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Computer-controlled Machining

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Project Undercoding

 

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Some of the examples that we made in teamwork with Luiz Bueno, is the work with the table for exhibiting my textiles in the Heimtextil event in Frankfurt:

Kerf Bending

I love the Kerf pattern, and it was my intention to use and experiment with this woodworking technique! The experiments in the third assignment gave me an inspiration for new parameters in Kerf bending. Some of the recommended websites from Ferdinand.

Kerf Bending References

https://es.pinterest.com/pin/385761524302456944/

http://fab.cba.mit.edu/classes/863.13/people/dipinoch/week4.html

http://www.gedankensuppe.de/kerf-bending-patterns http://obrary.com/products/living-hinge-patterns

http://fabacademy.org/archives/2015/eu/students/micalo_farroni.laura/index.html#CNC

 

Recommendations from Ferdinand:

Make the model in a small scale! Test the joints and clearance before cutting the whole design.

Don’t use MDF for Kerf bending, because it breaks easily. It is better to work with plywood.

 

Trial pattern:

In the beginning of the week, I did the design of a small part of the pattern, cutting it in the CNC mIlling machine.

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Modelling The Lamp

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Design of the lamp:

It was the first time I used 360 Fusion for designing a parametric pattern. It also permits the parameterization of the workflow in an efficient way.

I had heard a lot of this software from the Enabling the Future community.

 

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Symmetry

began with the modelling of the legs of the lamp, making the calculations symmetrical. In this part you can see the symmetry of the legs.

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Change Parameters

In addition, the measurements like the length and height of the lamps legs can be modified and saved in the option “Change Parameters” by changing the measurements. The software will adjusts the model automatically, (if it has any collisions). Modify > Change Parameters, in this panel you can find all the parameters of the lamp and personalize your own lamp.

As you can see, in the lower part of the software you can find a timeline. With this feature you can easily modify the parameters and the actions in the objects.

 

 

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Second Leg

For making the second leg, I copy and paste the leg rotating it 90°.

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Copy Properties

In this case, the copy will maintain the first parameters of the main piece, but after this point of the timeline it will work independently.

 

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Sketch lamp shade

 

 

 

 

 

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Symmetrical Extrusion

For making the lamp shade, I did an symmetrical extrusion of the head in order to have the lamp in the center, between the joint of the legs.

 

 

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Parameters

Distance: you can change this messurement in clang parameter La!

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Joints

With these three pieces I could proceed to making the joints for the pieces. First, making the joint of the legs, go to the command Sketch > Project. You can project and make the same sketch. Afterwards, I proceeded to making four tabs for the legs and the negative union in the lamp, and also the dog bones.

  

  

I did the round corners for the legs with the command Modify >Filet.

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Dog bones

In places that have 90° angles in the design, dog bones are a necessity. You obtain dog bones by adding drill holes with approximately half the diameter of the milling head, their midpoint being the corner of the 90° angle. With dog bones, you allow the milling head to change its direction at the right position when it is already within the work piece.

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Main object for the Pattern

I did the sketch of the bending pattern, projecting a plane in the top part of the surface, and drawing a rectangle. Also, when you project a plane you will see that the program generates the sketch of the solid parts. You can convert these lines to construction lines. The thickness of this rectangle is 8 mm, in order to leave enough space for the 6 mm drill.

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Extrusion: substract

After doing this, I extruded the pattern on the head leaving a thickness of 1.5 mm. I used a plywood of 12 mm thick and clearance of 0.1mm.

 

 

 

 

 

 

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Pattern Path

I used the pattern path to do the pattern of the bending form. It is in the Create Tools menu.

 

 

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Assignment

IMPORTANT: You have to select the faces, the features, or the objects. In this case I selected the faces and I repeated the pattern 99 times.

 

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Assignment
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small pattern
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messurments
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Assignment

Distance : I closed the path (you will see that the arrows are together) until the two lines were overlapped (this distance is important in order to do a flat pattern) Distance Type : extended Direction : Symmetric Orientation : Path Direction.

 

cutting pattern

After this is finished, you can close the path, and project the interior line for the cutting pattern of the acrylic part of the lamp.

Design of the pattern: doing all the work for nothing !

It was a guidance to generate the pattern of the final milling data. I did the shade of the lamp with the same measurements that I extracted from the pattern path. I integrated in this part of the pattern the joints making an offset of 0.1. With the same measurement, I proceeded to export the pattern of the lines and holes as DXF, as you can see in the image.

 

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Rhino Edition of the data

IMPORTANT: Try to work clean in the construction of the sketch avoiding editing the lines in Rhinoceros.

We work with the original CAM processor for the machine, which requires DXF Data. IMPORTANT: Make sure, that the lines and polylines are joined together. Otherwise, you have to close the lines in Rhino using the command Join.

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Separation of the layers

The interior areas and corners can not be narrower than your bits (in my case 6 mm), otherwise you have to use the dog bones. I tried to leave more in order to avoid conflicts in the cam processor. Separate the layers with the lines for each job. Always save your data in DXF, which is compatible with the Cam Processor for the E(SIGN machine software.

 

 

CNC job

http://www.elsign-cnc.com/ This machine is very robust. It's working area is big 2600 x 1400 x 300mm. In this assignment, we worked with the cam processor of the machine, the e(sign CNC 4.0.1. The machine allows four alternatives for tool paths: pocket, offset (inside or outside cut), engrave (cuts centric) and drilling. Our colleague Karsten Nebe wrote a very good tutorial on the e(sign EasyWorker MasterPro 2513 milling machine . For more details, please visit his website.

If you want to see the new features of the milling machine in our lab you can visit this small presentation with the new changes of the machine in the following presentation.


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Machine Homing

The first thing, that the machine will ask, is the reference of the Homing.

In the Button AUTO you will find another submenu you will find the Button LOAD, With this button you can upload the data. Afterwards you can go to the CAM processor .

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Assignment

n this you, can check the layers and also before beginning the work, please align all of the layers to the “LL”, left left ! Select the layer that you want to edit, and select the method: in my case I did all of those as offset method but in different depth. In the first part.

 

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test

parameters of the first test

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Result of bending pattern

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parameters of the offset and "pocket"

I used the same parameters , only the Z End is until 2 (mm)

Considerations

I did the offset job of the inside draws, meaning the bending pattern. This process could take up to 10 hours, nevertheless, it took only 6 hours, because I set the feedrate spindle to 200 of the milling process. Unfortunately, I didn’t know in that time that the drill bit that I was using was special for finishing, I broke two drill bits during this exercise. The second time I tried to do all the possible to finish the models !!! Other consideration was with the extraction of the pattern, the plywood began to loosen, and I had to use some screws, in order to fix the wood onto the working surface. Another problem with the machine was, that the motor in a quick start didn't achieve the necessary revolutions per minute, and stopping the job, in this case could damage the bit.

Results

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Assignment

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Assignment

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Assignment

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Assignment

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Conclusions

A wonderful exercise, but unfortunately still not finished. Because the wood sheet moves a little bit, I had to adjust the whole pattern which can be a little bit tricky. The lamp is pretty huge for my home, but I am still really happy that I did this pattern, and it gave me a lot of ideas for applications in furniture design. Amazing assignment !!!

 

FILES:

Lamp: Lampara 360 Fusion

Test Kerf Bending: .DXF, .3dm, dwg,

Shade Lamp : Lamp Head.dxf , Lamp Head_Offset.cnc Lamp_Head_ Engrave cnc

Legs: muestrita.dxf