Project Summary:
This project involves designing a box to hold dental retainers in a dishwasher. This is related to two group members’ capstone project, which is testing different materials for a dishwasher-safe retainer. This box will be able to hold 1 retainer, withstand the harsh environment of the dishwasher during repeated use, and protect the retainer from other objects inside the dishwasher. The first print used an Ultimaker with ABS as the box material due to time constraints, but our final product will be printed using SLA. The material that will be used is the “high heat” material in the makerspace, which should withstand the high temperature reached during a dishwashing cycle.
First Print:
- Design Changes:
The original solidworks file was a container designed with 2 compartments and surrounding meshed walls. These meshed walls were designed for water to penetrate and carry out the regular cleansing cycle. There was one open side that was left untouched as the exterior wall with hinges was supposed to go there. Before 4/3 I had not had the hinge system designed.
For printing, we hoped to use SLA with the “high heat” material available by the MakerSpace. However, the file was too large for the SLA machine to print with the regular generated supports. We were able to fit it in the SLA machine but the print time was about 22 hours. Knowing that our print time was to be under 8 hours, we tried to use cura and see how long the Ultimaker S3 would take with PLA material and breakaway supports, which turned out to be over 1 day. It was then decided to shrink the volume by ½ for the prototype. Cura allowed us to shrink the dimensions of the x, y, and z axis. This brought our print time below 8 hours, coming in at 7 hours and 50 mins. We figured this would be a great starting point for us.
As no one in our group has ever had any CAD experience, nor any 3D printing experience, a smaller prototype that costed less and took less time to make was ideal. This prototype would give us an idea of what would work, what needed improvements, and if our design was even feasible.
- Results:
The prototype was printed on the Ultimaker 3 with Cura slicing software due to the time constraints mentioned previously. It was printed with PLA material. It took 7 hours and 50 minutes. It only caused $4.50, which is extremely feasible for a prototype. Breakaway was used as a secondary material for the support structure. The first print went okay. The meshing for the top and bottom were sagging because of lack of supports. We believe our final print, using SLA, will fix this issue. The rest printed well. This project does seem feasible and something we can continue on.
We tested the box in the dishwasher to see how it reacted. It held up well and there were no visual defects or deformations.
Next Steps and Further Work
- Post First Print:
Since printing, some changes have been made. The solidworks file was modified. We decided to only take one half of the container, so that it can only hold one retainer in it, but still carry out its intended functions. Cutting it in half was able to decrease the print time in Preform for SLA by 11 hours. The next print should only take 11 hours, which is under the 12 hour mark set for the final print.
As of April 3rd, the solidworks file was further modified. The meshings were all centered and enlarged, with the hope that less material will decrease the print time further. Also a real meshing system was used for the top and bottom of the box which also will decrease the amount of material needed, again intending to decrease the print time. The containers open face was extended by a ?” on each corner and an arc sketch was used to extrude and round it off. A circle was extruded through both with a diameter of ?” for a rod for hinge system. The exterior door was also made with the same dimensions as one side wall which was 3.5” x 2”. The same meshing was applied to this and the top corners were extruded cut to fit in between the containers hinge system. That side of the door was also rounded off and a hole with diameter .135” (a little bigger than ?”) was made through it to match the hinge system but also leave some tolerance for a rod to fit and it to rotate on the hinge without friction being an issue. The meshing of this door was dropped down and centered to look clean. These parts were added into an assembly to see their fit (mate tool). These changes should allow us to print in the time allowed and have a working part.
- Future Work:
For future work of this file, a decision must be made on the rod that will complete the hinge system. A rod can be easily be made in solidworks and printed to fit, however this may add extra print time we might not have. Another idea is to use a metal rod with ?” diameter to fit and glue it to the hinge system of just the container and so the exterior door could swing freely. We also need to decide on a locking system to keep the door closed during dishwashing. This is something we still need to learn how to do in solidworks. After the next print, assuming it goes as planned, we should be able to test the container with our retainers made in our capstone project inside of a dishwasher to see how it works and how well it weathers the environment.
Special thanks to Clayton for helping with meshing designs and showing us how to use linear patterning. Also, special thanks to all the makerspace employees for helping the printing process and using cura and preform.