Tangential Oscillating Cutting Knife by luben111

Last crawled date: 3 years, 1 month ago

The tangential oscillating cutting knifes (TOCK) are used for cutting cardboard, rubber, plastic films, etc. They use a sharp edge knife which is moving (oscillating) in vertical direction and in the same time can be rotated to follow the tangent of the curve.
The oscillation of the knife up/down is done through a DC motor from some old ink jet printer, the rotation of the knife is done through stepper motor.
Normally the price of the TOCK is exceeding 1200 EUR and here you can make fully functional TOCK for less than 80 EUR on your 3D printer.
You'll need a CNC machine or router to connect the TOCK head, also one additional axis to control the rotation.
Here you can find a complete documentation how to build such TOCK by using 3D printer.
Video in YouTune showing how TOCK works on cardboard for making boxes (notice the smooth cutting of rounded shapes)https://www.youtube.com/watch?v=9aJhzyOltiY
Attached is also the program which takes PLT and converts it into GCode with the following features:
if the angle of the segment is bigger than some threshold - lifts the head. rotates it to the new angle and bring it back. This improves significantly the cutting quality of sharp edges
the program optimizes the order of cutting segments to minimize the head lift
the program makes possible to do the creasing without changing the tool (the knife was moved down partially and rotated by 45 deg to make semi cut). Lines in PLT file with red color are treated as creasing lines.
The program can also take GCode and add tangential commands
The generated GCode can be executed on Mach3
Oil less bushes are from RS components:http://export.rsdelivers.com/product/rs-pro/ob5812/oil-less-bush-8mm-od-x-5mm-id-x-12mm-l/5217758.aspx
The shaft is calibrated 5mm steel, if using hardened steel shaft it will be more difficult to drill the holes (you'll need carbide drills).
The stepper motor is standard Nema17 42x42x38 or 42x42x48 with 200 steps per turn. technically you can use motor with more or less steps - it's possible to adjust this in Mach3http://www.amazon.co.uk/3D-Printer-NEMA17-Stepper-Motors/dp/B00KS6I58A
I'll add in the next few days more info about some details (like stepper motor, shafts, oil less bushes, etc.), images of the working head and links to video on YouTube - stay tuned!
Adde IGES model of the design in case you can't open the SolidWorks files.
04/10/2016 - Increased limits of feed rate in Software