I have manually leveled the bed many times over and over. I then run the auto bed leveling function and all of a sudden the back of the bed is coming out low when I try manually bed leveling again. Is the Cr Touch off, I don’t know. And then when I start a print of course the filament at the back of the bed does not adhere and the front of the bed is too high.
I don’t know your specific printer. But I am having issues with my CR10 Smart Pro keeping ‘position’ with the entire right side. In one instance the bed leveling knobs fell right off.
I am now thinking stiffer springs and a bit of locktite and 5mm longer attachment screws are needed. No matter how tight I screw down the adjustments, then adjust the bed upwards, I nearly run out of threaded shaft on the two right side screws. I get really good prints for one to 4 runs after that, but then I am back to dialing it in.
I had to a similar thing with a very warped heated bed carriage for my daughter’s Geetech Prusa I3 Pro W. And there I used a combo of wooden spacer blocks and springs.
So from that story I would suggest checking how much ‘slop’ is in the adjustment knobs at the rear. If they move super easy, they are probably shaking loose as you do your ABL and printing.
I am sure the others here will have more ideas to offer.
@WBennett Were you ever able to diagnose your issue? I’ve had some progress with a similar issue after printing a new bracket for the CR Touch that repositions the probe to align it with the nozzle along the printer’s Y axis. The description for the zero y-offset mount on Printables gives some background with regard to how this avoids inaccuracies in creating the bed mesh.
I have not been using 3D printing for very long but consider myself a quick study. One of the first things for me to figure out was bed leveling. My initial thought was since there are springs that means I need to use them as springs and to some degree that may be correct but not like I thought. I would have the compression on the loose side of the whole compression. This created issues with bed movement side to side since the spring looseness now allows this. The video mentioned below actually shows both a loose and tight spring at different points in the video… Teaching Tech - are bed springs obsolete
If you look at the loose spring you can understand how the bed will have side to side movement and very easy compression. I learned that this is not the best thing to do.
If you look at the tighter spring take note that it is not fully compressed bar tight but still has a little compression left but not much. This significantly enhances the tightness of the bed and therefore betters the outcome of the print immensely. It also helps with stopping the bed leveling from coming loose over time since it makes the wheels harder to turn therefore harder to come loose.
I also recognized another issue with leveling and that was checking level with the
BLTouch each print. My main slicer has been Creality Slicer but I also played with Cura Slicer and found they are much the same so I stayed with the Creality one. In playing with Cura I saw that it likes to check the bed level frequently so I copied the GCode for this and added it to my Creality slicer printer settings.
This means I went from auto leveling only after I manually level to checking auto level every print. This created an unforeseen issue very quickly. I noticed that I needed to manually level the bed far more frequently. This is just a guess on my part but I deduced that auto leveling the bed every print was seemingly having a side effect. Everything has a tolerance threshold these days and this means that there may be a slight degree of error from that tolerance percentage each and every auto level function that would slowly induce inaccuracy in the bed level over time. The bed is still manually level but the software tolerance has slowly drifted from perfect. I was now having to manually level the bed far more often then before I added the auto bed level code for each time I print.
So I turned off the auto bed level for each print and performed a complete manual and auto bed level again.
I then print a leveling file for my bed size and I adjust the wheels to get a perfect thickness of filament that is not to thin but closes the gap between them. I adjust the four corners as the leveling print is printing to correct things as I see them in real time. This is my most crucial step in setting my bed to how my printer prints.
Now my printer is very level and very friendly in how it puts down filament.
The final piece of my behaviour, is the Brim, I frequently print the brim with my prints when the print allows. I watch this brim as it is printing and if need be and only if need be, I will adjust the wheels to get the perfect put down of filament. This keeps things going very well. I have been printing daily for two weeks now and still do not need to touch the printers bed level in any way.
One last thing, I tightened up every rail and wheel rolling location on the printer. The print head had a bit of a rocking motion in it and the whole bed could move slightly back and forth and side to side. After tightening up all moving points of my printer, I have amassing results.
I usually use a small level, after I make sure the Bed is flat, and the Z axes Bars are not twisted and the feet of the Printer is Level, and all the wheels are snug. You Can’t level a Bed when the printer itself is not level. Also, the printers have a Die stamped bed plate, and they get warped in transport and in production… So a Glass Plate is a Must!!.. Are you running a CR10?