Thanks for those links, most of which I had not seen before.
Can't get mine to lift the front end like the one in the first video though.
The PDF I could not paste in was this one
http://www.camex.ca/images/stories/r...andem_axle.pdf
When I first started looking round before building the model, I was amazed at how many varieties there were, took me a while to decide but the length of a tandem steer, tandem brive in 1:14 scale helped me to decide on the single steer , tandem drive version with a 28 foot bed. It nicely fits into the back of my car.
Thanks again!