Problem with my Prusa Mendel

Hi all
Short time viewer, first time poster. I bought one of these a few months back. It's been a bit of a rollercoster ride, but I bought it knowing that anyway.
I have over the past couple of weeks got it printing some really good bits and peices, except now it has decided to develop a bit of an issue.
The X axis won't move away from home cleanly. So say I ask it to move 100mm (or more correctly to X100), it moves from home, left to right, about 5mm, has a bit of a stop and think for a second then continues on and stops at 95mm. Repeatable.

I though it it was snagging on something so i cleaned and lubed the X axis rods, made sure the belt wasn't snagging anything or rubbing on the bearing washers - all that is (and was) all fine. I certainly can't feel anything out of the ordinary when I manually move it along.

So, my next step was to swap the x and y axis motor connections on the Sanguinololu board, so X instructions was now controlling Y motor and visa versa. Friggin X axis motor (now controllered by the Y axis on the board) still did it. Exactly same problem.

So I'm now left thinking it's the motor.

Opinions? Anybody had anything like this happen before? Anybody see anything I might have forgotten to check?


Cheers
Chris

Check the set screw(s) on the gear on your X motor. I'd bet they are a bit loose.

ahhh crap..... yep that makes sense. I'm out at work atm so can't check it for a few days. Will post up how I go when I get back.

Thanks UB!!!

Chris

They tend to loosen up .... I know this from experience (and a lot of yelling ...)

Spot on Uncle Bob! Grub screw was pretty loose.
Thanks for the tip. Will have to check and tighten every now and then.

Cheers
Chris