Cooling fan control with Thingomatic

[Nate Stalsworth]

Hello to all, 

I've been happily using my ToM for a long time now with ABS, but just recently decided to try PLA (I know, I know, I'm WAY behind the times!) Of course I discovered quite quickly that cooling fans are pretty much a requirement - perhaps I've just been lucky, but I've not needed one til now. 

I think I need two. One to blow across the heatsink at the thermal barrier and one to cool the print itself. To that end, I've already printed and installed the extruder barrel cooling duct. For the print cooler, I'm thinking about something similar to this one, unless someone has a better suggestion.

I want to be able to control the print cooling fan via x3g code. (I'm using Simplify 3D and the GPX plug at this point) and I've read that the extruder controller will turn the other fan on when the extruder reaches 50c.My real question is this: What connections to I use on the extruder controller and/or mainboard for this on my ToM? I've read that some people use the ABP wires and other use the 1A/1B terminals. What is the best / right way?

ToM documentation is getting hard to come by and google isn't really giving me definative warm-fuzzy answers. :) 

Thanks for any advice you can provide,

Nate

[Nate Stalsworth]

I should have mentioned that I'm using a custom mk6 equivalent extruder with a NEMA 23 stepper.(Still rockin the 3mm filament)

[Dan Newman]

> I think I need two. One to blow across the heatsink at the thermal barrier
> and one to cool the print itself.

Not supported by the Gen 4 electronics....

> I want to be able to control the print cooling fan via x3g code.

No can do with Gen 4 electronics. The command used for Rep 1, 2, and 2X
for the fan is M106 / M107. For Gen 4 electronics, that's used for the
Conveyor belt of the automated build platform. Except that GPX got
it wrong. (Indeed, I just fixed that bug in my private copy of GPX
earlier this week.)

The Gen 4 command to control the Extra FET (used by the cooling fan)
MUST NOT BE USED with Gen 4 electronics: it triggers a bug in the Gen 4
Extruder Controller and the HBP temperature will skyrocket and run
unchecked. So, you must not use M126 / M127 with Gen 4 electronics
and GPX will not allow it. It issues an error message if you do
try.

> What is the best / right way?

Small fan on your desk. Manually turn it on to cool the print.

However, why do you think you need a print cooling fan? If you're
going to print with PLA, you may need to rebuild your hot end as
the Mk7 does not work well for PLA in the first place: the heat
spreader bar doesn't have enough contact area with the thermal
barrier tube. The tube gets too warm after an hour or so.

Dan

[Robert Trescott]

ReplicatorG still supports x3g operation of M106 & M107.
I use those M codes in my Start/End.gcode to activate the ABP FET.
Of course you do need to use the "magic switch" in the machine configuration xml file to let everything know the ABP is present.
I slice with Simplify3D then open the generated gcode with RepG and create a x3g file to my SD card.
My ABP FET is wired to my platform fan and everything works like a champ when I build from the SD card.
Thanks all,
-Robert

[MacGyver]

I've been able to print PLA on my thing-o-matic but I've got the MK/7 extruder and have printed a fan adaptor for it.  It seems to work ok.  Not sure if there is a cooling fan adapter for the mk6.  

I used this one:

http://www.thingiverse.com/thing:22297