Fabrication. Production Options Available. By fabrication speed: By ease of access:

Transcription

1 Fabrication Production Options Available By ease of access: easy fast hard By fabrication speed: hand tools / Hebb42 laser cutter waterjet cutter 3D printer student machine shop slow hand tools / Hebb42 waterjet cutter laser cutter student machine shop 3D printer

2 Fabrication fabrication time Make! Design Laser! yes yes can it be hand made? can it be laser cut? or, no or, Water Cut! yes no can it be waterjet cut? or, Print! yes no needs to be 3D printed? or,

3 Fabrication For Waterjet and Laser: DXF file needed Videos: How to generate and prepare a DXF file How to use the waterjet cutter (watch, then check in with Bernhard for intro session) PDF Manual: How to use the laser cutter For 3D Printer: STL file needed Choose save as STL in Solidworks. Record your use: Waterjet Laser 3D Printer

4 Materials

5 Materials For Laser: For Waterjet: Our 3D printers use ABS plastic.

6 Hand Tools Sheet Metal Bender (Box Brake) Shears (Sheet Metal Only!) PCB Custom Sizing Tool

7 Waterjet and Laser Offset: Waterjet vs. Laser

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9 2D CNC machining Gears - Use Solid Works Toolbox to generate gears Check to make sure toolbox is activated (SW - tools - add-ins ) Use ISO standards for gear shape generation. This standard uses the module to determine gear size. Gears, and gears and racks, with the same module will always match properly Smallest gear size that can be made on waterjet and laser is module 1. Acrylic Polycarbonate But: Quoting Solid Works, Toolbox gears are representations for machine design purposes. They are not true involute gears that you can use for manufacturing.

10 Gears To make your gears work for your robots, make it a loose fit. (Real gears = not CNC d from a Solidworks shape use something called the pitch diameter to line them up correctly.)

11 2D CNC machining Gears Melting on a laser cut part (acrylic, O.D. = 16mm) Compare to waterjet cut: no melting, but a bit fuzzy. Laser: Use acrylic (PMMA, Plexiglas ) or Delrin, do not use polycarbonate ( Lexan or also Makrolon brand names) Waterjet: Use polycarbonate ( Lexan, Makrolon ) or aluminum, steel, or ABS plastic

12 3D printing design parts for fast production: (no parts that take longer than 1 hour to print) - flat on the ground: The printer automatically adds supports that can be very hard and time consuming to remove. No supports needed. Set 3D printer to low infill setting to use as little material as possible and make printing fast. - overhangs at an angle: Supports needed. No supports are added, as long as the overhang angle is greater than specified in the printer settings. - holes with teardrop shape: video link: overhangs and teardrop holes Supports needed. to turn off any supports in the Up! printer software, choose base only No supports are added, as long as this angle is greater than specified in the printer settings.

13 3D printing make them sturdy - use fillets wherever possible sharp corners make it easy for cracks to start and propagate fillets (rounded corners) reduce stress concentration

14 3D printing understand the loads on your parts consider effects of layering strongest corner not as strong the stongest corner is built with continuously extruded material, while the weaker corners are layers that have boundaries of lesser strenght.

15 Holes and Openings always make openings larger than the nominal diameter of what you are passing through. (M5 bolt = 5mm hole? Better: make 5.5mm!) shafts from motors: see if there are indexing collars (shaft bushings) around the output shaft on the motor even if not, make the hole for the shaft bigger to make sure the shaft will never touch the hole walls

16 Fabrication Videos: How to use epoxy How to use a battery drill There are different ways to make springs: 3D printed shaft adapters can be an option. Consider using mechanical cables like used on bikes: Push-and-pull linkages made from wire:

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18 wheel making Wheels - nice looking 3D prints? video plywood & metal waterjet cut?(see next page) use commercial wheels?(from old toys, or hobby supply) new ideas? Origami Wheels (video)

19 wheel making: plywood and sheet metal

20 timing belt or chain? Video showing how to customize bike chain (opening and closing chain links)

21 using a laser pointer to sense distance

22 The Evil Scotch Wheel Do mainly small parts, large parts like chassis are safer to do manually (hand deburrer, file, sand paper) Scotch Wheel deburring of holes is now entirely outlawed on large parts (10x10cm or bigger) always do holes manually For emergencies, call 911 or Thank you for keeping your work benches clean! Please do the same for the common work area