computer-controlled-cutting

Group assignment:

characterize your lasercutter’s focus, power, speed, rate, kerf, and joint clearance
document your work (individually or in group)

Individual assignments

Design, lasercut, and document a parametric press-fit construction kit, which can be assembled in multiple ways. Account for the lasercutter kerf.
cut something on the vinylcutter

group assignments

for the group assignment of this week we will work on laser cutter machine, the one we have here in the lap is Epilog laser mini 40 wat 24X12

so in this group assignment we got introduced how to use the machine to cut the design that we made using inkscape, there is some steps you have to do it from the pdf on the computer and the other is on the machine it self, so lets start with the one in the computer

computer steps

first you need to save the design from the inkscape program as pdf
then from the PDF click ( file – print ) or simply ( click Ctrl+P ) and choose the printer to be epilog
then click Properties to prepare the machine setting according to the material we are using

as you can see in the picture below is the setting window will show up once you click properties and here i will explain the main setting we need to change

1- Raster : this option is for engraving only 2- Vector : this option is for cutting vector lines only 3- Combined : this option will do both cutting and engraving in the same time, it will start by engraving then it will cut victors. 4- is the dimension of the sheet you are using 5- this option is for auto focus 6- is the material setting this setting we will load it from the advance tap i will explain it next

to load the setting for the material you are using go to next tap in advance, all the material setting was already saved here,

but if this is your first time using the machine and you want the recommended setting for the materials you can download the PDF from Here

now you are done here lets go to the machine and prepare the machine to cut the desing

Machine steps

first we will start by inserting the sheet with the same material and thickness as we put in the computer setting
then click Focus it will enable the focuse mode

make sure you put the focus tool on top of the lens, then using the arrow key move the bed till it touch the sheet

now lets set the origin, but firs make sure you are enabling the pointer light by click Pointer to make it easer for you to sett the correct place.

now Disable the x-y axis by click X/Y Off
now move the lence to your desired location, this pint will be the origin and starting point

once you reach the desired location Click Set Home to ssave the location

Individual assignments

for the individual assignment i decided to do it while helping on of my student in his project.

Press-fit construction is also known as interference fit or friction fit

what is a interference fit ( press-fit ) ?

An interference fit, also known as a press fit or friction fit is a form of fastening between two tight fitting mating parts that produces a joint which is held together by friction after the parts are pushed together.

Tutorial i followed

Press-Fit Construction Tips Make a Press-fit Construction Kit

Determine the base size of a press-fit notch

With calipers, measure the kerf created by your laser cutter. Cut a square, then measure the inner dimension of the hole and the outer dimension of the piece.

then Subtract and divide by two: this is the kerf for that material.

Kref = 0.15

Measure the thickness of the material, preferably with calipers.

the material suppose to be 6 mm but after measuring it with caliper it turn to be 5.84

Use these measurements to draw your best guess for a notch.
I Duplicate the notch a few times and bracket in .15 mm increments and decrement

then make the vector line equal 0.025 to make ready to be cut
i added the number to be engraved to know the dimension quickly

then i loaded the setting for the material i am using which is Acrylic 6 mm

then print it out and test it with the hall on the shape to get the perfect fit,

Cut and test the fit

Create a press fit feature in Inkscape

i followed this tutorial [Here](Create a press fit feature in Inkscape) to create my first press fit

Create a large box Create a smaller box, overlap and place on top (Object, Raise to Top) Center the 2 boxes (Object, Align and Distribute)

and then design a test joint according to the project,

Print and test

FreeCAD

i used freecad software to design the parametric press fit.

FreeCAD is designed to fit a wide range of uses including product design, mechanical engineering and architecture. Whether you are a hobbyist, a programmer, an experienced CAD user, a student or a teacher, you will feel right at home with FreeCAD.

Download

to download the software click here, then click download and choose the version according to your operation system, for me iam using windows 64-bit

Design a project for holding servo motor

First step is to drow the faces of the box, i opened part design woorkbench and created a new body, then choosed the XY plane and created a new sketch, then used the rectangle function to raw the faces

Then changed the workbench to Spread sheet workbench, and created new spread sheet to store my constrain values of the box, i added a vertical fit , horizontal fit ,and scrow size to secure the structure evevn more

Then using rectangle function and created the press fit at hte side of the faces as showing in the picture,
then selected all rectangle and used equal constrain to make them connected together, then applied dimention constrain and used the values from the spread sheet. spread-sheet01

then with the Trim function from the top bar i applied it to all rectangles.

then to make the structure secure i have aded a place for the scows to fit in and make it even more stable, and applied to it the dimention constrain and connected it to the value from the spread sheet.

now its ready to add the servo placement on the structure , the servo is going to fit only on the front face of the strucute.
so i added a place for it in the front face.
were the arrow the servo will fit here, and the x is empty space for the horn of the servo and the arm to go inside the structure.

where arrow is pointing is the place that will go throgh the front face of the strucure , and there is a rectangle at the bottom leg this one is to secure it whith fit acrilic
then exported the file as svg, and opend the file in Inkscape, then added a lable on each face to be able to identifiy it when it be cuted , then saved the file s PDF to prepare for the cut using Spilog Laser cutter.

and here is the result after the cut with laser

and here how the servo should fit in the structure
and then add the servo to the structure

Vinyl Cut

set the machine

Vinyl Cut

the final result

Download

Just Servo [just frpnt](just frpnt.svg) all together