Help! Prints are not Solid!

[classified 0]

Hello,

 

I've been 3D printing for a while now and I ran into my fair share of problems. I've managed to solve most of them but there is one problem which I can't seem to solve.  I'm finishing up printing some parts for my full sized humanoid robot and most of the parts print solid except for the parts I print on my Diggro Alpha 3 and Geeetech A10  3D printer. Now keep in mind that I have 2 Diggro Alpha 3 printers and 1 Geeetech A10 and only one of my Diggro Alpha 3 Printers will print a solid part. My other Diggro Printer and Geetech A10 printer used to print good solid parts until one day I clicked print on a part and it was no longer printing properly. I have included pictures below of my non-solid part. I had to spray it with liquid rubber just to keep it intact and give it some strength. I have tried different filament and infill types, higher temperature, lower speed, re-leveling the bed, I even increased the line width and infill percentage, but I am having no luck. Can someone please help me solve this very frustrating problem.

 

 

Thanks in advance.       

[GregValiant 1,455]

It would be odd for the printer to be making things up by itself.  Really odd for multiple printers to making up the same stuff.

That top image looks under-extruded and the layers don't look bonded together.  Is that what you mean by "not solid"(?) or is it more like vase mode and missing infill?

You have tried checking with a Gcode file you know is OK (like one of the bench models)?

Edited June 1, 2020 by GregValiant

[classified 0]

Hello,

 

To answer: “That top image looks under-extruded and the layers don't look bonded together.  Is that what you mean by "not solid"(?) “ Yes that is what I mean by not solid. It isn’t properly bonded and the infill becomes very “stringy”.  I don’t think it’s the G-code because I had printed the same object the day before and it printed fine (it was nice and solid and properly boned) but when I went to print the exact same part today it didn’t work. 

Edited June 1, 2020 by classified

[classified 0]

I also did a test print and because it was a bigger part the infill turned out fine (solid) but the top and bottom layer have lots of little gaps and the perimeter layers didn’t quite bond together. As show in the picture below.

[gr5 2,295]

That's underextrusion.  But I can see the infill below and you might simply not have enough infill layers.  with sparse infill like that the first solid layer tends to droop a bit so it's underextruded (that's normal for the first layer over infill).  Then the next layer recovers a bit and by the 6th layer it's perfect.

 

However the delamination of the sides - I can't see that clearly.  If it does it on every layer then that's normal, unwanted, problematic underextrusion.  It can have many causes.  I don't know your printer.  I have a list of about 30 causes for the UM2 printer but every printer is different.  Some of the most common:

printing too fast or too cold for your nozzle and volume combination

weak feeder, damaged feeder

teflon part in hot end gone soft due to age (and heat - the hotter it gets the faster it ages and goes soft and sags).

 

If you print at half the current volume (e.g. half the layer height or speed) you are printing it should improve quite a bit (but probably still not 100% perfect).  Or if you print 70% as fast and raise the temperature by another 10C.

 

You can test the feeder by fighting it - UM feeders can typically pull with about 10 pounds (5kg) of force.

[GregValiant 1,455]

It might be time (maybe past time) for some maintenance.  Take apart the nozzle and hot end, check the extruder drive, the belts,  clean the dust and fibers out of the fans and off the wheels and tracks.  If they have them, check the bowden tube fittings and see if the tube is sloppy and can be pushed in and out.

These machines work pretty hard and it sounds like you've had them running for a while.

[classified 0]

I have been running them a lot lately but I had already changed the whole hotend a few days before. I changed it again today and its staring to work fine again. Thanks for your help.