HGA newsletter – August 2011
Anyone who has used one of the popular blow/vac machines will appreciate that they blow far better than they suck.
With this in mind perhaps it would be worth trying to blow our nuts onto a tray rather than try to suck them up through a tube.
The Stihl 600 is a backpack blower. It has a four-stroke motor and produces a tremendous controllable blast which is ideal for shifting nuts on rough ground or in long grass, and it has no problem working nuts in damp conditions. This seems the ideal basis for a low-cost harvester.
To keep the weight as low as possible the tray frame was made of aluminium angle and joined with pop rivets. The bottom and sides are 10 mm galvanised netting (Mitre 10). Two hinged wings guide the nuts onto the comb, increasing the effective length of the tray.
The nuts and leaves ride up the comb fingers while any earth or smaller pieces are blown through the teeth and remain on the ground. An occasional blast along the tray floor blows the leaves up the plywood sheet and over the back, leaving relatively clean, earth-free nuts.
When the lift arm in the front is raised the rear wheels retract, the tray rises from the ground, and the whole assembly is easily wheeled up the lane to the next three or four trees.
This is a one man operation, although we usually use a golf cart (or could equally well use a ride-on mower) with a pivoted arm with which the driver raises and lowers the tray. This latter speeds things up considerably.
The tray is emptied by simply rolling it on its back onto a plastic sheet (Warehouse). We empty the sheets into a trailer and run the nuts through a farm made cylindrical dresser and into onion bags.
This was an experimental prototype so we were surprised how quickly and effectively it coped with our one and a half ton harvest, and we plan only minor modifications for expected increased yields. Compared with the commercial suction harvester we used in the past it was very much faster (especially with heavier crops) and produced much cleaner results. Only basic tools are required to make the tray.
If anyone is interested I am happy to provide further details:
lyddington @ xtra.co.nz