When I applied power to the motors on Zeetah VI (ZVI) for the first time, the motors seemed to struggle and the PWM value to get the wheels to rotate seemed higher than usual. Since this was my first four wheel mouse of this configuration (ZIV is a four wheel drive, four wheel steer mouse), I wasn’t sure if the higher load was normal or not.
These new soft tyres are so soft that it is difficult to get them onto the wheels without stretching them way out of shape. No matter how hard I try, they still run unevenly. Some of that is due to the tyre itself but mostly it is just a question of trying to spread the tyre evenly. After several attempts, I gave up and decided to make a small tool to help me with the job…
That was quick. One of the new sets of tyres just arrived. They are the PN racing 8 degree slicks. I ordered them 3 days ago from Kenon Hobby in the US. These tyres certainly are soft and sticky so I put a pair straight on the test rig and compared them to the tyres I have now. They seem to have about 20% more grip than the current ones. This was encouraging so I mounted them on the micromouse. That is when the first little issue came up…
It is true, I am losing my grip. A while ago I posted a link to a Japanese site demonstrating the grip available from a particular micromouse. A common way of doing this is to lock the wheels and place the mouse on a tilting surface. As the slope of the surface is increased, the downforce available to the tyres is progressively reduced until the mouse slips. Part of the downforce is lost due to the angle alone and is proportional to the tangent of the slope.