Finished the Motor-Arm CAD design!

1. I started with the cable canal, but I wasn’t sure if I should use a lid or just leave it open. I decided to first leave it open and not design a lid because it would be pretty complicated, increase the weight, and make debugging or modifying the drone harder.

While starting to design the tunnel in the 2D sketch, I noticed a mistake: I saw that the ends of the arms were rounded by mistake.

So I added corners for better next design.

After fixing this, I draw the tunnel which is 3 mm width, because the cable is 2.4 mm.

Then I extruded the canal by 3 mm so that the cables can perfectly fit:

But it didn’t look clean, so for better cable handling I rounded the corners / sides:

• the back line I added a 3 mm fillet
• the side parts I added a 1 mm fillet

Then I continued: I started designing a small part that extrudes from the end of the 2 arms so that I can put an M2 heat insert in it and later screw it onto the base for more stability. But because I didn’t really have a clear plan where everything should be / look like and how all sizes should fit, I first started with a design of how the arm connects to the base and how the PCB and other parts should be positioned.

After I had a plan, I decided to make the height exactly 3 mm because the insert is the same size. I also made it 10 mm long for more stability so the screw has enough space, but also the cable can go into the base without any problems.

After that I also rounded the corners (2 mm) and extruded the hole for the insert, then I copied and redesigned this part on the other arm.

Lastly, I also added an extra height of 0.1 mm to the whole arm to compensate for small errors, for example from the insert.

This session today was nice and I managed to finish the arms! I am happy with the design! In the next session I will start with the base (hopefully also today!).