PLA printing without heatbed using fans

I need a bit larger printing area and I'm mostly printing PLA and others and I though about the heating/warping problem. I read that PLA sticks very well on acrylic, so could I use acrylic plate and position fans around the part so the plastic cools as soon as it is extruded and only the very welding will stay melt.

Will the fan cool down the print too fast? Would it cool down the extruder too? What if it was insulated?

Edited 1 time(s). Last edit at 08/29/2014 11:18AM by Reprint.

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Will the fan cool down the print too fast?

With some parts it may cause you troubles, but in a general way, you should specify to the fan to be on only after a few layers in order to prevent warping.

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Would it cool down the extruder too?

Yes, absolutely. To get more precision on the air flow, a support to mount the fan on the extruder, with a fan duct embedded is, to me, the best.

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What if it was insulated?

It will be better, and I think hot ends will always benefit from an insulation.

I have used an Ultimaker original for about 2 years now and it has been great with no heated bed. I do use a sheet of single pane glass ontop of the acrylic bed though as PLA sticks a little to well to acrylic for my liking. With the glass I use Elmers glue sticks (label says Extreme). A single layer of this will allow PLA to adhear really well. Just make sure it dries fully to the touch before printing on it.

Also, if you want to insulate your head, then I would suggest a roll of Kapton tape and some ceramic cloth from Ultimachine. Its cheap, easy to cut with scissors and works really well. I have a layer of this with a double layer of Kapton around it to hold it onto my hot end and it has worked great. It insulates so well I can touch the heater block (on the kapton/ceramic) without getting burned. I wouldn't suggest leaving your finger on there for very long but it does help the hot end to help up faster and hold heat much better.

As for your question about cooling, I would agree with thib88 in that a duct for a cooling fan will help to put the cooling right where it needs to be for cooling PLA. If you look around on thiniverse you can prolly find a duct or shroud for the printer you are using.