Printed object being bumped/dislodged by printer  

The nozzle clipping the print is often due to poor adhesion, one end lifts off the bed into the path of danger.

Poor adhesion is usually due to either, or both of, an incorrectly calibrated first layer Z value or a dirty print-sheet.

Revisit your first layer calibration, if you are uncertain show us a picture of the calibration print.

At the end of the calibration you are aiming to print a single layer *sheet*. It should be possible to peel it off in one and fold it without the threads seperating. If it breaks into lines it is too high, not squished enough. If it is a single sheet but with wavy lines or drag marks on it you are too low.

Also clean the print-sheet with dishwashing detergent (Dawn/Fairy) and plenty of HOT water, rinse well and dry with a fresh paper towel. Handle by the edges only.

Cheerio,

RE: Printed object being bumped/dislodged by printer

Hi thanks for your response.

I revisited calibration (0.00) and was able to print the correct outcome (photo link), but when we get to the actual print, it only takes a couple of minutes before it becomes dislodged (video link).  I cleaned with soap, hot water, dried with paper towel, I have also tried using the alcohol swab that came with the kit...

RE:

Hi sunnydeveloper,

I noticed in your calibration photo - that the orientation of the print seems reversed - mine prints the little square at the northwest quadrant of the heatbed.  Do you have the sheet on your bed in this orientation (see attachment)?  Not sure if it will affect the initial adhesion, but the center tab on the sheet fits within the two screws on the north side of the bed - I think they are there to prevent lateral movement.

RE:

From your photo, your first layer calibration is putting your nozzle way too high. Look more closely at @Diem's recommendation. Also, the line that goes back and forth across the entire sheet should have nice sharp 90 degree corners. Your nozzle is knocking the print off because the first layer is not getting enough squish against the bed. The nozzle is too high, not too low.

RE: Printed object being bumped/dislodged by printer

Thank you so much, @sylviatrilling you were right, the nozzle was too high, I have never printed before, but this together with the nudge to focus on corners really helped!   We spent time comparing the corners at different heights and found one that we agreed looked best from the descriptions here, and we were able to make our first print!!! Thank you so much everyone for your time  - this is super fun, and will pay it forward to help others new get going.

RE: Printed object being bumped/dislodged by printer

@jemison and @sylviatrilling are both right.

The wrong way around print-sheet will not cause trouble until prints get big enough to apply warping stresses - typically several hours into a large job so first we must fix:

Your first layer has nowhere near enough 'squish'.  Don't be afraid to dial down, you will see the filament flatten almost to invisibility before you endanger the printer.  When the deposited thread is noticeably flat and the end square is rippling and dragging you can begin to undo the squish by steps until you get the clean print.

Use the 'Add Media' button to include pictures.

Cheerio,

RE: Printed object being bumped/dislodged by printer

Hello

I'm having a similar issue, but am confident that my first layer print calibration is OK and adhesion to the bed seems fine (printing with PLA and temperature of the bed set to 10 degrees hotter at 70).  The nozzle of the printer hits the model at exactly the same position every time.  I am trying to print the sheep from the usb stick that came with the printer (mini+ self build), which consistantly fails at 79% (5 attempts).

Any help would be greatly appreciated.

Stuart

Reinstate defaults and then show us your first layer Z calibration print.

Cheerio,

RE: Printed object being bumped/dislodged by printer

I'll just say that I printed the dog/buddy up to about 75% as well and it became dislodged, I will play more with lowering the nozzle a bit more, but I also wonder if for taller prints, there isn't some mechanisms for securing it a bit better as it progresses? 

RE:

When you use the calibration for z-offset, all your corners should be crisp and sharp.  Also, the little square at the end should be a solid flat sheet of plastic with no gaps or ridges.  Gaps mean the nozzle is too high, ridges mean it's too low.  When you're close adjust by .025 or .050 at a time until it's perfect.  Plan on 4 or 5 attempts at z-offset before you get it right, it all comes down to the box at the end, so you have to see how that looks before you know if you're done.

I see you're using a textured bed, in my experience the textured bed has poorer adhesion than the smooth 0ne.  You need to insure that the bed is absolutely clean before you print, a soap and water bath in the sink (sheet only) followed by a 91% isopropal alcohol wipe is a good start.  Even still the textured sheet may create problems with prints with small contact points.  If you have a smooth sheet I'd recommend you use that until you get a few successful prints under your belt and you know what to expect.  Cleanliness is paramount on a smooth sheet as well, but I find the smooth sheet allows better adhesion.

Lastly, if you're printing something that starts with many small contact points that eventually merge together it may be necessary to use a brim of 3 mm to keep it stuck to the bed even under the best of circumstances.

Cheers

-Bob

As @bob-2 suggested, you need a little more squish with the textured print-sheet.

The general advice for beginners is to print PLA on a smooth sheet if you have one and PETG on a textured sheet.  In a little while you will be able to discard that constraint as you get used to the process.

Cheerio,