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Whats my voltage limit for tapping into peek and layer fans?

Posted: Mon Feb 09, 2015 7:37 pm
by shentheory
So I decided that my extruder motor needs a fan, but that's another issue all in itself. Long PLA prints usually result in softened plastic and jamming, even after changing the MOTOR_CURRENT values that's recommended for the Kysan Motors.

Anywho, I found a slick looking 70mm fan that I want to design a mount for to blow on the extruder motor, and tap it into the Layer fan wires preferably. I am no electrical engineer, but this fan that I got is a 12V fan. And since the peek and layer fans are 5V, it made me hesitant enough to ask first!


Much appreciated!

Re: Whats my voltage limit for tapping into peek and layer f

Posted: Mon Feb 09, 2015 7:48 pm
by teoman
I do believe the peek and layer fans are 12V.

So you would not have any problems on that frontier.

However you should check how many amps are drawn by your 70mm fan and make sure that the rambo is capable of providint sufficient current for the new and existing fan together.

Re: Whats my voltage limit for tapping into peek and layer f

Posted: Mon Feb 09, 2015 8:05 pm
by shentheory
teoman wrote:I do believe the peek and layer fans are 12V.

So you would not have any problems on that frontier.

However you should check how many amps are drawn by your 70mm fan and make sure that the rambo is capable of providint sufficient current for the new and existing fan together.
Awesome, thanks. this fan shows the Amp Rating: 0.30, now how do i check the rambo? (I'm an idiot). Thanks again!

Re: Whats my voltage limit for tapping into peek and layer f

Posted: Tue Feb 10, 2015 1:28 pm
by BenTheRighteous
If it's a 12v fan, just install it. If the circuit is really going to be overloaded by adding one more cooling fan, then it's your fault for doing a bad job on your wiring. ;)

Re: Whats my voltage limit for tapping into peek and layer f

Posted: Tue Feb 10, 2015 11:39 pm
by Eaglezsoar
You should be able to parallel connect your 70mm fan to the existing layer fan without a problem.
The red wire from the new fan would connect to the red wire on the layer fan the black wires connect together also.

Re: Whats my voltage limit for tapping into peek and layer f

Posted: Wed Feb 11, 2015 3:51 am
by teoman
Power

Three independent power rails for flexible input power configurations
Heated Bed, 15A 12-24V (version earlier than 1.1 limted to 14A 16V due to fuse rating, see rambo_development for hacks)
Extruders and fans, 5A 12-24V (fuse can be exchanged for up to 10A capacity) 10V-26V input voltage
Motors, 5A 12-24V (fuse can be exchanged for up to 10A capacity) 10V-26V input voltage
Built in SMPS for 5V generation

from: http://reprap.org/wiki/Rambo

Have a quick read through that, you will learn about the capabilites of your board.

It only specifies extruders and fans, so i do not know how much of that is the fans. If they have used the same component as the extruder heater then you should not have a problem.

Connect and disconnect your 70mm fan, and see if you notice a change in the speed and sound of the existing fan. If there is a change then that is an indicator of voltage drop in which is either an indication of insufficient wire grade or the rambo is not happy delivering so much current.