When the Sigma gets stuck in the home position producing a loud screeching noise. This is a clear sign that you need to check the endstops, maybe one of them is stuck or broken and needs replacing.
Note: It's possible that you need to disassemble the endstops from the printer in order to check them properly, in the end of this article there are links with instructions that will help you in the process.
Below you can see where the printer’s endstops are placed:
The most common endstop related issues are:
1: Cable connection issues: Check that the endstop cable is properly connected to the
driver or extruder board in case of the Z axis one.
2: (Usually the Z endstops) Bent flat flexible cable. Check if the hotend flat cable is bent on the extruder board connection. If it is, you can straighten it manually and do a bed calibration to check if the problem continues.
3: Jammed switch. It can be unblocked using a cutter or a needle.
4: Broken endstop. Replace the endstop for a new one, see the parts list in this same article: Parts list.
If none of this works, replace the Endstop, you can learn how to do that in the following articles:
This article doesn't fix your issue? Check out our forum community for more info about this.
It's important to keep your printer in good shape to make the most out of it. In this chart, you can find a list of the extruder maintenance procedures and how frequently these should be done. Maintenance Plan
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