joberg
Legendary Member
Would the material being used influence the bridging or it has no input into that kind of set-up?
Let's Talk All Things 3d for prop creation, Scan, Design, Sculpt (real and digital), Print and Finish
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smithjohnj
Sr Member
The type of filament definitely plays a factor. And as the filament changes the print speed and cooling (fan speed) will probably also need to change as the nozzle temperature will. Nozzle size and layer thickness also are factors. I do not know of any AI or formula approaches to all these variables (and a few others). I do know the PrusaSlicer has a large number of control options (in the their Expert Mode - Beginner and Normal Modes have fewer choices to make) and their default values are good starting points. I assume other slicers have similar controls but my experience with them are dated.
TazMan2000
Master Member
Even though tree supports are now a standard method of building a 3d support structure, they still have their issues. Fortunately, companies are always trying to improve slicers. It was a little while ago, in CURA, that I set an object flat on the build plate, started printing and walked away only to return with part of my print sticking to the print surface, and a jumble of extruded PLA. I cleaned off the surface and used some fresh hairspray and started again only to have the same effect. I tried another model and it worked fine. Then I went back to the original, and found that, even though, I positioned the flat side down with CURA, the software only recognized part of the flat surface, and from underneath, I saw there was no complete bond with the print surface.
TazMan2000
In this specific failure we have a non bridge. This floating section is attempting to print the belly attached to nothing at all where a bridge means horizontally attaching items. This scenario is failing to create a support structure underneath the belly (pieces that will not be part of the final print) in a correct way. It could be a coincidence and simply be bad codinging coming from the phone app, which IS entirely possible but having the settings for the trees a little funky could do the same. I believe that there are 3 settings we need to check due to the tornado/vortex shape that need to be created in the tree structure. The x-y distance between the supports and the print, the distance between the supports and the objects touching the bed plate and the "top z"distance which should not be more than 2.5 in our current print.
I would suggest lowering the numbers in all 3 settings to allow the trees to be larger and stronger. But also, in the slicer it should sllow you to view layer by layer as it builds and check to see if the trees have an obvious failure likely.
I really think this will come down to the numbers currently set are forcing the trees to a non existent central support point. Because there are 4 legs and if the settings tell the trees to be too far away from print parts during their rise, it might be strangling the trees to a miniscule stalk half way up. This is easy to then knock over with the print head before it ever gets to the belly.
I would suggest lowering the numbers in all 3 settings to allow the trees to be larger and stronger. But also, in the slicer it should sllow you to view layer by layer as it builds and check to see if the trees have an obvious failure likely.
I really think this will come down to the numbers currently set are forcing the trees to a non existent central support point. Because there are 4 legs and if the settings tell the trees to be too far away from print parts during their rise, it might be strangling the trees to a miniscule stalk half way up. This is easy to then knock over with the print head before it ever gets to the belly.
TazMan2000
Master Member
This one is a huge deal. My bambu slicer did the same.
For ovjects that do not truly have any flat area, due to coming in from sculpting instead of geometry cad, I had to purposely cut off the bottom in the slicer. I don't want to muddy the current issue with a tangent but I was shown that this is a common use of slicers to put flat bottoms on production sculptures needing a flat base.
The common advice on printing first layer where you truly have no flat base and don't intend to add one, is the use of "RAFT". This builds a full layer up to the surface of the model and unlike supports, it is nearly solid making it extremrly difficult to remove. I have had NO success using rafts, yet but I believe they are pretty common but are especially useful for resin printers where the raft washes off with water.
One for the "words people mispronounce' thread.
I spent so many years proofing and found it is typically in the exact spot you offer quality or perfection or the actual name of the service provided that you will find the best typos. Fate loves a good ego slap in your quality statement.
TazMan2000
Master Member
More of a bad spelling thread. I think we can throw 50 percent of the entire forum into that.
TazMan2000
No stringy mess a clean plate
My spelling is atrocious I am always using the slang Prolly instead of probably.
That's a word my wife uses all the time and I have picked it up.
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super rough drawing but I think this is what is happening in the middle
TazMan2000
Master Member
We all have done it, whether it being "fat finger" typing errors, or autocorrect issues.
TazMan2000
TazMan2000
Master Member
Ok .... now I totally see itKeep that pornography off the site.
TazMan2000
on the topic of first layer z height: inner circle, z is too low and is A) pushing into and frying already layed filament but also B) completely head crashing in the area where the circle disappears. This will lead to clogs and shredded filament (not forwarding into line) in the drive motor (will need to remove, cut off and replace). C) outer circle, the smooth, not lines, brim after the z height was raised during the print (in the tuning settings available while live printing but also available when not printing). D) if raised too far, you get clearly separate lines and possibly birdsnest failures to adhere to surface.
After the first layer is done, z offset no longer matters but should NOT be adjusted again. Layer 2 is counting on layer one to be where it left it. Changing z after layer one is just causing the next layer to not know how high off the previous it is.
But I forced a print to show what happens when the supports (trees in my case) do not show up to do their job. Just note that even with supports on, they might fall off, go to the wrong area, not include the failing area, or stop too far below the supported zone and not support what they were meant to, all leading to this "above the plate level" noodling:
But I forced a print to show what happens when the supports (trees in my case) do not show up to do their job. Just note that even with supports on, they might fall off, go to the wrong area, not include the failing area, or stop too far below the supported zone and not support what they were meant to, all leading to this "above the plate level" noodling:
I am new to 3d printing but am purposely avoiding the word stringing because it has somehow been strictly associated with the fine spiderweb that happens when traveling across non print zones. I would have called them hairs or spiderweb but that is not industry jargon that I can see.
smithjohnj
Sr Member
I believe it depends on the slicer but you may need to understand the precise meanings of the slicer's terms. For example "top" layer does not normally mean the uppermost layer. If you are printing a staircase, each tread would contain a localized "top layer", and would use the fill pattern you select. "First"layer seems to be somewhat random in my experience. I believe because of the way the algothrims determine the layers, undercuts, and overlays, sometime a non-first-bed-layer can be treated as a localized "first layer". However, that is not something which I can count or or is consistent when some other variable changes.
Also I agree there does not seem to be an industry standard for the fine "hairs" or "whiskers" which can occur on some prints. There is a partial solution, but probaby not a practical one since this is often not a great problerm fo most. The solution is to provide for a "filament retraction" when the printed segment has been laid down and before doing a (fast) move to the next location.
Also I agree there does not seem to be an industry standard for the fine "hairs" or "whiskers" which can occur on some prints. There is a partial solution, but probaby not a practical one since this is often not a great problerm fo most. The solution is to provide for a "filament retraction" when the printed segment has been laid down and before doing a (fast) move to the next location.
smithjohnj
Sr Member
Just as an aside, I often "print in mid air" to achieve an effect I call a "watermark", although a more appropriate term might be "internal lithophane".
I purposefully subtract an object from the interior of another object. When creating my recent At Attin location punch cards which were 2.1 mm thick, I subtracted a .6 mm (using .15 print layers) Old Republic symbol from the center. These experiments always have a solid surface below and above but it creates a hollow. When light shines through a light colored filament, the watermark "appears". Attached is the .stl of a simple example if you have a non-opaque filament and can print .15 layers.
I purposefully subtract an object from the interior of another object. When creating my recent At Attin location punch cards which were 2.1 mm thick, I subtracted a .6 mm (using .15 print layers) Old Republic symbol from the center. These experiments always have a solid surface below and above but it creates a hollow. When light shines through a light colored filament, the watermark "appears". Attached is the .stl of a simple example if you have a non-opaque filament and can print .15 layers.
That's sort of what I was trying to explain.
Did those files work for you?
If not this a screen grab from Maker world.
I checked and Loaded the print from the laptop and the tree settings had changed I guess it's the model makers pre sets?
Tree was usual but instead of Auto it came up with something else which I've completely forgotten as I type this..
The Trees were super small on this print plus something Taz said earlier reminded me that instead of being central it printed bottom left of plate and kept cleaning nosel, maybe this affects the print due to traveling distance on such a small model?
I think I'm going to draw a line under this it's not an important print just something for my daughter but there are others available.
I re printed yesterday via the laptop, I centralised the print and rotated it to see if there was less travel and..
It came out the same.
The top of the tree looks too thin and also thinking back to my chrome casting days think it needs more Spru/trees..
I printed other things since and they are perfect!
I re printed yesterday via the laptop, I centralised the print and rotated it to see if there was less travel and..
It came out the same.
The top of the tree looks too thin and also thinking back to my chrome casting days think it needs more Spru/trees..
I printed other things since and they are perfect!
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