SCRAP Humboldt upcycled bicycle trailer instructions

These are the steps that our team The Trailer Park Boys used to construct our bicycle trailer. The components below include a wheel chair, a conduit frame, a road sign tub, a cover, the tongue, and hitch. Instructions are listed below for each component.

Preparing the Wheelchair

The wheelchair is an essential item in our design.

• Disassemble wheelchair into individual parts.
• Determine which parts of the wheelchair frame will remain.
• Remove excess material from wheel chair frame.
• Grind and file cuts
• The wheelchair frame will be the starting point from which the rest of the frame will be constructed.

• 
  Disassembled wheelchair
• 
  Determining where the cuts are to be made.
• 
  Making Cuts
• 
  Shave off rough ends

The Frame

The primary material of the frame was galvanized 3/4" conduit. Small sections of standard water pipe where used as well.

• After acquiring conduit, sketch a rough layout for the frame
• Using a conduit bender, bend the conduit appropriately based out your layout. (Note practicing with the conduit bend beforehand is good idea)
• Cut the water pipe into eight four inch sections, these will be used to attach the conduit to the wheelchair frame.
• Braze or weld the water pipe to the wheelchair.
• Cut eight six inch section of conduit and cut parallel half circles in the end, these will separate the two horizontal loops of the frame
• Tack weld the frame together and check for general fit before permanently welding the frame together.

• 
  Rough sketch.
• 
  Using a conduit bender to bend conduit.
• 
  Four pieces of cut water pipe.
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  Braze the larger bends of conduit to the wheelchair
• 
  Tack weld the smaller cuts to the conduit frame for temporary stability

Street Sign Tub

The tub was constructed entirely out of two aluminum street signs.

• Measure dimensions of your frame to sketch dimensions of your tub.
• Use a jig saw to cut the signs to your dimensions.
• Two sections of angle iron clamped to a table can be used as a solid base to make the appropriate bends in the sign.
• Use a large round object if rounded bends need to be made.
• Using extra sections of your sign for backing strips, pop rivet the tub together. (It helps to place the tub in the frame before riveting)

• 
  Tub dimensions
• 
  Cut the signs using a jig saw
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  Use a mallet and a piece of wood to hammer the road sign that is set against a sharp, straight edge.
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  The back end of the trailer is rounded. We used a rounded piece of aluminum to hand bend the tub to the correct position.
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  One side bent to the correct position.
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  Tabs cut out aluminum to be used for riveting
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  Pop riveting the tub together
• 
  The completed road sign

Cover Installation

We used Kokotat material supplied by SCRAP Humboldt for it's great defense from the elements

• Take measurements of the tub dimensions for a rough cut. Add additional length to drop down the sides for snaps and for vertical slack (in case payloads are taller than sidewalls).
• Once the cover is rough cut, lay atop the tub to fold, cut and trim as needed for a more finished fitting.
• Acquire snaps and separate female and male parts.
• Drill holes through the tub and pop rivet the male snaps in place.
• Use a proper punch to secure female snaps to Kokotat.

• 
  Sewing the cover.
• 
  Male ends fastened to tub.
• 
  Female ends fastened to the cover.

Tongue Instillation

We used conduit to construct the trailers tongue as well for maximum stability.

• The first bend you want to make is a 90 degree bend that lies parallel with the front of the trailer
• Next the pipe will need to be bent so that it has a lift from the ground, rotate and make another bend so that the desired section of the pipe is ten inches off of the ground
• The tongue needs to be attached to the frame. Our solutions was to mold some of the excess road sign into a shell that fit around both the frame and the tongue and bolt road sign shell and tongue together.

• 
  Here is how our tongue came out. It has two different types of bends so it can be hitched to the bike.
• 
  The tongue once it is fastened with bolts.

Hitch Construction

The primary components of the hitch are an aluminum slug, heim joint, angle iron, and hitch pin.

• The aluminum slug was fitting to the inside of the open end of the tongue.
• The aluminum slug was then drilled and tapped appropriately for the already acquired heim joint.
• Next the slug was fastened to the conduit via machine screws.
• A nut with a lock washer was threaded onto the heim joint prior to threading heim joint into the slug. This allows the heim joint to be fixed in a horizontally position
• The receiving end of the hitch is simply a small section of 1/4" angle iron that has be shaped and drilled to fit the rear axle diameter and the hitch pin.

• 
  This aluminum slug that is used to connect the heim joint and tongue together.
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  The heim joint before it is threaded into the aluminum slug
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  The heim joint is threaded into the aluminum slug which is fastened to the end of the tongue
• 
  The complete and assembled hitch assembly.