Why are round linear rails recommended over flat/square rails?

Question

Accepted Answer

It's a real tradeoff, not a one-sided rule. On heavy structural-steel gantries, round linear bearing rails dissipate heat and spread load across the bearing surface efficiently and are common on higher-end industrial routers. Well-specified square/profile rail systems can match or beat round rails on precision and load capacity — what actually causes premature wear and mechanical slop is an undersized rail system for the gantry weight, not the rail shape by itself.

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