Redesigning The Steering Mechanism

One of the trickiest parts to setup on our 2019 Pi Wars robot was the articulated steering, there are a lot of aspects to consider and very often if you adjust one aspect, it has a knock-on effect to rest of the steering components. It took a lot longer that I would have liked to get the steering dialed in, but we did manage to get it to a level that I was relatively happy with. So for 2020 we're not changing a lot in this area (if it aint broke etc), but there's always room for a little improvement.

We're sticking with the same size gears as we tried a number of different options before and these seemed to work out best for us, but we are moving the steering servo from the back to the front and now mounting it on same section as the wheels (the bogies?).

Relocating the steering servo has presented a few extra challenges though, it has altered the steering geometry and there seems to be a little extra play in it all, but we're hoping that the change in geometry will be sorted in the software tuning and the extra play will be solved with a redesigned servo mount.

When designing components, I always try to consider how these will effect neighbouring components and also consider if it's beneficial to integrate them in any way. By moving the servo mount to the front of the robot it makes sense to also use it as the front accessory mount too, that way accessories such as the Pi Noon adaptor or TOF sensors can be mounted and removed with ease.

 

Unfortunately the first servo mount I made for the 2020 robot was located in a way that seemed to allow the acrylic sheet to flex a little and it looks like this is where most of the extra play was, so the mount has been extended and reinforced in the hope that this tightens it all up.

Above is a picture of the 3D model and below is it being printed, in fact it's being printed as I write this.

We'll find out in a future post if this worked out or not.

 Update: It printed just fine and looks like it will work quite well.

 And here is it fitted into the prototype chassis.

It's solid now and has given a really firm base to fix all the front mounted accessories to.

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