T rex skull print failed twice - need advice
Im trying to print the makerbot trex skull found here: https://www.thingiverse.com/thing:308335
I've been printing well up until I decided to update to the new firmware and things haven't been quite as good. Wierdly i feel like the printer actually sounds different which I dont get 😕
Anyway I noticed a lot of comments saying they printed the TREX without supports so that's what i have tried. First print failed very quickly for a layer shift, which I've never had before. I checked my belt tensions and my Y is253 x was 272 , I thought this was ok. Being new to printing I couldnt quite work out how it shifts that badly.
So I then went back into slicer PE and re sliced the model and loaded it up again. IT got further along the print this time but I came back to it and it had nocked one of the printed parts off the bed and had some major layer shifts in the model ( absolute mess). I used glue stick on the bed and had a brim on the model, it was stuck down very well. Im just wondering why did my collision detection not work and also what is causing these huge layer shifts? Any advice would be great. ( photos attached)
Cheers
Jon
Re: T rex skull print failed twice - need advice
I#ve printed this model about 5 times so far.
These models are prone to severe curling.
You need to print slow here, at least 60-70% (rotate the knob while it's printing.)
Also most likely you've touched the bed beforehand, the oils from your hand doesn't let stuff stick even with gluestick.
Also don't use gluestick, use water to get rid of the gluestick, then use 99% Acetone to get rid of the gleustick residue, then use 99% Isopronalol alcohol.
Re: T rex skull print failed twice - need advice
I#ve printed this model about 5 times so far.
These models are prone to severe curling.
You need to print slow here, at least 60-70% (rotate the knob while it's printing.)
Also most likely you've touched the bed beforehand, the oils from your hand doesn't let stuff stick even with gluestick.
Also don't use gluestick, use water to get rid of the gluestick, then use 99% Acetone to get rid of the gleustick residue, then use 99% Isopronalol alcohol.
My first failed print was really well stuck down but it still had a big layer shift, how can a printer shift like that? I'm just trying to problem solve why is not detecting that it has shifted.
Thanks for the help, Im going to try the acetone and ISO tonight to see if that helps adhesion.
Re: T rex skull print failed twice - need advice
Try washing up liquid and hot water
Give it a really good wash. Then after drying it carefully. Don't touch the surface with your hands.
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: T rex skull print failed twice - need advice
My first failed print was really well stuck down but it still had a big layer shift, how can a printer shift like that?
The filament will curl up when it's not sufficiently cooled. The next layer on top of the current one will curl up even more, and so on. Until it builds up a sharp spike and usually the PINDA probe or the nozzle will crash into that sharp hard spike, resulting in a layer shift.
Printing very slow will cause the print head not to move away fast from the current hot extruded filament, giving it more time to cool down and stay stiff the way it's intended to.
Printing fast moves the airflow away from the extruded hot stuff, and this curls upwards.
The cause of 99% of layer shifts is insufficient cooling.
The MK3 also has a worse cooling solution than the MK2, so you've got a very very fast printer that could go beyond 200mm/sec, but due to the minimal cooling you have to print very slow.
I have yet to see a stock buyable printer from any manufacturer that has a great filament cooling solution. Thingiverse is full of cooling ducts, people are trying to improve on this on every printer possible.
One hacky way to see if this is really your problem, is printing with a big brim (more footing for the print and avoiding air to lift it), and letting a big desk fan blow directly at the print. There can never be too much cooling for PLA.
Re: T rex skull print failed twice - need advice
My first failed print was really well stuck down but it still had a big layer shift, how can a printer shift like that?
The filament will curl up when it's not sufficiently cooled. The next layer on top of the current one will curl up even more, and so on. Until it builds up a sharp spike and usually the PINDA probe or the nozzle will crash into that sharp hard spike, resulting in a layer shift.
Printing very slow will cause the print head not to move away fast from the current hot extruded filament, giving it more time to cool down and stay stiff the way it's intended to.
Printing fast moves the airflow away from the extruded hot stuff, and this curls upwards.
The cause of 99% of layer shifts is insufficient cooling.
The MK3 also has a worse cooling solution than the MK2, so you've got a very very fast printer that could go beyond 200mm/sec, but due to the minimal cooling you have to print very slow.
I have yet to see a stock buyable printer from any manufacturer that has a great filament cooling solution. Thingiverse is full of cooling ducts, people are trying to improve on this on every printer possible.
One hacky way to see if this is really your problem, is printing with a big brim (more footing for the print and avoiding air to lift it), and letting a big desk fan blow directly at the print. There can never be too much cooling for PLA.
I love the 3D print community on here, you guys are so helpful ! so I cleaned me bed with acetone, increased brim size and printed at 70% .15 layer height and no supports. IM at work at the moment but my wife just told me it had finished and sent me some photos (attached, IGNORE THE LENS CLEANING WIPES I USED THEM ON MY NEW PHONE HAHA). It's not perfect but for me I think it came out better than I thought and I've learned a lot from doing. Again thank you very much Joan and devilhunter for your willingness to help me. Really appreciate it, onwards and upwards!
Cheers
Jon