Overview¶
Subject Pages¶
This section is about everything related to design an production of mechanical parts and systems. Because the subjects sometimes need a lot of documentation, I have grouped them in:
Computer aided design, modeling and drawing in both 2D and 3D. NB: modeling in KiCAD is documented in the electronics section.
Computer controlled cutting with the vinyl cutter and the laser cutter.
Computer controlled machining of circuit boards.
Computer controlled machining of large sheets of wood and plastics.
3D scanning programs and 3D printing, mainly with filament printers.
Molding and Casting
Machine Settings¶
Something you use frequently during the whole fabacademy is the documentation of the settings of the machines. So putting them inside some lengthy story about what I did with that machine, I decided to make a list of all those settings on a separate page. And the best spot seemed to me to be the first page of the Mechanics section.
Vinyl Cutter¶
Because direct driving the vinyl cutter from inkscape can give unexpected errors, it’s best to control it via mods. Here are the settings for mods and machine.
- Important notice 1: depending on material, the image has to be flipped or not. Some materials have to be cut from the back side.
- Important notice 2: the with of the material is set by the machine from the location of the whit markers on the rulers.
| parameter | value | unit | remarks |
|---|---|---|---|
| tool diameter | 0,25 | mm | because being a knife this is not relevant |
| cut speed | 2 | cm/s | |
| image origine | 10 | mm | select dot for position relative to image |
| tool force | 50 | g | setting in mods |
| pen force settings | adjustment on machine depending on material | ||
| transfers | +1 | ||
| white sticker | +1 |
Laser Cutter¶
The laser cutter has it’s own driver program, which is very user freindly and integrated with drawing functionality.
- Important notice 1: switching on the machine:
- turn on key
- push button for power on
- turn on switch for laser head
- Important notice 2: don’t forget to turn on the suction installation before lasering and leave it on a while before opening the lid when finished.
- Important notice 3: kerf is depending on material and thicknes, but also on Z-leveling and conditions; should be checked if critical; values below are for current status and settings.
| parameter | value | unit | remarks |
|---|---|---|---|
| z-level | 12 | mm | above cutting surface: use gauge block |
| speed max | 10~100 | % | check material samples |
| speed min | deceleration for corners is automatically set by the machine | ||
| power max | 10~100 | % | check material samples |
| power min | 25~40 | % | low speed power for corners |
| kerf values: | |||
| plywood 3,2 mm | 0,08 | mm | |
| cardboard 2,9 mm | 0,15 | mm |
Modela MDX-20¶
Our milling machine has some important settings to remember, so here’s an overview of them.
| parameter | value | unit | remarks |
|---|---|---|---|
| x origin | 18 | mm | depending on position of your outline on the board |
| y origin | 6 | mm | depending on position of your outline on the board |
| z origin | 0 | mm | top surface of a fresh board |
| resolution | 1000 | DPI | check – is sometimes wrongly set by output E-program |
| imported traces | check – to invert or not | ||
| traces drill size | 0,4 | mm | actually 1/64” |
| traces cut depth | 0,05 | mm | for boards with cupper layer of 35 µm |
| traces max depth | 0,05 | mm | equal to cut depth |
| offset | 5 | usually 4 or 5 – for some boards 0 (remove all to board outline) can be used | |
| offset stepover | 0,5 | standard recommended setting | |
| outline drill size | 0,8 | mm | actually 1/32” |
| outline cut depth | 0,5 | mm | generally around 0,5•D |
| outline max depth | 1,8 | mm | > board thickness – to be measured! |
| offset | for the outline no offset or step over is used | ||
| cut speed 2 flute | 4 | mm/s | compare feed in ShopBot |
| cut speed 1 flute | 3 | mm/s | slower feed to reduce forces and avoid rough edges |
| jog z | 2 | mm | compare safe z on ShopBot |
ShopBot¶
2,5D milling
| parameter | value | unit | remarks |
|---|---|---|---|
| VCarve settings | |||
| material | fill in type and dimensions | ||
| x,y origin | 0 | mm | set on front left corner |
| z origin location | 0 | mm | set on bottom of model |
| spindle speed | 6.000 ~ 18.000 | rpm | select milling bit, then edit setings |
| move speed x, y (vf) | 30 ~ 120 | mm/s | edit milling bit settings |
| vf; rule of thumb | mm/s | vf = rpm * number of flutes / 400 | |
| move speed z | 30 | mm/s | edit milling bit settings |
| jog speed x, y | 120 | mm/s | edit milling bit settings |
| jog speed z | 60 | mm/s | edit milling bit settings |
| ShopBot settings | |||
| X-axis | long side of the machine, zero at the front | ||
| Y-axis | short side of the machine, zero at the right | ||
| move ramp rate | 10 | ramp value in shopbot program for acc. & dec. | |
| slow corner speed | 40 | % | percentage from full speed for gentle corners |
| machine x,y origin | 0 | mm | set by machine in homing process |
| job x,y origin | 0 | mm | set manually after writing down absolute x,y |
| z origin | 0 | mm | set with contact plate on bed |
3D milling (moulds)
For parameters not mentioned, see above.
| parameter | value | unit | remarks |
|---|---|---|---|
| VCarve settings | |||
| origin location | 0 | mm | set on top of model |
| ShopBot settings | |||
| spindle speed | 6.000 | rpm | |
| move speed x, y | 10 ~ 40 | mm/s | to be adjusted for rough cut or finishing |
| move speed z | 12 | mm/s | |
| z-origin | 0 | mm | set with contact plate on material |
More advanced program to generate G-code is found in Fusion. It has more milling strategies than V-carve and has also posibilities to avoid specific surfaces or select specific surfaces. You can select a special shopbot post processor, but be aware of the following important limit:
- the G-code specifies a line for the tool number at the beginning, but check if this is a small number, shopbot can give errors if not.
Prusa i3 Mk3¶
In PrusaSlicer, used for setting up the 3D print, a lot of materials are listed with presets for all parameters. Below are just the main ones I used. For Iglidur PF there was no preset, so I derived them from the datasheet found on the manufacturer’s website. On the PrusaSlicer website a lot of explanation and tuning advice can be found.
| parameter | value | unit | remarks |
|---|---|---|---|
| z origin | 0 | mm | set by the machine |
| filament diameter | 1,75 | mm | |
| settings other than below | standard settings | ||
| PLA settings | presets are in PrusaSlicer | ||
| bed temperature | 60 | °C | |
| nozzle temperature | 215 | °C | first layer |
| nozzle temperature | 210 | °C | other layers |
| PETG settings | presets are in PrusaSlicer | ||
| bed temperature | 85 | °C | first layer |
| bed temperature | 90 | °C | other layers |
| nozzle temperature | 230 | °C | first layer |
| nozzle temperature | 240 | °C | other layers |
| Iglidur PF i150 settings | no presets, derived from manufacturer | ||
| bed temperature | 55 | °C | first layer |
| bed temperature | 60 | °C | other layers |
| nozzle temperature | 240 | °C | first layer |
| nozzle temperature | 250 | °C | other layers |
| layer height | 0,2 | mm | first layer |
| layer height | 0,2 | mm | other layers |
| skirt height | 3 | layers | 2 mm from object |
| brim | useful to prevent warp, check Prusa website |
Ultimaker¶
| parameter | value | unit | remarks |
|---|---|---|---|
| z leveling | 0 | mm | follow machine instruction |
| filament diameter | 3,2 | mm | |
| nozzle temperature | 210 | °C | for PLA |
| layer height | 0,2 | mm |
Notes on leveling: the machine will guide you through a 3-point leveling: one at the back, adjustable with the push and rotate button, two at the front adjustable with knurled nuts.