Layer cooling fan

I want to get a radial fan to use for a print cooling fan. Is 50mm the smallest they come? That seems pretty big to be hanging off the carriage and I swear I have seen really tiny ones.

Edited 1 time(s). Last edit at 03/14/2016 12:21AM by msaeger.

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Newbie with Folgertech 2020 i3.

Search for micro blower and you should find many under 25mm or so.

Thanks for the suggestion but I am still not finding any with those search terms either.

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Newbie with Folgertech 2020 i3.

Found quite a number of 40x40x20 e.g. , but that's really no better than 50x50x15.

There's also a number of these in various sizes from 12-25mm, but they're axial. But they are described as blower fans... maybe the large disk in the middle helps in some way?

FWIW, I have a 50x50x15 mounted on my printhead, and it weighs very little.

Edited 1 time(s). Last edit at 03/12/2016 07:52PM by frankvdh.

I think that 40mm is the minimum size for CFM needs. Here are some.[www.aliexpress.com]

Here is a little one.[www.watercoolinguk.co.uk]

I have two of the 5015 blowers on my carriage, but I'm not winning any prizes in the light weight carriage department anyway I bought one of the 40mm blowers by accident (really should read the specs more carefully!), but it doesn't seem to move much air. Maybe I just got a bad one. The 5015s I've been using don't seem to stand up to the vibration very well. I've just ordered some spares in case the bearings fail on the current ones, they are certainly getting noisy.

I found a 50x15 one in an old piece of electronics in the basement so I am going to see how that one works. I hooked it up to 12 volts and I am thinking it may be too loud but maybe during printing with it not running at full speed it will be ok. Don't throw anything away no matter what anyone says

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Newbie with Folgertech 2020 i3.

So I have the fan now and have temporarily mounted it just for testing but I am not really getting good results. I am getting worse layer adhesion and it's not really helping with overhangs and bridges. I am guessing the issue is I don't have it aimed at the right place but where should I have it aimed?

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Newbie with Folgertech 2020 i3.

I recently switched from an axial to a radial filament cooling fan, and I'm very happy with the result... a huge improvement. Remember to only turn it on after the first layer is printed.

What duct do you have on it? I don't have any duct on mine (yet), and have it pointed vaguely at the nozzle tip, from about 30 degrees up. When then fan turns on, the hot-end temperature drops by about 5 degrees (which is why I want a duct on it).

Yes, like most things with 3d printing it's not completely straight forward. You want to avoid the fan blowing on the hotend as it will drop the termperature pretty significantly if you're not careful. A fairly well directed jet of air targeted just below the nozzle is useful for bridging, but it's prone to being very dependent on which direction the nozzle is moving at any time. A more diffuse jet (ideally from all sides) does better at cooling an entire layer so that it is rigid before the next layer starts. Once you decide on a duct shape and position, you then have to tune the fan settings to get good results - a whole lot of trial and error. Losing some layer adhesion when you start using a fan is normal, so you need to increase the hotend temperature to compensate. It's all a balancing act.

I'm surprised you didn't see an improvement with overhangs and bridges though. With pla I was getting very noticeable improvements pretty much straight away, but I did go straight to a pair of ducted radials that were very close in to the nozzle. They're further back now (space issues under the carriage with a new extruder) and not working so well. At full speed they are noisy, I use a max of 70% during printing and only use 100% for post print cool down.

Quote
frankvdh
I recently switched from an axial to a radial filament cooling fan, and I'm very happy with the result... a huge improvement. Remember to only turn it on after the first layer is printed.

What duct do you have on it? I don't have any duct on mine (yet), and have it pointed vaguely at the nozzle tip, from about 30 degrees up. When then fan turns on, the hot-end temperature drops by about 5 degrees (which is why I want a duct on it).

I don't have a duct yet which I am sure would help. I was seeing the temp drop too so I covered part of the opening on the fan so it was only hitting the nozzle and not the heater block. I have it turning on after the 3rd layer because that was the default.

What are you seeing improvements with? I am trying to help stop overhangs from curling up.

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Newbie with Folgertech 2020 i3.

Quote
JamesK
Yes, like most things with 3d printing it's not completely straight forward. You want to avoid the fan blowing on the hotend as it will drop the termperature pretty significantly if you're not careful. A fairly well directed jet of air targeted just below the nozzle is useful for bridging, but it's prone to being very dependent on which direction the nozzle is moving at any time. A more diffuse jet (ideally from all sides) does better at cooling an entire layer so that it is rigid before the next layer starts. Once you decide on a duct shape and position, you then have to tune the fan settings to get good results - a whole lot of trial and error. Losing some layer adhesion when you start using a fan is normal, so you need to increase the hotend temperature to compensate. It's all a balancing act.

I'm surprised you didn't see an improvement with overhangs and bridges though. With pla I was getting very noticeable improvements pretty much straight away, but I did go straight to a pair of ducted radials that were very close in to the nozzle. They're further back now (space issues under the carriage with a new extruder) and not working so well. At full speed they are noisy, I use a max of 70% during printing and only use 100% for post print cool down.

So I should try and get it blowing down on the print and not at the nozzle I was thinking having it cooling the stuff that just was extruded was the idea but obviously that was wrong. Any recommendations for a duct? even if it won't fit on my machine just so I can get an idea of what shape is the best.

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Newbie with Folgertech 2020 i3.

I'm still using these: [www.thingiverse.com]

I don't think it's ideal, but I haven't done anything better yet either! I also saw these in another thread today: [www.thingiverse.com] They look pretty good if they fit the geometry of your carriage.

Upon my Ormerod 2 I switched from the 40mm axial fan to 75mm x 35mm radial fan, which gave good results in cooling the print.
Also found this post about short layers (time needed to complete the first layer is too quick to provide a good base for the next, ends up looking like "Ice Cream" ) in which various fan duct and shrouds were tested. Also give links upon page to the STL files, which is good.
[www.desiquintans.com]

In slic3r's settings under the cooling you can disable the fan for the first or more layer

With overhangs curling up, up the print speed by 5 so 40 becomes 45 etc, also increase the temp, only if you started at the lower end of the manufactures stated temp range.
as I did 190 - 215. With good cooling I was able to set the temp at 205 and gravity kept the corners from lifting.

Edited 1 time(s). Last edit at 03/15/2016 06:45AM by orictosh.

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Supporting 3D Printers with Parts and Build services.
Printer: Ormerod 2 (528.4) Duel extruder set-up with Aluminium X-Rib, RRPro Firmware v1.11-ch (2016-04-08)

I am experimenting with using an aquarium air pump to provide print cooling. The pump will mount on the printer's frame and be switched on/off using the gcode and an SSR. It delivers 4 l/min of air through a 4mm silicone tube (pumps don't mind the back pressure at all). I'll design and print a dual nozzle to split the air flow. It is very easy to direct the air exactly where it is needed with a small, easily printed or bent metal nozzle. The tubing is very flexible and doesn't add much of a load to the extruder carriage. The down side is that it is either on or off and it hums when it is running.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

This design by Leadinglights looks very interesting, capable of 15l/min and I think pwm'able: [www.thingiverse.com]

You can get 5 l/min air pumps via ebay/China for <$10 (pump)

Forgetting about the time, effort, and cost involved in making it, that blower delivers air via 8mm tubing- that's getting pretty big/heavy/inflexible/costly.

Of course, all this speculation doesn't mean anything until someone tries it...

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
orictosh
Upon my Ormerod 2 I switched from the 40mm axial fan to 75mm x 35mm radial fan, which gave good results in cooling the print.
Also found this post about short layers (time needed to complete the first layer is too quick to provide a good base for the next, ends up looking like "Ice Cream" ) in which various fan duct and shrouds were tested. Also give links upon page to the STL files, which is good.
[www.desiquintans.com]

In slic3r's settings under the cooling you can disable the fan for the first or more layer

With overhangs curling up, up the print speed by 5 so 40 becomes 45 etc, also increase the temp, only if you started at the lower end of the manufactures stated temp range.
as I did 190 - 215. With good cooling I was able to set the temp at 205 and gravity kept the corners from lifting.

That is a good article in the first part their results show an "open" design like this [www.thingiverse.com] would be the best for warping and overhangs but the results between the different ones tested are not that far apart. Which makes me think it shouldn't be that hard to get an improvement so I don't know why I am having trouble

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Newbie with Folgertech 2020 i3.

I printed out this one [www.thingiverse.com] and tried it using an axial fan. All the people that say axial fans can't deal with the back pressure are right, I get no air coming out of the hole at all. I am not going to waste any more time on ones that use an axial fan.

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Newbie with Folgertech 2020 i3.