Luke Hospadaruk
07-24-2012, 11:17 AM
Before I get going - the last time I turned any wood was on a 9v battery powered kid's lathe in elementary school - so I wouldn't say I've got a whole lot of turning experience.
For various reasons (it's super cool) I've decided I need to build myself a lathe. I'm sure I could find a used one that would get the job done, probably be cheaper and better, blah blah blah, but I need a project to work on and it's going to be a lathe. In this particular case, it's going to be a treadle powered lathe (not only do I need a project, I also need exercise). I may later add a motor, but I don't really want to bother with that for now. And my questions would really be the same for a motorized or non-motorized lathe.
There's a nice little PDF here (http://www.manytracks.com/lathe/lathe.pdf) about building treadle lathes where most of my crazy ideas are coming from. Instead of describing the whole design to you, just take a look and see what I'm generally going at. Also attached are some pictures showing the basic idea.
Since I get to design everything about this lathe (and I've never used/owned a real lathe) I've got a lot of questions about what decisions to make.
Main questions:
1) What kind of fittings should be on the spindle? I'm imagining a female MT2 on either end (inboard and outboard), with a bore-hole through the middle so I can use a draw bar. Is this as standard as I think it is? Will I have an easy time finding fittings (drive centers, sanding plate, chuck, etc) that fit onto this? I have a friend who can machine the spindle, but if there's some cheaper option that will get the job done (he doesn't work for free), that would be desirable.
2) Does the outside diameter of the spindle really matter - are there any fittings (chucks, centers, plates, etc) that fit onto the outside of spindles?
3) Tailstock - probably just going to use a stock MT2 socket set into wood - maybe with some welded-on flanges to keep it secure, maybe weld it to a plate and bolt the plate to the top of the tailstock. This I'm not very worried about - again so long as I'll have an easy time finding MT2 live/dead centers, etc.
4) How big should I make this thing? I can pretty much go as big as I want (within reason and fits-in-the-basement rules) in terms of distance from bed to spindle and overall bed length. Probably if I go too big the lathe will loose some stability (bad), but I can't imagine I'll go that big.
5) Anything you really wish your lathe did/had that it doesn't that I should design for?
Other design thoughts:
- I plan on pouring a concrete flywheel for maximum mass. I'll probably use a round belt and a v-grooved flywheel/drive pulley instead of a flat belt and crowned pulleys. v-groove seems easier to set up.
- I may make it out of some local hardwood, birch or maple - or I may just use dimensional lumber. I was considering using LVL (those structural laminated roof beams) for the horizontals, they're huge and I'd imagine very dimensionally stable. I don't really want the whole lathe to be propeller shaped a year from now.
- I'd like to be able to turn just about everything (eventually, skills and tools permitting). I don't really want to build another lathe a year from now so I can turn X thing. Although as long as I can re-use the expensive bits (spindle/bearings/flywheel/tailstock) re-doing the wood parts wouldn't be the end of the world.
- It's fairly easy (read:inexpensive) to get pillow-block and flange-mounted ball bearings for any likely shaft diameter, that's probably the route I'll go (as opposed to bronze/hardwood/plastic bushings, or just sitting the spindle in a hole).
For various reasons (it's super cool) I've decided I need to build myself a lathe. I'm sure I could find a used one that would get the job done, probably be cheaper and better, blah blah blah, but I need a project to work on and it's going to be a lathe. In this particular case, it's going to be a treadle powered lathe (not only do I need a project, I also need exercise). I may later add a motor, but I don't really want to bother with that for now. And my questions would really be the same for a motorized or non-motorized lathe.
There's a nice little PDF here (http://www.manytracks.com/lathe/lathe.pdf) about building treadle lathes where most of my crazy ideas are coming from. Instead of describing the whole design to you, just take a look and see what I'm generally going at. Also attached are some pictures showing the basic idea.
Since I get to design everything about this lathe (and I've never used/owned a real lathe) I've got a lot of questions about what decisions to make.
Main questions:
1) What kind of fittings should be on the spindle? I'm imagining a female MT2 on either end (inboard and outboard), with a bore-hole through the middle so I can use a draw bar. Is this as standard as I think it is? Will I have an easy time finding fittings (drive centers, sanding plate, chuck, etc) that fit onto this? I have a friend who can machine the spindle, but if there's some cheaper option that will get the job done (he doesn't work for free), that would be desirable.
2) Does the outside diameter of the spindle really matter - are there any fittings (chucks, centers, plates, etc) that fit onto the outside of spindles?
3) Tailstock - probably just going to use a stock MT2 socket set into wood - maybe with some welded-on flanges to keep it secure, maybe weld it to a plate and bolt the plate to the top of the tailstock. This I'm not very worried about - again so long as I'll have an easy time finding MT2 live/dead centers, etc.
4) How big should I make this thing? I can pretty much go as big as I want (within reason and fits-in-the-basement rules) in terms of distance from bed to spindle and overall bed length. Probably if I go too big the lathe will loose some stability (bad), but I can't imagine I'll go that big.
5) Anything you really wish your lathe did/had that it doesn't that I should design for?
Other design thoughts:
- I plan on pouring a concrete flywheel for maximum mass. I'll probably use a round belt and a v-grooved flywheel/drive pulley instead of a flat belt and crowned pulleys. v-groove seems easier to set up.
- I may make it out of some local hardwood, birch or maple - or I may just use dimensional lumber. I was considering using LVL (those structural laminated roof beams) for the horizontals, they're huge and I'd imagine very dimensionally stable. I don't really want the whole lathe to be propeller shaped a year from now.
- I'd like to be able to turn just about everything (eventually, skills and tools permitting). I don't really want to build another lathe a year from now so I can turn X thing. Although as long as I can re-use the expensive bits (spindle/bearings/flywheel/tailstock) re-doing the wood parts wouldn't be the end of the world.
- It's fairly easy (read:inexpensive) to get pillow-block and flange-mounted ball bearings for any likely shaft diameter, that's probably the route I'll go (as opposed to bronze/hardwood/plastic bushings, or just sitting the spindle in a hole).