# Improved TAZ Fan Duct **URL:** \ **Category:** LulzBot TAZ\ **Created:** [June 25, 2014, 9:58pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658 "2014-06-25T21:58:26Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![American\_3D\_Printing](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/american_3d_printing/32/19_2.png) [@American\_3D\_Printing](https://forum.lulzbot.com/u/American_3D_Printing)\ **Post date:** [June 25, 2014, 9:58pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/1 "2014-06-25T21:58:26Z")
Ever since we deployed our TAZ 3 we’ve had issues with heat creep with PLA on certain builds. Basically the heat creeps up the 3mm filament and softens it inside the section of the Budaschnozzle where the PTFE tube runs through the heat sinks. As the hobbed bolt applies downward pressure on the filament, it expands inside the PTFE tube and gets stuck, and stops extruding. Then the hobbed bolt does its familiar half moon chunk carved into the filament and the build is failed. When AO came out with fan kits for the TAZ, we were really happy, but the duct only blows onto the build. This improves build quality and bridge capability, but fails to address the heat creep issue. We set about redesigning the duct so that it splits the airflow to both the build and to the fins of the Budaschnozzle. Here’s the link to the design files on Thingiverse: > **[Lulzbot TAZ Fan Dual Duct by American3DPrinting](https://www.thingiverse.com/thing:374906)** > > Aleph Objects has come out with a nifty fan kit to upgrade TAZ 3 and older printers, and comes standard on the TAZ 4. The original factory design of the duct only blows on the build. This is great for improving bridge capability, but fails to address... Now that we’ve gotten over 30 or so hours of build time with PLA with zero extrusion issues, we’d like to share this with the rest of the TAZ community. ![IMGP5432640.jpg](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/3/3b7f468d3a48ff0f8ec88597f9aa3981a6f9a266.jpeg) ![IMGP5430640.jpg](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/4/4bf070c22dae4f5117073ee7ba0f9f6b24d7d628.jpeg) ![TAZ Fan Dual Duct Cropped.jpg](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/d/d84daa60c2b6e1e41247c86c73eb61ad83ec549b.jpeg) ---
**Author:** ![jebba](https://avatars.discourse-cdn.com/v4/letter/j/9e8a1a/32.png) [@jebba](https://forum.lulzbot.com/u/jebba)\ **Post date:** [June 26, 2014, 11:40pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/2 "2014-06-26T23:40:10Z")
We printed one of these out, it looks really cool, thanks! -Jeff ---
**Author:** ![American\_3D\_Printing](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/american_3d_printing/32/19_2.png) [@American\_3D\_Printing](https://forum.lulzbot.com/u/American_3D_Printing)\ **Post date:** [June 28, 2014, 11:21pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/3 "2014-06-28T23:21:10Z")
> [@jebba](#): > > We printed one of these out, it looks really cool, thanks! > > -Jeff Let me know if you’d like the fan mount holes re-sized for those press-in threaded inserts. ---
**Author:** ![schlem](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/schlem/32/23_2.png) [@schlem](https://forum.lulzbot.com/u/schlem)\ **Post date:** [July 19, 2014, 7:35pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/4 "2014-07-19T19:35:16Z")
Hi Having same heat creep issue. I was thinking about designing this exact modification - nice job! Do you just leave the fan running all the time, or do you use the automatic cooling setting? Thanks Todd ---
**Author:** ![jebcom](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/jebcom/32/9162_2.png) [@jebcom](https://forum.lulzbot.com/u/jebcom)\ **Post date:** [August 5, 2014, 4:16am UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/5 "2014-08-05T04:16:56Z")
Jeff, Thanks for sharing this. I printed mine yesterday, and so far it works very well. Up until now with some PLA filaments I’ve never had a successful large print. I’ll be trying a 13+ hour print with one of these filaments within the next few days, so we’ll see if it makes a difference. Do you change the fan speed from the default in the Lulzbot profiles? Mine is at 35% (S89) for most of the print, but I can’t tell that very much air is blowing on the fins. Maybe a small amount is adequate. I also don’t want to blow too much on the tip. ---
**Author:** ![jebcom](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/jebcom/32/9162_2.png) [@jebcom](https://forum.lulzbot.com/u/jebcom)\ **Post date:** [August 9, 2014, 9:59pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/6 "2014-08-09T21:59:24Z")
OK, since I installed this new duct, I’ve done a 14-hour print and a 37-hour print in PLA. They were both successful on the first try, and they came out very good. Before this I couldn’t get more than about 2 hours into a PLA print with these filaments before the extruder would jam. These two prints used about the same amount of filament and used similar slicing profiles. The difference is that the 37-hour print is very intricate with a lot of multi-sided internal perimeters with short sides, so the feed rate was very slow. In my experience, the slow feed rate would have made it even more susceptible to jamming from PLA heat creep, so I’m sold on the new fan shroud/duct that cools the budaschnozzle fins. For the 14-hour print, I ran the fan at 35%, and for the 37-hour print I ran it at 55%. ---
**Author:** ![chiphead](https://avatars.discourse-cdn.com/v4/letter/c/4bbf92/32.png) [@chiphead](https://forum.lulzbot.com/u/chiphead)\ **Post date:** [August 15, 2014, 2:17am UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/7 "2014-08-15T02:17:32Z")
I did a remix of this thing and added a servo mount for auto bed leveling. > **[Lulzbot TAZ Fan Dual Duct and Auto Bed Leveling Servo by chiphead420](https://www.thingiverse.com/thing:428936)** > > I added a 9g servo mount for auto bed leveling, opened the fan opening at the top. ![20140814_175802[1].jpg](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/2/2be1a93cc4e5cc5fd5603c38e6deb290d5afd7f3.jpeg) ---
**Author:** ![dansmith](https://avatars.discourse-cdn.com/v4/letter/d/57b2e6/32.png) [@dansmith](https://forum.lulzbot.com/u/dansmith)\ **Post date:** [October 30, 2014, 12:30pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/8 "2014-10-30T12:30:44Z")
If you need some affordable inserts, checkout [http://www.fasteningsolutionsuk.com/](http://www.fasteningsolutionsuk.com/) ---
**Author:** ![neotheghost](https://avatars.discourse-cdn.com/v4/letter/n/c0e974/32.png) [@neotheghost](https://forum.lulzbot.com/u/neotheghost)\ **Post date:** [November 4, 2014, 6:57pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/9 "2014-11-04T18:57:05Z")
I figured that whenever you use a funnel like fan mount you loose a lot of the cooling power of the fan. this open frame construction allows 100% air flow and works much better as the funnel mounts out there. you can download my mount here: > **[Lulzbot TAZ 40x40x10 Fan Mount by gh0st](https://www.thingiverse.com/thing:529264)** > > I figured that whenever you use a funnel like fan mount you loose a lot of the cooling power of the fan. this open frame construction allows 100% air flow and works much better as the funnel mounts out there. ![IMG_20141030_190915.jpg](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/6/61548553b349b8ecf8995bce5e5d48b93792a106.jpeg) ---
**Author:** ![nostrout](https://avatars.discourse-cdn.com/v4/letter/n/e5b9ba/32.png) [@nostrout](https://forum.lulzbot.com/u/nostrout)\ **Post date:** [November 5, 2014, 2:34am UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/10 "2014-11-05T02:34:11Z")
I’m having issues with a few prints of mine and I’ve been attributing it to the fan based on the fact that I’m using slicing settings that have worked for me in the past. After seeing this post, I’m now considering if it’s a heat creep issue. I did this quick test print to show what I’m experiencing. I’m getting very chunky perimeters and some of the infill is as well. I have the original fan shroud that works great, but this upgrade looks great. Can anyone tell me based from the photos that the issues I’m seeing is from heat creep? ![photo 1.JPG](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/d/d18566dc583926df0dc569933ccda5502c7974e7.jpeg) ---
**Author:** ![AmyInNH](https://avatars.discourse-cdn.com/v4/letter/a/bbe5ce/32.png) [@AmyInNH](https://forum.lulzbot.com/u/AmyInNH)\ **Post date:** [March 12, 2015, 5:21pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/11 "2015-03-12T17:21:15Z")
If you’re talking about those bumps on the surface, it looks like what’s cited on this page as “pillowing”. [http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#ringing](http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#ringing) ---
**Author:** ![KosmoPi](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/kosmopi/32/9205_2.png) [@KosmoPi](https://forum.lulzbot.com/u/KosmoPi)\ **Post date:** [March 13, 2015, 5:19pm UTC](https://forum.lulzbot.com/t/improved-taz-fan-duct/658/12 "2015-03-13T17:19:03Z")
> [@AmyInNH](#): > > If you’re talking about those bumps on the surface, it looks like what’s cited on this page as “pillowing”. > [A visual Ultimaker troubleshooting guide - 3DVerkstan Knowledge Base](http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#ringing) Thanks for this link! Its a really good pictorial troubleshooting guide!