# TAZ5 control 5v heatsink fan in Marlin Firmware?

**URL:** <https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524>\
**Category:** Software\
**Created:** [November 25, 2015, 2:41am UTC](https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524 "2015-11-25T02:41:24Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![gremlinbot](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/gremlinbot/32/57_2.png) [@gremlinbot](https://forum.lulzbot.com/u/gremlinbot)\
**Post date:** [November 25, 2015, 2:41am UTC](https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524/1 "2015-11-25T02:41:24Z")

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Hello,

I have been searching the latest version of firmware to find where to control the two micro fans for my dual extruder heatsink.  
I cannot find a PID solution or a bang bang solution 💡

But, where in the firmware do you control, modulate voltage to these fan’s pins??? config.h, config.h adv., pins??? I can’t find it!!! 😊  
The problem is not how to control fans 0 and 1 with the m106 s255 and m107 commands. I want to control the 5v micro fans.This fan needs to be slowed down just a hare, but it is cooling my hotend too much. This will reduce the life, and cause an inconsistent temp for printing.  
  
  
  
  
  
Thanks Grem

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**Author:** ![gremlinbot](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/gremlinbot/32/57_2.png) [@gremlinbot](https://forum.lulzbot.com/u/gremlinbot)\
**Post date:** [November 25, 2015, 4:24am UTC](https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524/2 "2015-11-25T04:24:59Z")

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Hello,  
Not being able to control the fan is a design flaw. 😆 Giving less power to the fan was the objective.#less rpms is not an enormous thing to ask for.

I guess these fans are uncontrollable THROUGH the RAMBo board pins they are assigned? Right. 😐  
micro 5v fan (a front facing fan) too powerful? ❓ ![:ugeek:](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/1X/60aa0bc609d6c1cf1242a151e9c1410e4f9e6e44.gif "Uber Geek")

Not having some way to control a vital part of a the extruder’s design is a major design flaw? ❓

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**Author:** ![piercet](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/piercet/32/12_2.png) [@piercet](https://forum.lulzbot.com/u/piercet)\
**Post date:** [November 25, 2015, 5:11am UTC](https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524/3 "2015-11-25T05:11:27Z")

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Rheostat in line?

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**Author:** ![kcchen\_00](https://avatars.discourse-cdn.com/v4/letter/k/9dc877/32.png) [@kcchen\_00](https://forum.lulzbot.com/u/kcchen_00)\
**Post date:** [November 25, 2015, 5:24am UTC](https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524/4 "2015-11-25T05:24:15Z")

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> [@gremlinbot](#):
>
> Hello,  
> Not being able to control the fan is a design flaw. 😆

Umm… okay. If you turn off the heatsink fan, I guarantee you will need a new hotend from the filament melting in the chamber.

ENGINEERS design things for a reason. A heatsink to dissipate heat. A fan to assist because the heatsink alone can’t keep the chamber cool.

Here’s a thought, unplug the fan and run your hotend…

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**Author:** ![wmgeorge64](https://avatars.discourse-cdn.com/v4/letter/w/5fc32e/32.png) [@wmgeorge64](https://forum.lulzbot.com/u/wmgeorge64)\
**Post date:** [November 26, 2015, 4:43pm UTC](https://forum.lulzbot.com/t/taz5-control-5v-heatsink-fan-in-marlin-firmware/2524/5 "2015-11-26T16:43:14Z")

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He posted in the Hardware section also, the exact question?