BoSL Bead Beater
This section shows the BoSL bead beater The BoSL bead beater is a low-cost, open-source, freely available 3d printed bead beater for DNA and RNA extraction. The device can fit with any commercially available portable jigsaw, the 3D-printed components can extract six samples at a time and the bead beating function is achieved by driving the sample through the rapid movement of the jigsaw blade.
Design Journey
Design 1
At the start, the initial design key points are
- Using a screw base and top to hold the extraction sample.
- Connection parts to connect the jigsaw blade and screw base.
Firstly, we made a circular screw base and top with a 64mm diameter and 6 sample placement holes. Meanwhile, a two-piece cylindrical clamp component clutched the jigsaw blade with studs and M4 screws. Then that cylindrical component is connected to the screw base by using two M4 screws.
Results & Findings
For this design, we found that the blade was easily dropped out from the cylindrical clamp component, and the connection parts between the screw base and clamp component were easy to break. Therefore durability of this design was not good. Also, the total length of the design was too long, it causes too much horizontal vibration.
Design 2
Some further changes were made that combined the connection parts with the screw base. At the same time, invert the cylindrical portion under the screw case and decrease the overall length by inserting the blade part into the screw top. The screw base is divided into two parts with the addition of "studs" on the connecting surface in the middle. These two pieces can be combined with "studs" and used to fasten the jigsaw blade with M4 screws.
Also, a hole was carved in the middle of the screw top to ensure that the extension part of the screw base could be passed and screwed perfectly.
Results & Findings
Compared with the first design, this was relatively stable, but the blade still easily fell off. Simultaneously, the side connection parts were too cumbersome, and the overall design was too heavy, which led to horizontal wobble still exists.
