Read this sequentially from top to bottom, otherwise you will be confused.

Making the Railing Side Holder

Diagram

 This diagram assumes that 204mm<=focal_length<274mm

 This diagram assumes that focal_length>274mm.

 This photograph shows heels (parts "e") for 204mm<=focal_length<274mm

 This photograph shows assembled side holder with heel for 204mm<=focal_length<274mm

Create two holders according to the following guide. The guide describes only half of the work because the other half is identical and can be done in parallel with the first half.

Material needed

• Closed square jaeckel profile 30x30x2mm (120mm, 100mm, 85mm, 84mm pieces)
• Open square jaeckel U profile 20x20x20x2mm (90mm piece or 160mm piece or 230mm piece, depends on focal_length -- <= 204mm, <=274mm, >274mm)
• Water soluble primer paint, any colour.
• Water soulble top coat paint, black matte.
• galvanized M8 thread bar (twice the width of the railing plus 160mm)
• Six galvanized M8 nuts
• Two galvanized M4x40 bolts
• Two galvanized M4 nuts
• Three galvanized M5x30 bolts
• Three M5 nuts and three M5 washers

Action

 Cut pieces from the 30x30mm jaeckel profile: 84mm, 85mm, 100mm, 120mm if you do not have it already done in the shop where you bought it. If the railing is round instead of rectangular, cut out a suitable shallow wedge-shaped trough from the 120mm piece where it touches the railing. If the railing is excessively thick, it will be maybe necessary to cut 120mm and 84mm pieces longer and make the holes for bolts holding the railing more apart so that the railing will fit between them.

Determine the focal_length from pipe building guide. Cut 90mm or 160mm or 230mm from the 20x20 jaeckel profile if focal_length <=204mm, focal_length <=274mm, focal_length>274mm, respectively.

Cut two pieces of M8 thread bar of the length 80mm+railing thickness (the dimension of the railing along which the bars will go).

Drill holes in the pieces as specified by the drawing.

Grind off any rust using rough emery paper and wash the pieces with warm water and detergent using the old toothbrush. Dry it out in a clean dry rag.

Paint the pieces with two layers of primer.

Paint another two layers of top coat.

Screw together the two pieces containing 4.3mm holes using the M4 screws and nuts and tighten firmly. There are two possibilities how to do that. Try to think how the device will be mounted and choose the appropriate choice. The open profile is called heel and on this profile will be mounted the future pipe.