Week 12: Molding and Casting¶
This week I molded and casted a two part mold of a ring. First I chose my materials, The smooth on Moldstar 16 Fast for my mold, and Task 8 for my resin. I would also be milling from our labs Bantam Tools Desktop CNC with wax. I used fusion 360 for my designing software.
Fusion¶
In fusion I designed my ring by creating two circles then I extruded the outline. Next I added a small diamond like tip for texture, this would also act as my pour spout. Then I created a box the size of my wax, and used the combine feature to combine them. Then I created a sphere 4mm in diameter on the corner. Then I did a rectangular pattern to make the spheres appear in all four corners.
Next I Opened the manufature Workspace and selected added a new tool library, this library has the correct bits for machining wax. I used the 1/8 in rounded bit. I created a new setup with a relative size stock with a 0mm offset. Next I created an adaptive clearing toolpath with the 1/8 in rounding bit. I used the standard settings. Here is what the toolpath looked like.
Next I created a new nc program with the bantam tools post processing.
Milling¶
The first thing I did to mill was get a piece of wax in my lab. Next I applied nitto double sided tape to the bottom of the wax and stuck it on the bottom left of the mill.
Next I opened the bantam software and uploaded my file. Then I setup the material by measing the block of wax with calipers. Then I selected the tool as a 1/8 in round bit and I zeroed the tool from the bed.
Next I started the toolpath and waited for it to be done milling. Once it was done milling, I vaccumed the wax shavings.
Casting my Mold¶
Then I casted my mold, I used smooth on moldstar 16 Fast.
I poured 30 ml of parts A and B into seperate cups. Then I added part B to part and and gently mixed for a minute, Then I let it rest for another minute for the bubbles to rise. After that I poured it into the wax and waited 30 minutes, the cure time. Then I pulled the mold out of the wax mold and did the same process again until I had 2 molds.
Casting the Ring¶
I casted the ring with smooth on task 8.
I Prepared the mold by rubber banding the two side of the molds together.
I prepared the resin by adding 30ml of part A and part B to seperate cups then I poured them together and mixed gently for about a minute then I poured it in the mold.
After the ring was done curing, I pulled the molds apart and pulled out the ring.
Then I sanded it since there was a small amount of spillage. This gave me a great looking ring.
Finishing Pass¶
Initially I forgot to do a roughing and a finishing pass. So I went back to my fusion design, fixed the bits, and added a second toolpath. First I fixed the first toolpath to have a 1/8 in flat end mill rather then a ball nose. Then I created a new Parallel toolpath with a 1/8 ball nose for finer details.
I then did the same process of creating a nc program to mill out the wax. Then I opened the file in bantam tools, inserted the 1/8 flat end mill, and milled the roughing pass.
Then when directed I changed the tools to the 1/8 in ball nose and did the fishing pass. This is how it turned out.
This week’s files.
In this weeks group work I went through the datasheet for Moldstar 31T. I found its cure time, pot life, and some of the safety warnings for it.