Materials:
- a brush cutter with an unnecessary bar;
- adapter for SDS+ cartridge;
- drill chuck;
- self-priming mini pump - Ali Express (http://ali.pub/3iab6g);
- sheet metal;
- thick plywood or OSB;
- thin hose for supplying gasoline;
- sealed water tank;
- sprayer boom;
- hose for pump fittings;
- perforated tape.
Motor sprayer assembly
The pump was ordered in China Ali Express (http://ali.pub/3iab6g). It is specially designed as an attachment for an electric drill or screwdriver.
The motor of the brush cutter will be used as a power drive for the pump.
To connect them you will have to damage the rod and the scythe shaft. They are cut as short as possible.
An adapter for the SDS+ chuck is welded to the shaft trim.
A drill chuck is installed on it.
The shape of the brush cutter engine does not allow it to be mounted compactly. To fix this, you need to remove the tank.
Now the motor can be mounted on a board made of plywood or OSB. To mount it, 2 brackets are cut out of sheet metal. They will be fixed in front on the gearbox screws and behind on the starter. The cut brackets should be welded to a base made of the same metal.
A welded rack for the engine is attached to the supporting shield and the tank is attached with two bolts. Since the original fuel line hoses from the tank to the engine are no longer enough, they need to be replaced with longer ones.
The pump shaft is clamped in a chuck on the rod of a fixed motor. The pump itself must be fixed by pressing it with a bracket or screws to the shield. Before doing this, you should place a piece of board or block under the pump so that it remains in the same plane with the motor shaft.
Now you need to put the water tank on the shield.
To hold it in place, a shelf is cut out of the same sheet metal and bent under its bottom. The tank is installed on a shelf and additionally secured with a piece of perforated tape.
Now you need to connect the pump inlet and the tank with a hose. The second piece of hose is placed at the pump outlet and connected to the sprayer boom.
To be able to attach the sprayer to your back, you will need to attach straps to the back of the shield.
The proposed manufacturing option for a motorized sprayer can be used as a concept. This is a fairly simple design, made in haste. If you have an old bent forestay from a brush cutter that you don’t mind sawing, then a homemade sprayer will cost less than a purchased one. At the same time, the engine itself can be installed and removed in a couple of minutes, so it can continue to be used on the lawn mower.
