inch bore pulleys any more. I was lucky to find one on Ebay, and happily paid the "buy it now" price to grab it. Something to keep in mind if you want to build one of these lathes for yourself.
One final note. Sizing and tolerences! When dry fitting the components I puchased, I found that the pulley easily fit the steel tube from McMaster-Carr. The flange bearings were a no-go. No amount of Steve force was going to make the bearings fit the tube. Massive frustration insued! Re-checking the steel specifications in the MacMaster-Carr catalog I found a note telling me that the tubing was produced with a plus or minus tolerance of .0005 inch. My piece of steel was on the heavy end of the curve. I figured that my machine shop bill was going to get much higher as I saw no alternative but to ask the shop to turn down the steel on a metal lathe. A good night's sleep, and I seemed to remember that Lynch discribed a similar problem. He reduced the diameter of his pipe by turning his pipe on a lathe and using a flat file work down the diameter. Ten minutes work on the lathe in the morning created wooden plugs which fit the ends of a spare piece of cut-off steel tube. The plugs allowed me to mount the pipe on the centers of my wood lathe and some cautious turning while working the steel with a file resulted in a prefect fit. I am pretty sure that my former editor at American Woodworker would have had a case of the vapors if I had put that in an article.
Have a great day. Thank you for stopping by. STB
