Bed Leveling Woes

[izzy416]

Hi, I've had my Rostock Max V2 for a couple of months now, and I've made some relatively small prints without much problem up until now.

I've reached the point where I wanted to start printing some larger parts that I had designed, and I've been noticing some shearing at and adhesion problems near the Y Tower when I get near there.

So after some reading on the forums, I bought a dial indicator and printed off a mount for it and tried to do a more precise leveling with that.

Somewhere along the way, my bed got way out of whack on leveling and now I'm having a heck of a time even managing small prints. I had everything dialed in 3 points near the towers, and I took a small break. At one point, I noticed that the belt on the Y tower was rubbing against the rail because the top pulley was slightly off angle, resulting in the belt sliding to one side. I adjusted position, but did not think to consider testing and equalizing the belt tension on all three towers.

After I came back from my break, the bed was way out of level - I had to unscrew the Y-tower endstop screw several rotations just to get it back to level, and the X tower end stop screw had to be screwed almost all the way in, and now I had some weird doming when the nozzle was traveling from the middle out to the Y and Z Towers; the z height would raise and then lower on the way to the Y tower, and the dip and then rise back up again on the way to the Z tower.

The X tower has been fine this whole time. I've tried adjusting the tower rotation in the EEPROM, and it has had a minor effect, but I think I read somewhere that you should only change the values by 0.5 to 1.

So I redid the belt tension in all three towers today, and I bought a digital protractor and measured the angles on all the towers, and they're all within 0.1 degrees of 90 (unless I used it wrong).

But I'm still having trouble leveling the bed off now. It has a convex movement when travelling to the Y-tower, and convex on the way to the Z tower. I also did up a quick 6 point travel macro to have the hot end travel in a hexagonal route around the print bed, at it is *way* high at X0 Y-90 Z0.2 (like almost 20mm off of the print bed), and then low at the opposite points.

I'm at a complete loss as to where to proceed from here. I'm kicking myself for even messing with it in the first place. Can anyone help me please? Everything I have on the machine is stock, but it's with the most recent parts, the injection molded carriages and the arms that go with.

[Qdeathstar]

try adjusting the y endstop counter-clockwise. It should lower nozzle towards the bed near the y axis.

edit: didn't read the whole thing, Did you verify that the extrusions are touching the set screws on the top and bottom, someone could have knocked into the printer and moved one of the extrusions.

[izzy416]

Yes, all the extrusions are touching the set screws, the whole thing is locked down pretty tight.

Should I keep the X endstop rotated? I had previously given up and reset everything back to stock values.

[izzy416]

Okay so I tried increasing the Alpha B to 91, and it actually fixed a lot of the problems. At this point, it still dips a little going from center to the Z tower, but everything else is aligned near the towers.

However, at X-77.93 Y45, the nozzle dips way deep into the glass plate, as well as to a lesser degree at X77.94 Y45. At X0 Y-90 (a point furthest from the Z tower) it is still high, probably about 10 mm.

Is this normal or is there a way to correct it?

Here are a couple videos of the dial indicator in action:

https://www.dropbox.com/s/lpyx85fssaltt ... l.mp4?dl=0

On the way to the Z-tower you can see the dial move briefly as the head dips while it travels.

https://www.dropbox.com/s/m7yhznakyb3yp ... d.mp4?dl=0

In the second video I tried to drop the camera to show the amount of lift in the tip of the indicator as it moves to X0 Y-90 away from the Z Tower.

One other thing I noticed. I was looking through my EEPROM settings, and I saw that my X max length [mm] and Y max length [mm] values are at 350. Should they be the same as the Z max length [mm] value? I wish I knew more about what each EEPROM setting corresponded to.

I recently downloaded the newer version of MatterControl instead of the stock version from the SeeMeCNC website, and now I'm wondering if maybe the EEPROM settings got changed somehow. I remember having some issues with the Z max length being set way high which was sending my nozzle crashing into the bed.

[izzy416]

Okay, so I figured out that the x y max length values don't apply to delta style printers, and by changing tower rotation I've managed to get it to a point where it does not appear to be making a convex or concave motion towards the y and z tower respectively anymore.

I've also managed to level out the point between the X and Z towers, but the point between the Y and Z towers (X 77.94 Y45) is still low by almost 0.2 mm and the point between the X and Y towers (X0 Y-90) still about 1mm above the print bed. Everything else is pretty much level.

I've actually had to increase the rotation on the X and Y towers by quite a bit to get to this point, but from what I've been able to measure, the towers are physically square.

Does anyone know how to correct for the remaining measurements?

[boarddesigner]

Hello Izzy,
I had a similar scenario with leveling and belt fray. What I discovered was, I had actually installed the Z axis stepper pulley backwards. This made the stepper and belt act inconsistently, as well as allowing belt to rub on pulley with lots of torque. not good.

Now that the pulley is properly installed I am able to properly level and print with great results.

Note:
inproper pulley install was user caused. Due to an early start on beer.

[Johncoffee]

Check whether your glass plate is still flat. Mine seems rather tilted - and I don't know why. It's just like a 'chinese hat' - higher in the center.
To solve this I could did some calibration as you did but it keeps changing, especially when heating the bed.
Now I've decided to go this route:
I ordered a IR bed level sensor from https://miscsolutions.wordpress.com/min ... sor-board/ and a Smoothieboard to do auto leveling before printing like shown here https://youtu.be/xVrRGaeOiKA
looking forward for the day to come when all is installed