Out of fan headers with pin assignments but still need 1 more? - SOLVED

[Wannabe]

 

I'm running a Voron 2.4r2 with an Octopus 1.x. I've run out of fan headers that have pin assignments, all that is left is Fan 6 & 7.

I would like to run some 24v fans under the heated bed to circulate the chamber air and increase chamber temperatures.

My intention was to use AndrewEliss93 bed fan mod and macro but the macro requires a pin assignment which as far as I know can not be done on the Fan 6 & 7 headers.

Maybe I'm missing something but can anyone offer any suggestions to get the fans connected and use the macro.

 

Edited March 2 by Wannabe
Solved

[chrisalbertson]

If you are out of pins, you can drive a small 5-volt fan with a Pi3 GPIO pin.    You must use the pin to "sink" current and not source current.   Find a fan that uses no more than 16 ma, connect the positive lead to 5 volts and the black lead to the GPIO pin.   The pin name is !host:gp017 (or whatever) but you do need the "!"  to invert the pin.

Maybe you have a small LED or fan you can move to the Pi3 to free up a pin on the Octopus that can drive more power.

The other options  to add another small MCU or a driver circuit to amplify the Pi3 GPIO pin

[Dirk]

12 hours ago, Wannabe said:

I'm running a Voron 2.4r2 with an Octopus 1.x. I've run out of fan headers that have pin assignments, all that is left is Fan 6 & 7.

I would like to run some 24v fans under the heated bed to circulate the chamber air and increase chamber temperatures.

My intention was to use AndrewEliss93 bed fan mod and macro but the macro requires a pin assignment which as far as I know can not be done on the Fan 6 & 7 headers.

Maybe I'm missing something but can anyone offer any suggestions to get the fans connected and use the macro.

I remember requiring a fan header output for the exact same reason (under the bed fans). I used the 24v from the HE2 port, which on my octopus pro 1.01 has the PB10 pins.

[chrisalbertson]

I just re-read the question.  I thought the OP was out of pins.  But no, it seems he is only out of controllable fan headers.  If that is the case, yes use a spare heater connection.     You don't need to use a different MCU or the Pi3 GPIO until you are truly out of pins

[Wannabe]

3 hours ago, Dirk said:

I remember requiring a fan header output for the exact same reason (under the bed fans). I used the 24v from the HE2 port, which on my octopus pro 1.01 has the PB10 pins.

My HE2 port is already in use, the HE3 port is available pinned as PB11. I would assume that would also work?

As an alternative, I was wondering if I could wire all 4 bottom case fans to one header, currently I have each side (2 fans) wired to separately to a header.  Each of the Orion fans have a rated current of 0.15 amps?

[Dirk]

6 minutes ago, Wannabe said:

My HE2 port is already in use, the HE3 port is available pinned as PB11. I would assume that would also work?

As an alternative, I was wondering if I could wire all 4 bottom case fans to one header, currently I have each side (2 fans) wired to separately to a header.  Each of the Orion fans have a rated current of 0.15 amps?

Sure. Why not. He pins are simply 24v connections with a controllable pin, for you to use at your convenience.

Only extra above the fan pins, is that it has an extra electrical components, which accurately makes sure you get continuous 24 v, like a heater requires.

And yes. I have connected 4 fans to same heater output for my electrical compartment fans.

To be exact you will need to look at current specs of the fan and the current he3 provides.

Good luck:-)

[chrisalbertson]

Of course you ca parallel the fans, if they run on the same voltage and the fan header can supply the combined current of two fans.  All this seems to be the case.

 

The only reason to put fans on different pins is so that you can control them independently.

If you have some perf you can make a nice litter borad the has three or more 3-pin JST connectors wired in parallel, place that near where the fans go then run one cable back to the octopus.   Or just solder up a Y-cable.

Yes, one heate output is as good as another.

[Wannabe]

7 minutes ago, Dirk said:

Sure. Why not. He pins are simply 24v connections with a controllable pin, for you to use at your convenience.

Only extra above the fan pins, is that it has an extra electrical components, which accurately makes sure you get continuous 24 v, like a heater requires.

And yes. I have connected 4 fans to same heater output for my electrical compartment fans.

To be exact you will need to look at current specs of the fan and the current he3 provides.

Good luck:-)

 

9 minutes ago, Dirk said:

Sure. Why not. He pins are simply 24v connections with a controllable pin, for you to use at your convenience.

Only extra above the fan pins, is that it has an extra electrical components, which accurately makes sure you get continuous 24 v, like a heater requires.

And yes. I have connected 4 fans to same heater output for my electrical compartment fans.

To be exact you will need to look at current specs of the fan and the current he3 provides.

Good luck:-)

Thanks, for piece of mind I will try and find the current draw specs on the BTT Git.

[Wannabe]

6 minutes ago, chrisalbertson said:

Of course you ca parallel the fans, if they run on the same voltage and the fan header can supply the combined current of two fans.  All this seems to be the case.

The only reason to put fans on different pins is so that you can control them independently.

If you have some perf you can make a nice litter borad the has three or more 3-pin JST connectors wired in parallel, place that near where the fans go then run one cable back to the octopus.   Or just solder up a Y-cable.

Yes, one heate output is as good as another.

Thanks, I currently use genuine Wagos conncectors to accomplish parallel connnections. So it appears from the responses to my question, I'm good to go with either a HE3 connection or possibly run all 4 fans from a single pinned Fan header, though from the Fan header I will try and research the draw limits on those Fan headers. 

[Dirk]

Hi @Wannabe

Wagos is a good way to organise your cable connections. 

But as I said, It is safe to connect 24v fans, to the HEx octopus ports. And if you connect 4 fans through wagos to the HEx output, I think it will be perfectly okay.

For the output current on that port, is some unclarity as I can not find it in the octopus documents, but I am sure it is high enough. Since they are ports that are supposed to supply current to heaters. Such as the bed heater and the extruder heater. The current for these ports are regulated by MOSFETs( difference from normal fan ports). So I think there will be plenty of current to run only 4 fans

About what I could find concerning fans and current, there is this: which might interest you.

But I am quite sure you can without any problems connect 4 fans to a He3 port