Re: Why put 2 guides on the long sideof a gantry table?
You can build a machine this way you just have to size the components correctly. HVAC machines used to only be built with a wide gantry from some companies. This helped with fast loading of thin material. But time moved on and linear rail got much more economical (Even though some still don't use it or use it properly). So instead of flat bar steel with raised sides modern machines put the rail below the top of the work plane. This gives you an easy loading from 3 sides instead of 2. Depending on your works space an 8x4 may make more sense than a 4x8. But one is more efficient. Historically in the big router world once you get beyond 10' width of the gantry you would be using twin rails on BOTH sides of the long axis travel (Often 20 foot or more travel length).
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