Still can't figure out Nozzle knocking prints off

[truenorthtrader]

Hey folks

On certain prints with spaces in them and quite large, they get knocked off eventually by the Nozzle.

Seems the rate at which it is rising per layer is not enough to accommodate the plastic put down.

I've tried extruder calibration to a Tee numerous times. I then dropped it from 560 steps ( perfect setting for mine ) to 540 steps and I still get it happening.
I also reduced flow rate to 70% as well in Cura ( Use Cura for slicing )

I retightened the Timing Pulleys on the Motors to be sure there was no slipping.


Is there another way here?

Is it possible to increase a number in Repetier that tells it how much to HOP up for each layer and increase it slightly?

I'm wasting alot of plastic on big prints, haven' thad 1 finish without this happening for the last few months
thank you

[daftscience]

It sounds like the problem is your parts aren't sticking to the bed. How have you treated your bed? As far as the hop goes, that's set in your slicing program. In kisslicer it's called Z-lift. In Repetier host in the slicer settings it's under "Printer settings-> extruder 1" and it's called Lift Z.

[626Pilot]

Do you have stock arms or are you using something else? Also, if you print something that should have perfectly flat, 90 degree sides, do they actually print that way, or do they seem to lean in or out as they get taller?

[truenorthtrader]

Thanks Guys

I've done all the calibration for the Extruder done many test prints check cheapskates, heat levels, connections, belts etc. regularly I got mine at the Kickstarter and have made alot of items but occasionally depending on the model this happens

I have a glass bed and use Kapton Tape and on top of that Strong Hold hair spray.

The rafts break but only AFTER the nozzle keeps pushing against the model otherwise on their own they stay unless pushed against by the nozzle.
Rafts will break on the top layer but bottom still sticking to bed usually as shown in attachment. ( this was me trying to start the print from where it broke on the object the first time and abs glue them together )

My perimeters are set well my wall prints were near perfect as well as Pyramid and steps pyramid but I'll try some more tomorrow has been a while.

Z-Lift setting is something I don't use because of the extra time and bit of blobbing I get when it raises. I meant the lift it makes on every slice that info is in repetier somewhere.

Since I already dropped my calibrated extruder rate to 540 from 560, and have my flow rate at 70% it shouldn't hit the previous slice so I can only assume it's not raising high enough for each layer.

I've seen other printers printing objects with holes in them without ever touching the object and NOT using Z-lift.

There is no Z-lift feature in Cura sadly, Slicer is disappointing on most items I slice so I don't even use it anymore. Maybe I should try Kisslicer again but it seemed a bit confusing but there must be something I can do instead of resorting to Z-Lift feature on everything.

[truenorthtrader]

Did a quick hollow square print and no pushing against object so I don't get why some prints get squashed and some don't although this is a very small print

[626Pilot]

Is this ABS or PLA?

[lordbinky]

What do you get when you print one of these bed leveling prints?

http://www.thingiverse.com/thing:50505

For me personally, the area between the towers on the glass plate were trouble areas...I may have cheated and shimmed a couple pieces of thin cardboard under the onyx to correct this, that is an issue Future-me can handle better than I can.

[KevinValentine]

Did you try calibrating the towers and printbed by the manual?

I was having the same issue. If the print head assembly doesn't travel on a perfectly flat plane it could hit the higher side of the print as it is traveling to it...Running the G code calibration schemes in repetier host seemed to fix that issue for me.

[lordbinky]

For multiple objects like that if I am overextruding I'll I get raised areas from the print head squishing material upward, by the time the print head come back around those verticle ridges/bulges/etc are hard and so the print head will put considerable force on the object when it moves across and I don't have a high z-lift.