Unable to Level Bed Corner #2

Printer: GEEETech Prusa i3 X

Hi there well I've had my printer for a couple months now but this problem has started right after a month when I finally just got my printer "dialed in". So since I am unable to get that particular corner level I just deal with it and use the other quadrants since the other 3 can get level and stay there and seems to print fine using those quadrants I just try to stay away from that quadrant. But then what's the point of having a 200mm x 200mm bed or work area and you can't even utilize the whole thing? So yeah I no longer print parts in the middle or center anymore.

So as far as the attached file is a picture I made of how you are suppose to level the bed 1,2,3,4. Corner #2 is where the problem exists. Now when this problem first started I couldn't get ANY corner level it would keep going back and forth like the bed was twisted? So I then made sure my Y axis rods were level and straight. Then by doing that I think I made some improvement because then like I said what happens now I can actually level 3 points out of the 4.

So then now my theory is that the bed or Y carriage where the acrylic X is and mounted to the linear bearings is bent or out of shape? So I am here to get help and verify BEFORE going ahead and making any purchases fixing the problem and having a FULL work area again! Because I do have a couple big prints I want to run. So like I said in the meantime I am keeping my prints small and working around it.

PS I have also attached the actual part that I am assuming that is bent or out of shape.

If anybody can help me fix this issue I would greatly appreciate it!!!

Edited 1 time(s). Last edit at 02/05/2016 12:18PM by ScottieD369.

Tell us about how you level your bed? it might help us track down the problem, some pictures of your actual machine would be helpful too.

Well I level the bed using the paper method I think it's faster than using a dial indicator. I place the paper in between the nozzle and bed and adjust the screws. I'm sorry but any other pictures wouldn't help this issue sorry. There is no way I can take a picture of the corner not leveling. If you know what a Prusa i3 looks like then there you go. I have attached photos of what is going on. The part I think it bad and how you level the bed and what corner is not leveling. Corner #1, 3, 4 level perfectly fine and #2 is short and because soo alot of the time the wing nut tends to fall off. That no matter how much you unscrew you can't get that part of the bed higher. I could maybe put some extra springs on there for extra compression but I shouldn't have too?

Edited 1 time(s). Last edit at 02/05/2016 02:15PM by ScottieD369.

Ok, so if you can not get that part of the bed any higher, then you need to screw that screw half way down, then level all the other corners based off that corner. Basically if you can't beat it, then join it.

So nobody at all can tell me or verify about this problem? That if I should replace that part to get it better? Or if there is another issue going on causing this?

Did you try what I said?

Hi,
I got exact the same problem!
My corner #2 wont fit anyway, I brought a precision alu plate to conquer this issue, but nothing changed.
If I try to level in, the whole part 15 will bend and the bushings will block.

I dont know any solution jet.

May there is a hidden missalignment caused by the damn acrylic cuts.

Yes and when I try what you said Start from Corner to and adjust from there. Also I added some extra springs for stronger push. No it did not help me if I did then the corner switch to #1 instead of #2. When removing the glass, I can tell that the circuit board for the coil heated bed is warped because the glass tilts on it without clips. But you would "think" that clipping it together would help straighten it out or adjust to it? A heated base is suppose to be meant to be heated up again and again and really I barely only used this machine for now 2 months. So do you think that all I would have to do is replace the heated bed? The cost is $11 locally from Ebay. Just so that I can get the full 200mm x 200mm area again. Like I said I can use 3 parts of it for now just fine.

Is it solved?
"Warped Heated Bed" won't straighten even if clipped to flat straight mirror! But still works fine 75% of the bed can level perfect.
So until I order this for $11 I can update if it does solve this issue?...

Edited 2 time(s). Last edit at 02/07/2016 06:36PM by ScottieD369.

Just thinking...
Take a look at where the bearing are relative to your problem corner. Look for bends in the rails. Check the height of the carriage to the rails in the 4 corners to see if the bearings are at different heights. Since they are linear they want to align with the rails so if one of the pair of bearings has a different height to the other it may twist the carriage.

hi,

I got some hardened steel rods which are polished as well.
The bearings are no bearings anymore, they are some RJ4JP bushings. If I measure without the aluminim plate/heatbed right onto the carriage, its perfect aligned.

Well MCcarman
Like I mentioned that I have double checked the carriage and bearings and they are fine and if the would twist you would feel it when moving the bed manually by hand back and forth and no I don't feel anything. This is the only thing or problem I could find. Is that the heated bed itself is warped.

I found the issue!

Its related to the z-axis coupling, just loosen the lower part and push the flexible aluminium against the motor, so the M8 rod will touch the motor shafts with some constant pressure from the aluminium couplings.

Edited 1 time(s). Last edit at 02/10/2016 11:36AM by Kev0.

Hmm. If it was me I would:-
Check the alignment of the X rods (extruder). If the Y rods are sloping front to back and the X rods are sloping left to right you get compounding measurements in the corners.
Its probably best to do the corners on the Y rod with the 2 bearings on first. I will assume this is the one nearest the home position. If not you may need to go round the loop a few times.
Adjust the two corners on the Y rod nearest the home position. I will assume they are 1 and 4 on your diagram. Then set 3. Go to 2. Find out what the error is (up or down) and adjust the z height on that end of the X rods (turn Z motor) to get half the error. Go back to 3 and readjust. Recheck 2 to see if its improved - if so adjust Z again. Home the Z axis and recheck all corners.
The reason for not adjusting the end near home is that that end is positioned on the Z end stop switch so if you adjust it you have to rehome the Z travel.

Hope this helps

Quote
Kev0
I found the issue!

Its related to the z-axis coupling, just loosen the lower part and push the flexible aluminium against the motor, so the M8 rod will touch the motor shafts with some constant pressure from the aluminium couplings.

I'm not sure how much lower I can go? But I still have this issue.

Another issue I found was the play in the right z-axis. make sure you push it a little bit down on the x mounting points so the rod wont be at a dead play spot.
make sure your x belt tension wont block the z axis in this way.

I have this issue if my bed is fully forward the back left corner is always low adjusting Z for proper distance when I go to the left front it is so high the adjuster needs to be too tight if you go to the front right loosen and tighten it while measuring back left you will notice the y axis acrylic bearings plate will bend up and down and its on the side with only one bearing. My thought was to replace acrylic with aluminum but due to the cutouts needed to clear the stepper and belt idler it weakens the aluminum solving nothing. Another thought is to use a long LM8 bearing on that side or use two like the other side. 3 point leveling is hard to do with the heat plate as the hole is under the wiring and drilling elsewhere cuts into heater element on the board. What does work is getting rid of the springs and putting the thumb nuts on the screws then placing on the acrylic and adjusting level and locking with wing nuts or more thumb nuts on bottom to lock it all only problem is bed has no play if nozzle is brought too low or slicing through a glob on part I did the Z axis coupler thing. Another thought is to use 10 or 12 mm rods for Y axis. From what I can see the problem is caused by that acrylic plate with bearings that has the belt connected to it. If it was x axis it would be a left to right issue. My future plan is to replace the Y axis with a linear slide zero backlash leadscrew.

my solution is two epoxi bonded 3mm alu plates. would like to upload a picture but I'm on mobile and its currently to big.

Hi Guys

Don't know if this will help, but I had a problem with the Right BACK corner of my bed [in the OP's image this is corner #2] always wanting to push higher than the other 3 corners. I have a Geeetech Aluminium printer, a PCB heater bed on an Aluminum base and a Borosilicate Glass bed on top. The only way I could print was to force that RIGHT BACK edge down by tightening that screw, but this put stress on my glass plate. Also to dampen the vibrations I had the printer sitting on the table on the White foam sheet it comes packaged in.

Finally I decided to strip and rebuild it again, and on removing the foam, and placing the printer on the flat table I noticed that the base WAS NOT LEVEL and WAS NOT SQUARE. It was askew and only 3 surfaces were touching the table. Leaving the printer standing and not touching it, corners 1,3 & 4 touched the table but corner 2 was not touching.

This was what was stopping me form getting a proper leveling of the bed.

I loosened all the main screws for the base and Y and leveled the base to the table, so that all 4 corners of the base were touching, before tightening the bolts. I also bored a hole in the MIDDLE of the Al plate just below where there already was a hole in the PCB heater bed and instead of 2 screws for the rear, I used just one in the MIDDLE.

I now tried leveling by Zeroing the Z in the MIDDLE of the bed, then corner 1, 2, 3 and 4 and repeating the sequence and it went perfectly and in about a minute I had the bed level, where before I had spent HOURS with no success. Also having just 3 points to level made things simpler as 3 points are always easier and better to level than 4.

If the OP ar anyone else is having a similar problem, please check that your Y base is absolutely SQUARE.