1 (edited by lawsy 2012-09-21 22:53:48)

Topic: Fan installation

I've got a pretty nice fan installation based on Ian's fan duct over in the STL part of the forum:

http://www.soliforum.com/topic/182/nozzle-fan-duct/

I managed to put the previously unused 12V and ground pins from my Panelolu installation to use to power the fan.

Installation Steps

First step is to organise the following components:

- small switch
- 1m of red wire
- 1m black wire
- 40mm fan
- 2x connectors with pins to crimp

http://imageshack.us/a/img341/9720/01fancomponents.jpg

Crimp connectors onto the fan wires and one end of the red and black wires.

http://imageshack.us/a/img20/2872/02firstconnectorscrimpe.jpg

Close to the electronics end of the Panelolu ribbon cable, cut pin 1 (red stripe) and peel each side of the wire an inch or so.

http://imageshack.us/a/img641/6456/03ribboncablesplit.jpg

Now add a little bit of extra wire to each end and crimp a connector onto the wires. Orientate the black and red as shown.

http://imageshack.us/a/img829/4831/04ribboncablecrimped.jpg

Undo the four hex bolts holding the stepper motor to the extruder.

http://imageshack.us/a/img88/6737/05extruderdisconnected.jpg

Push one end of the 1m black and red wires through the black loom so that it goes from near the extruder to out the back of the machine. I wrapped tape around the wires, spiked in a wooden skewer and used this to push the wires through. Make sure the connector for the fan matches the connector near it on the red and black wires. Cut the wires to a good length and crimp a connector onto the other end once it's through.

http://imageshack.us/a/img835/6365/09loomwired.jpg

Previously in the Panelolu ribbon cable, pins 1 and 2 were unused and simply tape to insulate them. Open up the Panelolu case and find these wires. Solder pin 1 (red stripe) to the center switch pin and pin 2 to one of the other switch pins. Heat shrink will keep everything neat.

http://imageshack.us/a/img7/6348/06switchwired.jpg

An updated Panelolu front and back case have been uploaded to Thingiverse here:

http://www.thingiverse.com/thing:30049

Download and print the new cases pieces. In the corner of the front case panel, there is a blank section where a hole can be drilled to mount the switch. Drill this hole, poke the switch head through and do up the nut to hold the switch in place.

http://imageshack.us/a/img855/8803/07switchattached.jpg

From the front it should look like this:

http://imageshack.us/a/img843/7711/08newpanelolucase.jpg

Print the either Ian's original file linked to at the start or my modified version from here:

http://www.thingiverse.com/thing:30828/

My modifications include simplifying of the fan duct, modifying the mount to use 1/4 x 1/4inch magnets (derived from Ian's dial indicator mount), and adding an adjustment screw which can be turned to push against the extruder and change the angle of the fan duct to get it square. My derivative with everything in place is shown below:

http://imageshack.us/a/img402/1781/10modifiedfanductassemb.jpg

Setup and Printing

Place the duct in place and plug in the connectors at the fan and ribbon cable ends. Home the z-axis and turn the leveling screw in the fan duct to get it sitting parallel to the bed.

Printing performance is vastly improved on tricky parts. Previously, printing anything with small, angled, pointy edges would make them curl up and distort from the uneven heating and cooling. The image below depicts such a part mid print with the layers cooling and staying flat.

http://imageshack.us/a/img211/5526/11printingwithfan.jpg

A before and after of the finished piece shows the dramatic improvement.

http://imageshack.us/a/img228/3315/12beforeandafter.jpg

Bridging is also massively improved with the fan on. I know technically this is not what is called bridging, but you can see the trouble I had been having without the fan.

http://imageshack.us/a/img20/2764/13bridgingtest.jpg

Print Settings

I had already switched to printing at 200 degrees C, and this seems to work well with the fan. I have had no layer separation issues like Ian mentioned, and bridging performance is improved too. I usually switch on the fan as the first layer is finishing its fill, just to help it stick. I also run the first layer bed temp at 95, and then 90 for the rest of the print.

Fine stringing has now started to happen, but no doubt this can be fixed with some Silc3r retraction settings.

Big thanks to Ian for designing the original part so that my process would be so smooth and successful in his foot steps.

2

Re: Fan installation

where does the fan blow air on to ? does the air blow onto the build platform as its printing ?

3

Re: Fan installation

Sure does. I think with the case in place the air inside the unit is still quite warm, so it's not like the fan is pumping really cold air. I figure if I do need a part to be cooled more, I'll open the door.

4

Re: Fan installation

Even if the temp inside the case is 60c, that is still cool air as far as the plastic is concerned.  You only need to get the plastic down to maybe 140C (at a guess) so air that is hot for you is still freezing to the plastic.

The duct is designed to blow air in a circle around the nozzle, but not onto it.  This way the plastic will be cooled (and hardened) more quickly right after it gets extruded and hopefully before it has a chance to curl up for overhanging perimeters, or droop down for bridges.

It also has a tendency to cool the bed.  Mine only gets up to the mid 70s when the fan is on, and it is a good idea to leave it off for the first couple of layers.  A good companion to the fan would be a ceramic build surface, ie a piece of tile placed on the bed-

https://groups.google.com/forum/?fromgr … UuS-4SGRQE

It retains heat better than aluminum, letting the bed get hotter.  I expect it would be more resistant to cooling from the fan.

The fan is also good for printing PLA.  PLA tends to be more runny when it melts, so you want to cool it fast for the best results.

5

Re: Fan installation

Added new pic showing improvement in 'bridging' performance with fan.

6

Re: Fan installation

lawsy wrote:

Added new pic showing improvement in 'bridging' performance with fan.

The proof is the pudding... nice to see the (major) difference in print quality.

7

Re: Fan installation

Lawsy,

What do you think about a side mounted fan, on the left?  It would bump into the left carriage only about 1-2mm before it already does, and wouldn't bump into the door. 

I've been thinking that I want a full time fan to blow on the top of the heater barrel to protect the PEEK, so I can print at higher temperatures to improve extrusion at high speeds.   That fan can mount flat on the front of the extruder with a duct that directs the air to the barrel above the heat core.  Then a second fan could go on the side to blow into the duct around the nozzle, being turned on or off as needed.  On the Sanguinololu there is one more space to add another pair of headers next to the LED connector which can be used to power the front fan full time.   I'm currently using it to cool the electronics, but I can use a hacked wall wart to power that fan.

8

Re: Fan installation

Has anyone considered using an aquarium pump and some silicone tubing?

9

Re: Fan installation

I made this fan duct and used this mini column retraction for testing: http://www.thingiverse.com/thing:23550 This is a very tiny print (12mm diameter).

I printed at 0.1mm. The one on the right is with the fan off, the one on the left is with the fan on.

Yes it is that big of a difference. All my prints so far have had serious oozing problems, even with retraction set to 1.5. I'm considering this fan duct an absolute must have and I'm hoping all my prints will come out as nicely as this column test from now on!

http://i.imgur.com/DptBx.jpg

10

Re: Fan installation

roughtyper wrote:

Has anyone considered using an aquarium pump and some silicone tubing?

I thought of doing that, but I'd prefer a fan that I can control the speed of.  I'm not sure how much different it makes, but I'm pretty sure the amount of airflow from an aquarium pump would work fine.

11

Re: Fan installation

So, if I would replace the 40mm fan with on that pushes a bit more air and place a peltier element in front of it to cool down that air, will that improve the quality of my print even more?

12

Re: Fan installation

You don't necessarily want cold air blowing on the piece...  Then you might have to deal with the layers not sticking to each other. The 40 mm fan blows hot air on the piece allowing layers to cool a little bit but not become cold. Adjustable speeds might be good, but not necessarily cold air.

13

Re: Fan installation

I got the mod done for gcode controlled fan.  It is on and off only. You are supposed to be able to control the speed, but the speed values don't seem to do anything. Also it appears to conflict with the SD card.  When the fan and SD are both plugged in, the printer just restarts over and over. 

I haven't had a chance to try a print with selective fan cooling yet.  I got a high Cfm 50mm fan, and will experiment with blowing air from the fan into a hose to make the duct more low profile at the extruder.

14

Re: Fan installation

can I ask how you secured the fan  to the nozzle ? i see a black screw going through the hole of the printed fan mount. did you then drill a hole in the lexan to secure it ?

15

Re: Fan installation

There are holes for magnets which go up against the mounting screws. May or may not fit your extruder, but should be close. The screw helps to keep the bottom of the fan mount parallel to the bed.

16

Re: Fan installation

There are holes that fit over the bolts at the bottom of the extruder, and magnets to hold it tight against them.

17

Re: Fan installation

Did this mod (and I just press fit the fan holder onto the board with no magnets or screws... ghetto rigged the power supply off a small 12v one I've got here....

Wow.  This is how the printer should have come.  It's a night and day difference really.

18

Re: Fan installation

Thanks Lawsy! Forgive me if this is a stupid question, but is there any way to attach a potentiometer instead of an on/off switch so that you can adjust the speed of the fan?

19

Re: Fan installation

goofygrin wrote:

Did this mod (and I just press fit the fan holder onto the board with no magnets or screws... ghetto rigged the power supply off a small 12v one I've got here....

Wow.  This is how the printer should have come.  It's a night and day difference really.

We would love to see pictures of this - this is how design improvements are born.

Former Solidoodle employee, no longer associated with the company.

20

Re: Fan installation

what the whole mod or the press fitting?  The press fitting stopped working (it vibrated loose on a long print with lots of small strokes).  For now I've got it loosely zip tied around the print head.  Too tight and it actually shifts the feed path of the filament and it jams, causing the filament to not feed... but I've gone a half dozen prints since then and it works fine.  I did have to carve out part of where the fan carrier sits because it was pressing on some stuff.

21

Re: Fan installation

(Total newb question)
Are there extra headers on the OEM board for a fan or two?   Otherwise, could I just steal power from the main board power for the fan over the board and the fan for the extruder? Or will the fan on/off change the +12v enough to glitch the board?

B

22

Re: Fan installation

On the side where the fan and the LEDs plug in, there is a place to add a third pair of headers.  I used it to power the fan I have mounted on my electronics cover.  There is also another 12v in the expansion area that you can use for a gcode controlled fan.  See my posts here - http://www.soliforum.com/topic/303/ramp … olidoodle/

23

Re: Fan installation

I have bought myself a 40mm fan and a 240v to 12v adaptor.

the adaptor i bought off ebay, is actually meant for a led light system of some sort and it has come with a little connection that goes on the existing plug. That connection/adaptor has a positive and negative terminal.

My question is, can i simply connect the red and black wires from the fan to the positive and negative terminals on the adaptor plug and it should be fine to plug into a wall socket and go?

Ive attached a picture of the adaptor and plug.

sorry but my knowledge of electronics is minimal at best.
I know some of you are hooking your fans directly to the solidoodles board but for now and the sake of destroying my new printer when i get it ill stick to just plugging my fan in when I need it.

thanks guys

Post's attachments

fan adaptor.jpg
fan adaptor.jpg 91.1 kb, 6 downloads since 2012-10-18 

You don't have the permssions to download the attachments of this post.

24

Re: Fan installation

Yes, you might have to put the red to - and black to + if the polarity is wrong... but easy to check.  On the side of the fan there should be an arrow saying what direction it will blow and turn (well 2 arrows).  Wire it up and if the fan moves the right way/blows the right way, then the wiring is correct.  If it's backwards, swap the wire.

25

Re: Fan installation

Would someone point me to an explanation of why this fan is beneficial? I've read discussions about problems that can occur if the extruded plastic cools too quickly (adjacent layers not sticking), so this seems counter-intuitive to me.  Does one need to adjust various settings in order to compensate for the fan?

Thanks!

Jon