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Fablab Seoul

JIN`s Fab Academy 2018:
How to make almost everything


week8: Computer-Controlled Machining


-Group assignment-

test runout, alignment, speeds, feeds, and toolpaths for your machine

1. My design (umbrella stand), CNC router theory

There is an umbrella stand in Fablab Seoul and it is said that it has been too long.
And it is not pretty and is made from MDF and is vulnerable to humidity.
So I designed a new umbrella stand to suit Fablab Seoul.
Designed to accommodate both long and medium umbrellas.
In CNC case, Rodrigo Instructor gave a total of 200 CNC theory ppt.
So I learned theory, safety, feed, speed, problem, etc. about CNC when I study with it.
Furthermore, I learned press fit, joint, fillet, and `V-carve software`
.


The umbrella case was so old that I made a new design with fusion 360.

At first, the appearance was confirmed through modelling.

I made an umbrella stand about the size of an umbrella.This was redesigned in 2D and parameterized.

Describe the safety of the shopbot CNC. Pull out the feed rate da ta and t . to find the relationship to RPM.

Look for the feed rate and the sweet spots at RPM. Then, they will not break the end wheat nor burn trees. The common mistake breaks, bends, or burns endmill.

They make various mistakes in materials. Materials burn frequently. Reduce mistakes through TIPs

There is a T.I.P. for safe CNC use.

Show when CNC is broken. Let's be careful about Too High added stars. Don't forget the spindle switch! Fillet should be inserted in the vertical area.

The dog bowl is good for the individual. Let's make a joint so that we can do the press fit.

Toolpath will be created by V-Carve.

2. How to Use V-carve and Shopbot CNC Louter

Import the file from V-carve into Import. Toolpath can then be set on the line. This time, only profile and pocket toolpath were used.
When using tool path, you must understand what endmill I use. Then, calculate the Feedrate, Chipload and RPM and enter the numbers well.
The formula is Chipload=Feedraterpm * number of flutes.
I used a flat down cut this time.
So I cut off the plywood and set the RPM at 15,000, I checked how to cut Feedrate-195, 180 and 150
When setting the tool path,
1.Enter a value for the cutting months.
2. Select endmill and enter Feedrate, RPM.
3. Choose from outsitde, Inside, or Onside.
4. Set the Tabs and hold the cut-out object away.
5. Set the ramps to set the cut direction.
6. Calculate.
7. Save the file.
8. Load and cut the file in CNC.


You should always be careful of safety when using CNC. Eye protection must be worn. This is because a chipload or end mill can come to the eye with a broken eye.
And be careful not to get caught in the machine.
How to operate a device
1. Loosen the emergency stop button.
2. Switch it on.
3. Press reset button.
4. Align the X, Y, and Z axes.
5. Load and cut the Toolpath file.
6. Start and press the spindle start button.
7. Listen to the sound and see if RPM and Feedrate are appropriate.
8. Make sure it's hot with your hands when you're done.
9. Check the thickness of the chipload as well.

-My mistake-

Various RPM tests failed. And endmill should have tried an upcut or various fluts, but only use the down cut 1 flute. And because the spindle start button was not pressed, endmill broke. You must be careful with this, or the CNC can be broken. When I cut the test, I worked on the design too small. So it was hard to find the right RPM and Feedrate.


Select toolpath to save the selected file. And cutdepth, endmill, vectors, tabs, and ramps should all be selected.

For endmill, you must enter a diameter, type, RPM, feedrate, etc.

Ramps and tabs must be set up to work well.

There are various safety tips on the CNC machine. Let's make sure.

I worked with my goggles on. Eye protection is essential.

Be careful not to get your clothes caught between machines. You can turn on the equipment by turning the switch button.

Release the emergency button and press the reset button.

Set the x, y, and z axes. Check the temperature of the endmill after the operation.

Check the chipload to ensure proper RPM and feedrate.

Be careful because endmill can break. RPM 15000, Feedrate - 195,180,150

RPM - 15000 Feedrate-155 was most appropriate. Figure can be obtained through Chipload chat.

3. Assemble and complete umbrella stand

Studying shopbot software and V-carve toolpath does not have a big problem using CNC.
But you have to study a lot about the type of endmill, the feedrate, the RPM, and safety depending on the chipload.
Therefore, CNC routers have more knowledge and safety and consideration than using laser cutters or 3D printers.
I worked on the Plywood down with a cut-1 flute at Feedrate:150, RPM : 15,000.
The result was satisfactory.

-My mistake-

Instead, I was thinking of doing press fit, but I had a problem.
There was a problem that had to go in well, not just in the case of the Middle Patz.
So I couldn't take this part into consideration, so I sanded it up. So, my hands hurt too much and my work took longer.
Many things can save time and strength.

Run the Shopbot software and turn on the spindle RPM control. Then it runs at my set RPM.

And V-carve can draw simple shapes and should be given a fillet where it is perpendicular to make no problems.

Import my designMake sure to set any Tabs not supplied above. Then, my work is fixed during cutting.

I cut the cardboard with a laser cutter before cutting it with CNC.Prototypes must be made. That way, you can make fewer mistakes and save trees.

I cut it up. It looks well fixed to the tree.

Here's a problem. I fit perfectly without any tolerance for press fit. It did not go down ... So I sanded that part.

And finally, the finished look.

Make sure to clean up after yourself. This is because Fablab is shared.
We put an umbrella here and have a good use. Success !!

-This week Notification-

This opportunity helped me understand the principles of CNC. And I also knew that I had to consider Feedrate, RPM, and Chipload so I could work well.
And be especially careful about safety.

-Download File-

umbrella stand(parametric).f3d
umbrella stand.dxf
chipLoadChart