# X-axis homing failed with odd results on Tevo Tarantula

I recently finished building my Tevo Tarantula but now I have an issue with homing the X-axis.

I have uploaded MarlinTarantula EasyConfig 2.0.x firmware with Arduino Version 1.8.15 on to the Tevo Tarantula. Whenever I press Home X on the LCD, or by sending the g code command G28 X0, the X carriage moves to activate the end stop, it activates the end stop, then the carriage moves to the right, or away from the end stop, then it moves back and jams in to the end stop.

When I physically press the X end stop and check the state with the G-code command M119 the end does register as 'triggered' so I don't think the end stop is the problem. However after reading some other threads I'm not sure anymore. I will link a video to show how the problem I have just described.

This is the link to the video: https://streamable.com/kbdnwc

Edit: When I do press the X end stop manually with my hand during homing of the X axis, the carriage has very similar behavior. It stops, then it goes to the right, which is away from the X end stop then it comes back to the left and I get the message of "Homing Failed. Please Reset."

• Just to confirm, you hear the impact/stalling motor sound when the carrage moves towards the end stop for the 2nd time during the X home? Aug 9 at 3:19
• Yes, when the X carriage moves to the end stop for the second time the X motor makes a weird stalling noise like it's being jammed and then I get the error message that the Homing was Failed. Aug 9 at 3:42

The first thing that jumps out to me is where the frame is pushing on the switch. It looks to be directly over the switch actuator and not at the end of the little metal switch arm. This will make the gap from switch activation point to hard stop and bottoming out the switch really small. Any software delay after endstop detection or flex in the system may could cause the delicate switch to be used a hard stop.

Speaking of flex in the system is hard to tell for sure but the belts do look slack and not well aligned. The chance is not zero the two issues could combine to create this problem you are seeing

A informative test might be able hold a credit card size of plastic against the frame in front of the sensor so it contacts the end of the metal arm first as it homes.

• Yeah I also noticed that the frame was hitting the switch right at the actuator which seemed odd but now that you mention it there is a chance it could be missing it completely since there is such a slim margin of error. I will try to add a little plastic piece that extends the frame to see if it helps with the issue. When you mean well aligned in reference to the belts do you mean they don't look tight enough? I totally see that, although I don't get any issues in terms of moving the X carriage either distance and the motor missing the teeth of the belt but I will definitely tighten it. Aug 9 at 2:30
• It's difficult to make it out in the video but the top of the belt seems to have a arc to it, implying the tension is not proper. Also the closer it gets to the extruder the lower it seems to get, I don't know if that is normal for this printer but it does strike me as odd and worth investigating. Aug 9 at 2:35
• I also want to add that when I do press the X end stop manually with my hand during homing of the X axis, the carriage has very similar behavior. It stops, then it goes to the right, which is away from the X end stop then it comes back to the left and I get the message of "Homing Failed. Please Reset." Aug 9 at 2:57
• Good to know, you may want to add that info to the question. Aug 9 at 3:02