Molding and Casting

The goal for this week was to make a mold that I could use for ice cubes. The idea I liked the most was making a two piece mold of a football

First I made the molds in fusion, and then I clicked on the manufacture tab in fusion to start generating the tool paths for my mold following the CAM recitation notes. The first toolpath I created was the 3D Adaptive Clearing which is a roughing pass, and just takes away a bulk of the material quickly and I used 1/8 in endmill for this pass.

After the toolpath has been generated you can simulate it, to make sure that the endmill does not cut anywhere that it should not or that there are no collisions

After generating the adaptive clearing toolpath, I generated the parrallel tool path which scans across the top of your print line by line and slowly carves your final model. By default parrallel toolpath only with scan across your part in one direction, but for a better finish I prefer to do perpendicular passes, so I generated a parrallel toolpath that went both in the x and y direction to get a smoother piece. (Also every blue line is part of the tool path, so for the finishing pass takes considerably longer than the roughing pass)

After generating the toolpaths I exported the gcode as a sbp file to use on the shopbot. I then set the origin of the shopbot to the bottom left point on the wax block to be the origin of the shopbot, I inserted a 1/8 in endmill, and I ran the roughcut (shown on the top left). After the rough cut I inserted a 1/16 in endmill I zeroed in the z axis to the top of the material and I ran the finishing pass which came out pretty good (image on the top right). However, their were 2 major problems. First, there were still machining lines because my stepover was too large. Second, the endmill was hitting the walls which was slightly shifting my wax block which also ruined the quality of my wax block

However, in the interest of time I thought I would make a mold out of this block even if it is not perfect, and then come back and get a much better mill for a job that takes less time. I used the silicone rubber that is non toxic to make my 2 part mold, which came out well.

The ice cube cast definitely was not the cast of my dreams, the lack of clarity in the ice cube definitely lost alot of the detail of the football and my ice cube looks less a football and more like melted ice cube

However, we persevere and it is time to make a new mold, and this one will be a self portrait. So for this one I wanted to keep it simple and have a nice and smooth mill. First I figured out the issue I had before with my collisions. When defining a tool in fusion CAM I forgot to specify that the shank of the 1/16 in end mill was 1/8, so I made sure to change that for this time around

Since I had changed the size of the endmill when I generated and simulated my toolpath this time I saw that their was a collision in the walls So I just put them at an incline this time in order for the shank to not collide with my print. I also made sure to decrease the stepover for the parallel tool path

Overall, this lead to a much better final product which I made my mold with oomoo and then cast in the smooth-cast urethane which lead to some good results.