Recommend a fan mount?

I've been plagued by prints that curl on the top layers causing the nozzle to bump into them and basically ruining prints so I printed this fan mount and things improved dramatically.

However, I'm still having curling issues on the opposite side of where the fan is. I tried printing pulleys and it's comical how one side is perfect and the other side has curled spikes like a crown. I was going to attempt to print this one with a ring but I don't know if it'll really be effective or not. Considering the extra work to modify the mount to fit the belt clamp distance of the Mendel Prusa i2 x-carriage, and what looks like a lot of plastic, I wanted to ask

What fan mount are you using? Am I better off forgoing all that and just picking up a stand fan and pointing it at my printer? I'm already printing at the lowest temperature I can without stripping and I don't think I'm printing very fast at all at 60mm/s.

Edit: My fan itself is a 6.8CFM fan and it's hooked up to an always-on 12V connector on a Sanguinololu. Would my situation improve if I got a high speed (high loudness too, probably) fan like this one?

Edited 1 time(s). Last edit at 07/13/2012 12:03PM by Mazaw.

I just use a 120mm case fan running at 9V blowing across the entire print surface, from the front. I don;t experience any difference front vs. rear in terms of non-curling.

-Rob A>

What layer height are you using. It sounds like the layers aren't sticking together properly. Does the print stay flat on the bed with just the top curling? And is this with PLA or ABS?

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Experimenting in 3D in New Zealand

@NelsonRap:
I'm using a 0.2mm layer height with a 0.35mm nozzle. Comes up on Josef's calculator as the suggested layer height for the nozzle size. I'm using PLA to print, and generally speaking it stays flat on the bed. I say generally speaking since, once the curling happens, the nozzle will run into the curls. If the curls start low enough in the piece, which they do when printing bar clamps, the repeated force of the nozzle striking the curled plastic will eventually yank it off the heated glass bed. When there is no curling, it stays perfectly put on the bed and I get that groovy perfectly flat shiny bottom.

I haven't experimented with changing the layer heights since I've been real comfortable at 0.2mm, but I could always reslice at thinner or thicker settings.

@RobA:
Do you have your fan suspended on the printer frame (not sure if you're using a Mendel based printer)? Or it it just placed on it's side on the table near the printer?

I had the same problem along with the guy who made this [www.thingiverse.com]