Magicmaker wrote:The odd thing is, if I unclip the wiring from the extruder fan, and reverse the clip, the case fan turns on. and if I leave that one alone, but reverse the case fan, the extruder fan comes on. If I reverse both, nothing happens. If I leave both normal, I get a electric buzz from the extruder fan.
Jon
Jon,
Could you examine the two 40 mm fans and tell us what voltage is marked on them? Are they 24V or 12V fans?
(In typing the following, I assume you're not familiar with wiring in general, and I try to cover how the circuit should be laid out. If you're an electrical engineer or an amateur extra class ham radio operator or such, I apologize for telling you what you already know.)
If they are 12V fans (what they should be), the fans should be wired in series. What this means is: power to the fans should go:
1. from the + terminal on the "Extruder 1 Fan" connector on the RAMBo board (picture on page 3 in this document:
http://cdn.shopify.com/s/files/1/0030/7 ... 13.pdf?917 ) to the red wire of one fan (electronics case fan, I believe);
2. then from the black wire of that fan out the harness to the red wire of the other fan (extruder cooling fan, I believe);
3. and from the black wire of that fan back along the harness to the - terminal on the "Extruder 1 Fan" connector.
So, in "picture" form:
[RAMBo Fan 1] + --------- red [electronics case fan] black -------- red [extruder fan ] black -------- - [RAMBo Fan 1]
where the ------- are wires.
Check page 5 of that document for the layout of the wiring harness and make sure the fans are on the right connectors with the right polarity. If you have an ohmmeter or continuity tester, you can unplug all the wiring harness connectors and ring out the connections to make sure there's not a problem with the wires.
If they are 24V fans, let us know -- we can help you re-arrange the wiring in the harness to power them in parallel instead of in series. (I have an older M2 that used 12V and 19V power supplies and had the fans wired in parallel; when I upgraded to 24V, I bought some 24V 40 mm fans and kept the parallel wiring. So my M2 is definitely a "one-off"...)
Next, try controlling the fans by sending G-code commands to it using your machine control software (e.g., Machine Control Panel in S3D). Sending these codes will cause the fans to start and stop as follows:
M106 S255 ; this should make the bed cooling (50 mm) fan run full speed
M106 S0 ; this should make the bed cooling fan stop
M108 S255 ; in the as-shipped firmware, this should make the electronics case fan and extruder cooling fan (40 mm fans) run full speed
M108 S0 ; this should make the 40 mm fans stop.
Note that some folks here are using various modified RAMBo firmware -- for example, cmenard's firmware examines the extruder temperature to control one or more fans rather than accepting the G-code commands above. There are also firmware variants that change the PWM frequency to the fans. But M106/108 S255 should have the output to the respective fan(s) OFF 100% of the time, and M106/108 S0 should have the output to the fan(s) OFF 100% of the time, so the PWM frequency shouldn't matter for the test you do above.
If the commands above work, you can add these to your starting and/or stopping G-code scripts so that the fans will run as you want at least during a print.
Let us know if any of the above helps you diagnose the problem!
Dale