This model is loosely based off the x-y offset calibration sequence used on the Stratasys Fortus 250mc 3D printer. There are three sets of models for varying levels of resolution. The 0.2mm model is the course resolution and should be used first. If further accuracy is required, the 0.1mm and 0.05mm resolution models may be used. I have found that the 0.2mm model gets you very close and the use of a higher resolution model may not be necessary, however I have included them just in case.
Recommended print settings for 0.4mm nozzle:
Extrusion width: 0.48mm
Layer Height: 0.2mm
First Layer Height: 0.2mm
Top Solid Layers: 2
Bottom Solid Layers: 1
Outline/Perimeter shells: 1
Print Speed: 2400 mm/min
Allow Single Extrusion Walls
It is highly recommended to use a prime pillar of at least 8mm (simplify3d) or similar structure to ensure that the second nozzle is appropriately primed for the single wall extrusion on top of the base model.
How to use this model:
It is recommended to use contrasting colors in the two heads to make it easier to read the indicated offset.
On each base model (T0) there are two evaluation lines and multiple tick lines along each evaluation line on the bottom and right-hand side of the model. The top model (T1) is a skewed single extrusion wall which will cross over each evaluation line close to one of the tick marks. You evaluate the offset of your extruders by the crossover point of the top model (T1) and the evaluation line on the base model (T0). The right-hand side of the model indicates offsets in the X direction. While the bottom side indicates offsets in the Y direction. In line with each middle tick mark along the evaluation line is an indication arrow that denotes the origin for the x and y calibration scale. Each tick line refers to an offset based on the resolution of the model used. For example, one tick line above the origin arrow on the right side of the 0.1mm resolution model would indicate an offset of 0.1mm in the x direction. If the offsets for your machine are set correctly, then the top model (T1) will cross over the evaluation line on the base (T0) in line with the origin arrows on the bottom and right-hand sides.
Once printed you can hold the model up in front of a source of light (careful not to blind yourself) to get a better idea of where the crossover point is.
Setting up in Simplify3D:
-Import the T0 and T1 models of the resolution desired.
-If your printer is setup as a dual head printer you can use tools>dual extrusion wizard to setup the model. I made T0 my left-hand extruder and T1 my right-hand extruder and used PLA for this print. Ensure that the check mark for group and align models is checked!
-If you are using two separate processes then highlight both models and go to edit>align selected model origins and edit>group selection. Then individually select T0 for your left extruder process and T1 for your right extruder process.
-I have suggested print settings above to ensure that the print is legible once finished.
-On my printer the offset between the heads is locked into the firmware and I cannot change it on the printer. Due to this I change the offset on the G-code tab and ensure that the Apply toolhead offsets to G-Code coordinates is checked. This is simply what worked for me, if you can change yours on your machine or in another fashion then do so. Double check however because your offset values might be opposite of mine (+ -).
The top model (T1) extrusion crosses over the evaluation line 2 ticks up from the origin arrow on the right-hand side of the 0.2mm resolution model. This indicates that the offset for the two heads are off by 0.4mm in the x-direction. For my method of setting offsets, this indicated that I needed to add 0.4mm to my right extruder (T1) offset value. The top model (T1) extrusion also crosses over the evaluation line one tick left of the origin arrow on the bottom side of the 0.2mm resolution model. This indicates that the two heads are offset by 0.2mm in the y-direction. For my method of setting offsets, this indicated that I needed to subtract 0.2mm from my right extruder (T1) offset value. If you have chosen the correct direction to add your offset, upon reprinting the 0.2mm resolution model (or higher resolution model) your upper model should cross over close to the origin arrow on the right and bottom hand side of the base model. Repeat until satisfied.