Large Delta printer build - advice and suggestions welcome

[AutoWiz]

Linear rails aren't bad, but I feel like it's a bit of a sledgehammer to swat a fly scenario. Lots of printers with round rails produce great results, even ones that are indistinguishable from those made on printers with linear rails. It's up to you, but I feel that many people go for linear rails because for the same reason they like to buy fancy cars. At the end of the day you're squirting molten plastic from a 0.4mm bore, and 0.2 is considered a good fitting tolerance, if your round rail can't hold that tolerance it's bent. The biggest practical advantage linear rails have on a 3D printer is that they can be fully supported, so on longer spans there isn't the bendy and flexible bit in the middle that can wobble under inertial forces (or sag if its not appropriated sized, but the rails on a delta are vertical so they wont sag).

This is even more so the case with idlers, pulleys and belts, the cheap stuff from china works fine and is manufactured to much higher tolerances than your printer will be outputting. Belts can sometimes cause problems from what I've heard with the rubber wearing off the belt, or not having fibre reinforcement but I've never run into these issues myself. Any difference someone claims between a chinese idler bearing and a name brand one is entirely in their head.


I don't know how much money, if any, you'll save buying a 24V bed vs line voltage, but at that size/power requirement I can virtually guarantee you'll spend more money than you saved on a 24V power supply that can handle that much current.

Man you are chock full of great advice. The linear rails get bolted to the frame every inch or so whereas the rods mount through holes only at the very ends of the rods and the entire length of rod can flex and the holes can get loose and then the rods themselves can move not the bearing against the rod. That is why we all upgrade to the linear rails. Because it stops the z wobble completely even with less than perfect leadscrews. You should just read more on this forum and try to limit the amount of advice you are giving here.