Forgot to insulate the corners from the heatbed! DOH! Thought of it, realized I needed to, a few test prints is all… was what I was thinking just before I forgot… this was after maybe 12-15 hours of printing with the bed too hot at 65c didn’t even need it really, 45c or so would have done the job I needed. PLA box 150mm x 120mm and tall enough to take 10 hours (duet case on .14 going for a super nice surface). Noticed bad layers but it was still actually printing reasonably well, as the motors pivoted skyward…
Live and learn this DIY was first of all to teach me about this, I learned something so still on the right track.
For now the insulation plumbers use to put behind pipes they are brazing might do the job nicely. Plumber told me about it once related to another project but from the description, thin sheet that resists the heat from a blowtorch to preserve wall building materials, it might be really good for this at totally isolating the heat zones of bed and motors.
I need some of that to try out, anyone tried it already? Looking on Amazon… 1000c resistance ‘felt plumbers pad’ showing the stuff with a blowtorch on it, but over 15 hours how much heat transfer? Buildup of heat? Will it break down? various materials available… any recommendations besides felt plumbers pad that is cheap? I think I have seen cork used… is that a good material? does it burn or char over long term use? I plan on using some fans on the motor side of it all, tight fitting insulation against the bed. Sound ok or is there a better method?
going to loose build height, 10mm or so, but sort of no choice if I want to print anything really big and tall and have a flat base. 5 hours no problem but 10 hours at 150mm wide with no heated bed and the corners will lift, ever so slightly to ‘omg NOOOOOOO YOU UGLY HORROR!!!’ it’s a bit random but it just won’t lay flat reliably to prototype versus troubleshoot.
@VolksTrieb it was understood they would not last, ABS units are printing right now, after a little incident with layer shift that turned out to be the PLA belt tensioner in the 40c enclosure under the 90c heatbed… another lesson. Frustrated for a half second but for some reason this feels right, like a necessary learning step in understanding printing better in the only way that really works for me, doing and experiencing. The rebuild was nagging at me, ‘should I rebuild with the redesigned parts?’ well now I am, decided for me and honestly a relief. I encourage laughter at this one. PLA corners on a cheap i3 clone did an amazing job for what they did! soon to be buried with honors in a recycling bin. Never prototype in anything more than biodegradable and cheap, then make the tested final parts in the good expensive long lasting stuff.
I use 3 layers of cardboard wrap with aluminium foil and put cheap kitchen silicone mat on top, push the bed to 110 degree C and still fine, my corner is injection mold ABS part by the way.
Even so I still print some spare with PETG just in case
You could turn the current down a bit unless it starts missing steps, or you could add a heat spreader. There’s a few choices of high temperature PLA which work better than standard PLA too if you don’t want the hassle of ABS curling.
One final point, What about supporting the motor from the back as well, then it’ll have to work harder to pull itself put of line.
@Duncan_Gunn we think alike. designed braces from the side extrusions to the motors a few days ago even before this melted corner incident, working out the tensioning, set screws or threaded rod to motor, possible plate of copper as interface/heatsink.
but for a holistic approach, i am thinking bent steel plate corners, simplest lowest energy budget most recyclable strongest… not many reasons to not go make some or commission them. just to easy.
this DIY was first of all to teach me about this, I learned something so still on the right track.
