Printing without Hot End Fan

[riddelln 0]

Hi,

We've just bought 2 Ultimakers for evaluation. I've just finished building the 2nd one and we have a problem with the hot end fan not working. However this is with support.

I have been printing without using the fan and the quality seems good. I'm using UM Black PLA @ 210.

My question is when would you not print with the fan on?

Cheers Niall

[owen 19]

For the first layers to make your print stick to the platform better

[zungara 10]

I only print the first layer without fan. I have got the same problem at the beginning. After same nice calls we found a solution and i got a lot of very usefull tips. Now my fan is working and the results are much better then without fan.

[riddelln 0]

Hi,

Thanks. I understand that printing without the fan makes the first layer stick better. I definitely don't have "a first layer not sticking" problem as it's pretty hard to get the print off sometimes ;-)

So what we're saying is that (apart from the 1st layer) you should always print with the fan on. If so why? Is it to reduce smearing, to ensure subsequent layers stick or that the pla will not be cool enough to print overhangs, etc. or any other reason ?

Cheers Niall

[zungara 10]

i can only say is what i personally observe.

When you use a fan you are able to print faster or if you print small things the PLA get the form you want.

try to print this:

http://www.thingiverse.com/thing:24238

For me it was not possible to print the pyramid without problems after the 3. 5mm Layer. With fan the result was ok.

[technicality 0]

The fan cools the topmost layer to avoid the printhead 'pushing in' the next layer (because it is still soft).

Print small-diameter towers or overhangs without fan are hard to do; the top layer will curl up at the edges and get the printhead to take the print with it or snap it off.