Pool Cue Shaft Taper Lathe

Some one convinced me to modify an Atlas TH54 lathe into a pool cue taper lathe.

 

Original Atlas TH54 LatheAtlas lathe before modifications

 

Purpose:

Modify lathe to turn thin wood pool cue shafts with long taper

 Requirements:

CNC would not be used

Modify lathe so compound will follow taper templates

Select easily between several taper profiles

Continuously variable spindle speeds

Continuously variable lead screw speeds

Limit switch at end of lead screw travel to shut off lead screw and spindle

Large metal backdrop and structure and dust shield

 Approach:

Modify an Atlas lathe so that the compound and cutting tool position would be controlled by a taper template.  The compound slide was disconnected from its lead screw.  A bearing was attached to the compound slide that would bear against the taper template.  Springs were used to insure that the bearing stayed in contact with the profile. Multiple cue shaft template profiles were to be used. Both lathe spindle and lead screw were to be independently powered and speed controlled allowing for feed and speed tweaking. A limit switch was installed at the limit of travel to turn off the lead screw and spindle after a taper pass was finished.

First step was concept and fab of how to switch easily between taper templates. Design was to mount multiple templates on a square tube and rotate tube to change tapers.

 

 

Template TubeTaper template tube with 3 mounted templates.

Lathe BackplateBackplate for dust control and template tube mount with L brackets that will hold the square template tube.

 

Blackplate Assy Template tube mounted in the L brackets.  The lathe will mountin front of the vertical plate close enough that an extended cross slide can contact the taper plates.

 

Taper Lathe BackplateVertical back plate mounted on the base platform with the lathe in front.

 

Machining Template Tube BracketsMachining template tube L brackets two at the same time.

 

Measuring cue shaftsCue shaft taper measurement.  existing cue shafts were used to generate the taper for a given template.  This was accomplished by measuring the diameter of the shaft every 1/2 inch along the length.
Cue Shaft MeasurementsCue taper measurements were performed on 3 shafts of 2 different designs.  The graphs show the diameter of the pool cue shaft along it length.  Theygo from about .5 inch diameter to .85 inch diameter.

 

Cue shaft taper dxfA single template dxf was drawn up from the shaft measurements for the two profiles we were interested in.  In addition a two level constant diameter template was drawn to assist in cutting dowels of a specific diameter.

 

Taper Templates and AluminumThree different taper templates cut from aluminum plate using the three dxf files that were drawn up.  A large aluminum cutting CNC router did the job.

 

Milling template SlotsBack to the CNC knee mill for machining template adjustment slots.  These slots will allow fine tuning of shaft taper diameters while the template is mounted.

 

Templates and Tube InstallTemplate tube mounted on back plate.  You can see the all thread bolts used to maintain the distance between the vertical plate and the lathe.  You can also see the cross slide extension with bearing that rides against the template taper.  Not yet mounted are the springs that will force the cross slide to maintain contact with the taper template.

 

Template Tube and L BracketTemplate tube mounting detail.  The steel plates in the interior are nutplates for the taper template that are about 6 inches long.  That was done so that the nuts could be aligned from the end of the tube.

 

Check Fit of Tube and BearingExtended cross slide bearing and taper template.

 

Next task was mounting the router.

 

Machining Router BracketMachining the router bracket.  Needed another L bracket but wanted to make sure that it was 90 degrees.  So it got milled.

 

Router bracketRouter bracket mounted to compound.  Nice and vertical.

 

Mounted RouterRouter mounted on the milled L bracket and attached to the toolpost.

 

Leadscrew Limit SwitchLimit Switch mounting.  Again the CNC knees mill made simple work of the slots.  The switch wheel contacts the underside of the apron when the cross slide is close to the headstock of the lathe.  The lathe spindle and the lead screw motor are turned off with this limit switch.

 

Three Phase Motor3 Phase motor conversion.  The original Atlas motor and reversing switch were removed and replaced with a three phase motor.  By using a VFD infinitely adjustable spindle speeds are possible.

 

DC Motor and ChainA DC motor is used to power the leadscrew.  Mount for the motor is courtesy of the CNC mill again.

 

Leadscrew Chain DriveChain drive from DC motor to lead screw.  Gotta keep this bushing oiled it we expect the lathe to last.  The DC motor running the lead screw gives the lathe infinitely adjustable feed rates.

Electrical SchematicThe Lathe schematic is basic.  A VFD controls spindle speed.  A DC motor controls lead screw speed.  A contactor is used as a high current relay.  Both VFD and DC control are hooked into the limit switch.

 

Electrical BoxElectronics box was not complicated enough to justify a separate inside panel.  And the controls are mounted to the far side of the box so they can face the operator.

 

Instrument Panel ArtworkPanel artwork was generated in Inkscape,  dxfed from CorelDraw,  and G code generated in DeskProto 6.1.

 

Engraving Panel LabelWe had a CNC rotary engraver so we built the panel ourself.  First time we tired to do this.

 

Electrical Box LabelControl panel worked out pretty well.  The text got dug in a little deep but we will know better what settings to use next time.

 

Vacuum Hose MountA vacuum nozzle is mounted next to the router bit to suck up as much sawdust as possible.  It rides in the second toolpost slot.

 

Finished Taper LatheFinished lathe ready to ship.  Whewwwwww!  This would have been a lot better and easier to build as a CNC.

 

You Tube of lathe cutting some dowels

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