Bed warped suddenly?

[maxed280]

Hey guys new to the 3d printing stuff but had some very good results out the box with my ctc.

unfortunately after my last print everything has gone wrong and cant get it back again.

I have changed the filament from what come with the ctc to rigid ink stuff and leveled the bed countless times. also checked the nozzle for a block.

some parts of the bed i get a good print then in the center or towards the back seems like nothing is coming out the nozzle and drags parts of the print off the bed.

could it be the bed is warped already? has anyone had issues with the alu bed?

thanks

[EagleSeven]

??? There are spring-loaded adjustment Screws at all 4 corners of the bed-plate, under it .
Are you saying that those will not adjust the bed height correctly ?

(the springs may have caused the change)

Those screws normally have Wing-nuts on them that can be a little difficult to adjust,
so I printed some knobs to replace the wing-nuts, which I downloaded from thingiverse.com

I suggest that you add a piece of glass to top of bed-plate, if you have not done that already.
Glass will correct any warping in bed-plate.
(glass is held on with same Aqua-net spray as used to hold printed objects on glass)

[maxed280]

yeah i have adjusted these screws many many times im afraid and alwys the same result.

what i dont understand is ho wi was getting good prints then now this warping problem? do this just happen over time?

im now looking for a glass plate in the UK

[EagleSeven]

yeah i have adjusted these screws many many times im afraid and alwys the same result.

what i dont understand is ho wi was getting good prints then now this warping problem? do this just happen over time?

im now looking for a glass plate in the UK

We have Not seen any major changes in bed-plate like that,
so don't have any ideas as to what would cause it, Sorry.

Could it be that nozzle/heat-block assembly is moving up and down, and Not the bed-plate ?
I had to replace that small set-screw in heat-block with a larger size, since threads stripped very easily

I think adding glass will be big help !

[maxed280]

I'm sure it's the bed, in the center seems to be a dip of about 1mm.

This wasn't here before as prints have been fine.

Can't even get a raft to print now. Totally useless.

[EagleSeven]

What Temp is Bed-plate at ?
If you are using PLA filament you can lower temp to 60 or 70 C and get good prints.
Maybe lowering temp will keep bed-plate from warping so much ?

Note: remember that Temp on top of Glass is about 15 C lower than indicated temp

[Bobby Lin]

Hi! Based on my experience, here are the possible reasons for bed warping issue:

1. Bed temperature needs to be accurate

2. If printing large items (or just long items) infill matters a lot. Less infill or the hexagon/honeycomb infill really really helps with warping. A lot of my warping came from trying to print large items at >60% infill. If you get good layer adhesion, there really should never be a need for such heavy infill.

3. An enclosure of some sort. The piece I put on the top of the printer seemed to have made the biggest difference.

4. Getting a good first layer. Getting your bed leveling right makes a big difference. You want that first layer to push into the bed a bit, but not so much that it distorts your layers. Set the distance between nozzle and bed to about 80% of your first layer height. I use feeler gauges. I heat everything up and let it soak for a bit. Then I place my nozzle directly over each screw and adjust that screw. Then I repeat and repeat until it stops changing. Then I confirm by moving the nozzle to the center and if adjustment is needed, I adjust all four screws by about the same amount. Then one more pass over the screws.

Let me know if this will work for you. Hope this helps!

[maxed280]

OK update,

Glass plate installed, bed prepared and filament sticking well enough.

However seems like there is a hump smack bang in the center of the build plate. if i level on all four corners the put the nozzle in the center it touches the glass. this means i have to back off the four corners that causes its own problems.

so what could it be now? cant be the glass warped also. so now its got me thinking something is bent or loose?

any ideas where to start?

cheers

[EagleSeven]

Did you try putting a known Straight-edge, like a metal Ruler, on bed ?
To try to see if it is really warped.

I'm thinking the Tubes, that extruder assembly moves on, may be Bent down in center ?
But I don't see how they could get bent with normal use.
The tubes in our printer have not bent and I've put a Lot of pressure on them during extruder Clean-outs.

[maxed280]

Yeah I've used a rule and seems flat enough. Certainly not enough to cause the problem I'm having.

Something is moving as it stops extruding half way through a print probably due to a blockage.

I cable tied to two rods on the left and right that run front to back as these have a tiny bit of slack.

I'm also thinking the rods on the extruder are bent and it's almost perfectly in the middle on the bed it will touch. No idea how this could have happened.

Getting frustrated now tho