Dual Extruder Allignment

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maxamillo
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Joined: Mon Mar 19, 2018 8:27 pm

Dual Extruder Allignment

Postby maxamillo » Mon Mar 19, 2018 8:35 pm

Hello! I was wondering if someone could help me out with an interesting problem I'm having....

On the N2+ I am working with (it's belongs to the company I work for) I have started doing dual color prints. Dice to be exact, with the main body of the die being one color, and the dots a different color. The prints have come out great so far, but there's a little error that keeps bugging me. It seems that the right nozzle/extruder (using the left one as a point of reference) is out of alignment. Not in the Z direction, but in the X and Y direction. In other words, I believe it is not perfectly perpendicular to the build plane, or parallel to the left extruder/nozzle. To make matters worse, it needs to be shifted back and to the left, but the screws only allow you to adjust it so it moves forward and to the right.

Any thoughts? The only other way I see to fix this is to move the left one in relation to the right, but that's (in theory) been aligned by the factory, and do not want to touch it.

Thanks!

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Vicky@Raise3D
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Re: Dual Extruder Allignment

Postby Vicky@Raise3D » Tue Mar 20, 2018 6:12 am

You can set X Y offset for the distance between two nozzles in ideaMaker to compensate the hardware offset.
1.png

maxamillo
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Re: Dual Extruder Allignment

Postby maxamillo » Tue Mar 20, 2018 1:07 pm

Vicky@Raise3D wrote:You can set X Y offset for the distance between two nozzles in ideaMaker to compensate the hardware offset.
1.png


I figured there was a software solution. Thanks!

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Allan Sche Sar
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Re: Dual Extruder Allignment

Postby Allan Sche Sar » Thu May 10, 2018 2:45 pm

Hello,

I have a offset issue with my Raise3D N1 Extruder heads. Here you can find my test example.
The left part is printed with the left extruder. The right part with the right extruder.

IMG_20180510_163715128.jpg


In witch direction must the "Extruder Offset Y" value set. Positiv or negativ?

Jetguy
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Re: Dual Extruder Allignment

Postby Jetguy » Thu May 10, 2018 3:12 pm

So I want you to better learn the machine and coordinate system. Doing this only helps you in the long run.
A couple of facts:
#1 This is a corner 0 coordinate system. So 0X and 0Y starts in the front left corner and all values moving back and right are positive.
#2 The left head is primary- aka the reference. The right head is secondary or the offset.
#3 The heads are spaced in X roughly 25mm and in theory, if everything is square and true, then 0 y offset as are are in the same line.
#4 This is the most important one, Ideamaker is subtracting the offset value from the coordinate system. So it shows a positive value of how much the offset is compared to the reference.

So, if the right side head print result is that the right side is shifted back, then that means the result AKA error is a + coordinate distance in Y compared to left nozzle which is "the reference". This distance of how much further back the right nozzle printed is positive value in this example.
So, next question, how much?
Since I only have the picture as a reference, and say this is roughly a 0.5mm wide extrusion from a 0.4mm nozzle, then the shift in y appears to be roughly +0.5mm result or error, so we record or input a +0.5mm Y axis offset in the settings.

Again, just understand how this works. On a per layer basis, the slicer is creating the gcode for the object layer consisting of lines, but the cardinal rule of gcode is the line you are reading is the target, the line before the current line is where you are (because that's where you ended up). When toolhead change is invoked, now the offset is applied to the sliced coordinate.
Example is, printing with T0 AKA left toolhead 0, this follows the true original coordinate.
G1 X50 Y50
To then logically park the right nozzle in the exact same coordinate (tool1)
G1 X25 Y49.5 by applying the toolhead offset of X25 Y0.5 by subtracting it from the original coordinate
Ideamaker extruder offset.jpg


Hint, this is also why the right nozzle when in dual extrusion cannot print in the left 25mm of the bed because you cannot move to a real coordinate of less than 0 in X. If the right nozzle is offset by 25mm, at coordinate X1, the right nozzle is at X26 (25+1). But that's a topic for another day.

Jetguy
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Re: Dual Extruder Allignment

Postby Jetguy » Thu May 10, 2018 3:23 pm

Again, the way Ideamaker works, you are putting in the actual value of the result of the right nozzle compared to the left.
The right nozzle is supposed to be offset a real physical X+25 (we don't normally show the +) and Y0.
In your case, the real world result was right side was shifted back, away from the left nozzle print. Since corner 0 is in the left front corner, back and right movement is always positive values increasing from 0.
If the resulting right nozzle print was shifted forward of the left reference, then that is a negative value compared to reference.


I will say this, I think here is another example of where ideamaker and Raise 3D in general strays from the rest of the 3D printing world.
Example is, most other 3D printers, the offset is ADDED not subtracted in the actual math. So you the user, you are putting the offset, the amount you need to "correct" the coordinate by. Ideamaker chose to use the error and let the math hide the offset. On one hand, in theory, if this had detailed instructions, that might be a simple thing, the offset you put in ideamaker is "the error" VS most systems, you already know the error, you are applying "the correction" and that's the value inserted. It's just a change of understanding. Same reason folks trip up in S3D over this too.
Last edited by Jetguy on Thu May 10, 2018 9:18 pm, edited 1 time in total.

Jetguy
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Location: In a van, down by the river

Re: Dual Extruder Allignment

Postby Jetguy » Thu May 10, 2018 3:49 pm

Again, lacking detailed instructions, the giant hint is that ideamaker uses a +25mm offset in X in the settings.
If we know the real mechanical nozzle offset physically is 25mm positive from the reference left nozzle, and the setting we use is the positive difference as measured from the origin, the logically, we treat the Y axis the same as X, meaning your nozzle physically is 0.5mm towrds the back of the printer compared to the left nozzle, and since that too is a positive measurement from the origin, we then put a positive value into ideamaker and let it do the math to invert that and apply against the coordinate.

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Allan Sche Sar
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Re: Dual Extruder Allignment

Postby Allan Sche Sar » Thu May 10, 2018 8:10 pm

Thanks for your detailed information. I get now the correct value


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