Tools & Such

This page is being used to showcase a number of home-brew tools for various

projects.  Please click on an image for a larger view.

400W Spindle as Low Profile CNC Mill Lathe:

The video clip link included at right shows a

400W air cooled spindle, used as a low profile lathe for a CNC mill. 

When I upgraded my mill to a 1,500W water cooled spindle, I decided to

use the original 400W spindle as a small lathe for pen turning.

The live center mount at the right is made up of three layers of 1” HDPE,

to hold an MT0 live center.  The mount has a 5/16”-18 screw at the back

to adjust the live center travel.  And a 10-24 set screw at the top to lock

down the live center once it’s adjusted if necessary.

In this video I’m cutting a pen blank out of Mahogany, for a Dragon Twist Pen kit that I purchased from

Penn State Industries.  The turning mandrel used for the lathe is a Drill Chuck Mandrel, also from Penn

State Industries.  The CNC mill first cuts three separation areas in the blank, then trims the blank to 0.7”

diameter for a size check.  If the trimmed blank doesn’t measure 0.7”, the mill “Y” position is adjusted as

needed for correction.  In this example the blank measured 0.703”, so close enough.  The two pen

sections of the blank are then trimmed to the pen body dimensions.

The pen body is milled 0.030” oversize, for a pre-form that will be trimmed

to final size on a larger lathe.  Then sanded to allow a CY (Cyanoacrylate /

Super Glue) coating to be applied to complete the project.  The images at

right are examples of two PSI Dragon Twist Pens and a PSI LED Penlight. 

Two were milled from African Padauk hardwood blanks, and one from a

Central American Cocobolo hardware blank.

Sherline 3700 Manual Rotary Table Converted for CNC:

The latest update for the CNC mill is a Sherline 3700 Manual Rotary Table, that has been adapted as a

fourth axis for the CNC mill.  A 3-piece adapter was milled out of HDPE, to attach to the rotary table to

support a double ended stepper motor.  This allowed the rotary table handle to be attached to the stepper

motor, to allow manual operation if needed.

A brass mandrel was milled out of some 3/4” brass rod, as a support for milling a ring out of green

jeweler’s wax.  The ring blank is milled with four holes in the blank.  Three holes to slip over the brass

studs for alignment, and a center hole for a #4-40 screw to attach the ring blank to the brass mandrel.

Included below is a link to a YouTube video, and some pictures from tests, milling a wax ring with a

Dragon, Wizard, and Castle image on the ring face.  The backdrop was milled 0.035” deep, on a wax band

that was approximately 0.070” thick.  A first pass was run along the entire face of the ring with a 1/8”

two flute end mill to true it to the CNC mill spindle.  A roughing pass was then run with a 10 degree

Tapered Ball End Mill with a 0.010” end (Bits & Bits TEB10-010).  A finish pass was then run with a 6

degree Spiral Pyramid End Mill with a 0.002” end (Bits & Bits 815-SPY6C 002).  Total time to run for the

mill was approximately 20 minutes.

Water Cooled Spindle Flow Meter:

The image at right is of a flow meter fabricated for the 1,500W water cooled spindle. 

The fluid pump used is a GRI +24VDC pump.  The small almond box with dial and switch

is the speed control for the pump.

Alignment Fixture for “Y” and “Z” Axis:

An alignment fixture was milled to set the “Y” and “Z” axis positions and is shown at

right.  A 3/16” hole centered over the mandrel shaft, and small bubble level in the top

side, allows a 3/16” end mill to set the “Y” axis.  The top of the fixture sets the “Z” axis

position as 0.6” above the center of the mandrel shaft.

Chip Clearing Air Assist for CNC Mill:

The photos below show an update made to the CNC Mill vacuum shoe, to help with chip clearing while

milling.  The change used a set of 1/4” Loc-Line parts from McMaster-Carr, and either an air pump or a

small compressor attached to the Loc-Line port.  This produced enough air pressure to help clear chips

while milling.  The small compressor works best, but in some cases the high pressure air flow isn’t

needed.  The rightmost photo shows a milling example without air assist, left side, and with air assist,

right side.  Without air assist the milled channels are pretty much filled with sawdust.  With air assist the

channels are almost free of debris.

Milling Press-Fit Stainless Steel Pins:

I recently milled some stainless steel pins for a press-fit application.  I placed a length of 1/4” stainless

steel rod in the 1.5KW spindle, and a 4-flute 1/4” carbide end mill in the 400W spindle.  The stainless

steel rod was turned at 10,000RPM, and the end mill was turned at ~6,000RPM.  The left end of the 400W

spindle mounting block was raised 1/16”, so that only

the upper edge of the end mill was cutting the rod. 

This was to reduce chatter, and seemed to work very

well.  Moving the 1.5KW spindle manually, and slowly,

I was able to reduce the stainless rod by 0.040” on the

first pass.  Final passes were at 0.005” or less.  The

rod was milled slightly oversize, and then sanded with

600 grit sand paper on a wood lathe to finish.