george wilson
06-30-2011, 2:56 PM
This treadle lathe was modeled after one that is in the Science Museum in London. Jon and I made this lathe quite a few years ago,maybe in the early 90's.
It was formerly in the Gunsmith's Shop. When they moved it was put into storage where I couldn't get at it to photograph it in spite of requests. Apparently in their new location at the Geddy Foundry,they hadn't room for it,and there was already a treadle lathe there(albeit a completely made up fantasy lathe made in the 1950's).
When I went to see Mack Headley wast week ,there it was in the Anthony Hay Cabinet Shop. I had no camera and asked Mack to email me some pictures. These MAY have been taken with a cell phone,I don't know. They are clear enough to see how the lathe works.
Any dimensions I have are from memory.
The lathe is made from red oak. The flywheel is about 2' or more in dia.,and IS 5" thick. I recall that. The steps in the flywheel and spindle pulley are not there to change speeds. They are there to put the ever stretching leather band in the next larger groove to tighten it up. The band is joined with a simple staple about 1/16" thick,shaped like a squared off "C",and stuck through drilled holes in the ends of the leather band through the HAIR side(which is the strongest part of the leather. If the band gets too stretched,you have to cut it and drill a new hole. I just used sewing machine round leather belting. Gut would be good too.
The spindle has no hole through it. Its nose is threaded 1"-8 thd.. There is hardened tool steel wrapped and welded around the front end of the spindle,so that the threads, and MORE importantly,the tapered conical front bearing could be made very hard. The spindle itself is iron.
The front bearing runs through a mating tapered hole in a hardened tool steel plate about 5/8" thick and about 3" wide. It sits snugly in a wide dado on the front of the head stock,with a single big bolt holding it tightly against the front of the headstock. This bolt has a tapered square head that is in a mating hole,sunk in flush so it doesn't stick out and hit the faceplate.
The rear end of the spindle is pointed,and hardened steel,too. It rests in a mating female tapered hole. By screwing the large rear bolt in,the play in the front bearing can be adjusted to a running fit. With the wooden bed and headstock parts,this can change with humidity,and had to be readily adjustable.
The headstock pulley we turned from elm so it wouldn't split,and hand mortised a tapered hole through it to jam over the square tapered spindle. Hasn't come loose yet!
The most important thing about this lathe is the VERY HEAVY flywheel,which gives decent power. The lathe started out as a metal turning lathe,for which I made several accessories,such as a cast iron face plate with hold down fingers(to hold metal objects like a candle stick base),a cathead chuck,which I'll try to find a picture of,a pitch chuck( a flat bottomed,hollow chuck you fill with pitch. The pitch is warmed up until an odd shaped metal object could be pressed into it. The pitch would be allowed to cool while you shoved the object around until it ran true. The pitch hardened and you did the work. The pitch was re warmed,and the object pulled loose.) Actually,a very handy chuck we do not have these days,but ANY odd shaped metal object could be held and made to run perfectly true by a skillful operator. I've thought about making myself 1 for my modern lathe,and will when the need arises.
I guess the gunsmith kept these accessories to use on the other treadle lathe,which I also made the spindle and babbit bearings for(the original spindle was just too inauthentic).
The crankshaft that the flywheel runs on is a heavy forging about 1 1/4" square(at least). It has welded in tool steel points on each end that run in tapered holes in steel. There is a bolt holding 1 end of the crankshaft so it,too,can be adjusted.
The flywheel is 2 layers thick. The layers are cross grained to each other,and bolted together with hand forged 1/2" diameter carriage bolts. There is a large 12' square iron cross shaped forging on the front of the flywheel which is bolted on,and has a square hole through its center that tightly fits the square crank shaft. The true running of the flywheel can be adjusted by hammering in wooden wedges.
When I made the flywheel,I bandsawed the tapered perimeter of the flywheel,but had no lathe large enough to cut the grooves. The flywheel had to be running on its crankshaft anyway before the grooves could be cut to run true. I mounted the wheel with its crankshaft on a jury rigged wooden frame,and put the leather band to an electric motor,through its 2" pulley. I just used a substantial block of wood sitting on the floor for a tool rest. The small motor pulley turned the wheel reasonably slow,and I was able to cut the grooves quite true. The rest of the lathe wasn't assembled,so I couldn't just put it in the lathe and make the cuts-which would have been a better plan.
The flywheel only has to run true enough to keep the leather band from jumping the grooves. It still ran surprisingly true after all these years,plus being moved about.
All the iron forgings were made by the blacksmith's shop,and I trued up and threaded the several bearings and threaded the spindle. Then,appropriate bearings were hardened.
NO DRAWINGS were made of this lathe. It was a 1 off job. I have had several requests for drawings over the years. This lathe is not complicated enough to need more than rudimentary sketches. It's the large iron forgings that the home builder will find difficult.
I found this old image of the cathead chuck. I don't know how to get it loose from the early style ivory knife picture,and can't get it to enlarge. You just put your metal into the chuck and could adjust the square head knuckle busting bolts until it ran true. They didn't make more advanced chucks in the 18th.C.,because the metal bars they had were so crude that they wouldn't run true anyway. They did have collet chucks for metal that HAD been made true and round by the turner.
It was formerly in the Gunsmith's Shop. When they moved it was put into storage where I couldn't get at it to photograph it in spite of requests. Apparently in their new location at the Geddy Foundry,they hadn't room for it,and there was already a treadle lathe there(albeit a completely made up fantasy lathe made in the 1950's).
When I went to see Mack Headley wast week ,there it was in the Anthony Hay Cabinet Shop. I had no camera and asked Mack to email me some pictures. These MAY have been taken with a cell phone,I don't know. They are clear enough to see how the lathe works.
Any dimensions I have are from memory.
The lathe is made from red oak. The flywheel is about 2' or more in dia.,and IS 5" thick. I recall that. The steps in the flywheel and spindle pulley are not there to change speeds. They are there to put the ever stretching leather band in the next larger groove to tighten it up. The band is joined with a simple staple about 1/16" thick,shaped like a squared off "C",and stuck through drilled holes in the ends of the leather band through the HAIR side(which is the strongest part of the leather. If the band gets too stretched,you have to cut it and drill a new hole. I just used sewing machine round leather belting. Gut would be good too.
The spindle has no hole through it. Its nose is threaded 1"-8 thd.. There is hardened tool steel wrapped and welded around the front end of the spindle,so that the threads, and MORE importantly,the tapered conical front bearing could be made very hard. The spindle itself is iron.
The front bearing runs through a mating tapered hole in a hardened tool steel plate about 5/8" thick and about 3" wide. It sits snugly in a wide dado on the front of the head stock,with a single big bolt holding it tightly against the front of the headstock. This bolt has a tapered square head that is in a mating hole,sunk in flush so it doesn't stick out and hit the faceplate.
The rear end of the spindle is pointed,and hardened steel,too. It rests in a mating female tapered hole. By screwing the large rear bolt in,the play in the front bearing can be adjusted to a running fit. With the wooden bed and headstock parts,this can change with humidity,and had to be readily adjustable.
The headstock pulley we turned from elm so it wouldn't split,and hand mortised a tapered hole through it to jam over the square tapered spindle. Hasn't come loose yet!
The most important thing about this lathe is the VERY HEAVY flywheel,which gives decent power. The lathe started out as a metal turning lathe,for which I made several accessories,such as a cast iron face plate with hold down fingers(to hold metal objects like a candle stick base),a cathead chuck,which I'll try to find a picture of,a pitch chuck( a flat bottomed,hollow chuck you fill with pitch. The pitch is warmed up until an odd shaped metal object could be pressed into it. The pitch would be allowed to cool while you shoved the object around until it ran true. The pitch hardened and you did the work. The pitch was re warmed,and the object pulled loose.) Actually,a very handy chuck we do not have these days,but ANY odd shaped metal object could be held and made to run perfectly true by a skillful operator. I've thought about making myself 1 for my modern lathe,and will when the need arises.
I guess the gunsmith kept these accessories to use on the other treadle lathe,which I also made the spindle and babbit bearings for(the original spindle was just too inauthentic).
The crankshaft that the flywheel runs on is a heavy forging about 1 1/4" square(at least). It has welded in tool steel points on each end that run in tapered holes in steel. There is a bolt holding 1 end of the crankshaft so it,too,can be adjusted.
The flywheel is 2 layers thick. The layers are cross grained to each other,and bolted together with hand forged 1/2" diameter carriage bolts. There is a large 12' square iron cross shaped forging on the front of the flywheel which is bolted on,and has a square hole through its center that tightly fits the square crank shaft. The true running of the flywheel can be adjusted by hammering in wooden wedges.
When I made the flywheel,I bandsawed the tapered perimeter of the flywheel,but had no lathe large enough to cut the grooves. The flywheel had to be running on its crankshaft anyway before the grooves could be cut to run true. I mounted the wheel with its crankshaft on a jury rigged wooden frame,and put the leather band to an electric motor,through its 2" pulley. I just used a substantial block of wood sitting on the floor for a tool rest. The small motor pulley turned the wheel reasonably slow,and I was able to cut the grooves quite true. The rest of the lathe wasn't assembled,so I couldn't just put it in the lathe and make the cuts-which would have been a better plan.
The flywheel only has to run true enough to keep the leather band from jumping the grooves. It still ran surprisingly true after all these years,plus being moved about.
All the iron forgings were made by the blacksmith's shop,and I trued up and threaded the several bearings and threaded the spindle. Then,appropriate bearings were hardened.
NO DRAWINGS were made of this lathe. It was a 1 off job. I have had several requests for drawings over the years. This lathe is not complicated enough to need more than rudimentary sketches. It's the large iron forgings that the home builder will find difficult.
I found this old image of the cathead chuck. I don't know how to get it loose from the early style ivory knife picture,and can't get it to enlarge. You just put your metal into the chuck and could adjust the square head knuckle busting bolts until it ran true. They didn't make more advanced chucks in the 18th.C.,because the metal bars they had were so crude that they wouldn't run true anyway. They did have collet chucks for metal that HAD been made true and round by the turner.