Workbee / FLexible Coupler / Problem

I am at the stage of homing the machine now and it works great except for the Y-Axis.
You can see in the pictures which I put in this mail that the left side (looking from the front to the machine) has a problem with the flexible coupler when the machine tries to home the y-axis. It doesn't get far enough to reach the limit switch; some centimeters before the machine starts to chatter really loud and the left coupler looks really cramped compared to the right side.
I have no idea how to fix this issue - maybe you can help me out.

I tried out different things to solve the problem. I switched the Motors on both sides (including flexible couplers) with the same results. It's always on the left side despite heaving a different coupler or motor. It "works" when I loosen the screws from the Motor - it relaxes the Flexible Coupler so far that I can home the Y-Axis. But now I have a loose nema Motor on the left side.

 

Thanks for the fast Reply.

The Limit Switch is on the Left Side (Looking from the Front)

Here Is what i did/checked regarding this Problem:

*machine Squareness - check (is on point as far as i can measure)
*distance from the Gantry Plates - check (also perfect on the millimeter)
*the Lead Screws are as far in the coupler as i can do it. (i cant see if they are touching but i can imagine they are)
*changed motors and Flex Couplers - no difference
*changed Y-End Plaates - still no difference


its just doing this on the las few centimeters at the back of the y-Axis.


Slowly i begin to get worried.

Thanks alot!

 

I dont think so - i think if it where bent, the Problem would also be present when the Gantry ist at the front of the machine.
Or am i wrong?

 

Thanks you for your help - i really appreciate it.

Because you both mentioned the Lead Screws i dismantled both of them and gave them a look.
They look both identical and straight.
I even switched the Lead Screws on the machine and tried it - but its the same as before.

I bought the kit directly from Ooznest.

 

UPDATE: i finally figured it out.

on the left side i placed the wrong aluminium spacers to the backlash nuts.
They needed the 3mm spacers - like on the right side - this caused the leadscrew to bend slightly.
I fixed it now and everything seems to work fine now.

 

Yes i did everything right now.
Thank you very much.

I hope i didnt damage anything on the machine with this fault.
But i cant imagine that it was too problematic - i didnt run the machine like this and the flexible coupler counterbalanced the force which was caused by the bending of the lead screw.
I wonder that the nurblocks are still fine since they are made from plastic.