Combi-3: Home CNC Lathe

The photo shows that the saddle, leadscrew and cross slide of the standard C0 lathe are dispensed with leaving the cast iron bed with the single function of locating the headstock and tailstock. Also replaced is the sheet metal plinth on which this lathe is usually supported, the plinth is perfectly adequate in standard use but as this mounting would be in the mechanical path between work and cutter it is nothing like sturdy enough and has been replaced by a solid mounting plate. Photo L1 shows details.

The XY cnc motions are now performed by slides and leadscrews that are much bigger, wider, longer, better protected from swarf and easier to lubricate than the originals.

This lathe will pass 10mm through the headstock, swing 100mm diameter, hold 120mm between centres. It has a variable spindle speed up to 3800rpm with 150watts of power.

Use of a quick change tool post allows as many tools as necessary to be assigned in the program, the operator being prompted to make the next tool change.
Note: the included software (X1P2) does not offer single point screwcutting.

For automated cycles the tools, including drills can be carried on a platen and once the operator has fed the bar to stop length and tightened the collet, the process is automatic. Photos L1c, L1d show a typical setup turning 4mm:1FT loco chimneys (the chimney is shown on T1 shank).

By replacing the saddle, which is the achilles heel of this particular small machine, the resulting mechanism is suitable for continued use on batch work in a craft workshop.

Uses include:

• Bobs, pillars and bases of clocks.
• Parts of model planes such as found in landing gear etc.
• Stern gear for model boats including small props.
• Model loco chimneys, domes, buffers, fluted & tapered connecting rods.
• Craft working in Pen / Pencil sets etc.
• The multitude of small turned parts in musical instruments.
• The turning & engraving of custom ceramic beads prior to final firing.

Optionally for 'special' work the spindle could be driven via toothed belt from a stepping motor with 2:1 reduction. Using 'live' tooling, (rotating tools such as a router etc) offers the facility to engrave graphics and text on the turned work on both the cylindrical surface and the end face.

See Photos L2, L3 and L4 which show a remotely powered spindle mounted in three configurations suiting Pocketing, Fluting and Engraving. Custom tooling such as this would be quoted for on a 'one-off' basis.