big drums
How much line pull and speed do you have with those big drums obviously they are driven using hydraulic motors they must be reasonable size? would be interested to see some close-ups of the winches and drives.
Is anyone using bigger yarders madill, t-bird etc.?
Hi prolog,
The biggest majority of excavator skylines in the uk are based on small drum skyline winches, in wales and the welsh borders is where you find most of the big drum machines.We use track gear boxes from other excavators,the bigger the drum the more speed.The drums on my old jcb in the photo are 6'6'' dia but on single speed track box, but by putting output from both pumps into the motor gives you a line speed of about 3.5 m a second.A fellow contractor has 8' drums on two speed hydash boxes can get 7m per second.Pulling power ranges from 4 to 8 tons pull depending what track box is used.
My jcb i built myself to my ideas i have since rebuilt it on a daewoo dh 220,it is so simple to drive my granny could drive it.The sky line winch is operated by a pedal on the floor, the haull in and haull back are one hydraulic four way servo lever and one three position switch.put the switch to the left it operates left drum and the right when the switch is on the right and the middle both together. If the servo lever is pushed forward the drum pays out pull it back is comes in.Move it to the left it brakes on the left drum and right brakes on the right.
I will try and find a bit more time next weekend to post some more photos as it is i have run out of time this weekend and the caravan in the wood and the harvester beckons me for another week of long shifts.