[thesavageblade]

Hi--I bought a laser off eBay about a year ago and I've got to say it's decent for my purposes. Lately I've been having a problem with it slipping when traveling on the Y axis. Not all the time, but it sounds like a BANG when it slips, and ends up in the wrong position. Is there anything I can tighten or something? Thanks for any help you can provide!

[Dean448]

sounds like it is hitting a stop. These are open loop systems where pulses go into the motors but nothing is used to feedback where it is. So if you hit something it will just loose steps and position. Normally machines have limit switches that tell the controller to stop before they hit anything.
if you think this could be the case try to run the pattern with the lid open, and laser disabled, and see if anything is in the way.

[thesavageblade]

I don't think it is hitting anything, although after a year of reasonable use, I could see maybe something foreign getting in there, even if it is dust or someting on the track. Like I said, it doesn't happen all the time and it helps if I turn the laser off/on. Waiting to turn the laser on until after I start MoshiDraw2012 also seems to help, although it's not 100%. I'll do a thorough cleaning and see if that helps. Thanks again!

[Things]

Check your belts and make sure they are still reasonably tight, but not overtight. Also, make sure that the carriage is still aligned on both sides. If one side is closer to the back than nother, for example, it creates a bunch more force against the linear bearings, possibly too much for the little stepper motors to handle. From memory the K40 machines have belts on both sides for the Y axis. It's uncommon for one belt to slip a tooth or 2, but it can happen, especially if they're too loose.

[thesavageblade]

Thank you for that--I will check the belts and the alignment. Would it help to lubricate the rails? If so, what sort of lubricant should I use--would 3-in-1 oil do the trick?

[pippin88]

Sounds like a loose belt. There are tensioners on each belt, adjust with a screwdriver.

[jackyliu]

if you have further question tell us .....or why you do not contact your supplier ,they can you to fix it for you......that is they`s obligation....