First off, I've managed to print despite these issues. I think I may have tamed the z-motion, but the platform wobble may haunt me on future projects. The wobble is only bad on one side. If I adjust the guides to remove the wobble, the other side is too tight causing the gantry/platform to "stick and jump" rather than glide smoothly. It seem to be a linear change. In other words it less and less snug until there is noticeable wobble, or vice versa: more and more snug to the point of restricting movement. I've spent hours trying to adjust the guides, but wound up leaving them a little loose.
One thing I noticed is that the angle of the folded edges may not be uniform. If I place a straight-edge along the turned down face (the side that contacts the lower groove in the guide) I can see there is a gap. I'm not sure if this the cause or not, but it's my best guess. I accidentally delete the photo of it (it wasn't all that revealing anyways) ... but, if anyone thinks there may be some merit to this, I can try again.
Oh, and I did add some lube to the edges ... which helped significantly, but didn't fully resolve the issue.
I used a dry chain lube called "Rock 'n' Roll" (meant for mountain bikes). I felt that would collect less grime than oil or silicon grease.
To get the Z-axis right, I removed the screw drive so I could "feel" the alignment and quickly work-in the lube. First remove the coupling completely, then you can lift the screw straight up and out of the gantry. Might want to place some foam or something nice and soft to catch the print head in case it gets away from you. You need the bottom to slide the best. Otherwise it will be EXTREMELY difficult to get the correct z offset ... and even more difficulty printing---the print head will eventually push the part off the surface (or slide the flex-plate surface)
Sounds like I'm not alone with this issue. And like I said, I can't completely remove the problem. I lose about 100mm (maybe more) off the left side of my printing area because that's where I can see the whole platform shift due to the wobble.
Has anyone else noticed the folded-down sides being uneven? ...or has anyone managed to achieve wobble AND stick-free motion on all axises?
Thanks for the tip on the oil. My grease should be here today and I'll see how that works.
Onto what surface are you printing? Directly to the metal platform? I highly suggest getting some borosilicate glass to print onto if nothing else. Something like this: https://www.amazon.com/GO-3D-PRINT-250mm-Borosilicate-Printer/dp/B07QL9WZSN//
I've already been looking for an approx 200x300mm version but haven't found anything that matches yet. If you do this be aware, the probe will not compensate for the glass. The material will need to be less than 4mm thick, I'd say try to stay under 3 for margin. The inductive probe needs metal to trigger so if your glass is too thick it will slam the nozzle into it. You'll also have to redo your bed leveling (tramming). The benefit however, is that glass doesn't have the same warping as metal so it should be a very flat surface to print onto. You can then use hairspray or glue stick to make the filament stick when extruded.
I used vegetable oil (camellia oil from my woodworking tools to be exact) and removed a lot of slipping on my X/Y movement. I am just mapping out dead spots on my platform. Some places it touches the nozzle and no filament is laid down until the second or third layer and other places the nozzle is too high and does not stick to the platform. I only have the standard platform not the heated or magnetic one.
I really hope this helps with mine. I gave up on my bracket design. I just couldn't find anything that worked. What kind of lube did you use? I just ordered some silicone grease.