It's Lathe Time ......maybe

 With spring warming the unheated shop an old man's fancy lightly turns to thoughts of lathe.  Click any image to enlarge.

The construction is based on commonly available stock sizes of 3/4" cold rolled steel.  Most of the pieces are 3" width and the largest pieces are 6" width.

With an all bolted assembly there will be no distortion introduced by welding although milling operations may cause the steel to spring a bit.  I hope to keep milling operations to a minimum.  Tapping all those 3/8-16 holes will be a chore but rigidity will be more than adequate.

 

 

A mock-up in plywood.  A physical model gives a sense of scale that images lack and even a machine this small eats up bench space.  A bed this length can use a tail stock but that detail hasn't progressed beyond a rough sketch.

 

 

The current power transmission.  To the right is a dc motor complete with flywheel,  both salvaged from a treadmill.  To the left of the motor is the intermediate shaft that transmits power from the motor to the headstock gears.  To the left of the intermediate shaft is the gear shift lever which looks a lot like a long bent bolt.

 

The lowest pulley in this image is driven by the intermediate shaft and in turn drives the gearbox.  The pulley immediately above the the gearbox pulley exists only to spin the encoder shaft.  To the left is the encoder shaft and associated pulley and the encoder itself.  The encoder will allow thread cutting and provide an RPM signal.

For now the dc motor is powered by the same controller that powered it on the treadmill.  The stepper motors, stepper drives, linear rails and ballscrews  exist only on a shopping list.  Most of the steel needed is on hand or available locally so cutting, drilling and tapping will be the starting point.  More pictures to come in a future post whenever there's enough progress to bother with photos.