Precision Tine Cultivator
Skills needed: Simple metalworking (welding steel, or finding someone who can); also available commercially with an Allis G belly mount from Roeter’s Farm Equipment, but their version may not be optimized for your application.
Summary: Tine weeders, like those built by Lely or Kovar, are often used on vegetable farms for cultivation of transplanted crops or sturdy direct seeded crops like corn and beans. Usually they are used “blind” (see video), raked over a crop while being pulled behind a tractor, and therefore their use is limited to those crops that can tolerate the “raking” action of the thin, flexible tines, spaced 1.5″ apart.
This project creates a version of the tine weeder that can be belly-mounted to a cultivating tractor, so that individual tines can be lifted up so as not to engage the soil. This allows the tool to be used in between rows of crops that cannot stand the raking, such as just-germinated small seeded crops like carrots, beets and greens.
This is a good tool for a smaller farm that cannot afford many different types of cultivators; it can be used for many different crops, however by itself it is not an ideal cultivator for all crops, since it is not aggressive enough to kill more tenuous weeds such as perennial grasses, velvetleaf, bindweed, or weeds that have established beyond a “white thread” stage. Horsepower requirements are very low.
How to build it:
This article focuses on building a tine rake to belly mount on an Allis G tractor. Of course, if could be modified to be used on a different tractor. Depending on your Allis G’s wheel spacing, and whether you have spacers on the front that give you a longer wheelbase, it may be tricky to design your frame to fit your particular tractor’s dimensions. Be careful to leave enough room for the front wheels to turn. Also be aware of the placement of the mounting brackets for the frame and their relationship to the tine brackets. A non-obvious design feature of the frame is the separation of adjacent tines. The tines need room to wiggle and let trash and plants flow around. The only place there are two tines mounted together is in the center. These are known to be problematic and are the most likely spot to clog and dig small furrows in poor conditions. I have not figured out a better solution so they remain paired, one can be raised if they are creating a problem.
The Lely tines and brackets each cost about $15- pretty pricey for not a lot of metal, but there aren’t many other options out there. Market Farm Implement in Pennsylvania seems to be the best source – they use the tines to build their Williams Tool. If they don’t have them in stock they could take several months to order. Another option is to find a used Lely and strip the tines and brackets. The tines should have a good 3-4” plus of wire after the bend. They do wear down over time.
Building the frame: Here is a 3D model of the frame that I built, as a Google Sketchup file. The frame is built from 1/4″ thick steel: 1 1/2″ angle iron and 1 1/2″ flat stock. The front and back rails for mounting tines are angle (with the L facing the back of the frame) and the two middle rails are flat. Two pieces of angle facing out, 16 1/2″ long, tie together the three back rails on the outside edges. Two pieces of flat, on edge and 22 1/2″ long, tie together all three rails. The placement of these two pieces depends on the spacing of your lift arms but is also limited by the placement of the tine brackets. Two flat pieces, 5 1/2” long and cut at a 45 degree angle on top, are mounted just in front of the 2nd rail back. They are welded to two 4″ pieces of 2″ x 3/4″ bar stock, which sits in the lift arms of most Gs.
Tines are mounted every 6″ along each rail. With four rails that gives a tine every 1 1/2″. Starting at the center and moving right (looking from the drivers seat of the G), the first tine is a left (adjustment loop on the right of the bracket) and is mounted on the back rail. Second tine is a left on the second rail from the font, third tine is a left on the third rail from the front and the fourth tine is a right mounted on the front rail. Repeat that pattern until you get to the end. The first tine is mounted so that the tine comes out of the bracket 3/4″ from the center line of the frame. Once you have your first hole for each rail, the next holes are just 6″ over.
How to use it:
Tine rakes work best when used on very small weeds; weeds in the “white thread” stage, which may not have visibly germinated yet, are particularly susceptible to the disturbance of the tine rake. The quicker you can go, and the more frequently you can use the tool, the better control you will have. It will rarely clog, except in very high residue situations.
It works well with surface drip irrigation systems and can be adjusted quickly in the field, without tools, to work on any crop. It can also be used to mark planting lines on the bed which helps line things up for future cultivation. The tine weeder is fairly forgiving of poor driving, or crooked planting lines so it is a good tool to learn on.
The rake can be used with all of the tines engaged on many types of transplanted crops, as well as direct seeded beans, corn, and other sturdy plants. When using the rake to cultivate between rows, it is usually necessary to lift either the two closest tines to the row, or the four closest tines. For example, with newly germinated carrots, the tool could either be operated with four tines around each row of carrots raised, and driven at a moderate speed, or with just two tines raised, and driven at a very slow speed so as not to disrupt or bury the carrots sprouts.
Suggestions for improving or modifying this tool:
It would be great to create a version of this tool that uses less expensive components, such as Kovar tines.
Credits for this post: The first version of this post was published here by Josh Volk of Slow Hand farm.
The farmhack version of this post was edited by Benjamin Shute of Hearty Roots Community Farm, who built a version of this tool for his own Allis G, that’s what’s in the photos here.