Overview¶
This week, we will mainly focus on cutting tools, specifically using a laser cutter and vinyl cutter.
I will be making, along with several other classmates a group project on the laser cutter, as described here:
characterize your lasercutter's focus, power, speed, rate,
kerf, joint clearance and types
Coordinate this work with all your group members
My individual assignments are:
cut something on the vinylcutter
design, lasercut, and document a parametric construction kit,
accounting for the lasercutter kerf,
which can be assembled in multiple ways,
and for extra credit include elements that aren't flat
Notes¶
These are some notes I took during Dr. Gershenfeld’s lecture:
- Some computer controlled cutting machines use ultrasonic sounds to make cuts in the materials.
- Photography engraving 300dpi, try 4 different methods, 3 different materials. Keep settings the same for each material.
- Make some sort of parametric press fit toy kit that accounts for kerf. Extra credit is to include curving and not just flat elements.
-
Ultrasonic knife pumps ultrasonic energy into the blade, cuts through wood and melts plastic.
-
Vinyl cutters can be used to make circuits with some other materials.
-
When cutting, you should barely drag over the surface, and not push through it. When weeding don’t pull up pull from side to side(Shearing).
-
Joint Types:
- Bump joint: slides into slotted material that bumps in, after it’s put in ,it can’t pump the other way
- Pinned joint: slide tabs together with no flexures, and then put in a pin to hold them together
- Finger: joint common tab joint, father neil doesn’t like
- Snap joint, better than finger
- Wedge joint, common in woodworking, slot goes through with tapered wedge on the other side, tab wedge to keep it in place
- Joint design: Neil has parametric freecad joint file
- Make a comb to find best joint fit.
- Fillet joints for less stress concentration
-
Cut hinges:
- Helps you curve a flat piece.
- Sometimes a laser will blur if it’s out of focus
-
Whenever there is smoke coming out of a laser cut, it means it is not working correctly because the fumes are supposed to be drawn down and out of the vent.
-
Kerf is what is removed.
- A good joint = 0.001 inch.
- Offset the laser beam by the joint diameter.
- When a laser cuts through a piece of material, the laser’s own width displaces a little extra material than is specified in the original design.
-
Dithering techniques try to reproduce shades of gray by pixelating image of incredibly small black dots.