Our sensors and batteries need to be secured to our Spot:Bot's chassis somehow.
The sensors are required to be located and oriented appropriately. For instance, the distnce sensors must be front and side facing and the motion sensor should be flat on the chassis and facing forwards.
More importantly, we must find space on our chassis for the motor battery pack and a way of securing it such that it doesn't fall off in the rough and tumble of competition day. Actually, those batteries are quite heavy and liable to destabilise the robot if placed at either end so we should probably find a way of siting them centrally for stability.
We decided that we wanted to try and make use of the holes in the carpenters blocks as mounting points for the distance sensors (why look that particular gift horse in the mouth?) but we weren't so sure of what could we do to secure our battery pack?
Armed with the following parts, we decided to knock up a basic prototype for our proposed solution for distance sensors mounting:
2x carpenters assembly joints
2x M4 x40mm bolts & nuts (vertical chassis layer mounting)
2x M2 x 19mm bolts & nuts + M3 washer (sensor mounting)
2x 4mm ply offcuts (representing the two layers of our chassis)
Then on to the battery mounting solution. Using the same offcuts of ply, we wondered if we could cut a hole in the top layer just big enough to stand the battery pack inside it.
The following Tweet shows what we finally came up with.
What did we learn from this experiment?
Well... for the sensor mounting we needed the M3 washer because, without it, the M2 bolt would simply have fallen through the holes of the carpenters blocks.
We decided that what we really needed was a casing for the sensor with much larger holes (M4 perhaps) that would allow us to use more substantial bolts to secure the sensors to the carpenters blocks with. More on that in a later post.
Regarding the battery mount solution, we must say that we're rather pleased with the results - it is both simple and effective. We definitely think this idea will make it into the final design.