Here we will print another cylinder, but with a material (PETG) that does not stick to Kapton. There are many solutions to the bed adhesion problem, but we will solve this by printing an "adhesion layer" of TPU before we start printing the PETG. This now becomes a multi-material print.
- T4 and T5
- Nozzle diameter: T4-0.4mm, T5-0.4mm (Instructions to change nozzle)
- Loaded materials: T4 - Ninjatek Cheetah, T5 - PETG
- Bed surface: Kapton, cleaned thoroughly with Acetone
Starting with the same exact factory file as the previous tutorial and import adhesion.stl as a new model (attached below).
Select both models and click Edit->Align Selected Model Origins. This will make the models concentric. In this case, because the origin of each model is coincident with its base, they also overlap on the first layer. Because this is an adhesion layer, and not integral to the part, we will leave this as-is. We want solid contact between the two materials, and printing on the same layer will ensure that. Later, as you get more advanced, there are a few ways to adjust this:
- Model the parts together and place them exactly where you want them. When you align their origins they will return to their modelled positions.
- Move the CalCylinder up by 0.2mm
- Reduce the first layer height of Adhesion and increase the first layer height of CalCylinder
Now we will select which Process will be used for which model. You may want to read up on processes in S3D before continuing. Basically, any process can use any Tool (or combination of Tools); nothing says that a process has to be named as, or associated with, a certain Tool. However, our convention IS to do so. In most of our .factory files, you will see Processes named T1, T2, T3, T4, or T5. As you progress, and want to try different things (like encapsulating materials), then you will need to utilize more advanced Process features. For now, the T4 process will only use Tool 4. The T5 process will only use Tool 5.
Back to selecting models: double click T4 to enter the T4 Process settings. Click "Select Models" and highlight the part that should use T4 (TPU): Adhesion. Do the same for T5 and select CalCylinder. The sanity check for this will happen during the print preview, which will show which Tool is printing which model.
The only differences in settings between T5 and T4 are Extrusion Multiplier (T5 is 1.0) and Temperature (T5 is 240 - this could be higher [and should be for a critical part] but 240 is the limit for the standard hotend and this guide should be applicable to everybody).
Highlight T4 and T5 and click "Prepare to Print".
The preview, with Active Toolhead selected for Coloring, confirms that the correct Tools are printing the correct models. Save the file and enter the Wizard.
As before, select your machine if it is recognized, otherwise "Configure manually" and proceed. On the second screen, we need to pay attention this time.
There will be one toolchange mid-print, when the adhesion layer (Tool 4) finishes and the machine brings up Tool 5. Because Tool 4 will not be used again, set the Standby Temperature to 0, so that it simply shuts off when it is done printing. We will set the Tool 5 standby Temperature to 175C, with a preheat time of 20s - this should give the tool time to preheat before it is called up. This is not at all critical - with or without Auto-Clean, the tool will wait until it reaches its active temperature before printing - but it saves quite a bit of time.
As a reminder - Auto-Clean runs the cleaning station prime cycle before printing. Turning Auto-Clean off will begin printing without priming. We will turn Auto-Clean on for both Tool 4 and Tool 5.
The next screen is also important for this type of print:
Simplify3D does not allow the adjustment of first-layer speeds per-tool. That is, we can adjust the first-layer speed for the print as a whole, but not for an individual tool. This is a problem, because we get better adhesion on the first layer above the Adhesion Layer the slower and hotter we print. To include this functionality, we will adjust only the first layer of Tool 5 with the above table in the Wizard:
Tool 5 - Layer 1, Any Print Region, 50 Speed Factor %
If you look at the resulting Gcode file, this line will follow the T5 toolchange (which is actually M98 P"tprime5.g" to run Auto-Clean):
This sets the Speed Factor to 50% (this will be reflected in the web control slider in Job Control, which will be at 50% during layer 1, and can still be adjusted manually). The Speed Factor is then returned to 100% at layer 2. Note: it is layer 1 here because we are printing both T4 and T5 on layer 1 (they are interfering) Depending on how you configure that interface, you may actually need to adjust layer 2. Your first few times doing this, it will help to sanity check the Gcode file. Looking at the Z height is the best indication of what layer you are on.
Save that file (also attached below), Upload and Print, and you should get this:
Note the significant offset between Tool 4, which had X-Y offset set in the previous tutorial, and Tool 5, which still has an X-Y offset of 0,0. As with the last tutorial, we will now jog the Probe into the cavity, Find Center, and set Tool 5 X-Y Offset.
After setting the offset and running the same file again, well-aligned: