220 Mower - Chassis and Sensors Build Instructions
Lawn Mower 220
STL Files can be purchased here to print
Using a parts slicer such as CURA, the parts should be prepared for printing. I used a 0.4mm print nozzle with a 0.2mm layer height. 40-50% infill. Most parts can be positioned with the flat side on the print bed. Exceptions are the main covers.
The construction of the mower is fairly easy and can be easily done just based on the pictures provided. Here the parts are labelled should you be unsure where a certain print should go.
The 220 Mower has 2 rear cover shelves. These shelves hold the rear cover to in place and complete the part by extending it into the wheel arches..
The 220 Version of the mower has a split rear back plate. This plate is joined together with M3 bolts and locking nuts.
To attach the blade disc you will first need to make the adapter:
The blade disc is then attached with 2 M5 bolts into the adapter. the cutting blades are then attached using the M3 bolts and nylon safety nuts provided in the pack.
Arduino Parts 220 Mower
The Arduino parts are assembled in the following positions:
15mm bearings are pressed into the wheel arches and secured from moving using some screws and washers. The 1:200 geared 12V wheel motors are then fitted into the chasis of the mower using the motor brackets. the 70mm 15mm diameter wheel axle are fitted through the 15mm bearing and secured to the wheel motor using a locking screw.
To attach the rear wheel you will first need to make the adapters . The rear wheels are then pushed over the adapters and fixed with an M4 bolt through the wheel hub (hole provided) into the wheel axle adapters.
Front Wheel Casters & Wheels
The 625ZZ Bearings are pressed into the casters. The casters are then fixed to the frame using flat head M5 bolts through the M5 holes provided at the front of the mower. Spacer washers are required on the M5 bolt to allow the bearings to turn against the frame. An M5 nylon lock nut is used so the M5 bolts dont need to be over tightened. Leave them a little loose to allow free movement of the wheel.
For the front wheels I used 50mm rubber wheels fro the DIY store with an M6 axle. Front wheel STL files are provided but I have not tested them yet...
Rear wheel Prints
Rear wheels were printed with the following settings
Line width 0.8
Layer Height 0.3mm
No support structure used.
Main Cover Prints:
To print the large front main covers I used the flat side of one of the edges as shown here. In CURA I enabled "Support" on and set the "Support overhang angle" to 85% with a "Support density" of 15% which creates a small tower to support the top curl of the cover.
Layer height was 0.2mm and infill 40%
Ensure that the snap rotation is turned off in CURA and rotate the part so it fits onto the 220mm² bed. Also ensure that 'Build Plate Adhesion :SKIRT' is turned off otheriwse the part will print outside the bed.