Week 6: Computer-controlled machining

The task for this week is to "make something big". Our toolset mainly includes the 2.5-axes-ShopBot (or the Shaper origin) and a variety of sanders. Our main material is the provided oriented strand board (OSB) with the dimensions of 48"x96"x7/16". After a few days of thinking, I have decided to build a stand for my final project's tube amplifier and speakers.

Designing a speaker stand.

As one can see from the design files, my goal was to make a stand from as fewer elements as possible, with (hopefully) a decently-looking design.

The design of the stand in Autocad

Import of the design to the ShopBot

The design considerations are similar to the ones used for a laser cutter in Week 2. However, unlike with the laser cutter, we did not need to compensate for a laser diameter in the joints. We only needed to specify if the tool needs to perform the outer or the inner cuts. Also, for the finger joints, we needed to place points at the inside corners of all notches, such that the tool drills holes prior to milling. This ensured that the joints will have no rounded corners.

With the file ready, we started the ShopBot. It took around 40 minutes for a cut plus around 20 minutes for initial preparations (installing, fixing and unfixing a board with screws). For this week we heavily relied on a team work, as the tool demands a lot of attention and we had a limited amount of booked time.

The ShopBot at work

After the cut was ready, I spend around 2 hours sanding the parts.

The parts are ready

The audio system stand for my final project is ready!

The parts were finally assembled. From the last figure, one can understand were the (future) amplifier and the (future) speakers would eventually go. Just for a matter of comparison, I have placed my current DIY-kit amplifier, and Week's 4 3D printed object. One could argue that this speaker stand is a little bit to big, on which I would argue that the stereo speakers should be relatively far apart, but also (ideally) approching in the height of our ears location. But regardless, wasn't the goal of this week's project to make something big?

Used/learned tools

• AutoCad

Issues

• No glue or nails were used. However, I will probably glue the board together just in case.
• The stand is not rigid in along the diagonal directions. I could have made the stand smaller and with wider legs.
• Dealing with joints is much easier, if one mills holes at all 90 degree joint corners . Though it was useful, it wasted ~30 minutes of the milling time.

Files

• The design of the stand with Autocad