How to fix non-connecting walls
I got my Core-One, and have started back on my air exchanger, but I'm hitting the same problem as with the old printer -- my slot walls are not properly connecting to the frame, causing air gaps (making the device ineffective). On a test print I'm getting the following:
In my settings, I set seam gap distance to -100%, but it does not make a difference (maybe this is not considered a seam?) Any ideas how I might get around this? Is there a setting which can cause these types of walls to extend further?
RE: How to fix non-connecting walls
what thickness are the thin walls?
they MUST be thicker than the nozzle extrusion width.
try setting external perimeters to 0.4mm with a 0.4 mm nozzle
it's probably defaulting to 0.45mm at the moment !
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: How to fix non-connecting walls
The walls are .4mm thick, and the nozzle is 0.4 mm -- but the walls at the ends are 1.2mm thick. Because of this, the slicer first draws all the walls, and then draws the rectangles at the end separately, and the two don't end up meeting. You are correct, the default extruder width is 0.45, but even if the walls were made 0.05mm longer, I don't believe this would resolve the issues. I will of course give this a try (as soon as my current print finishes).
I did figure out that if I make the wall ends 0.4mm as well, the slicer treats these as a single line, and the gaps disappear. A test print shows that these are not as prone to damage as I feared, so I might go along with that solution.
air exchanger,
This is a heat exchanger?
You will find that none of the standard printing plastics are much good for heat transfer - copper and bronze filled plastics are better but overly expensive for the task. Better is to make a frame into which you can slot thin metal sheets or even frames holding aluminium foil. Don't forget to make provision for condensation.
Your filament is damp which does not help, dry it, but in general the thinnest walls that can be printed without careful calculation are around 2mm. As a rough guide, assuming a 0.4mm nozzle, your default 0.45mm extrusion is the thinnest reasonable single extrusion wall - use 0.86mm for double extrusion walls. These are not rules, you can choose other values but you are going to get deep into extrusion theory if you do. Again, to ensure neat joins at the end you will need to pay attention to the thicknesses here - if you go to 3mm ends it should be fine even with single thickness walls but much less and the slicer has no room to adjust the deposition paths.
Cheerio,
RE: How to fix non-connecting walls
I set the wall thickness to 0.45 (which is my default extrusion width), but am hitting the same issue.
I also discovered that while setting the front walls to 0.4 (thereby making it a continuous wall) would get rid of the gaps for all the middle connections, as soon as that 0.4 mm wall meets something thicker (i.e. the outer wall), a gap appears. For personal use, I can mend the gap with glue (As it happens to be in a very predictable and accessible location), but I wanted to publish this model, and I don't want to have instructions forcing people to use glue to fix up their prints.
RE: How to fix non-connecting walls
@Diem -- yes, this is indeed a heat exchanger, intended for venting my 3d printer room when printing ABS or painting during the winter months. While plastic is not the best conductive material, the final model (which is a single print) will have over 11 square meters of 0.4mm plastic (with a .5 second exposure time), which should transfer over a sufficient amount of heat.
One of the goals of this was ease of production -- I had considered using metal with some TPU layers between them to guide the air, and then using bridges to move the air between layers, but then you need metal cut to the right size, you need to do a lot of printing with TPU, and then you have to assemble without any air gaps. In the end I gave up and am going with my current design.
The .8mm walls do work (I had tested it earlier), but I was hoping that there would be some settings to allow me to use .4 mm walls. The .8 not only decreases conductivity, but also near doubles print time (which is 14 hours with the .4 mm walls...). I'm currently doing a print with 2mm between the walls (actually 1.6mm). It seems to be working at the moment. I will have to clean up the corners a bit (though I may have a solution to that as well -- I noticed that if I have a T joint, then I don't get any air gaps -- I only seem to get gaps when I'm connecting to a corner of some sort... So all I have to do is extend the outer walls a few mm, and it should hopefully get rid of my issue for the outside walls... -- I'll be able to test that theory in 14 hours or so 🙂 ).