From: muratlanne@gmail.com   
      
   "Richard Smith"  wrote in message news:m1plciujj7.fsf@void.com...   
      
   I thought about that - is it time to have my own machine-tools...   
      
   Build a lean-to for solid fuel - empty the outbuilding as much as possible.   
   Board out the rafters and put lighter rarely used things up there.   
   Buy a compressor and park it 4/5ths the way up the wall not taking up   
   floor-space.   
   Lathe, maybe a mill, in.   
      
   I got a lathe as a kid.  But my dreams were bigger than all of my   
   {abilities; mentoring; pockets; etc; etc.}   
   I can see it now and forgive myself a lot.   
   Now I have a range of abilities, something in my pocket, and small   
   dreams.   
      
   --------------------------------   
      
   My South Bend lathe holds up to 10" (254mm) diameter, big enough for my   
   projects, maybe not for yours. The practical work diameter is smaller, to   
   allow for chuck jaws, unless you can bolt it to a faceplate. The diameter   
   capacity is less over the carriage. Student abuse has degraded its precision   
   though I can still turn a shaft and hole or ball bearing recess to a light   
   finger pressure fit, tediously by repeatedly measuring and removing most of   
   the excess.   
      
   It has a threaded spindle and leather belt drive, both long obsolete but   
   still adequate. It is slow and loose enough that carbide bits don't work   
   well, localized wear prevents snugging the gibs over the full travel, the   
   slides are tight at the ends and looser in the middle. High Speed Steel   
   (HSS) tool bits are fine to cut mild and somewhat hardened steel like the   
   rock drill rod or high strength bolt shanks.   
      
   The ways of small Sears lathe I bought first were worn low near the spindle   
   which meant I had to thread and turn diameters precisely at the barely used   
   tailstock end. The worn area was still good enough for more usual short   
   parts like adapter bushings, it lowered the bit height more than the cutting   
   diameter. When I took a night class to correct what I had been doing wrong   
   by guesswork I milled the bed straight. It was still too small for useful   
   cuts in steel so I grabbed the 10" South Bend when I saw it, and lived   
   happily ever after. The SB has made hydraulic pump drive components for an   
   18HP engine.   
      
   Finding parts can be a problem for an old lathe, or a new import one.   
   Tooling such as chucks and cutting bit holders is more generic and should be   
   easier.   
      
   The Sears has separate change gears for threading, which is acceptable for   
   occasional use, a quick change gearbox is very nice but not essential. A   
   complete British change gear set for threading would be different from what   
   I have, your BSP pipe thread has different pitches.   
      
   The exact metric conversion gear pair for an inch pitch leadscrew is 127   
   teeth driven, 100 (or 120) driving the next gear. 47/37 is very close and   
   more compact. I use 1mm = 0.040" to mentally convert metric drawing   
   dimensions to inch dial readings for roughing near final size.   
   https://www.reddit.com/r/functionalprint/comments/1gxe960/3d_pri   
   ted_gears_for_my_lathe/   
      
   A small air compressor may be enough in a manual machine shop, you don't   
   want to blow sharp chips all around. Cheap paint brushes are better for chip   
   cleanup.   
      
   jsw   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)