Hello, does A350 A250 use mgn linear rails or what inside aluminum profiles?
I know all 5 use leadscrews right?
It’s purely leadscrews, there’s no linear rails inside. Here’s a video about checking them;
So this is built like ender without using replaceable linear rails, I mean it does not use mgn linear rails, but also round metal rods are not replaceable? No easy way to lubricate it.
Seems bad design for price it is sold if you ask me.
The plastic tension nut instead of brass is very strange.
The round metal rods are replaceable, but you would probably have to get them custom made/cut. They don’t really wear out though; it’s the u-groove bearings on the carriage that go bad, and the plastic backlash nut. Ideally the backlash nut would not even be brass, but rather POM. It really is not a very well thought out design.
Yes POM nut would be better, yet if you would use iron brass that would be lasting lifetime. The u shape bearings have a bearing in them or they are bearings themselves? I wonder what is the hardness of the “u bearings” and linear rails. Not hard to test these days with harness tester from aliexpress. for somebody who has the printer that is.
A brass nut used on a steel lead screw (like those in the SM) would actually wear quite quickly, especially when faced with the type and direction of forces that the SM linear modules are subjected to, and would require MUCH more frequent lubrication. A POM nut on a teflon coated lead screw would not require any lubrication, would last several thousand hours of use, and be much cheaper to replace.
The bearings inside of the linear modules are SG10 U-Groove Bearings, they are a pressed together “sealed” bearing, not designed for disassembly. They can be purchased for about $2 USD each. Both them and the track rods they ride on are made of stainless steel.
The actual “nut” is the plastic portion. The aluminum is just the attachment point for the nut; it is not threaded.