First print shifting

[dylantep]

Hello all, I'm still trying to get a good first print. I have calibrated the machine very well however when I go to print the first layer tends to dig into the bed a bit. I raised the z height to get it to work but now every layer seems to shift away from the x tower and the print dosn't get any taller. just shifts. help please!

[DavidF]

how about a pic of your first layer for starters? If the layer shifting in on one axis compair it to the other axis's and see if you feel anything binding up.

[Mac The Knife]

How did you raise the Z height? Did you reset the Z zero per the manual, but set it for less drag on the paper?

[dylantep]

I already threw away the print. sorry. Ill take a pic when I try again. The x dosn't feel any more resistant to movement than the other axis

Yes to raise the z I just bumped up the Z0 by 0.3mm

[DavidF]

is the loss in steps occuring on the first layer? or is it continous?

[dylantep]

continuous. in fact it only happens on layer change.

Each layer has the correct shape and dimensions but each layer is not placed directly on top of the next but shifted a couple millimeters

[dylantep]

Attempted another print after some tweaking. same result

[mlapaglia]

Attempted another print after some tweaking. same result

That looks like you are pushing the head way too far into the bed. Get it further from the bed, make sure when lines touch each other as the first layer goes down and there is a even amount of filament across the line.

[dylantep]

I raised it up by .7mm and screwed in the screw on the x tower so it would be a bit higher. had a pretty similar result. still smashed into the bed in the part closest to the x tower.

[mlapaglia]

Check your x tower belts, make sure they aren't slipping which causes the print to shift.

When you set your z height are seeing if a sheet of paper can fit under the nozzle? I realize lifting the height up that much seems like a lot, but if the z height is set below the bed it needs to come up more.It looks like 4 or 5 layers all have the same amount of tape showing through, making me think even though the height is technically rising the nozzle isn't because it's nailed to the bed.

[Mac The Knife]

At this stage of the game, if all of the mechanicals check out, I would reflash the RamBo and start from scratch.

[dylantep]

Check your x tower belts, make sure they aren't slipping which causes the print to shift.

When you set your z height are seeing if a sheet of paper can fit under the nozzle? I realize lifting the height up that much seems like a lot, but if the z height is set below the bed it needs to come up more.It looks like 4 or 5 layers all have the same amount of tape showing through, making me think even though the height is technically rising the nozzle isn't because it's nailed to the bed.

I did a piece of paper folded in half for the center and the points closest to each tower. there was the same amount of friction (enough to still slide the paper around) at each of the points. now its way above the paper if I go to Z0 but when I print it seams it gets lower on the side near the x tower instead of going up each layer.

The belt is very tight and not slipping and the cheapskates seem to be just as tight as the other two towers. I'm really lost here.

[DavidF]

when you calibrated the printer did you have to adjust the horizontal radius?
Sounds like you may need to go back over the calibration and check this.
Edit, think i misread your previous post......when you calibrated you had it gripping the paper at all towers and z o?
Not that the nozzle was high in the center until after you increased your z height?

[dylantep]

yes, I did have to adjust the horizontal radius.

When I originally calibrated, the paper could slide under the nozzle with some friction at each tower and z0

I later increased the z0 height and screwed in the endstop screw on the x tower (to raise the nozzle even more by the x tower as that was where it was digging into the bed).

after these adjustments I had a similar result and the nozzle began digging into the bed again though it took longer.

[mlapaglia]

Alright, get your bed back to the point where it's the same pressure on the paper on all of the towers and z0.

Do you have access to a camera? Can you get a clip of the first layer going down?

[DavidF]

I'm leaning to this being a mechanical problem. it really looks as if something is binding. what machine are we working on exactly.
Edit, just went back thru some of your older posts. Early rostock!! That explains the bed..but opens up a whole new set of questions about the differences in that version of printer.

[dylantep]

I'm leaning to this being a mechanical problem. it really looks as if something is binding. what machine are we working on exactly.
Edit, just went back thru some of your older posts. Early rostock!! That explains the bed..but opens up a whole new set of questions about the differences in that version of printer.

Mechanical makes the most sense, i'm just not sure what the problem is. I bought the extruder platform and replaced that and all the u joints with the new plastic ones because I thought the problem may have been caused by me not sanding well but It didn't seem to solve the problem. The belt is tight and the cheapskates seem to work just as well as the other towers (unless its something to subtle for me to feel by hand or see by eye

[DavidF]

Are you still running the 20 tooth pulleys? What steppers do you have? And what current settings?
Try going into your slicer and set everything to turtle speed (10 mm/sec) and re slicing the part and watch it print, maybe it will help you eyeball something....

[DavidF]

What slicer are you using? Cura seemed to have a nasty rapid just after the nozzle reached temp and it went to start the print. This was with its default beginning g code where it would lower the nozzle 10mm off the bed before heating up.
I hated that configuration so i quickly changed it. But i remember the sudden snap bang it did right before starting the print.

[dylantep]

I have 15 tooth pullys and wantai steppers and the current is set to 175 (which should be the correct)

I am using slic3r. I will try setting it slow and seeing what happens.

[DavidF]

Any luck??

[dylantep]

just got around to giving it a shot. I was printing at 20mm/sec previously so it was already pretty slow. I tried it at 10mm/sec and basically got the same results. I tried to get a video but I need to set up some better lighting before you'll be able to see anything. Even running it slow, I didn't notice anything different about the x tower moment from the others

[dylantep]

Alright. So I noticed a huge problem when I move the hotend in midair. when moving in the x or y directions it seems to dip downward and not just move flat across. I took a video of the problem and I'll attach it to this post

https://drive.google.com/file/d/0B-yR9N ... sp=sharing

[DavidF]

Holy cow!! (actually thats cool as shit) whats your horizontal radius set to? Strange though if you went thru the cailbration and it meets the bed at all 3 towers and at center....

[dylantep]

My horizontal radius is set to 129.000. But I got to that from doing calibration. Also wouldn't that cause it to smush into the bed everywhere? not just in one corner?