MDF Rose Engine Lathe 2.0

Control System for Multiple Stepper Motors

Helical Flutes using a Profiled Cutter

The idea behind this approach is you are cutting one flute helically down the entire length of the Z axis. A shaped cutter which is moved along the Z axis to cut one flute, the spindle is indexed, and the whole process is repeated until all the flutes are cut.

Basically, it is the same as multi-start threading.

Rosette	No rosette is used for this approach. The shape comes from the cutter's profile. The headstock is held fixed (the centering block is inserted in the back, and the fading wedge dropped down).
Spindle	The spindle is rotated slowly whilst the cutter is moved in the Z direction. The spindle is indexed after each flute has been cut to the desired depth. (This may be multiple passes.)
Cutting Frame	The cutting frame selected and the angle of cutting can have great effects on the results achieved. Typically, a horizontal cutting frame is used. The cutting frame is moved slowly down the Z axis. Movement of the cutter along the Z axis must be synchronized with the spindle, so it really needs automated movement using a lead screw (e.g., a curvilinear slide). Note: a Drill Spindle could be used with this, especially when using specialty cutters.
Cutter	Use a cutter with a profiled shape which will yield the desired cut. Hold it in a cutting frame, and move it down the whole length.
Rubber	The shape of the rubber has no effect as no rosette is used for this.

Screen

Actions

Ind

On the Indexing page,

Set the variables on the screen as:

Divisions = number of desired flutes around the piece.

The radio button selections are set as:

Div Deg
Fixed File

Note: Indexing is not done using this screen; rather the and the buttons on the Synchronization screen use these settings.

Z Axis

On the Z Axis Preferences page,

Ensure the Leadscrew is set for your cross slide's motion.

	Left Hand		Use when using an apparatus with a left-handed threaded rod. A Hardinge compound slide-rest has a left-hand thread.
	Right Hand		Use when using an apparatus with a right-handed threaded rod

Sync

On the Synchronization page,

The radio button selections are set as:

Z X B
Helix Type: either of these is OK, depending on what is desired.
If cross hatching is desired, then a set of flutes will be cut with Left and another with Right. Also, consider using a Drill Spindle for cross hatching.

Set the variables on the screen as:

Revolutions
- Straight flutes - set to 0
- Helical flutes - Typically, this is set to 60° or 90°, though different values can also yield nice effects.
Distance = distance to be traversed

The Max Spindle Speed is recommended to be no higher than 5000, and the Max Z Axis Speed is recommended to be no higher than 2500.
This screen will limit the overall speed of the spindle and the Z axis to whichever is lower. This is based on the settings in the Preferences pages for the Spindle and the Z Axis

Turn the cutter on, and plunge to an initial cutting depth.
It is a best practice to cut the first two flutes shallower, then recut until the desired distance between the flutes is reached. You can have the peaks meet, or have a small flat between them.
Touch either
to cut towards the headstock or
to cut away from the headstock.

If additional depth is needed for the flute, use the opposite movement as in previous step.

At this point, you can:

recut the same flute in the opposite direction,

cut the next flute in the opposite direction, or
retract the cutter and return to the starting point of this flute (using ) before indexing to the next flute.

To index to the next flute, use the or the button.

Repeat steps 7 thru 11 for each flute.

Cutting Downhill

Cutting to the Left

Cutting to the Right

When cutting with a spinning cutter, just as on a router, it is a good practice to always cut downhill. This is not always possible, but it typically leaves the smoothest surface.

The choices for the direction to move the cutter (the red arrow) and the cutter's rotation (blue arrow) should be made to ensure downhill cutting happens.

This is an advantage for using a fly cutter over a carbide bit. With a fly cutter, the direction of the cut can be reversed. (For more information about fly cutters vs. carbide bits, see also Cutters on the Cutting Frames page at the Ornamental Turning Book of Knowledge.)

Click on any of the pictures on this page to see bigger images.