7. Computer-Controlled Machining¶
This week I worked on making something big by using CNC machine.
We also check the machine safety and cut test plot as a group work.
This week’s Assignments¶
Group assignment:¶
- Complete your lab’s safety training
- Test runout, alignment, fixturing, speeds, feeds, materials and toolpaths for your machine Document your work to the group work page and reflect on your individual page what you learned
Individual project:¶
- Make (design+mill+assemble) something big
Learning outcomes:¶
- Demonstrate 2D design development for CNC milling production
- Describe workflows for CNC milling production
Group Work¶
This week’s group work page is here.
Individual Work¶
Make Something BIG¶
Basic Idea¶
I want to make a simple stool chair which can be assembled easily. It also can be used as a small table with my final project.
Design¶
- Fusion360
I started designing it with Fusion 360.
I wanted to make almost same design of 2 legs assembled and round seat.
As I designed using several circles which related to each other,
such as 4 circles are all the same diameters.
Parametric values are really useful.
I also think the basic value, such as hight or width of the seat,
are easy to change with parametric value.
By the way, I decided the hight not to high, not too low for sitting and using as a table.
Mistake
I found a mistake: I put one of the “fit part” in wrong way.
After I designed them, all of bodies are changed to components for assembling.
Legs are assembled by the press fit at the center of the legs.
I checked how it works.
As it seems ok,
I selected “project” at the sketch-mode and made 2D design data for transferring to VCarve.
And export this data into dxf file.
- Vcarve
Vcarve is started and dxf is imported into it.
After adjust each place and put tabs.
I tried to put tabs to a minimum.
(→ I should use nest function for putting products more efficiently)
And put “dog bone” at each corner of the holes.
- Setting in Vcarve
| Setting parameters | Value | Tab settings | Value | |
|---|---|---|---|---|
| Start depth | 0 mm | Length | 11 mm | |
| Cutting depth | 16 mm | Thickness | 3 mm | |
| Machine Vector | Outside | |||
| Tool | “Minatomirai Shopbot End Mill 1/4” |
Check tool path and cutting image
- Cutting
Now I put the board on the Shopbot and adjust the position.
End mill Setting data
| Category | Item | Value |
|---|---|---|
| Note | 57-910 | |
| Tool Type | End mill | |
| Geometry | Units | inches |
| Diameter | 0.25 inches | |
| No. Flutes | 2 | |
| Cutting Parameters | Path Depth | 0.125 |
| Step over | 0.1 inches 40% | |
| Feeds and Speed | Spindle Speed | 12000 r.p.m |
| Feed Units | inches/sec | |
| Feed Rate | 3 inches/sec | |
| Plunge Rate | 1 inches/sec | |
| Tool number | 1 |
Through checking the cutting image, put the screws on the board for fixing it.
Because my board is really big and there was no space to nail it,
I get up on the table and screwed them.
Then I put the End mill.
Input C3 to reset X and Y position.
Then 0 position of Z is reset with metal bar after pushing C2.
Check file name and select 3D offset.
Start cutting!
Done!
Then I took out all the parts and assembled it.
What I learnt¶
This week, I learnt how to use the Shopbot with Vcarve. Also made a chair from a design. It was a bit difficult to imagine the design only from the fusion. Therefore I made a part in cardboard.
Problem¶
After assembled my product, the fit is too tight and parts doesn’t fit completely. Therefore I scratched the fitting part a little, it gets smoother.
Research¶
I already had a idea of making a stool.
So I checked the stool over internet.
- Stool Idea
- Pinterest Stool Idea 1
- Pinterest Stool Idea 2
Also I found a stool in Minatomirai lab.
