Computer controlled machining¶
Group Assignment¶
Our group assignment involved working with a Shopbot PRSalpha and VCarve Pro to prepare and cut various shapes from wood. The safety training was emphasized before we began operating the machine. We learned to never reach for the tool when it is working, always wear safety glasses and earpads, not wear gloves while operating the machine, and make sure that the part is well fastened to the machine.
After getting acquainted with the machine, we used VCarve Pro to set up the job, including defining the rectangle size of the base material, drawing basic geometrical shapes, setting up the toolpath, and adding tabs. We then proceeded to cut the wood, which involved fastening it to the MDF sacrificial layer using clamps and screws, turning on the machine, engaging the spindle, setting the zero point, and sending the job.
The results of our cutting were not exactly as expected, with deviations from the measurements and a small runout. We learned about the two families of cutting bits - upcut bits and downcut bits - and how they affect the cut quality. Overall, it was an insightful experience that taught us the importance of precision, attention to detail, and safety when operating a CNC router. You can find our Group Assignment here.
Individual Assignment¶
DXF file¶
I decided to make one of Armenian natioanl symbols - ԽԱՉՔԱՐ (Khachkar - tr. cross stone)
Check out this link
I found some images of it and tried to make it vectoric
I am using CorelDraw
After many tries, i couldn’t make it up, and decided to draw khachkar my hand.
It tooks really much time.
After choosing material (piece of mdf) i took its sizes to scale my drawing.
Scaleing.
Then i Exported it as DXF file
VCarve¶
I am opened DXF file and set material parameters.
I rotated cross to make cutting more comfortable.
VCarve has option to connect lines togeather and make 1 line, it is “Join open Vectors tool”
After that i choosed Profile Toolpath, then selected tool
I am using 1/2 inch 60 degree mill, and to cut “ON” the line.
I checked Preview
Yes, thats exactly what i need.
ShopBot¶
I will set my (0,0) position in right upper corner, as i did in VCarve.
I always put material on the wooden parts, not on the table
Then i started to cut.
And its ready.
Closer view on Errors¶
P.S.¶
I didn’t get what i want , so i ordered wood , not to make it from MDF.
So i’ll update this page soon.
Guitar Stand¶
I saw on internet guitar stand for 6 guitars, that worths 1000$, i have 5 guitars, so i decided to make guitar stand like that, but much cheaper.
I will start from designing it in FreeCad.
Design¶
I will use SpreadSheet to make my design parametric, i wrote much more about Spreadsheets in my CAD week assignment
Firstly I calculated what Height my stand must be. I am using pythagoras formula.
I am using parameters to set Height of materials, radiuses etc..
I will use 10mm plywood so value of first parameter is 10.
I tried to design my bottom part this way,
But then I realised that i can make one sector then with “Polar Pattern” tool multiply it
Here i have my bottom part.
I will have details that will connect to bottom part.
Oh, Wrong :(
Yea, like this :)
I have 2 details that will connect to each other, and will conect bottom part to top part.
Top Part.
Also I must add 4 holes in top and bottom parts, to connect them with “height” detail.
Assemble.
Material¶
i am taking sizes of my material to cut it into size of my ShopBot RS Alpha table.
You can see black lines on my material i will cut square with 24 inch size, to fit ShopBot.
I am measuring Chainsaw wall size, to add that size to my lines, so chainsaw goes right way.
VCarve¶
I am using VCarve to generate g-codes for ShopBot.
Putting pieces to optimize material use.
Then i will use “Dog Bones” to cut angles, to make details connect in right way.
Then i made profile toolpaths for cutting inside bottom part.
And Pocket Toolpaths for coneection details.
I added some Gaps to my details, not to break-out from my material after cutting.
Checking Safe Z.
Oh! I forgot to put here 4 profiles that will connect to Height detail))
ShopBot¶
Cutting
You can see gaps
After cutting some details it started to look like what i want.
I am using Towel wood part, to make straight round pieces, i cut them by hand.
Final View¶
That’s it ))) I will bring it to my house and then put photo with 5 guitars)
Files¶
Here is my files for FreeCad 0.19 (or older)
Parts that are connected to bottom part
and Assembly of all.