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Topic: Help! Layers shift during printing.

I recently got a SD2 and have had issues with clogged nozzle and prints not sticking to bed. I have been able to solve the clogged nozzle problem thanks to this forum. However, I am still having problems sticking prints to bed. I have used hairspray and it works but I dont like how I need to keep using hairspray to stick the prints to bed each time before I print. Is there a permanent solution to this?

However, The major problem i have been facing was with a recent design of mine. The file is attached. Shortly into the print, the prints shift towards the centre. The images of both the G code during print and the actual prints are attached. You can see that the preview of the print from the repetier host is not the same as what the printer is printing. I have heard a kind of cracking noise so this might be a problem with pulleys or belts slipping. I have tried with both .3mm and .1mm and the problem persists. Any idea how I might be able to solve it?

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Re: Help! Layers shift during printing.

Hi, a few more details will help troubleshoot the problems you are having like temps,speed,layer settings and what calibrations you have done. From the looks of the pics I would say there are a few settings that could use some changing , if the first pic is the one you mention shifting towards the center then I would check that your filament spool is not binding because this looks like the classic symptoms smile the other pics I would guess flow rate is a little short or partial clog... does the filament drop straight down from the extruder when extruding into air?

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Re: Help! Layers shift during printing.

Hi,

The settings could be seen in the snapshots from the repetier host. Anyways, the extruder temp was 198 and 196 in the two instances and the bed temperature was 85. I tried both 0.1mm and 0.3mm and the problems remained. I had printed good looking parts with these settings but have been recently having this issue with these arc like designs.

I did think about a partial clog so I cleared the clog in one of the instances when it was occurring by pausing the print and moving the extruder around. The clog issue was fixed and yeah it did drop straight. My concern is that the filament does not follow the radius that was given in the design. The first few layers are printed ok but as more and  more layers are printed the layers keep shifting away from where its supposed to be. I have been mostly using the stock repetier host settings for speed with 50% speed for the first layer. Here is a snapshot of my slic3r settings for 0.3mm layers.

Thanks a lot for the help!

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Re: Help! Layers shift during printing.

It looks to me like the main problem is Z-height and bed level.  First if your not printing on glass you should as your bed is probably not perfectly flat.  This makes leveling difficult if not impossible. 
Second squish your first layer more by adjusting your z Height.  Also you can go into your slice settings and set your first layer height to a lower number like .3 if it's a .3 profile.  it is probably at .35 I never understood that why that first layer height was set higher than the rest of the layers.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

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Re: Help! Layers shift during printing.

I would say that is a mechanical issue. The belts slipping, drive gear slipping on the shaft, stepper skipping from to low or to high of current. Do you hear anything abnormal, popping ect?

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Re: Help! Layers shift during printing.

I did the extruder caliberation. It was overextruding by 15mm. I corrected it but the problem isnt solved yet.

It looks like a mechanical issue. The belts slip. Here is a link of the video. You can just watch the first 10-15 seconds and should  see the belts slipping with a popping sound:   

dropbox.com/sc/a3jiqby6kovvaty/QsoIodH4yN

Also, It always happens with this design in layers 7 and 8.  Here is an image of initial stages when the layers starts to shift. If you zoom in you will see one side of the arc the supports are shifting but on the other its pretty much printed in the centre. I printed the same thing before so not sure why this problem would happen now.

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7 (edited by ronsii 2014-01-26 21:20:04)

Re: Help! Layers shift during printing.

from the sounds of it it's not slipping, the belt sounds extremely tight...

but you can clearly see the left Y belt is not tensioned properly with respect to the right Y belt

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Re: Help! Layers shift during printing.

Both belts are loose but the left belt is exceptionally loose. What was that popping. Sounded like the belt skipping on the drive hub. Every-time the belt skips a tooth then you will loose a step and the part will be slanted.

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Re: Help! Layers shift during printing.

If the belts are not evenly tensioned and in sync(loosen one back pulley when tensioning) then they will fight each other and you can get missing steps and other problems.

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Re: Help! Layers shift during printing.

Also your stepper drivers might be overheating. Place a fan on them when you print.

SD2 w/ mods: Rumba controller, ATX PSU, SD pro case, glass bed, with more to come...

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Re: Help! Layers shift during printing.

Also your stepper drivers might be overheating. Place a fan on them when you print.

SD2 w/ mods: Rumba controller, ATX PSU, SD pro case, glass bed, with more to come...

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Re: Help! Layers shift during printing.

DigitalWhitewater wrote:

Also your stepper drivers might be overheating. Place a fan on them when you print.

Will a stick_ on heatsink work?

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?

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Re: Help! Layers shift during printing.

Photog wrote:
DigitalWhitewater wrote:

Also your stepper drivers might be overheating. Place a fan on them when you print.

Will a stick_ on heatsink work?

It will improve the situation, but its a magnitude below what any sort of active cooling will provide. The default currents for a SD3 mean that the controller really needs to be actively cooled when in use for any period of time in any sort of realistic ambient environment (if you can print in a 18°C AirCon controlled room, then you can probably get away without active cooling ). A heatsink might get you working to print one of the many fan covers available here or on thingiverse ...

The symptoms either way will drive you nuts long term and be entirely intermittent.. so if nothing else, taking the step of active cooling it means that you can rule out the issue in the future when trying to troubleshoot print quality issues.

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Re: Help! Layers shift during printing.

adrian wrote:
Photog wrote:
DigitalWhitewater wrote:

Also your stepper drivers might be overheating. Place a fan on them when you print.

Will a stick_ on heatsink work?

It will improve the situation, but its a magnitude below what any sort of active cooling will provide. The default currents for a SD3 mean that the controller really needs to be actively cooled when in use for any period of time in any sort of realistic ambient environment (if you can print in a 18°C AirCon controlled room, then you can probably get away without active cooling ). A heatsink might get you working to print one of the many fan covers available here or on thingiverse ...

The symptoms either way will drive you nuts long term and be entirely intermittent.. so if nothing else, taking the step of active cooling it means that you can rule out the issue in the future when trying to troubleshoot print quality issues.

if I get a 12v fan can I just splice it into the wires that are going to the stepper motor? If not what about the heatbed?

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?

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Re: Help! Layers shift during printing.

no, don't splice into the wires that power the stepper, Hmmmm hadn't thought about the HBP... should work smile

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Re: Help! Layers shift during printing.

Wait a min. Does fan go on the stepper motor or the motherboard? I think I may have misread. I was thinking putting the heatsinks on the stepper motors themselves.  Would that help? Or is it the mOtherboard that needs to be cooled?  If the latter can I just buy a table fan and put it next to the mobo? Thanks

My SD3:  Clear plexiglass case, case heater, X axis stabilizer, Z axis stabilizer, thumb screws, filament guide, heatsinks on all motors, extruder fan, controller fan, heatsinks on motherboard, Y rod pillow block, USB and Power on/off switch, fully calibrated including trimpot tuning. Am I missing anything?

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Re: Help! Layers shift during printing.

you can put fans on the m/b and steppers smile