1 Topic by H_Alex

  • H_Alex
  • H_Alex
  • Member
  • Offline
  • From: Illinois, United States
  • Registered: 2015-03-26
  • Posts: 55

Topic: Extruder Cooling Fan with Hose Connection

Unlike many other printers, the Press doesn't have much room on the print head for accessories like cooling fans, so you must either choose a very small (~25mm) fan, which doesn't move much air at all, or... why not just pipe in air from a larger fan sitting somewhere outside the printer?

http://soliforum.com/i/?osA1I4p.jpg
I downloaded an assembly from Thingiverse that holds a 25mm fan, but the airflow was almost non-existent, so I started down this path.

http://soliforum.com/i/?6arqKbl.jpg

http://soliforum.com/i/?wPWwarI.jpg

http://soliforum.com/i/?umOSdnu.jpg


I'm still modifying these parts for fit and effectiveness, and I've yet to print the cone that will go over the large fan (connecting it to the other end of the pipe) but I will post updates and eventually the STL files as this project progresses.

Frustration is part of the process.

2 Reply by IanJohnson

  • IanJohnson
  • Moderator
  • Offline
  • Registered: 2012-08-07
  • Posts: 2,815

Re: Extruder Cooling Fan with Hose Connection

You will probably have better luck with a blower rather than a fan.  A fan doesn't seem to have much ability to overcome back pressure, and you may feel air coming out the back of it.  Another possibility is an aquarium pump, though it won't have much airflow either.

3 Reply by H_Alex

  • H_Alex
  • H_Alex
  • Member
  • Offline
  • From: Illinois, United States
  • Registered: 2015-03-26
  • Posts: 55

Re: Extruder Cooling Fan with Hose Connection

You will probably have better luck with a blower rather than a fan.  A fan doesn't seem to have much ability to overcome back pressure

You know, I completely forgot about blowers. And you're right, I've run into back pressure issues before in another project that used a fan. I've made the cone fairly tall, so hopefully it won't create a ton of back pressure, but if this doesn't work, I'll try a blower next. Thanks!

Frustration is part of the process.

4 Reply by H_Alex (edited by H_Alex 2016-02-28 20:45:51)

  • H_Alex
  • H_Alex
  • Member
  • Offline
  • From: Illinois, United States
  • Registered: 2015-03-26
  • Posts: 55

Re: Extruder Cooling Fan with Hose Connection

Confirmed: the airflow out the end of the nozzle is minimal at best, and there is a lot of air coming out the back of the fan. The blower route it is!

http://soliforum.com/i/?L3gxybZ.jpg

Frustration is part of the process.

5 Reply by H_Alex

  • H_Alex
  • H_Alex
  • Member
  • Offline
  • From: Illinois, United States
  • Registered: 2015-03-26
  • Posts: 55

Re: Extruder Cooling Fan with Hose Connection

I've opted for the blower, which IS successfully moving air through the hose and out the nozzle, but it's still not quite as much as I would have liked: the airflow is barely noticeable. As with any fluid system, the longer the hose, the more pressure loss you have. Unfortunately, the hose needs to be this long in order to have enough flex to follow the print head properly and to not pull the blower around either.

I used this blower:
http://www.amazon.com/75mm-0-36A-Comput … an+by+Gino

http://soliforum.com/i/?tEZVas7.jpg

http://soliforum.com/i/?kpO7k4J.jpg

http://soliforum.com/i/?YedNZgz.jpg

http://soliforum.com/i/?1rD60C6.jpg


I plan to use the blower linked below for the next iteration. It has a higher airflow, and a built-in throttle so I can test different airflows. I'm also adjusting the nozzle geometry to be slightly closer to the extruder tip.
http://www.amazon.com/gp/product/B012CL … ge_o00_s00

Despite its low airflow, it appears to be making a difference: I couldn't make a bridge at all before, but now it's actually decent.

http://soliforum.com/i/?YVsZysv.jpg

Frustration is part of the process.

6 Reply by H_Alex

  • H_Alex
  • H_Alex
  • Member
  • Offline
  • From: Illinois, United States
  • Registered: 2015-03-26
  • Posts: 55

Re: Extruder Cooling Fan with Hose Connection

Alright, I think I've got it: bigger blower, closer nozzle, better bridging. The airflow is strong enough that the corrugated tube actually whistles slightly at full blower speed. Here are the STL files if you want to print your own:

http://www.thingiverse.com/thing:1393549

Frustration is part of the process.

7 Reply by n2ri

  • n2ri
  • Member
  • Offline
  • From: St Louis MO USA area
  • Registered: 2013-02-03
  • Posts: 2,539

Re: Extruder Cooling Fan with Hose Connection

blowers can be designed to work effectively with back pressure just like old mobile home furnace fans did. when you restrict airflow on a fan it 1st causes the motor to 'over rev/speed" and if the blades/squirrel cage is designed with the pitch on the blades pushing better at the higher speed it works. if you check RPMs on an old Mobile homes blower (still in service in the under sized ductwork) that 1050RPM motor is spinning over twice rated speed yet moving proper air volume to cool furnace and the motor while moving the warmed air (or cooled for AC).
but yes I have been using a small aquarium pump as parts cooling fan on My SD2 when needed. and you can buy larger air pumps even medical use type for such use, be sure to check if the pump adds its own heat to the air though as some will.

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs

8 Reply by n2ri

  • n2ri
  • Member
  • Offline
  • From: St Louis MO USA area
  • Registered: 2013-02-03
  • Posts: 2,539

Re: Extruder Cooling Fan with Hose Connection

also if ducted right you can draw air over the extruder with a vacuum instead of blowing. this is another method used in air handling units and about 50% of home HVAC units, called 'Down Draft' instead of upflow where air is sucked across the AC Evaporator coil instead of blown through it. if your air filter is next to the coil instead of the blower this is the type unit you have.

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs

9 Reply by seven2099

  • seven2099
  • Member
  • Offline
  • Registered: 2015-03-03
  • Posts: 101

Re: Extruder Cooling Fan with Hose Connection

interesting but this doesn't solve the issue with directdrive and poor cooling which was the main problem I had with my stock extruder and dd system.

Bowden was much more effective after upgrading to e3dv6. I think however this could be a great solution for cooling the bowden motor as it gets quite hot in 20 hour prints, but none the less never hot enough to cause an clogs like dd would cause.

10 Reply by n2ri

  • n2ri
  • Member
  • Offline
  • From: St Louis MO USA area
  • Registered: 2013-02-03
  • Posts: 2,539

Re: Extruder Cooling Fan with Hose Connection

the flat fan with small reducer wont do well other than over heat fan. the small squirel cage one may for the hose and part cooling.

the factory fan on side of DD extruder motor needs an aluminum heat sink sandwiched between it and motor to cool motor like the other Solidoodle models have on rear instead of side but I dont know if it can be done without limiting travel of the carriage in that printer. the metal heat sink on hotend is just to keep upper part of feed tube cool from heater. it cant compensate for excess motor heat during long prints in enclosure. again just poor design by SD R&D not thinking ahead

Solidoodle 2 with Deluxe kit cover & glass bed with heater. and 2nd board SD2 used not 3rd and alum platform not installed yet still wood. also need cooling fan installed to board. use Repetier Host couple vers. Slic3r also have all free ware STL programs