Prusa i3 pro b second layer failure


I just bought a 3D printer => Geeetech Prusa i3 b.

I build it myself and I'm trying to print the famous boat, the Benchy one.

Here's my settings (I've tried Repetier host and Slic3r or Ultimaker Cura):

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And that's the results..

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Any tips about the settings? The problem seems to be when I print every other layer but the first one which seems reasonable enough.

I used Slic3r with the settings taken from this video, eBay Prusa i3 slic3r settings (comment response video)

Now the first layer is almost perfect but I still have problems with every other layers, too much filament comes out and it's all messy, a bit like the picture I posted above.

A video of the print can be found here.

The steps per mm value for the Z shaft is 2560.


Posted 2018-10-29T09:56:29.457

Reputation: 51

Hi and welcome to SE.3DPrinting! Please do not post links, instead post the pictures so that people do not have to click on them. SE websites are driven by questions and answers. Please read the [help], accessible through the button with the question mark at the top right menu. Please take the [about] and also have a look at the [ask] section! – 0scar – 2018-10-29T10:10:43.273

Cropping the photos is a good idea too :-) – Greenonline – 2018-10-29T11:43:17.047

Can you post your printer settings. My guess: A mixture of bed leveling and maybe underextrusion. – dgrat – 2018-10-30T15:30:47.647



You need to level the bed properly by setting the correct distance between the nozzle and the bed. Ideally, you need to be able to drag a piece of plain A4 paper between the nozzle and the bed when the nozzle is at Z = 0 giving you a little drag (you feel that by a stuttering movement). From your pictures you can clearly see that the nozzle is way too far from the bed when depositing the first layer (as seen from the video you posted in the comments) as the hot filament drops/falls down to the hot plate. Once it is too far from the plate, each consecutive layer is too far from the previous layer.

From the images you posted, it is clearly visible that you have a mechanical/calibration issue. Your belts are probably not tight enough too, but it is difficult to say at the moment as the products are way off from what they should look like.

Note that the printer configuration could be incorrect (although very unlikely as it is out of the box). E.g. the stepper motor needs to make a certain amount of steps to advance the carriage in Z direction. If the mechanical layout requires 400 steps per mm (which is typical for TR8x8 (p2) lead screws on 1.8°(200 steps per revolution) stepper motors and 1/16 microstepping) but is configured as 800, your layer height advances twice as much although the Z=0 level would be okay! I now read (from the updated question) that the value for the steps/mm for the Z axis is 2560, this implies that you are using M8 lead screws with a pitch of 1.25 mm on a 1/16 microstepping board and 200 steps per revolution steppers.

From the specifications of your printer follows that the Geeetech Prusa i3 Pro B uses:

  • Stepper Motors: 1.8° step angle with 1/16 micro-stepping

This image show the configuration of the axes: Configuration of the Geeetech Prusa i3 Pro B

So 2560 is correct!


Your initial leveling and height setting is incorrect, when you printer is at Z=0, it actually is positioned higher. Hence your first layer has very bad adhesion and is not properly flattened and each consecutive layer shows the same problems of falling hot filament. When the speed increases on the next layers the hot filament deposition cannot follow the nozzle, hence the "spaghetti" looks.


Posted 2018-10-29T09:56:29.457

Reputation: 25 570

But why does the first layer works fine? I adjusted the high with the paper before printing – Miriam – 2018-10-29T10:30:35.557

2@Miriam Your first your does not look fine. Also, how many steps per mm does your Z axis have. You should be able to get that from the menu. – 0scar – 2018-10-29T11:34:18.960

If you mean "Lift Z" under "Retraction" section is set to 0 mm If you mean "Z offsets" is set to -0.1mm

I've changed my settings with the ones on the video i posted and the first layer i'd say that is pretty decent ( not like the photo i posted) but on every other layers come out too much filament, looks like spray cream if you know what i mean. I will try to post a video in action as soon as i can – Miriam – 2018-10-29T13:12:48.563

@Miriam I understand exactly what you mean, it sprays out because the height between the nozzle and the bed is too large, you hot filament just falls down to the plate, it is not pressed flat. With steps per mm I meant that how many steps per mm your stepper needs to take to advance a millimeter in Z direction, usually this can be found in on of the menus on the printer display, or found when you send the M503 command to the printer over USB with a connected computer using a terminal program like Pronterface for instance. – 0scar – 2018-10-29T13:26:42.353

So ZSTEPS/MM = +2560

Here's a video of the printer at work

– Miriam – 2018-10-30T08:21:52.837

@Miriam From the video you can see that my answer describes your problem. Your nozzle to bed distance is way too high (the filament drops down). The value of 2560 steps per mm is clearly correct if you have M8 (p1.25) lead screws. – 0scar – 2018-10-30T10:20:50.017

Allright, i'll try to lower the bed distance even thou it's almost in touch as the first layer comes out ok! Thanks – Miriam – 2018-10-30T12:16:59.070

@Miriam Your first layer is far from OK! You can see that from the video, at one point the filament is laid over a piece that is in the way and it is just laid over, not even squished! You need to either lower the Z endstop, or raise your bed; by the looks of it it could be a mm off! – 0scar – 2018-10-30T12:33:26.437