Telescopic Flagpole



For this project to work, the staves used must be straight and quite thin, no more than 2cm in diameter. If your staves are larger, try using bamboo canes or use different sizes of collar.




Equipment


- 12 x staves 1.8m long
- 3 x collars (drainpipe) 10cm in diameter
- 3 x collars (drainpipe) 4cm in diameter
- 1 x small pulley
- sisal and a thin rope suitable for the pulley

Method

The mast is made up of three sections which slide together. Care must be taken during construction to ensure that there is sufficient clearance for the flagpole to operate. The collars used were cut from plastic drainpipe and were about 2.5cm in length.

The base section is made with four staves and three large collars. Fit one collar close to each end and the third about 40cm from the top.

Lash the staves to the outside of the collars using square lashings.

Break a few rules here - to reduce the amount of rope inside the collar, start and finish with a clove hitch on the stave and only use two turns instead of the normal three.

The base section can be held upright by guy lines or additional staves can be lashed to it to form stabilizing legs.

The middle section uses the smaller collars and three staves. It is constructed in a similar way to the base with the staves lashed to the outside of the collars. It is a good idea to lash all three staves on to one collar and check that the collar plus the staves will slide into the base section before tying the remaining lashings. It may be necessary to select thinner staves to increase the clearance or to use a smaller piece of pipe for the collar.

The top section of the mast is a single stave and should slide freely inside the collars of the middle section.

Assemble the flagpole as follows:

Slide the middle section into the base.

Hang the small pulley from the top collar of the base section. Pass a thin rope through the pullet and tie it to the bottom of the middle section.

The middle section should rise easily when the rope is pulled.

Tie two thin ropes to the bottom end of the top section and slide it into place inside the middle part, while tying the free ends to the top of the base section.

To raise the flag pole, gently pull on the single rope attached to the middle section. As it rises, the top section will be pulled up as well.