Delamination and Z axis movement

[JohnFox 25]

Hello,

I am attempting to print some small geometric shapes, typical dimensions are 60mm x 40mm on the X & Y and 30mm on the Z axis.

Periodically and at random, I am seeing what appears to be the Z axis travel to be more than the set amount. Current setting is 0.1mm and I suspect the drop on the build plate to be around 0.15 - 0.20mm when the problem is seen. This causes an obvious band all the way round the print, which in some cases starts a delamitation. When I peel the object apart at the fault, I can see that the walls have not fused to the layer below, implying a greater than normal Z axis shift.

The problem bands occur once or twice per print and always show all the way around the print with the next layers looking perfectly normal.

The printer is only 2 weeks old, seems to perform perfectly apart from this. I am using ABS.

Any ideas?

thanks in advance

John Fox

[gr5 2,005]

Which printer do you have? Please update your profile settings to indicate this. Also update your country/location as advice changes often depending on the country.

What you describe can happen but usually if there is a layer like this it can also be caused by underextrusion due to temporary tangling filament, temporary cold layer (often due to fans coming on) and similar things like that.

[JohnFox 25]

Just done the profile - forgot about it.

I certainly have had problems in under extrusion, (something in the nozzle), that seems to have cleared now.

I am about half way through a spool of filament, is it necessary to try and uncoil it? It seems to be quite highly coiled as it nears the centre.

John

Which printer do you have?  Please update your profile settings to indicate this.  Also update your country/location as advice changes often depending on the country.

What you describe can happen but usually if there is a layer like this it can also be caused by underextrusion due to temporary tangling filament, temporary cold layer (often due to fans coming on) and similar things like that.

[JohnFox 25]

Just had another 'event'.

About 10mm vertical height printed perfectly, then one whole layer incorrect with quite an obvious gap all the way round, subsequent layers then OK until I aborted the print.

Spool is OK, extrusion of all the layer seem OK, what is happening occurs to a single layer only.

John Fox

 

Which printer do you have?  Please update your profile settings to indicate this.  Also update your country/location as advice changes often depending on the country.

What you describe can happen but usually if there is a layer like this it can also be caused by underextrusion due to temporary tangling filament, temporary cold layer (often due to fans coming on) and similar things like that.

[JohnFox 25]

I think I have fixed it!

I suspect the problem is a mix of the ABS (with high warping ) and my design. The object had several right angle corners and I think these create a lot of stress which caused explosive de-lamitation across a whole layer. I have redesigned the item with radius curves on most of the corners and the latest print was fine.

thanks

 

Just had another 'event'.

About 10mm vertical height printed perfectly, then one whole layer incorrect with quite an obvious gap all the way round, subsequent layers then OK until I aborted the print.

Spool is OK, extrusion of all the layer seem OK, what is happening occurs to a single layer only.

John Fox

 

Which printer do you have?  Please update your profile settings to indicate this.  Also update your country/location as advice changes often depending on the country.

What you describe can happen but usually if there is a layer like this it can also be caused by underextrusion due to temporary tangling filament, temporary cold layer (often due to fans coming on) and similar things like that.