MiniSumoWiki: AnotherFormulaMiniSumo

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AFC-Chassis-01sml.jpg	16 KB
AFC-Chassis-03sml.jpg	13 KB
AFM-02.jpg	20 KB
AFM-03.jpg	27 KB

Another Formula MiniSumo

AFM conforms to the lowcost FormulaMiniSumo Specification, utilises PICaxeControlBoard with a PICaxe18X controller and a pair of low cost motors and wheels from MURT. This minisumo is still a work in progress, some discussion on the build can be found on the MiniSumo Forum.

The chassis for this minisumo has been cut from a sheet metal case of an old video recorder and bent over the edge of a work bench. The front edge has been folded back on itself and squeezed in a vice, this removes sharp edges. The motors are fastened to a balsa block, which is then attached to the folded sheet chassis. This balsa block will be replaced with steel or brass to increase the minisumo's weight - it's too light at the moment (210g, so giving less that 1/2 the possible push!).

The low cost wheels are doubled up to give extra width. The internal one was drilled to match the shaft diameter of the gearbox and to allow a grubscrew to be fitted for torque resistance. The tyre has been made by smearing the outer edge with silicon gasket sealant, in this case Loctite 5926 Acetoxy silicone.

Reflective IR Edge Detection uses surface mount components on a simple hand drawn PCB, permanent marker directly on to the copper board. The part was a Sharp GP2S27 (now discontinued), the basic IR Edge Detection circuit info can be found here.


These pictures show the modifications to increase the overall weight. The underside has two plates 25x4mm and 25x2mm cross sections, the thicker of the two has been tapped for M3 for direct fastening. The block on the topside still requires it's fixing hoes, it'll replace the current balsa block.
	With the holes drilled and tapped for the mounting the gearbox, and a lick of paint the chassis is finished. This picture shows the gearboxes back in place with PCB carrier fixed to the top of each. With the control board and battery back in place and the sensors refitted the total weight comes to 499g. This is a little close for any modification to the sensors or tyres but could be addressed by a hole or two in the mounting block.

Opponent detection is still being finialised.... more info to follow.

Links:

MUTR (Middlesex University Teaching Resources) - http://www.mutr.co.uk/

Loctite (Henkel Ltd) - http://www.loctite.co.uk/

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