From the various builds I looked at while researching ideas, using an internal skeleton to essentially hold the key mounting surfaces in place was a method quite commonly used.
However my concern was if the skeleton was too rigid, would there be any long term issues with the different materials and changing temperatures. It's not likely to be an issue on small builds, but over a 1m length, the internal stresses could get quite high.

The common thing I found, was although different people used different methods, I never found any sort of academic/industrial papers that gave much practical scientific answers. It was more a case of people used what they thought would work for them.

Personally I was swaying towards using embedded mounting surfaces that could be machined after casting, as it would be near impossible to keep accurately positioned surfaces in position within a large casting, however epoxying surfaces onto the main casting after curing can also be done (Chaz used this option on his big build which can be found on here).

John's build was also one worth looking at, as he did do a lot of research, but the basics of his build did still come down to what suited him.


Even looking at the commercial options, from what I gleamed from various sources, was they all seemed to have their own proprietary epoxy/granite mix, and seemed to use different methods for final surface accuracy, ranging from surfacing the cast EG, to embedding machinable rails. The techniques used all seemed to come down to what equipment they had available.