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Wheelbarrow construction manual

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Ingénieurs Assistance Internationale - Ingénieurs sans Frontières

Equipment designed and manufactured in Haiti By the workshops-schools of Camp Perrin

Construction manual of a wheelbarrow Developed in cooperation with Codéart and the workshops-schools of Camp Perrin

Philippe Carlier (†) Cédric Vanhoolandt Project engineer ISF

Construction manual of wheelbarrow [1]

Equipment designed and manufactured in Haiti by the workshops-schools of Camp Perrin Collection "Technical manuals" Manual directed by ISF with the support of the Directorate General for International Cooperation (DGCI)

© International assistance Engineering - Engineers Without Borders 2003 http://www.isf-iai.be mail@isf-iai.be Avenue du Marly, 48, 1120 Brussels - Belgium

We thank all the people without whom this manual could have not seen the light of day, and in particular: Members of the workshops-schools of Camp Perrin, Roger Loozen (Codéart) and Michel Taquet (GRET).

Wheelbarrow construction manual ISFIAI image 0.jpg

Technical sheet - Characteristics Application: building sites (solid and sturdy wheelbarrow) Capacity: 80 liters Thickness tray sheet: 1.3 mm Wheel: Ø 400 x 80 mm

Introduction[edit]

This guide is intended for all workshops, wishing to set up production of a wheelbarrow that is easy to manufacture and with a minimum of imported parts. This wheelbarrow has been produced successfully since 1987 in Haiti by the workshop of Paul Gideon, an independent craftsman that is part of the workshops-schools of Camp Perrin (A.E.C.P.). This feature ensures it is well adapted to the limitations of those countries where the technical expertise is limited, both in terms of its manufacturing as its its use.

Many arguments plead for local production:

  • In case of failure or wear, spare parts can be found easily and are therefore available in a timely fashion;
  • A exportable wheelbarrow must be dismantlable and is therefore not very rigid. A soldered wheelbarrow assembly is far more rigid;
  • Manufacturing of the wheelbarrow provides work for the main local workforce;
  • Production costs for the machine are lower, which allows a wider distribution of a tool that benefits the entire community;
  • A pre-industrial technology transfer takes place, marking the first step of a shift towards serial manufacturing.

Nevertheless, in many countries (including Haiti), it is economically advantageous to import parts of which the manufacturing is more difficult. For the purpose of information, this document also provides details of suppliers of each of these parts for the workshop at Camp Perrin. However, one country is not another and in some difficult to access countries, a piece as the tray of a wheelbarrow is perhaps less expensive if it is manufactured locally. For further technical information, or assistance for the purchase of parts, you may contact the Belgian A.S.B.L Codéart (2).

This manual includes not only the detailed drawings of all parts of the wheelbarrow, but also those of all the specific tools for their manufacturing: pliers, die stamping and bending jig and folding templates. The tools presented here are inspired by those used at AECP, but they may be adapted according to the machinery and materials available at your workshop.

1 Workshops-schools of Camp Perrin - BP 183 Les Cayes - Haiti info@aecp-haiti.org 2 Codéart ASBL - Chevémont, 15 - Homburg 4852 - Belgium Tel: +32 (0) 87 78 59 59 - Fax: +32 (0) 87 78 79 17 www. codeart.org - info@codeart.org

Welding of the feet
Fixing the bearings of the wheel
Completed wheelbarrow

Equipment List[edit]

Manufactured parts[edit]

Qty. Number Name Material Standard 1 00-001 tray steel 1 00-002 main tube steel St35 1 00-003 front reinforcements steel St 35 2 00-004 handle reinforcement steel St 35 2 00-005 foot steel St 35 1 00-006 reinforcement foot steel St 35 2 00-007 sole steel St 37 1 00-008 rear angle steel St 37 1 00-009 front angle steel St 37 2 00-010 bearing cast iron FGL 250 1 00-011 tire rubber 1 00-012 axis steel St 37 2 00-013 flange steel St 37 Note: See table of standards for the metals in Appendix 3.

Standard Parts[edit]

Qty. Designation Material Standard 4 hexagonal screws M10x50 steel 8.8 DIN 933 4 hexagonal nuts M10 steel 4.6 DIN 934 6 hexagonal nuts M6 steel 4.6 DIN 934 6 hexagonal screws M6x20 steel 8.8 DIN 934 12 washers M6 steel DIN 125 A

Materials List[edit]

2520 mm tube Ø 22 ep. 2 4620 mm tube Ø 32 ep. 2 160 mm round iron Ø 20 480 mm angle of 25 x 25 x 3 100 mm flat 50 x 5 2 sheets 300 x 300 x 1.5

List of used tools[edit]

The workshop which would engage in the manufacturing of the wheelbarrow must have the following:

  • A welding post;
  • A plate cutter;
  • A bender for pipes;
  • A pipe cutter
  • A drill;
  • A hand saw;
  • A hammer of + / - 1500g and a anvil of + / - 100kg;
  • Templates described in the appendix;
  • A press with adapted stamping matrix;
  • A circle-saw (or other device that can cut rounds in sheets).

Note: The last 2 tools are not necessary if the manufacturing of the rim is outsourced.

Manufacturing[edit]

Identification of the different elements[edit]

Circular shears

Rep. Qty. Number Name Material Standard 1 1 00-001 tray steel 2 1 00-002 main tube steel St35 3 1 00-003 front reinforcement steel St35 4 2 00-004 handle reinforcements steel St35 5 2 00-005 foot steel St 35 6 1 00-006 reinforcement foot steel St 35 7 2 00-007 sole steel St 37 8 1 00-008 rear angle steel St 37 9 1 00-009 front angle steel St 37 10 2 00-010 bearing cast iron FGL 250 11 1 00-011 tire rubber 12 1 00-012 axis steel St 37 13 2 00-013 flange steel St 37 14 4 hexagonal screws M10x50 steel 8.8 DIN 933 15 4 hexagonal nuts M10 steel 4.6 DIN 934 16 6 hexagonal nuts M6 steel 4.6 DIN 934 17 6 hexagonal screws M6x20 steel 8.8 DIN 934 18 12 washers M6 steel DIN 125 A

The tray[edit]

(Rep.1, see Appendix 1, Plan 00-001) The tray has a capacity of 80 liters. The thickness of the sheet is 1.3 mm. The border has a double fold, which greatly improves the rigidity and facilitates handling of the wheelbarrow without injury.

At Camp Perrin, the choice was made to import the tray. This decision was taken after some economic considerations. Haiti is a country where this type of part can be imported with relatively low costs. The price of a kilo of imported tray is even lower than the price of sheet one needs to buy to construct the tray locally. Nevertheless, in some harder to access countries, it could not not be the case! For informational purposes, the tray used at Camp Perrin comes from the VABOR society 3. The model is K10BLZZ round nose, bare and without perforations. In 2000, the purchase price was 8.8 euros / piece per 500 pieces.

In the case of a container ship order, you may serve Codéart as an intermediary.

The main pipe[edit]

(Rep.2, see Appendix 1, Plan 00-002) The main tube is one of the most important parts of the wheelbarrow. The pipe serves both as the handles and the support for the tray and the wheel. This is realised through a steel tube (Ø 32 Th.2) of a length of 3410mm. As the standard lenghts are 6m, the losses can be be recovered and used to create any of the other parts of the wheelbarrow, or welded to other losses of pipe to to get sufficient length to create another pipe.

The main pipe must be bent on a template. The radius of bending of the central part of the pipe (front of the wheelbarrow) is in such fashion that it is virtually impossible to not to scratch the pipe while bending. That said, this is not harmful for the rigidity of the wheelbarrow as this part of the pipe takes almost no stress. This bending is done first. As for the other bendings, we must ensure that the pipe is scratched as little as possible. This requires a bending material that is well matched to the diameter of the pipe. The drawings of the bending templates can be found in Appendix 2, drawing A3-000. In addition, the pipe should be slightly flattened by hammer and anvil, in a fashion that ensures a good seat of the wheel bearings. The last operation consists of making the holes for the fixing bearings. So far, AECP has drilled these holes using a bearing as guide. However, the use of a drilling template will certainly lead to a gain in time and precision.

To reduce corrosion, we can cover both ends of the pipe with weld-on small round metal plates or with plastic plugs plastics, but this is not essential.

3 VABOR Ruisbrockdorp 40 - 2870 Ruisbroek (Antw) - Belgium Tel: +32 (0) 3 886 59 26 - Fax: +32 (0) 3 886 50 66 www. vabor.com - info@vabor.com


The front reinforcements (Rep.3, see Appendix 1, Drawing 00-003)[edit]

This piece serves to strengthen the connection between the main pipe - tray, it helps to prevent the tray not to collapse or the main tube not to bend under the weight of the load. It is made from a pipe (Ø 22 Th. 2) in standard steel with a length of 750mm. A decrease of working time on the wheelbarrow may be made by sawing the tube directly at an angle of 15 degrees.

The radius of bending is such that it is difficult not to dent the tube. We thus use a suitable bending material to limit this problem. The stress in the elbows of the wheelbarrow are not too large, which limits the importance of this remark.

Both ends of the tube must be flattened by hammer and anvil to facilitate the welding of the main tube.

Handle reinforcements[edit]

(Rep.4, see Appendix 1, drawings 00-004) These parts serve to reinforce the connection main pipe - tray, so that the handles do not bend under the weight of the load. They are made from a pipe (Ø 22 Th.2) of standard steel with a length of 170mm. Both ends of the pipe must be flattened with hammer and the anvil to facilitate the welding.

The feet[edit]

(Rep.5, see Appendix 1, drawings 00-005) The feet allow the wheelbarrow to be placed on the ground. They are made from a pipe (Ø 32 Th.2) of standard steel with a length of 600mm. A decrease of working time on the wheelbarrow can be made by sawing the pipe directly on an angle of about 13 degrees. The radius of bending is such that it is difficult to not damage the pipe. We thus opt to use a bending material adapted to limit this effect. Stress on the elbows is not too large, which limits the importance of this remark (the feet manufactured at Camp Perrin are completely dented without this posing a problem).

Both ends of the pipe must be flattened by hammer and anvil to facilitate welding on the main pipe.

The feet reinforcements[edit]

(Rep.6, see Appendix 1, drawing 00-006) As its name suggests, these strengthen the feet of the wheelbarrow hereby preventing that they collapse under the weight of the load. It is made from a pipe (Ø 22 Th.2) of standard steel with a length of 175mm.

The remarks made in the preceding paragraphs regarding the bending and the denting are also applicable for this piece.

The sole[edit]

(Rep.7, see Appendix 1, Plan 00-007) The soles are used to protect the feet of the wheelbarrow against wear from a abrasive floor. These parts are not strictly necessary, the wheelbarrows produced at Camp Perrin also lack them. These are only added during possible repairs.

The angles[edit]

(Rep.8 and 9, see Appendix 1, drawings00-008 and 00-009) The two angles each serve to ensure better support of the tray and the correct spacing of the main pipe.

The bearings[edit]

(Rep.10, see Appendix 1, drawings 00-010) The bearings are used to support the axis while also allowing of turning. They are made in cast iron. The driving system is a simple plain bearing without ball bearings or bronze ring. The reader could be suprised by a system which is so rudimentary, but this solution provides robustness and an unbeatable cost while still ensuring adequate performance. It is important that the axis is made in steel and the bearings in fonte: the wear is much lower than with a connection of steel on steel, thanks to the lubrication provided by carbon contained in the cast iron. This lubrication is however, insufficient on its own: we must also regularly grease the bearings.

When it exits the foundry, the bearing does not have the 2 fixation holes, but only a slight hollow center which serves to center the mèche to forer it.

The workshops that have no foundry can subcontract this piece locally for a modest cost. When this is not possible, Codéart, which has the foundry models, can you send you these bearings.

The tire[edit]

(Rep.11, see Appendix 1, drawing 00-011) The chosen "tire" is a full bandage rubber (this is a mix of natural rubber and recycled rubber). This choice was made because these "tires " are extremely robust and are not too expensive. The actual tire, well widespread in industrialized countries, is more comfortable but are nevertheless delicate to maintain in non-industrialized countries. The tire, eventhough it is rudimentary, asks nevertheless know-how for its manufacturing: the choice to outsource this piece was made at Camp Perrin. Their tire-suppplier was the French firm MPR4 which stopped production only recently. The Belgian A.S.B.L. Codéart is actively seeking another supplier. You may contact it to ask it to serve as an intermediary.

The axis[edit]

(Rep.12, see Appendix 1, Plan 00-012) The axis consists of a round standard iron with a diameter of 20 mm and a length of 160 mm. No particular modifications are required.

The flasque[edit]

(Rep.13, see Appendix 1, drawing 00-013) The rim of the wheelbarrow is composed of two plates that are screwed together. These flasques are made based on bolted sheets. The depth of the emboutissage is low enough to avoid having to use special steel. The method of the manufacturing of the flasques in AECP is the following:

  1. In a square plate of 300x300x1.5 mm, the drilling of holes: 1 central hole of Ø16 and 6 holes of Ø6 on a circle of Ø198. This may be done per package of 15 discs.
  2. The cutting of a disc of Ø290 by means of a circular saw, centered on the hole of Ø16 (this could also be done by punching).
  3. Bolting with a press (for the exact characteristics, contact Codéart). The drawings of the matrice are in Appendix 2, drawing A1-000. We also note that in the drawing, the inside diameter of for drilling moves from 16mm to 20mm.
  4. Pushing back the tour to do the edge
  5. Painting
  6. Mounting.

4 M.P.R. (bandages) - 10 rue Julien Boursier - 95,400 Villers-le-Bel - France Tel: +33 1 39332833 - Fax: +33 1 39949235

Mounting of the wheel[edit]

To mount the wheel, we install the tire between the two flasques and we slide the axis into the central two holes. Then, we screw the two flasques, the one on the other by means of screw M6. The last step then consists of well centering the axis and soldering it on each of the two flasques. The first wheelbarrows manufactured at Camp Perrin did not have sufficient tolerance on the central hole to properly perform this operation. The axis was thus welded onto the flasque by means of an inermediary of thick bolts. The welding is better if we solder the washer onto the flasque and the axis on the washer, as, when we solder the axis directly onto the flasque. This solution probably offers a better attachments because the thickness of the sheet of the flasque is a little weak to bear the load in a local context.

The assembly of stretcher and tray[edit]

For the welding, we first place the template and execute the continuous markings.

The assembly of wheel - stretcher[edit]

The mounting of the wheel on the stretcher is done by fixing the bearings on the main pipe with the M10 screws. These screws have a strong tendency to loosen but a small welding on the interface screw-nut quickly eliminates this problem.

Manufacturing of the templates[edit]

The drawings of the templates given in this manual are not exactly the same templates used in Camp Perrin since 1987. These latter have ctually been modified as time progressed and have taken along many historical features. In addition, they have often been made or adapted based on the first metals available, which explains why the materials they are composed from are heterogeneous.

The templates presented here are other templates based on the same principle, but whose design has been streamlined. These templates have been made and tested in real conditions to verify their validity.

bending of the main pipe

Maintenance[edit]

The bearings must be regularly greased if we wish to avoid early wear on the axis of the wheel. The reader should also note that regular cleaning increases the life-expectancy of the tray.

Economic considerations[edit]

The figures presented in this section only provide an indication and need to be taken with great caution, some prices may indeed vary significantly from one moment to the other and from one country to another.

At Camp Perrin, the wheelbarrow is sold at U.S.D. $75. The prices of the different components are listed in the table below. These prices were collected in July 2003 and also include import fees in Haiti.

Components Price $U.S.D. Tray 18.00 tire 26.00 2 bearings 3.50 2520 mm pipe of Ø22 2.10 4620 mm pipe of Ø32 6.50 160 mm round iron of Ø20 0.40 480 mm angle of 25x25x3 0.50 100 mm flat iron 50x5 0.20 2 sheets 300x300x1.5 1.40 screws 1.50 Total 60.10

Appendixes[edit]

7.1. Annex 1: Drawings of the parts 7.2. Appendix 2: Drawings of the templates and matrice 7.3. Annex 3: Tables of standards of the metals

References[edit]