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yannick1234

Print Head not centered to builtplate (How to fix)

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bdwjl5.jpg

As you can see in the picture the cross is not located in the centre of the builtplate. Its distance is 8 mm from the left side and 23 mm from the right side ; 6 mm from the front and 15 mm from the back.

So how can i make sure that all prints are centered?

In my opinion the only solution is to bend the limit switches a lot to get the right center point in the middle of the builtplate. Am I right or is there an other way of fixing this issue?

(also the left Fan is scratching the wall (already read some topics about that problem, but nobody complained about the "not centered" - thing))

Best regards,

Yannick

 

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I think that is is mainly because of the head position being at the left side and that the fan on the right side is shortening the build volume at the right side.

So not a problem it's intented (Cura works like that in the latest versions at least).

I do think the build plate size was changed in Cura due to the fact that dual extrusion was abandonned (correct me if i'm wrong)

 

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I do think the build plate size was changed in Cura due to the fact that dual extrusion was abandonned (correct me if i'm wrong)

 

You are wrong. I only changed the positioning. Something I noticed when I added the 3D models of the clips (the Cura 3D model is from the CAD model of the printer)

 

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But because of the shift in the y-axis a collision with the clips is possible (and also happend once) even if the clips in cura do not collide with the print model.

This is why I would like to have the y-axis centered to avoid those collisions.

And the only thing to achieve this is to bend the limit switch, right?

And in the x-axis the diffrent distances to the edges are normal? (assuming x-axis is from the left to the right)

 

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There is a problem: "nozzle can hit clips" yet you are trying to fix it by "centering" the print. Well the print can't be centered unless you center the nozzle in the head. Currently the head should be able to come within 1mm of the left and right blocks. So you can "center" by maybe 1mm at the most. But the more you move the X axis endstop to "center" your prints, the smaller your build volume will be so don't move it much.

Since your fan is hitting the left side you should consider either bending it in a bit by pushing hard on the metal fan shroud. Or bending the limit switch out by a tiny amount.

As far as the problem "nozzle can hit clips" this is the true issue. Daid may have fixed this in the latest version of Marlin because he fixed it I believe for the Ultimaker2 go and the Ultimaker2 extended. So in other words this might be fixed in latest cura.

 

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I am already using the latest version of cura but how can cura prevent the collision with the clips if it does not know where the print head can be?

I don't understand why the built volume should be smaller after bending the limiters, because from the home position it should run 230 mm in the x-axis and 205 mm in the y-axis right? So in my opinion you just shift the start point to another point by bending the contacts.

Correct me if I'm wrong with that.

Greetings,

Yannick

 

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how can cura prevent the collision with the clips if it does not know where the print head can be?

 

Hopefully in cura the clips are shown on your computer dispaly as *right* of center. If not Cura still needs some corrections. Cura shows the build area - not the actual glass. The build area is shifted left because the nozzle is shifted left. The plan was to have dual nozzles where the second nozzle (on the right) would print more to the right.

 

So in my opinion you just shift the start point to another point by bending the contacts.

 

The black plastic print head comes very very close to hitting the black plastic endblocks. That's what usually physically stops travel (although sometimes the fan shroud hits the wall first). The tolerances for travel are very tight. This gives you about 230mm. But you need the head to stop before it hits either endblock because there is a danger that the stepper motor will skip a step. So to get 230mm you need the limit switch "just right". Maybe 1mm from hitting the left end block.

If you bend the end stop, now your travel is say 1.5mm from hitting the left end block and now it will hit the right end block that much sooner. You can tell the head to move to position X=230mm but it might not actually reach that position. It might even loose a step on the stepper. More likely the belt will stretch a bit.

If you try to print something that uses the full 230mm you will see the problems. If 228mm is plenty of printing space for you then go ahead and bend the limit switch.

 

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Hopefully in cura the clips are shown on your computer dispaly as *right* of center. If not Cura still needs some corrections. Cura shows the build area - not the actual glass. The build area is shifted left because the nozzle is shifted left. The plan was to have dual nozzles where the second nozzle (on the right) would print more to the right.

Hi gr5,

my Version of Cura (14.09 , help-->check for update says that I already have the latest version) shows the clips in the corners (so not "right" of center).

But in that direction I would never have problems with collisions. If you look at the test print from my first post you will recognize, that the print just has to by centered in the y-Axis direction to avoid collisions. (The cross is 205 mm in Y-Axis, wich is the maximum range specified)

The clips to be shown "right of center" in Cura would prevent collisions in the x-Axis direction I think.

Or does the upcoming update of Cura also fix this problem in y - direction?

Greetings,

Yannick

 

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