Can't raise extruder off bed

I got my Robo3D set up and my first print job wasn't close enough to the bed to print properly, so I lowered the extruder head but apparently too low, because it began tearing the blue tape I'd laid beneath it.

The problem is that I now can't seem to raise the extruder by twisting the screw either left or right - it twists for a few rotations and then just seems to stiffen as if encountering resistance. Just to confirm: If I'm facing the Robo3D, twisting counter-clockwise is supposed to lift it, right?

I don't know if this has anything to do with it, but I noticed that a bolt around the screw on the left-hand side seemed to descend from its housing (as pictured here: http://i.imgur.com/0jP8moj.jpg). It's the same way on both sides. Should those screws be up in the black housing above it? If not, does anybody know what might be going wrong?

Thanks!

 

lol what's wrong with your link

Ok first off you need to get your nuts back in place, they unscrewed themselves a lot. The nuts sit inside the x carriage ends and that's what raises and lowers the axis. Without those in place nothing will work.

 

If you're talking about the Z axis threaded rods (of which there are two) then no, twisting counter-clockwise will lower the X carriage on that side. So if you need to lift the X carriage on that side then you need to twist the threaded rod in a clockwise direction.

When you do twist the threaded rod, you need to also hold the other threaded rod immobile with your other hand. This is because as you rotate the rod, the other side may also rotate too, thus negating whatever work you do.

I think you mean the nut?

The nuts should be fully hidden within the enclosure for them underneath the X carriage. If you can see the nut then it isn't fully enclosed. You should be able to put slight pressure on either side of the X carriage and it should be steady with no movement.

 

OK, I just want to be clear: the image I linked to above is not my Robo3D printer. It is, in fact, a capybara, which I had previously linked to on Twitter. This combined with the fact that I called a nut a "bolt" pretty much explains why I had a hard time with my Robo3D setup.

Here's the correct image: http://i.imgur.com/0jP8moj.jpg

However, the advice I've received here sounds like it'll solve the problem. I'll try it out tonight.

Thanks for your help everyone!

 

Yup, you've "thrown" your bolts.

The way the Z axis works, is that it moves both motors simultaneously and the X carriage rides on top of that nut by gravity. THIS IS ON PURPOSE. The reason for this is that in the event the Z axis stop switch does not engage, the hot-end cannot be pushed into the bed of the printer. This would result in shattered glass which is bad.

Those nuts should be fully up on the inside of their little pockets on either side of the printer and should allow the hot-end to float above the bed. You'll need to "level" the bed which means you want the hot-end to be the exact same height when X=0 and when X=200. You'll have it correct when you can *just* get a single sheet of paper to go under the nozzle. You'll learn over time when it's just right.

You want to test this, btw, by raising the Z axis by +10 and then homing it. When it comes to home, that's where you should just be able to get a sheet in there. If goes in without any resistance, you're probably still too high. Adjust the Z axis screw counter-clockwise to allow the 'home' position to go further down before it engages. If the hot-end hits the bed then you're too lower, adjust the Z axis screw clockwise to raise the home position. Remember, after each adjustment, check by going +10 on Z and then homing.

Typically I like to get one side (usually the one closest to the Z axis home screw) just right first. Then move the X carriage to the other side, and then WHILE HOLDING THE ORIGINAL Z AXIS SCREW STILL, adjust the Z axis screw the to which the X carriage is now close.