G-code generation - PyCAM and OpenSCAM

PyCAM

Install and open PyCAM. Open DXF file.

Remove unused tools, set your tool diameted – 3mm in this case.

Leave only Engraving proces.

Set Max. Step Down = how much material – 0,5mm in this case will be removed in one pass

Engrave Offset = Tool Diameter/2 – 1,5mm in my case because tool was 3mm

Set lower margin for x,y - 5mm

Set upper margin for x,y – size of outside dimentions + 5mm

5mm because cutting tool has 3mm, so 2mm as buffer.

Set Lower Z=-3 – material thikness in my case was 3mm

„Move model” Lower Z=-3 – material thikness

Model Extension – enable supports

Press „To Origin”

Press „Shift”

Press „Generate All”

Press „Export All”

 Preview in PyCAM

 OpenSCAM

Simulation in OpenSCAM - Start

Simulation in OpenSCAM - End

Little nail - concept

Several times I have suffered because lack of milling machine in my little toolshop. A few month ago the time came to change this. Requirements were quite simple:
- it has to be relatively small - ~50x50x50cm
- it has to be quite powerfull - mill alloy and be able to handle steel at low speeds
- it has to be CNC machine
- it has to be cheap - round 500 euro

Components:

- used base from old, very good Polish drill WS15 - very robust and heavy with M14 mount holes and t-slot, weight ~30KG: price 50 euro

- brand new cross table from China - Range X = 100, Y=201, weight  36KG, price 150 euro:



- new 2 x stepper motors - nema 23, 3NM price 60 euro, used 1 x nema 23 1.8 NM Price 10 Euro:

- right from China CNC Kit 3 Axis Stepper Driver Controller TB6600, price 45 Euro:

- used Kress spindle 1050 FME, Price 60 Euro

- metal case with 2 din rails, 314x396x130 mm, Price 20 Euro

- used HP terminal 512MB ram, 1,2 GH CPU, usb stick as harddrive and lcd screen 17' price 30 Euto

- power supply 24v 4.2A

- pulleys and belts htd-5m - 2xPulleys 14 5M 15,   2xPulleys 28 5M 15, Belt HTD 450 5M 15, Belt HTD 375 5M 15 Price 25 Euro

- alloy column PA6 80x80x450, and plates for Z axis, lead screw 16x4,... - 80 Euro

- screws, linear roods and bushings, buttons, cables, ,...