You are not logged in. Please login or register.
SoliForum - 3D Printing Community → 3D Printer Discussion → fan cooling right below the nozzle?
I see there is one or two fans in other printers cooling the plastic immediately as it comes out.
I think if you can print the first (first few) layers with such fans off, then the rest of the layers with it on, you won't get warping.
Solidoodle doesn't have such a fan.
is it a good idea to add one for a warping solution, or am I missing something?
Worth a google, red. Lots of chatter about both warping and use of nozzle fans.
What's your theory on why the fan will reduce warping?
My guess (completely unverified, yet to install a nozzle fan) would be the fan would actually increase warping: the mechanism for warping is that when a layer goes down hot, then cools and contracts, it pulls on the layer underneath and bends it up like a bimetallic strip. Compounded every layer, it can create quite significant bends. I suppose you want the layer to cool as little as possible, and the whole part to stay as hot as possible, to minimise this - hence the enclosure and heated bed.
Pretty sure I read somewhere the cooling fan reduces interlayer adhesion if you leave it on, as the new plastic likes to stick to other hot plastic rather than cool (just like welding) - so you may run the risk of creating more splits.
Worth an experiment I suppose!
From the reading I've done on the forums, an enclosure combined with a nozzle fan results in a more uniform temperature distribution throughout the print, which results in less stress within the print. This has the consequence of increasing inter-layer bonding and lessening the chance of delamination and warping. I have also not installed a fan yet though.
The obvious advantages for a fan are finer small details, improved bridging and less drooping in overhangs.
For best results your fan will need to be GCode controlled. Folks have put a lot of work into the logic of these fans. You're gonna need a new board unless the Printrboard has pins you can solder to. An always-on fan will be more detrimental from my understanding.
Printrboads have a pinout for gcode controlled fan. You have to solder into it, but it's next to the thermistors on the board.
What's your theory on why the fan will reduce warping?
...
My guess (completely unverified, yet to install a nozzle fan) would be the fan would actually increase warping: the mechanism for warping is that when a layer goes down hot, then cools and contracts, it pulls on the layer underneath and bends it up like a bimetallic strip.
That's the logic I had.
But I thought of it differently now. I might be completely wrong without knowing the physics of this stuff, but thinking of it logically,
Yes, the plastic warps if it cools, but eventually all our prints reach home temperature after done printing. They don't keep warping after you remove them from the print bed, right?
So there's probably some temp range at which the plastic warps.
And maybe if the plastic stays longer in that temp it has more time to warp more?
So if you cool the plastic sooner to go below that range maybe it will have less time to warp so it will warp less?
And if you don't cool the plastic, not only it will have more time to warp, but there will be more hot layers, so more plastic to warp, which will warp together, by pushing each other up and each adding to the force of the top layer, which is worse?
The heated bed I think is to keep the plastic stuck on the bed more than prevent warping? (because eventually it turns off after printing is finished and the object doesn't warp after that?)
I could be wrong on all of these as each can have a different explanation.
SoliForum - 3D Printing Community → 3D Printer Discussion → fan cooling right below the nozzle?
Powered by PunBB, supported by Informer Technologies, Inc.
