Plans for a specialized harvest cart. A tip sheet on labor efficiency for berry and fresh-market vegetable growers by Bob Meyer, Marcia Miquelon Astrid Newenhouse and Larry Chapman. University of Wisconsin Healthy Farmers, Healthy Profits Project. Cart design by Hal Bohne, Bob Meyer and Jim Schwarz

A worker harvests strawberries with the  cart.

Make your own cart from these plans. Then you can sit and creep along while you harvest. Refer to the accompanying publication “A Specialized Harvest Cart for Greens” for more details on using the cart. This cart has been modified from its original form so that it is easier to build and has better height adjustments.

This cart can reduce or eliminate the time you spend in awkward or potentially damaging postures, compared to kneeling or stooping. You can work directly over the crop bed instead of twisting from the aisle. The cart carries you and your container, so there is less stress on your body compared to carrying by hand. You can change position more frequently so you are less tired than you would be without the cart. This cart may let you work slightly faster. It is not suitable for tasks where you need to cover a long distance in a short time.

There are 7 main parts to the cart; 6 are fabricated from steel, the seat is made from plywood. The wheels are ready-made, and common hardware is used to put it all together. Later you can add accessories such as a sun shade or radio bracket. This set of plans first describes how to make each part, including what machines or tools are needed. Assembly instructions follow. Drawings help explain each task. Note that measurements on drawings follow engineering convention, for example, showing 2 inches as “2.0.”

Diagram of harvest cart.

 

Table 1. Parts of cart that need to be fabricated

Part Description Material
1 Axle/seat supports (2 per cart) 2" x 3" x ¼" angle steel
2 Seat tubes (2 per cart) 1" square tube steel 1/8" wall
3 Front arm (1 per cart) 1" square tube steel 1/8" wall
4 Rear axles (2 per cart) ¾" cold rolled round steel
5 Front axle (1 per cart) ½" cold rolled round steel
6 Seat brackets (2 per cart) 1" x ½" u-channel
7 Seat (1 per cart) ¾" plywood deck, foam, vinyl, 4 screw-in furniture connectors

Buy the materials listed below. You can find wheels in a local hardware store or from a tool and equipment catalog such as Northern Hydraulic (PO Box 1499, Burnsville, MN 55337, 800-533-5545). This reference is provided as a convenience and is not an endorsement by the University of Wisconsin.

Materials List:

17' of 1" square steel tubing, 1/8" wall (for 4' wide cart)
2" of 2" x 3" x ¼" angle steel
5" of ½" cold rolled round steel
15" of ¾" cold rolled round steel
2' of 1" x ½" u-channel steel
¾" plywood 14" x 24" (approximate seat length)
2" thick high density foam to fit plywood
vinyl to cover foam and wrap around plywood
primer and paint
(4) screw-in furniture connectors
(14) ¼" x 20 x ½" hex head bolts
(10) ¼" x 20 nuts
(4) ½" flat washers
(4) ¼" x 20 x 1" U-bolts
(2) ¾" steel shaft collare
(1) ½" steel shaft collar
(2) 26" pneumatic tires and wheels, ¾" axle
(1) 12" pneumatic tire, ½" axle2

Part 1: Axle/Seat Support - 2" x 3" x ¼" angle steel, 12" long, 2 per cart

The axle/seat support is the piece that ties the cart together; this is why we used such a heavy-duty piece of steel. It supports the axle from one side (called a stub axle) and also holds the seat tubes and front arm. The three-inch wide face of the steel will get four holes drilled into it. These holes need to be exact otherwise the seat tubes will not adjust properly. The two-inch wide face of the steel is set up in a mirror image or book pattern. (See Figure 3 - Finished axle/seat supports) There are four holes at the back of each 2" face, to hold the u-bolts that fasten the axle in place. Two holes at the front of each 2" face fasten the front arm and wheel that balance the cart. You can put this arm on either the right or the left side, to give your dominant hand more room.

Task Operation Machine Tool Comments
1 Cut 2"x 3" angle into (2) - 12" pieces. Metal cutting saw   Put stop at 12" so each piece is exactly the same length.
2 Drill seat support holes. Drill press 13/64" bit In 3" wide face, drill 4 holes. See Figure 1-Axle/seat support, side view.
3 Drill axle support and front leg holes.   1/4" bit and jig In 2" wide face, drill 6 holes. See Figure 2 - Axle/seat support, top view.
4 Tap holes in 3" face.   ¼" x 20 tap, cutting fluid Cut threads in the four holes in 3" face.
5 Deburr Drill with deburring bit Vise, file, wire brush Deburr all holes with deburring bit, and edges with file.
6 Clean   Degreaser Clean and dry all surfaces.
7 Prime and paint Paint booth   Spray primer on all sides. When dry, spray paint.

 

Figure 1 &2 - Axle/Seat support views.

 

Figure 3 - Finished axel/seat supports.

Part 2: Seat tubes - 1" x 1" x 1/8" square tube steel, 2 per cart

The seat tubes are the u-shaped pieces that hold the seat. Again, the sets of holes at the ends of the tubes need to be exact or they will not line up with those in the axle/seat supports. The tubes can be bent metal parts bender such as a "Hossfeld." Another option would be to cut a pie-shaped notch, bend by hand, and weld. (See Figure 4--seat tube options) The supports can be inverted to clear taller crops like beans or peas, or can be placed at nearly ground level for weeding or transplanting (rolling backward -- so you don't flatten the seedlings).

Task Operation Machine Tools Comments
1 Cut 2 tubes to length. Metal cutting saw   Tubes need to be exact same length (6'2" for 4' wide cart).
2 Drill 4 attachment holes in each end. Drill Press 9/32" bit Mark from top and drill 4 holes on center at 1", 3", 5" and 7". Do this on each end.
3 Deburr Drill with deburring bit Vise, file Deburr all holes with deburring bit, and edges with file.
4 Bend or cut and weld into u-shape.

*See Fig 4 for cut and weld option.

Metal parts bender or welder Metal cutting saw for cut and weld option. Place each tube in the bender with 13" from end of tube to the mark on round die. Make sure tube has the holes facing out of the slip form. Use spray lubricant when bending.
5 Clean   Wire brush, degreaser Clean and dry all surfaces.
6 Prime and paint   Paint booth Spray primer on all sides. When dry, spray paint.

 

Figure 4 - Seat tube options.

Part 3: Front arm - 1" x 1" x 1/8" square tube steel, 48" long, 1 per cart

The front arm and wheel hold the cart on a flat plane and provide support. See Figure 5 - front arm. The tube can be bent using a metal parts bender such as a "Hossfeld" or bent by hand with the cut and weld option. You can put the arm on either the right side or the left, depending on whether the worker is right or left handed. You can use a clamp or two to fasten crates and flats to the arm.

Task Operation Machine Tool Comments
1 Cut tube 48" long. Metal cutting saw    
2 Drill attachment holes. Drill press 9/32" bit Drill (2), 9/32" holes in one end of tube, at 1" and 5" on center from the end.
3 Bend or cut and weld. Metal parts bender or metal cutting saw and welder square Bend a 90-degree angle in the end opposite the holes just drilled (same plane). Set the mark on the die at 11" from the end of the tube.
4 Drill axle hole. Drill press ½" bit and jig, square Using the square, mark a line 8" from the top of the tube. Drill the hole in the center of the side of the tube, perpendicular to the bend.
5 Deburr Drill with deburring bit File, vise Deburr all holes with deburring bit, edges with file.
6 Clean   Wire brush, degreaser Clean and dry all surfaces.
7 Prime and paint   Paint booth Spray primer on all sides. When dry, spray paint.

 

FIgure 5 - Front arm options.

Part 4: Front axle -- ½" cold rolled round steel, 5" long, 1 per cart

The front axle attaches the smaller 12" diameter wheel to the front arm. A 6" long, ½" hex head bolt could also be substituted as an axle.

Task Operation Machine Tool Comments
1 Cut stock into a 5" piece. Metal cutting saw    
2 Deburr Drill with deburring bit File, vise Deburr holes with deburring bit and edges with file.
3 Clean   Wire brush, degreaser Clean and dry all surfaces.

Part 5: Rear axles -- ¾" cold rolled round steel, 7" long, 2 per cart

The rear axles are held to the axle/seat support with 2 u-bolts each (fig. 7). The u-bolts support the rear wheels from one side.

Task Operation Machine Tool Comments
1 Cut stock into (2) 7" pieces. Metal cutting saw    
2 Deburr Drill with deburring bit File, vise Deburr holes with deburring bit and edges with file.
3 Clean Wire brush, degreaser   Clean and dry all surfaces.

Part 6: Seat brackets -- 1" x 1/2" X 11" u-channel steel, 2 per cart

The seat brackets hold the seat to the seat tubes by compression. They are made of two pieces of u-channel steel, and are drilled to match the connectors that are in the bottom of the seat (fig. 6, Seat and bracket details).

Task Operation Machine Tool Comments
1 Cut stock into 11" (2) pieces. Metal cutting saw   Set a stop to ensure both pieces are the same size.
2 Drill two seat support holes. Drill press 9/32" drill bit Drill two holes in the piece. Mark the center and measure 4" on either side.
3 Deburr Drill with deburring bit File, vise Deburr holes with deburring bit and edges with file.
4 Clean   Wire brush, degreaser Clean and dry all surfaces.
5 Prime and paint   Paint booth Prime all surfaces.

Part 7: Seat -- 3/4" plywood, covered with 2" foam and vinyl, 1 per cart

The seat is made of a plywood platform covered by foam and vinyl. Use a light colored vinyl so the sun won't make the seat too hot. A garden tractor seat could be also be used, but they limit the ability to work directly over a crop. The seat is held to the seat tubes with (4) ¼" x 20 bolts that are screwed into (4) furniture connectors fastened to the bottom of each seat (fig. 6 - Seat and bracket details).

Task Operation Machine Tool Comments
1 Cut plywood to size. Wood cutting saw   Standard width is 12", length of seat depends on width of cart (fig. 6).
2 Drill holes for furniture connectors. Drill press 11/32" bit, or size required for connectors Drill (2) holes in each end of seat blank (fig. 6). Measure from the center, 4" in either direction and 4" from the short edge.
3 Insert furniture connectors.   Hex key, M6 or size to fit connectors. Twist furniture connectors into each hole. Make sure they are perpendicular.
4 Cut foam to size.   Knife, square Cut foam to size of plywood seat platform.
5 Cut vinyl to size   Scissors, square Cut vinyl to size of foam, with 4" overlap in all directions.
6 Attach vinyl to seat.   Upholstery tacks and hammer, or staple gun and staples. Starting on one long side, fold vinyl over itself and tack along bottom side of plywood, where connectors show. Put foam in place over plywood, stretch vinyl over it, wrap around edges of plywood and tack to bottom side. Then stretch, fold and tack vinyl on short sides of seat.

 

Figure 6 - Seat and bracket details.

Assembly Instructions -- See Figure 7 -- Exploded Assembly View

Assembly Materials needed:

(14) ¼" x 20 x 1½" hex head bolts
(10) ¼" x 20 nuts
(4) ½" flat washers
(4) ¼" x 20 x 1" u-bolts
(2) 3/4" shaft collars
(2) 1/2" shaft collars
(2) 26" pneumatic tires, ¾" axle
(1) 12" pneumatic tire, ½" axle
A 7/16" wrench or socket

Step  
1

Attach rear axles to axle/seat supports with u-bolts.

  • Lay the axle/seat support so the short face is flat on the ground, the wider one should be sticking straight up.
  • Lay the axle at a 90-degree angle between the two rows or ¼" holes.
  • Push 2 u-bolts through the holes to secure the axle.
  • Tighten with (4) ¼"x 20 nuts.
  • Repeat for other axle/seat support.
2

Attach seat tubes to axle/seat supports using (8) ¼"x 20 hex bolts.

  • First, decide the height of the seat.
  • To make the seat low, place tubes on the floor as shown in Figure 7, with the open end of the "u" up.
  • For the lowest possible seat height, fasten the axle/seat support to the uppermost set of holes with (4) ¼"x 20 bolts per side.
  • Axle/seat support should be placed so the axle seems to be hanging under the 2" wide face.
  • If seat height is high, place seat tubes so they look like an upside-down u.
  • To make the seat high, fasten the axle/seat support to the lowest set of holes (farthest from bend or weld) with (4) ¼"x 20 bolts and nuts per side.
3

Attach seat to seat tubes using seat brackets and (4) ¼"x 20 hex bolts.

  • Place the seat upside-down on a flat surface.
  • Put the seat tube & axle/seat support assembly on the seat.
  • Position (2) ¼"x 20 bolts in the holes in each seat bracket and rest these brackets on top of the seat tubes.
  • Line up the bolts and the furniture connectors and tighten to hold the seat in place. (In the low position, the seat will need to be raised).
4

Attach front arm to axle/seat supports using (2) ¼" x 20 hex bolts and nuts.

  • Place the completed seat assembly with the seat facing up.
  • Position the front arm under the axle/seat support on the appropriate side and connect it to the axle/seat support with (2) ¼"x 20 bolts and nuts.
5

Attach rear wheels to axles using 3/4" shaft collars.

  • Slide the rear wheels onto the axles.
  • Place a 3/4" shaft collar on each axle and tighten the set screw with a 5/32" allen wrench to hold the wheel in place.
6

Attach front wheel to front arm using ½" axle, (4) ½" washers and (2) ½" shaft collars.

  • Place (4) ½" flat washers on front axle
  • Slide axle into hole on front arm (axle should extend to the outside of the cart).
  • Place 1/2" shaft collars on either side of wheel and front arm and tighten the set screw with a 5/32" allen wrench.

 

Figure 7 - Exploded assembly view.

Material is not copyrighted. Feel free to reproduce and please mention source: University of Wisconsin Healthy Farmers, Healthy Profits Project, Oct, 2001

Authors: Bob Meyer, Astrid Newenhouse, Marcia Miquelon and Larry Chapman: Healthy Farmers, Healthy Profits Project, Department of Biological Systems Engineering, College of Agricultural and Life Sciences, University of Wisconsin, 460 Henry Mall, Madison, WI 53706.

Technical Drawing: Bob Meyer

University of Wisconsin - MadisonCenters for Disease ControlResearch for this publication was funded by the U.S. Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health (NIOSH).This material was developed by the Healthy Farmers, Healthy Profits Project, whose goal is to find and share work efficiency tips that maintain farmers’ health and safety and also increase profits. For more information, call (608) 262-1054 or visit our website at http://bse.wisc.edu/hfhp/