4 ms·
Heated build plates and enclosures are primarily to prevent the part from warping and pulling itself off the build plate. The problem with trying to bond two h
by cptskippy 9y ago
Heated build plates and enclosures are primarily to prevent the part from warping and pulling itself off the build plate.
The problem with trying to bond two hot layers together is that they distort. Typically the previous layer has not solidified enough and so most printer employ a cooling fan to lower the temperature of the previous layer, not raise it.
It's very hard to find the right balance of extrusion temperature, fan speed, feed rate, and a myriad of other factors that affect print quality.
Honestly your comment makes me think you've never actually used an FDM printer.
- jstanley 9y agoActually the fan is to cool the current layer, immediately after depositing, to solidify it as quickly as possible. That it also cools the previous layer is just an accident. I think Animats is right. It would be better to locally heat the previous layer right before depositing, and then cool the joint right after. Unfortunately that requires highly precise heating and (even harder) cooling, so is probably still a few years away.
- Animats 9y agoLocalized cooling isn't hard. Laser cutters do it; they have a tiny nozzle spraying compressed air (in some machines, an inert gas) on the cutting site. For temperature feedback, a non-contact IR sensor would work. Operate the IR sensor only during the off time of the laser (presumably pulse-width modulated) and you can read the temperature while heating.