40mm fans not working

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Magicmaker
Posts: 5
Joined: Sat May 03, 2014 7:41 am

40mm fans not working

Post by Magicmaker » Sat May 03, 2014 7:45 am

Hello everyone,

I have just finished assembling my M2. Everything tested out ok, except the 40mm fans will not turn on. They are making a buzzing noise.

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.

I checked all wiring, all seems good, what's happening? So close to printing, yet so far haha.

Thanks for all the help,

Jon

Dale Reed
Posts: 376
Joined: Thu Apr 10, 2014 1:39 am
Location: Cleveland Heights, Ohio USA

Re: 40mm fans not working

Post by Dale Reed » Sat May 03, 2014 3:48 pm

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

Magicmaker
Posts: 5
Joined: Sat May 03, 2014 7:41 am

Re: 40mm fans not working

Post by Magicmaker » Sat May 03, 2014 4:45 pm

Dale,

Thank you for such a detailed reply, this will really help me find the solution, and I fully appreciate you taking the time to help me out!

The fans are 12V, and I am slowly working through the wiring (which is VERY tricky considering how long and intricate the wiring is, especially after assembly.)

I ran the required commands, and the M106 S255 works perfectly.

When I run M108 S255, nothing new happens, however when I run M108 S0, I noticed the buzzing went away. When I did M108 S255 again, the buzzing came back and I also noticed the extruder fan looks like it REALLY wants to spin but it isn't getting the required power (it just kind of twitches).

I'll continue looking through the wiring, I'm confident it's hooked in according to the assembly instructions, but I have a feeling a wire is mixed up (or possibly damaged?) along the way somewhere. All other motors, fans, and end stops were wired perfectly first go, so I'm stumped on this one.

Thanks again Dale, I'll keep you posted with any more progress and if you have any further suggestions to investigate please let me know.

Kind Regards,
Jon MacDonald

Magicmaker
Posts: 5
Joined: Sat May 03, 2014 7:41 am

Re: 40mm fans not working

Post by Magicmaker » Sat May 03, 2014 4:57 pm

Ok, so I took a good look at the wires as they are.

I got Rambo red wire -> Case fan Red wire, Case fan Black wire -> Extruder fan red wire, Extruder fan black wire -> down the harness to Rambo black wire.

This is how the clips of the fans connect correctly and looks to be correct. UPDATE: When it's like this, both fans twitch and theres a buzzing coming from both fans

However, I switched the connector on the extruder fan to be like this (as an experiment):

Rambo red wire -> Case fan Red wire, Case fan Black wire -> Extruder fan black wire, Extruder fan red wire -> down the harness to Rambo black wire.

This stops the buzzing, and stops the extruder fan from attempting to spin, but actives the case fan.

jsc
Posts: 1864
Joined: Thu Apr 10, 2014 4:00 am

Re: 40mm fans not working

Post by jsc » Sat May 03, 2014 5:47 pm

It sounds like your wiring is correct, and it is just not getting enough power to power both fans at once. In your experimental hookup, what I think is happening is that your fan has reverse polarity protection, which I presume is just a diode to short ground to power when hooked up in reverse. So you are feeding your case fan 24V (minus a tiny bit).

Maybe your fans are bad. You don't happen to have some extra fans to test against? Can you "kick start" them by giving them a little spin?

If you really want to get printing, you can cut the case fan out of the circuit (Rick has said that they have tested without it and it is not required) and see if you can run the extruder fan at half power using M108 S128 (or at full power until it fries). You should probably contact MakerGear support by email, though, and get replacements.

Magicmaker
Posts: 5
Joined: Sat May 03, 2014 7:41 am

Re: 40mm fans not working

Post by Magicmaker » Sat May 03, 2014 10:37 pm

Thanks everyone for the help on this one,

I contacted support and Rick is sending out new fans. Apparently these "sunon" ones are the cause of the issue.

Hopefully they come soon, I'm excited to have a new printer up and running!

I do have some other 40mm fans kicking around from my makerbot, but I'm just going to leave it until the new ones arrive.

Again, thanks for all the support everyone, I'll definitely contribute to this forum as my time with my M2 continues.

Cheers!
-Jon
CEO of Magic Maker Ltd.

Dale Reed
Posts: 376
Joined: Thu Apr 10, 2014 1:39 am
Location: Cleveland Heights, Ohio USA

Re: 40mm fans not working

Post by Dale Reed » Sat May 03, 2014 10:48 pm

I agree with Jin. Take the electronics case fan out of the circuit and wire it so that it only powers the extruder fan, + to red and - to black. You "probably" won't destroy the extruder fan running it at 24 volts, but as soon as you can after powerup, send M108 S128 to send it a "half speed" command. This won't send 12 volts all the time --- it will send 0 volts half the time and 24 volts half the time, so it sort of evens out. If this runs it at a "normal looking" speed, you should be able to print with it this way (so long as there is nothing blocking the air vents around the RAMBo board), but, as Jin advised, definitely contact MG support on this!

Note: if the fan buzzes or runs slowly, bump up the number on the M108 --- S140, S160 maybe, but not more than about S200. These fans use an electronic circuit instead of brushes for commutation, and sometimes the little electronic doo-dad in the fan doesn't play well with the 24 volts / 0 volts / 24 volts (pulse-width modulated, or "PWM") depending on the frequency at which the PWM is pulsed. These little fans were originally designed for computer cases or CPU heatsinks and expect power that is fed 12 volts continuously (DC, not PWM).

I ordered a few of these: http://www.3dmakerworld.com/store/parts ... ll-bearing and am using them for the electronics case and the extruder, wired in PARALLEL, with good success, if you want to just order online and have at it.

One of the great things about the M2 (especially in kit form, for me) is you know what all the parts are and you can try other items (all-metal hot ends and such) from other vendors, or variations on the printed parts posted by other owners, with some confidence if you are good with tools and electronics. For me, I think I'm better at the electronics side: I bought SEVERAL fans because I'm so good (NOT) with the 2.5 mm hex driver used on the M3-size hardware, I keep sticking it into running fans and shearing off the blades. Oopsie.

(The other thing good for me personally about the M2 is I live right down the street from MG, and if I break something, I can PayPal a replacement and go over during lunch and pick it up. "YMMV" ;) )

So there are things that are covered under warranty and things that aren't. I'm VERY good at doing the things that aren't. :roll:

Sounds like you'll get it fixed up right soon.
Dale

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rpollack
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Re: 40mm fans not working

Post by rpollack » Mon May 05, 2014 1:57 am

The problem in this case is that some Sunon MagLev 40mm fans won't work in series. They are designed to work at any orientation but when wired in series some of the fans just twitch.

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