Rather than skidding your logs with the excavator, you might try a technique called hoe chucking. Essentially you start at the farthest end from the chipper, and working perpendicular to the chipper make a windrow of logs. Then sit the machine between the windrow and the chipper, lift the logs from the pile and make a new pile closer to the chipper. (Think of it as picking up the pile with the left hand and making a new pile with the right hand).
http://en.wikipedia.org/wiki/Shovel_logging
http://s291.photobucket.com/albums/ll308/Again_Duh/?action=view¤t=HoeChucking.flv
This video and explanation shows the technique that you could modify to suit your job.
http://en.wikipedia.org/wiki/Shovel_logging
http://s291.photobucket.com/albums/ll308/Again_Duh/?action=view¤t=HoeChucking.flv
This video and explanation shows the technique that you could modify to suit your job.