I though many of you might like to browse a sight that is dedicated to designing and building two 1 1/2" scale geared logging locomotives.
Nelson Riedel's fabulous site details how he designed and built a Shay engine based on the Cass geared loco. He is also almost done with a Heisler engine #6 from the Cass Senic Railway.
Many pictures and techniques are disscused in building both engines. A very interesting read.
Bring a coffee, you may be there a while.
Nelson's Locomotive WorksEnjoy. If your not in railroading. He has some very nice shop pictures.
BTW, I have the castings to build one of these engines. Perhaps if I get my $h@t together I can build one too.

Bernd