I'm in the very early stages of planning to build a custom CoreXY printer, 400mm on each axis (big enough, but without needing to get custom heater or print bed parts), maybe with a little extra Y and Z. While I had thought of starting from an easy to source set of parts, I realized that I would end up spending much more time, and hundreds of additional dollars, to convert printer A into printer B, while still only having one working printer, and neither exactly being cheap. I have access to laser and water cutting, but not milling. While I have to pay market value, with no scrapyards within two or more hours of driving, used brand name rails seem to only be about double the cost of chiwins on eBay, so my current plan is to dump money into those, for linear motion, with a solid top plate (or two) for the motors and pulleys. V-slot would work, but those costs add up to being pretty similar to used rails, and have their own set of issues. No interest in printing large enough parts from ABS or others to justify a heated enclosure. My main goal is a combination of speed and precision across very wide ranges of print, up to about 350mm on each side, mainly with PLA and PETG.
What is the typical process of aligning the axes? Like, the diagonals measure OK on the enclosure, and X/Y motion frame, but now I have rails that I don't want to bind, grind down, nor cause the X rail to off-parallel. But, I don't have a machine with which to make an accurate jig. Would 3D printed guide brackets be good enough, following the other guide by feel, or a combo of the two?
I would like to build the frame with extrusions for easy assembly and mounting (2020?), strengthened by panels, with only the top and front being open. For the sake of visibility, I think it would be nice to use 1/4" polycarbonate sheet panels for the sides (no holes but for mounting screws), with aluminum on the front (that one a big enough opening to get in there and remove the bed), bottom, and maybe rear. Does anyone have any experience with that, or other thoughts? Acrylic can be kept looking clearer, and might be slightly better against frame twisting, but is a lot more fragile (also typically less flammable).
I'm frustratingly torn on the Z-axis. Linear rails and belts are how I'm doing it, for sure. However, there are a few styles that should be viable, and I'm wondering if there would be any real functional differences. First would be 3 rails, one front-left, one front-right, one middle-back, with a platform held between them: most expensive, and the most parts to design, measure, drill, assemble, and align. Another being the same, but with a floating leveling bed holder on each, rather than an additional platform: this one reduces parts and weight, and since the bed alone will be several pounds, I wonder if there is any real risk of anything bouncing around - this is definitely the one I like most right now, but I wonder if there are hidden issues (other than having to keep the printer upright during transport). Another yet being two rails down the side, with a platform between them (UMMD style): moderate amount of parts to deal with, but less aligning between them (compared with three rails on the frame), the advantages of cantilever beds without cantilevering; but I wonder about print artifacts, if I were to not have quite a rigid enough structure for the rails to be attached to.
What is the typical process of aligning the axes? Like, the diagonals measure OK on the enclosure, and X/Y motion frame, but now I have rails that I don't want to bind, grind down, nor cause the X rail to off-parallel. But, I don't have a machine with which to make an accurate jig. Would 3D printed guide brackets be good enough, following the other guide by feel, or a combo of the two?
I would like to build the frame with extrusions for easy assembly and mounting (2020?), strengthened by panels, with only the top and front being open. For the sake of visibility, I think it would be nice to use 1/4" polycarbonate sheet panels for the sides (no holes but for mounting screws), with aluminum on the front (that one a big enough opening to get in there and remove the bed), bottom, and maybe rear. Does anyone have any experience with that, or other thoughts? Acrylic can be kept looking clearer, and might be slightly better against frame twisting, but is a lot more fragile (also typically less flammable).
I'm frustratingly torn on the Z-axis. Linear rails and belts are how I'm doing it, for sure. However, there are a few styles that should be viable, and I'm wondering if there would be any real functional differences. First would be 3 rails, one front-left, one front-right, one middle-back, with a platform held between them: most expensive, and the most parts to design, measure, drill, assemble, and align. Another being the same, but with a floating leveling bed holder on each, rather than an additional platform: this one reduces parts and weight, and since the bed alone will be several pounds, I wonder if there is any real risk of anything bouncing around - this is definitely the one I like most right now, but I wonder if there are hidden issues (other than having to keep the printer upright during transport). Another yet being two rails down the side, with a platform between them (UMMD style): moderate amount of parts to deal with, but less aligning between them (compared with three rails on the frame), the advantages of cantilever beds without cantilevering; but I wonder about print artifacts, if I were to not have quite a rigid enough structure for the rails to be attached to.