A ‘quick and dirty’ passvly heated build chamber…
Been trying to print out the parts for a big Delta and have run into problems with delamination and curling. This helped a bit. Bottom print is in the chamber, top is without.
Any hints about how to reduse this further. I’m printing a fairly descent ABS at 255C with bed at 100C, 25% infill, slight overextrusion , 0.2mm layer height(0.3mm just gets worse).
The parts are completely usable due to the angles of applied forces, just not as pretty as I’d like them to be.
How many shells? I found 2 or 3 has helped in the past.
We built a similar enclosure at our hackerspace for our LulzBot AO-100. We put a 120mm fan at the top to circulate air and that helped us improve quality. We also have a small household thermometer sitting inside of the enclosure to check the temperature.
I agree that 255C is very hot for ABS, is that from your thermistor or have you manually checked the temperature with a real gauge?
I also need to try with 3 shells and 20% infill.
Its a e3d hotend thermister with the right temp table so it should be close. The high temp is an attempt to improve layer adheasion based on what the up-minis seem to like but it might be increesing the cooling stresses.
And a fan is not helpfull in this enclosure as its not sealed well enough.
Well for us the fan is just to circulate air, not to provide any sort of actual cooling. I would definitely try lowering the temperature a bit though.
Those are some impressive stress cracks! I also built a triple height Kossel vertex, and had troubles with cracking. Eventually what I did to get them to work was add a printed hollow cylinder surrounding the part. It took forever, but insulated pretty well. I was even thinking something like a cone starting 40cm out and narrowing and getting closer to the part would take heat from a bigger part of the bed and channel it up past the part via convection. This was dead of winter and super cold in the basement, so some extreme measures were called for.
40mm