Central Housing Tube

The central housing tube easily prepared for assembly. After the tube had been received from Rock West Composites it was measured so the dimensions of the blade housing, Makita housing, and aluminum set rings would accommodate the tube (the dimensions of the tube were different from the website values). The tube was then cut to the length of 31 inches as specified in the design phase. There was a concern that the tube would fracture when cut with the saw in the stock room in the machine shop. The tube did crack, but it was only a surface crack.

Aluminum Set Rings

After the tube dimensions had been verified and drawings had changed, the set rings were made from 2 inch round 6061 aluminum stock on the manual lathes at the Central Washington University machine shop. The inner diameters of the rings were then sanded so the 3M DP 420 Epoxy could be applied, and the rings were then pressed on the tube. After curing overnight, the central housing tube was finished. There were no manufacturing issues when making the rings or setting them onto the tube.

Blade Housing Construction

The blade housing pieces were manufactured on the CNC mill in the machine shop at Central Washington University. These pieces took the longest to machine at approximately 25-30 hours for both of them. The only manufacturing issues that were encountered during the machining process coding issues. After a couple of broken tool bits and the team brushed up on their CNC coding, the pieces came out 100% in spec. The second blade housing piece was made as a result of the first blade housing piece failing. This piece took less time to manufacture because only the necessary cuts were made.

Makita Housing

The Makita housing was the easiest part of the pruner to create. Initially the Makita housing pieces were to be made from 6061 aluminum but due to time constrains the team ran some quick calculation and determined that 3D printing the pieces would be the best option to save time and still have a working product. For both pieces the 3D printing time came out to be approximately 16 hours. The team will make the housing pieces from aluminum in the future. There were no issues when 3D printing the pieces. However, the Makita housing pieces are beginning to crack do to the Makita moving slightly each time a cut is made.