looking for a good 3d printer

[cropwell]

Understanding the engineering and physics involved will show the elegance of the Prusa design, this is that the 8mm unsupported rods are not loaded dynamically the way they would be in a router or mill, the carriage acceleration loads are transferred by the drive belts, motors and motor mounts to the frame with the rails simply supporting carriage weight.
Failure to understand this might lead to over engineering the rails and under engineering the frame when it is the frame which supplies the required rigidity for this style of machine, if you sensibly move to a tube feed system with the reel off the machine the only significant loads experienced by the 6mm Aluminium plate upper frame are in the + & - X travel directions where a planar frame performs extremely well indeed.

- Nick

I bought the Wanhao 4DS because of the steel frame, everything else is Makerbot, which has been cloned a lot, so it must have some plus points. The filament reels are on the frame, tube fed to the extruders. The machine has a heated base, which I have a borosilicate plate on. I only print in ABS and on glass I find a thin wash of ABS solution in DMK (acetone ) or MEK (methyl ethyl ketone) gives me good adhesion and easy separation when the bed cools. The other thing it has is a hood to maintain the temperature in the enclosure, which reduces (but not always eliminates) corner lifting. There was mention of a £259 Makerbot clone, and if this has a steel frame, I would consider it a good buy, if I were looking for a 3D printer.

I haven't seen many Hiwin railed machines, probably for a good reason

Cheers,

Rob