middle x axis lower than sides

Hello, i own a BQ Hephestos 2016 printer(same as Prusa i3) with official heated bed(glass on top and clips holding) and im having an issue that unfortunnaly i cant print my parts.
when i tried to manual level the plate using only X axis manually, i notive that sides are leveled good but on middle (no matter if the plate(y axis) is at begginning/middle or end, the middle
is always bit lower(like 0.2mm, not sure) than sides and this leads to nozzle jamming.
Already dismantle the x axis and checked the rods , they are not bended.
i really spent a lot of time trying to fix this, and cant print medium size objects, because on middle of bed(no matter the Y axis value) is lower than sides.
Litteraly out of ideas, need some ideas , anyone can help please?

Really apreciate
Regards,
FF

There are many possibilities of how to correct the bed level.

1. Get a piece of Borosilicate glass this will give you a level bed to print on.
2. Setup automatic bed leveling
---a. If you have Marlin or Repetier
------1. you can set up bed Leveling with or without a Proximity sensor
--------aa. You can add a Proximity Sensor and configure the automatic bed leveling
--------bb. You can continue to use the existing End-stops and configure the Manual Mesh bed leveling
---b. If you have Other firmware
------1. post what firmware you are using so the forum can assist you.
3. I adjusted my bed for a happy medium at first to account for the highs and lows. And printed on Vinyl transfer Paper tape (similar to Blue painters tape though smoother).

These tapes are more forgiving of distance tolerances in my opinion.

This is not a suggestion, this is what I did in the beginning of my 3D Printing experience to get the models to stick.
I even 3D Printed on releasable pressure sensitive carpet adhesive
(However this takes 1/2 hour or longer to setup)(And most models have to be cleaned of the adhesive after, and should be applied on Tape for easy removal)

As you can see in this video I Really did print on releasable pressure sensitive carpet adhesive on Vinyl transfer paper tape.
(looks ugly, but allowed me to print and this was after a week of printing)( this was also before I aligned the printer to make almost no noise)
[youtu.be]

Edited 1 time(s). Last edit at 06/20/2018 12:33PM by Roberts_Clif.

thank you very much for your answer , my printer dont have automatic bed level, i will implement(custom) using a proximity sensor(already have it) after i fix this issue.
My printer is from BQ manufaturer but its marlin based firmware. (its almost the same as prusa i3)
why my center x axis is lower than both corners?

regards,
FF

Edited 1 time(s). Last edit at 06/20/2018 12:20PM by x4code.

My Hictop Aluminum 270X220 Bed is high in the center by about the same distance.

I had the same problem few days ago with my prusa i3.
It may be the bed holes is not aligned with the y carriage holes so it is bending.
I learned maual bed level compansation and it is working now.
Chek this:

[reprap.org]

Edited 1 time(s). Last edit at 06/23/2018 05:13AM by serdar415.

any news on this topic? anyone solved this problem??

Thanks

Put a straight edge (e.g. of a steel ruler) across the bed to check that it is flat, just in case the bed is warped or the way it is held down is bending it.

If the bed is flat, then this problem (nozzle too low near the middle of the X axis, regardless of Y position) is typically caused by the X axis rod sagging a little under the weight of the hot end and extruder. In which case, a thicker rod to support the X axis would solve it; but the usual workaround is bed compensation.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].