User:Rando/Maslow

Maslow CNC Tutorial

In this tutorial we'll cut a Noisebridge sign designed in Inkscape.

Concepts

1. Creating paths out of text objects
2. Cut types
3. Bit locations
4. Z-axis and material depth
5. Tabs and router bit width

Quick Basics on CNC

You want to cut something. You have a thing that moves which has a thing that cuts on it. Sometimes you want that tool to "work" aka be cutting, and sometimes you don't, so the machine can move to the next cut. The way the machine knows to what to do and where to do it is location based commands which tell it where to move and how fast. For the Maslow, movement consists of left, right, up, and down. The z-axis for the maslow is the depth which the router bit descends into the material.

If you are using 3/4" wood and you want to be absolutely sure the cut goes through, then you need to specify the cut depth as > 3/4". In this case, 0.80" works great.

Design

Use the text tool to write Noisebridge. Add a line underneathe with the line tool and surround it with a rectangle with the rectangle tool.

Select All and then go to Paths -> Object to Path. This will break each object up and create a set of paths. Paths are required for vector based plotter operations.

Once complete, save the drawing as a plain svg.

MakerCAM

It's a web-based application and it's not great. Zooming is goofy, and undo does't work. However, if a mistake is made, it's possible to redo the operation, and at the end of the process, only export the operations you want. More instructions to come using other software but this is a good tutorial and MakerCAM can be to the CNC what Inkscape is to the Laser.

A note about selecting lines, it's best to drag the select square than try to click. Using shift and control to group works fine, just use selection dragging instead of just clicking.

The workflow is to load the file, define what kind of cuts are needed to produce your desired result, calculate the paths, add tabs, and export gcode.

Cut types:

Profile

This cut will cut out a complete closed shape, but the side of the cut needs to be determined, e.g. inside or outside the line. Inside and outside only make sense if the shape is closed.

Follow

A follow cut puts the center of the bit on the line.

Drill

A drill puts the router bit in one places and drills a hole to the desired depth.

Set the text cut, which will only go partially through. For this sign we want the letters inset, so we will cut the inside of the shape.

tool diameter

the diameter of the router bit. The Maslow should have a 1/4" bit on it but this is Noisebridge so please check.

target depth

How far from the front face (e.g. z-axis zero) should the bit drive into the material. In this case, we do not want the bit all the way through, so we pick some reasonable distance into the material.

inside/outside

Determines which side of the shape we chose will be cut. If we cut "inside the lines" for the text, it will be inset into the wood, which is what we want. If we choose "outside" then the wood around the text will be routed, outlining each letter.

safety height

how far to pull the router up. Note this is positive, so it is 0.50" above the zero, which should be 0.50" above the marterial.

stock surface

surface of the material in z-height (e.g. the zero on the z-axis) if not actually at the zero'd value for the z-axis

step down

the cuts don't go all the way through at once becuase this puts a lot of stress on the router bit. However, if the depth is 0.80" and the steps are 0.05", it's going to take 16 passess to cut. No thanks. This can safely be increased to 0.15" or 0.20".

feed rate

how fast the router bit moves laterally when in the material

plunge rate

How fast the z-axis moves into and out of the material.