Assignment #: Shoko's Fab Exploration

#13 Molding and Casting

This week I learned how to make mold and cast the shape.

Assignment

Group assignment

Review the safety data sheets for each of your molding and casting materials
Make and compare test casts with each of them
Compare printing vs milling molds

Individual assignment

Design a mold around the process you'll be using, produce it with a smooth surface finish that does not show the production process, and use it to cast parts

What did I do this week: 1. Group Assignment

The group assignment page - week13

Review the safety data sheets for each of your molding and casting materials
Make and compare test casts with each of them
Compare printing vs milling molds

We compared five different materials.

For details, please see the group page: The group assignment page - week13

What did I do this week: 2. Individual assignment

Design a mold around the process you'll be using, produce it with a smooth surface finish that does not show the production process, and use it to cast parts

Since I use the glass globe for Final Project, I thought it is nice to have a support parts with soft material for the glass.
*My first plan was float the globe, but it seems no time to do it for 1st spiral…So this new part is needed.

1.Test model

Modeling - Fusion

It was my first time to do casting, so I made a small test piece first.
I made the curve surface with the site below:
https://forums.autodesk.com/t5/fusion-ri-ben-yu/ping-mianni-duisurukubomi-dinpuru/td-p/7121074

Parameter for test model

Made a model

Check the cross section

This time, for testing purposes, I set it to 0.35x.
To make a mold, create a box with the size of the wax and select Combine → Cut.

Check the cross section to see if the mill can pass through without any problems.

CutPass - Modela

Modela
Open file, choose “Model” menu and confirm the orientation. And Origin

Setting for Roughing
Tool(blade): 3.18 mm square mill
Set cutting area and shorten the cutting time
Scan Lines X+Y
XY Speed : 20mm/sec

Setting for finishing
Use same tool
Contour Lines Up Out
XY Speed : 15mm/sec

Check time from “Preview Cutting” menu
Time for roughing: 0:12
Time for finishing: 0:21

Output path file from “Cut” menu on right bottom

Milling

Tool: 1/8 SE 4FL EM

Apply double-sided tape to the backside.
Make a mark in the center of the wax.
Fix the wax so that it is parallel to the base of the machine. (Use a ruler, etc.)
Set the XY origin in the center of the wax.
Set the Z origin on the top of the wax. (Use a piece of paper to lower the Z axis until it stops moving.)

Roughing

Finishing

Since it seems still rough, I added finishing path with
Scan Lines X+Y
XY Speed : 20mm/sec

Casting

Use ease release as release agent

Use moldstar 16 fast for casting - mix A and B = 1:1

I keep it for 1 night

I could cast it successfully!

2. Final Model

Modeling - Fusion

From the test model, I adjusted the parameters.
I scaled the glass and decide the number
Parameter for final model

Check the cross section

I wanted to add a hole for cables.
Add hole with “Slot“ form Sketch menu and extrude it.

Since the wax is smaller than the model size, I made the half cut mold.
To make it divided in the center, use the “Center of mass”.

This is the final model for 1st half.

Path

This time I alse chosed 3.18 square mill.

Setting for roughing
Scan Lines = X + Y
XY speed = 20 mm/sec

Setting for Finishing
Contour Lines : Up out
XY speed = 15 mm/sec

To will without leaving any edges, I have to delete margin.
I set margin bottom = 0mm from Modeling Form menu.

Check time from “Preview Cutting” menu
Time for roughing: 2:53
Time for finishing: 1:37

To set tool, I have to check the depth of workspace, and height of wax, and calculate
depth of workspace : 31mm
(depth of design: 30mm)
height of wax: 37mm
→tool length should be between 31-37

Start cutting.
Roughing goes well.

Finisinng

However, while finishing, the wall broken…(for make hole)
It seems the width is too thin.
Since the mill blades go in from the same direction every time, I think too much pressure was being applied in that direction only.