[1:14,5] Terex rt 130

hello
i try to made a terex rt 130 but i have a probelem to made a arm i find into a forum this scheme

but this scheme is good to open the telescopic but when i try to close the telescopic the cable not pull the part of telescopic

can you help me to made this part?

thank you

Boom up ..... then it comes by gravity back again .....

Lg Lukas