This will be my 3rd year growing for market. I have been searching for a better way to plant our onions from sets. I have seen the hand held dibblers online but needed a faster way to make the holes (this year we will be planting 6,000 onions).
I designed a hole dibbler to make 1"x1" holes, 1" deep. It is a wheel with inserted dibbles on the outside which can be removed and blank inserts put in to change the spacing of holes. It will make 2", 4", 6" 8" 12" and 24" spacing between plants. It replaces the back wheel of my Earthway planter to make the holes.
Here are a few pictures of the building process. I started with a 8" diameter by 3" piece of 6061 T6 aluminum for the wheel and 3 pieces of 1.5" by 1.5" by 12" pieces for the dibbles.
All parts were machined on Vertical Milling Machines. I then used a sand blaster to remove debris and prep the surface. To finish the wheel I used an at home powder coating gun and a toaster oven to bake it in.