Avisos
Vaciar todo

X-Axis problem  

  RSS
andrew.l7
(@andrew-l7)
Eminent Member
X-Axis problem

Hi,

When carrying out the initial calibration prior to a print, my print head only moved about 80% of the distance to the left of the X axis (to get to calibration point 6) and suddenly hits the bed. This is despite carrying out a good XYZ and Z calibration beforehand. If I let it go, it will do the same for points 7, 8 and 9.

I am running the latest firmware and I have done a Factory Reset, XYZ and Z calibration.

Any ideas?

Respondido : 08/06/2017 1:58 pm
JeffJordan
(@jeffjordan)
Miembro Moderator
Re: X-Axis problem

check out the following:
go to the settings - > Live adjust Z menu and remember your value.
set the value now to 0.000.
do a "calibrate z".
does the 9 point calibration run through ?

now select "Auto home" inside the calibration menu.
the printhead should now move to it's auto-home position.

now go again to the settings -> Live adjust Z menu and set your previously remembered value.

what's the height now between nozzle and printbed ? one sheet of paper should fill the space between tip of the nozzle and the pei sheet. two sheets should be to much.
now measure the height between the tip of the p.i.n.d.a. probe and the printbed. it should be something between 0.7 and 0.9 mm (thickness of a credit card is about 0.8 mm).
if the probe height is > 0.9 mm while the tip of the nozzle nearly touches the bed -> lower the probe a little bit.

dem inscheniör is' nix zu schwör...

Respondido : 08/06/2017 8:12 pm
andrew.l7
(@andrew-l7)
Eminent Member
Topic starter answered:
Re: X-Axis problem

Thanks very much - I was beginning to think that no-one had an idea, or was interested.

I will try it out tomorrow.

Cheers,

Respondido : 08/06/2017 11:02 pm
andrew.l7
(@andrew-l7)
Eminent Member
Topic starter answered:
Re: X-Axis problem

Hi,

On checking the live adjust Z level it was already at 0.000, although I am sure that I was running at -0.650

I try to run the Calibrate Z again but as soon as it moves towards point 6 it stops short and moves well down the Z axis to the point where it is pushing the bed and I have to turn it off. A clue perhaps is that on initialization of the Calibrate Z process, and to establish the correct X position (I assume) it is now really testing the left X axis stop point by hitting it for around 5 seconds before proceeding to the first Z calibration point, much like it does when verifying the top Z stop.

I have checked my Probe/Nozzle height using the zip tie method.

Respondido : 09/06/2017 9:14 am
JeffJordan
(@jeffjordan)
Miembro Moderator
Re: X-Axis problem

ok, so it seems that your printer doesn't find the reference pads inside the heatbed where it expected that they should be.
so you have to check your complete assembly of the x/y frame.

the distance between the z-frame (at the point where the notches for the 10mm threaded y-rods are located) and the corner-piece of the right and the left edge should be 18.6cm (equal at both sides):

and the distance between the edge of the MK42 printbed and the trapezoid spindle at the left side should be 3.2cm.
and of course, the distance should remain the same, regardless of the y-position of the printbed (rear and front):

check these values at your assembly and post the results.

dem inscheniör is' nix zu schwör...

Respondido : 09/06/2017 10:58 am
andrew.l7
(@andrew-l7)
Eminent Member
Topic starter answered:
Re: X-Axis problem

Hi,

I am convinced that the problem is not due to misalignment because I have had some great results so far - it just started happening after the firmware upgrade I think.

The attached photo shows where the impact is happening, plus the results that I have had to date.

Thanks,

Respondido : 09/06/2017 12:39 pm
andrew.l7
(@andrew-l7)
Eminent Member
Topic starter answered:
Re: X-Axis problem

Jeff,

I have managed to take this video: https://goo.gl/photos/1cgK9n84xTBfTNAa7

if you can pick it up.

Thanks,

Respondido : 09/06/2017 12:49 pm
JeffJordan
(@jeffjordan)
Miembro Moderator
Re: X-Axis problem

Jeff,

I have managed to take this video: https://goo.gl/photos/1cgK9n84xTBfTNAa7

if you can pick it up.

Thanks,

yes, i know how this looks like. usually it's a problem with calibration point #4.

but when i watch your video, it seems that the printbed is not aligned perfectly.
i think i can see it when the printbed comes forward at the distance to the right edge of the z-frame.
but this could be an optical illusion as well...

did you measure the distances i've mentioned ?
i haven't asked without purpose.

and by the way: you can get out very nice prints, even without calibrating the z-height at the beginning of every print.

furthermore: as far as i know inside the firmware they've targeted the "point #4" problem, with a slightly altered lock-in-range.... maybe this has lead to your problems with point #6.

dem inscheniör is' nix zu schwör...

Respondido : 09/06/2017 2:56 pm
andrew.l7
(@andrew-l7)
Eminent Member
Topic starter answered:
Re: X-Axis problem

Jeff,

The distance from the print bed to the middle of the spindle is 3,7cm on the left and 3,9mm on the right. The other distance I am not quite sure what you mean - can you explain further, please.

Thanks,

Respondido : 09/06/2017 5:09 pm
JeffJordan
(@jeffjordan)
Miembro Moderator
Re: X-Axis problem

3.7cm at the left between the middle of the rod and the edge of the printbed is nice.

i think a picture, about the other distance i meant, should explain it best:

it should be between 18.5cm and 18.6cm, and much more important: equal at both sides (at the right and at the left rod) !

it's just to check your geometry, as good as it gets from "remote" :mrgreen:

dem inscheniör is' nix zu schwör...

Respondido : 09/06/2017 7:28 pm
Knickohr
(@knickohr)
Miembro Moderator
Re: X-Axis problem

Checking the orthogonality is really easy !

- check if the z-frame ist not skewed :

- check if your heatbed is planar :

- check if x and y axis are orthogonal :

Yes, there is an missing axis, the y-z, but if you tighten the nuts carefully, its OK.

Thomas

Respondido : 09/06/2017 9:59 pm
andrew.l7
(@andrew-l7)
Eminent Member
Topic starter answered:
Re: X-Axis problem

Okay,

I have checked the distance and it is 18,45 on both sides. Not 18,5 I know but the software Prusa check is okay. It is also square on Z/X Axis.

I am still convinced that the problem is software related though because the initial Z calibration works fine, and the software finds all of the calibration points okay. It is just the pre-printing calibration that fails, on points 6 and 7.

Thanks,

Respondido : 12/06/2017 11:20 am
Compartir: