What do you need in order to build a $100 12" screw cutting lathe?



Tools:

Basic mechanic's and carpenter's tools, a dial test indicator (looks like a pocket watch with a rod sticking out, $10 in the US)

a drill, a 4" angle grinder will be needed to get full use of the machine but that can be added later

Materials:

scrap wood for the concrete form

four sacks of concrete mix

5 pounds non-shrinking grout (looks like cement, used by tile setters)

2, four or five foot lengths of inch and a quarter pipe or inch and a half steel shaft, must be truly straight and smooth, Used or new pipe or even drive shaft sections must be carefully checked for straightness. The best way to do this is to put the 2 pieces side by side, rotate one while it is pressed against the other and use a feeler gauge or light from behind to check for a gap.

A junked hydraulic cylinder with a smooth 1.5" to 2.5" diameter piston rod at least 12" long

Scrap aluminum and piston metal for casting bushings and other parts

3' 3/4" or 1" all-thread rods and coupling nuts to use as lead screws.

Short lengths of pipe and steel bar, at least a few bolts and nuts

Bicycle sprockets, chain and a broken electric drill to use for the thread follower threading device

An auto flywheel to use as a chuck back plate

If there is no access to a metal or wood lathe to machine the aluminum parts then a rear wheel hub assembly from a small car will also be needed for use as a "temporary" lathe

Skills:

Good mechanical skills.

Very basic aluminum casting using a primitive furnace

Metal casting is common in Developing Countries. Our furnace can be as simple as a hole in the ground half filled with charcoal. Our simple shapes are easily cast.

Less than 5 minutes of welding