Strong pivots can be achieved using structural elements such as channels and axles. This section shows one way to make such a pivot.
1. Determine where you need to place the pivot. This will be the center of this pivot configuration. Count over three large holes to one side of the center. With two 5/16" SHCSs, attach two stand-off posts on top of the chassis so they are parallel to each other (Figure 1). Whether you use 1" or 2" stand-off posts depends on how tall you want the pivot to be.
2. Now, count three large holes to the other side of the center. Attach two more stand-off posts of the same height as those in Step 1. They should be in holes parallel to the first pair of posts.
TETRIX® Tip: Y connector
The Y connector can be used whenever you need two servos to work in tandem.
3. Mount a single-servo motor bracket on top of one set of stand-off posts with two SHCSs – make sure the bracket is attached so the servo faces the center. Remove the horn from the servo. Place the servo into the bracket so the servo shaft is centered with the channel piece on which the
bracket is mounted. Secure the servo with four SHCSs and kep nuts (Figure 2).
4. Using 1/2" SHCSs, attach a set screw axle hub to the outside of a 32 mm channel piece (Figure 3a), but do not tighten them all the way. Insert
an axle into the hub so it is flush with the outside of the hub. Turn the axle so the set screw faces the axle’s flat side, and tighten the set screw.
Note: Take care not to push down on this piece as it is connected to the servo.
5. Attach any structural element – such as a tube – to the top of the 32 mm channel piece at this time. On the side opposite the set screw axle hub,
attach the servo horn to the outside of the 32 mm channel piece with four 3/8" BHCSs and kep nuts (Figure 3b). Attach the side with the horn to the
servo on the bracket and secure with the servo screw (Figure 4).
6. Find the second piece of channel you want to use. Another 32 mm piece is good if you don’t want it to extend over either side of the chassis channel (Figure 5). Alternatively, a longer piece can be used to reach the other side of the chassis and be another part of the construction (Figure 6).
7. After finding the piece you want, place a bronze bushing into a large hole where you intend to place the axle.
8. Push this side onto the axle. Before pushing it out the other side, place an axle set collar on the axle. Then, push the piece until the channel piece holes line up with the two stand-off posts beneath it. Use two 5/16" SHCSs to attach the channel to the posts. Push the set collar against the bushing and tighten the screw (Figure 7).