Active cooling for Replicator 2x

[Miguel Alvarez]

When I got ordered the replicator 2x, my main interest wasn't to be able to print with ABS but to be flexible in general with using different materials and also being able to dual extrude to use PVA as support. That being said I still like printing PLA in general because of the reduced warping and start up speed (platform doesn't have to be heated). 

Since the 2X doesnt include an active cooling fan, I decided one of the things I want to do is install my own. This is what I know so far from searching around.

The replicator 2X motherboard has an unused connection which is what the replicator 2 uses for the active cooling fan.

This image was provided by Kobus du Toit in another thread showing the open port 

http://www.flickr.com/photos/92380311@N04/8630148713/in/photostream/lightbox/

After going through some of the replicator 2x documentation. I found this under the "menus" link in their documentation page

"The Filament Fan setting allows you to turn an active cooling fan on and off during a build. Your Replicator 2X does not come with an active cooling fan installed."

This leads me to assume that the replicator 2X allows control of an active cooling fan if it were connected to this open port

I found the model of the active cooling fan from a video of somebody removing it from the replicator 2. http://www.youtube.com/watch?v=shv-ssIgQFY

Here is a digikey link to the part number for the fan which I'll be ordering soon.

http://www.digikey.com/product-detail/en/BFB0524HH/603-1116-ND/1014447

This I believe is the proper connector for the motherboards fan connection

http://www.digikey.com/product-detail/en/XHP-2/455-2266-ND/555485

Once I get some parts in I will test things out and eventually design a mount to attach the fan. Thought I'd post this for other people that might be interested in doing the same.

Miguel Alvarez

[David Celento]

Thanks for the new thread and the info. If it helps, MBI Support says that one may tie two fans to that one port, and edit the GCode to turn the lower cooling fan(s) on/off.

The question that is open relates to fan electrical load and if the motherboard can/will handle this. Loads are light, but care is advised. There is a thread on this topic in the new 3d Tips and Tricks group.

I should add that MBI warns that meddling may make it harder to diagnose issues.

[Laird Popkin]

I'd wonder if it would be possible to vent the current fans on the Rep 2x to cool the print, similar to http://www.thingiverse.com/thing:40524 . I've been using that to print PLA on the Replicator for ages, and it works very well. And on the plus side, it's easy way less work than adding a fan (with wiring, connectors, etc.), and you can slide the vent in place / remove it, so swapping between ABS (no vent) and PLA (vent) is easy.

[Dan Ujvari]

Yes, what Laird Popkin said.  I've also been using this for quite some time.  Great results.  The fans cool the heads just as well blowing in or out.  Air flow is air flow, don't let anyone tell you differently.  On the RepDual, I had to close the gap between the heat sink and the fan, because there was quite a gap.  On the Rep2X the fans already seem close enough, so just spinning them around is probably enough.

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[Miguel Alvarez]

Thanka for the replies!
David, could you give me a link to this thread? Also, I have taken the load considerations. I was thinking of maybe using the output on the board to trigger a relay for the fans using an external power supply. Im assuming the fan port activates automatically when I choose PLA as the printing material in makerware. I also ordered 2 12v fans of the same dimensions accidently before realizing the bot runs 24v (thing o matic is 12v and i made assumptions). I could probably run these two fans in series with 1 port. I'll have to test the current and everything though to make sure it doesnt draw too much.

Dan and Laird,
Great suggestion, I actually used something like this on my thing o matic and it does work great. However when I pay $2800 for a machine and it has an extra port for an automatically controlled fan with better/colder airflow, I dont want to settle for less. An extra $30 at this point doesnt hurt. If this fails though, I will probably end up resorting this

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[Eighty]

> Im assuming the fan port activates automatically when I choose PLA as the printing material in makerware.

I would assume so, but you probably want to make sure the profile includes DoFanCommand=true, then confirm the gcode. You'll be looking for the M126 T0 command after the 3rd layer.

[David Celento]

Miguel,

No thread on this, but here is the exact email from Josh (who, btw, is GREAT) at MakerBot support:

Josh Masson (MakerBot Industries Support) Apr 10 19:00 (EDT) Hi Dave, I'm so sorry for the delayed reply. I've been waiting for an answer on the fan before I got back to you. I finally got a minute with one our lead engineers. You will not have to actually add a second port for another fan. You will need to splice the wiring of both fans into a single plug that will go into the existing port. The single [sic] When printing with PLA you will need to create a custom profile and enable the fan in the gcode. You will want to set the status in the "do fan line" to true and then reset it to false when you return to print with ABS. With that being said, I have to let you know that making any modifications that lead to any damage to your printer will restrict our ability to fully support your printer. Please be careful when doing any mods. Best, Josh MakerBot Customer Support

[Miguel Alvarez]

Eighty,

I just created a custom profile on makerware based off of the default PLA profile and I can confirm it includes the "DoFanCommand=true" by default. I also tested generating gcode with the default PLA profile. The profiles for the makerbot slicer include the M126 T0 command so those should activate the fan as well without the need of a custom profile. The high setting which uses skeinforge instead of makerbot slicer does not include this command though. I'm not sure if it is implemented differently or if its not implemented at all. If I have time when I get home on sunday I will test all of these profiles with a multimeter on the fan output. I have finals coming up soon :/

[Miguel Alvarez]

Thanks David,

I think its pretty clear now that the fan will work if using the right profile settings to turn it on. Looks like the main concern now is if board can handle the extra power. Only reason I see it wouldn't is if the extra extruder(cooling fan, heater, and extruder stepper) compared to the rep 2, consumes enough power to the point that the motherboard cant handle the extra fan. I guess we'll have to see, but I doubt it. The fan is only rated at 2.64 Watts haha

[Eighty]

Miguel,
Skeinforge will have it in the start.gcode, and it may not exist for the R2X version. But it's pretty east to add. Or add it manually in your sliced gcode after layer 3, if you'd like.

[Miguel Alvarez]

Ah you're right, I generated the gcode with the rep 2 profile and it did add in the command. I guess I'd have to add it in manually if I use skeinforge

[David Celento]

From Dan Newman in an earlier thread somewhere in the (three piled) heap:

The MOSFET they use for the cooling fan is a 2N7002K which is good for 60V but 

only 0.3 A.  So make sure that the two fans combined use do not exceed that 

current rating @ 24V. 

[Miguel Alvarez]

Thanks David!

This is just the info I need! The 12V fans are rated at .170A each so it should be fine. I'll check how much current they draw in series when I get home tomorrow. The other thing I wanted to do is implement a switch that will allow one of the two fans to run, or both simultaneously in case I do a dual extruder print such as PLA with PVA (unless PVA also favors active cooling). 

[David Celento]

I'm with ya'.

Don't you need 24v fans, though?

I like the manual switch idea to turn either one off -- I was thinking the same thing for the same reasons. Let's hope we get this bad boy printing with PVA!!!

[Eighty]

David,
If you artsy architect types took any courses in Electrical Engineering, you'd understand how two 12V fans in series can run on 24V...:-)

[Miguel Alvarez]

Like Eighty said,

Two get the total voltage drop of two objects in series, you simply add them. i.e. if I have a 24v supply and I have two components in series, the total voltage drop across both components must be 24v. Since both fans are the same (should have equal internal resistance). The voltage across each of these should be half of the 24v, so each will have a voltage drop of 12V. If i were however to bypass one fan and only turn on the other one, there would only be one component connected to the battery meaning the voltage drop on that fan would be 24V. To prevent this from happening, I'd have the switch redirect the connection from the other fan to a resistor of equivalent internal resistance. That way the voltage drop across both components would be 12V. Im not sure if this explanation is very good, if you'd like I can make a diagram that might show it better

[Dan Newman]

On 13 Apr 2013 , at 11:25 AM, Eighty wrote:

> Miguel,
> Skeinforge will have it in the start.gcode, and it may not exist for the R2X version.

MBI never added Rep 2X profiles to RepG and neither have Jetty nor myself. MBI
hasn't as I expect they have no intention of release another version of RepG.
Jetty and I do not have a Rep 2X to test on making it awkward. My guess is
that the Rep 1 Dual profiles but changed for Rep 2X dimensions would be what
would work best. I'll put it on the to do list but would need someone to test
them….

Dan

[Eighty]

Architects work much better with abstracts. Details just confuse them.
Man, this is fun. I could do this all day!

[David Celento]

"If you artsy architect types took any courses in Electrical Engineering, you'd understand how two 12V fans in series can run on 24V...:-)"

OHHHH, SNAP!!! :-)

On Apr 13, 2013, at 8:10 PM, Eighty wrote:

> Architects work much better with abstracts. Details just confuse them.
> Man, this is fun. I could do this all day!
>

[Eighty]

Couldn't help myself. I spent 10 hours today in a committee meeting full of engineers, updating ACI specifications. Committees drive me insane, but I was glad that we could agree on at least one point: The term "Engineer/Architect" is preferable to "Architect/Engineer".

[David Celento]

Wise choice on your committee's selection of Engineer/Architect.

Given that Architectural licensure requires structural analysis and calculations, I know more Architects who have Engineering skills than Engineers who have Architectural skills. ;-P

(it never gets old, does it?...)

On Apr 13, 2013, at 10:14 PM, Eighty wrote:

> Couldn't help myself. I spent 10 hours today in a committee meeting full of engineers, updating ACI specifications. Committees drive me insane, but I was glad that we could agree on at least one point: The term "Engineer/Architect" is preferable to "Architect/Engineer".
>

[David Kessner]

Don't run the fans in series.  At best, it won't work as you expect.  At worse, you'll fry the fans and maybe your bot.

Fans (and other motors, DC brushless or otherwise) are not like lightbulbs and LEDs.  They switch the current flowing through the coils on and off, at precise times, so that the motor spins.  The problem with running fans in series is that one fan is going to be turning the current off at the same time that the second fan will want to turn the current on-- but it can't because the first fan turned it off.  The two fans will always be fighting to control the current, and odds are that neither will win.

The other problem is that the voltage drop across the fans might not be very uniform.  It can vary depending on how the motor itself is switching the current.  It is entirely possible that one fan will see much more than 12 volts.  If the fan cannot handle it, the fan could blow.  A standard DC Brushless Motor, as is used in most fans, has a small IC that contains the control circuit to manage the current switching.  If that IC cannot handle 24v in, on a 12v fan, then it could get damaged.  Unless the fan is rated to run at 24v, you should not run it at 24v.  It may or may not be damaged, but there is no way to be sure unless the fan is rated for 24v operation.

-DK

[Miguel Alvarez]

Oh crap you're right! Thanks for pointing that out, I guess I've never actually implemented a fan in any of my circuits and never took their form of operation into consideration. I guess the best thing to do would be to have the 12v fans parallel to each other, and have a resistor in series with each to make the voltage drop across each 12? That plus a small resistor before both parallel lines to limit the current from passing .3A? Am I missing something else here?

[David Celento]

On Apr 14, 2013, at 1:13 AM, David Kessner <david...@gmail.com> wrote:

Don't run the fans in series.  At best, it won't work as you expect.  At worse, you'll fry the fans and maybe your bot.

BAM!  Take that, Eighty!!! ;-P

Thanks for the great insights here David K!!!  So is running two fans possible via some type of electronic wizardry? It would be great to develop some kind of little wire harness that electronic idiots like me could easily build armed with a trip to Radio Shack and a soldering iron. :-)

~David

814-321-5229

Sent from mobile device inspiring brevity and/or typos...

[Joseph Chiu]

Yes, you can easily wire up a 7812 from RadioShack plus two capacitors thrown in for good measure.  The only problem is that by dropping 12V at 0.1 A, you're potentially dissipating 1.5 watts - not a ridiculous amount, but it would start to get a bit hot without heatsinking.  And, you probably should not be using any of extruder as the heatsink, as they will be hot already.

[David Kessner]

You can't use resistors in series to drop 24v to 12v.  To do that correctly, the current consumed by the fan needs to be consistent-- but it is not.  It pulses on and mostly off.  When it is mostly off, you will have close to 24v to the 12v fan.   Even if it did work, you would be consuming double the current that is required-- current that the Rep2 doesn't have a lot of to spare.  Here are your options, from best to worst:

1.  Use two 24v fans in parallel.  (Easy, 100% power efficient)

2.  Use a different 12v power supply, run two 12v fans in parallel, use a transistor or MOSFET to power the fans from this supply but turned on by the Rep2 fan output.  (Slightly more complex, 100%-ish power efficient.)

3.  Use two 12v fans in parallel, but power them from a switching regulator that drops 24v down to 12v.  (Complex, beyond most people do to, about 80-90% power efficient.)

4.  Use two 12v fans in parallel, but with a linear regulator (50% power efficient)

If you have little to no electronics design experience, I highly recommend option 1 (and only option 1).

-David K

[Miguel Alvarez]

The second option was actually the first thing I thought about doing before I knew the current the board was capable of since it was probably the safest for the board. I also considered the other options after I realized I had ordered the wrong voltage fans haha. I guess the best thing will be to get the 24v fans since they both are rated at less than .15A anyway. The first option shouldnt require any additional components to limit the current. I'll order the new fans and get that tested once they arrive.

Thanks again David!

[PhGeis]

These fans you are planning to set up, axial or blower fans? Can you post some pics when set up? I am not supernfamiliar with the set up so more information the better :-) thanks in advance
Philips

[Miguel Alvarez]

Dan I'd be willing to test for you. Its the least I could do for the improved thing o matic :P, but I have to say I wont be very free until after my finals which will be around May 8th. If you'd like I could give you my email and we can discuss this separately

[Dan Newman]

On 14 Apr 2013 , at 3:42 PM, Miguel Alvarez wrote:

> Dan I'd be willing to test for you. Its the least I could do for the
> improved thing o matic :P, but I have to say I wont be very free until
> after my finals which will be around May 8th. If you'd like I could give
> you my email and we can discuss this separately

Thanks for the kind offer. However, much to my chagrin, there are
Rep 2X profiles in RepG 40rX - Sailfish. I simply forgot that we
had put them in…. And, I've been told that they are working.

Dan

[Miguel Alvarez]

Oh alright! I havent tried using repG with the 2x yet so I hadnt noticed myself.

[Miguel Alvarez]

Damian,
I agree they're not hard to use,
but as some people have pointed out, they're not 100% energy efficient and dissipate heat. If this can be avoided it makes the setup much simpler and easier for others without electronic experience.

On Sunday, April 14, 2013, Damian Gto <dami...@gmail.com> wrote:
> Just use a voltage regulator and reduce the volt to what ever volt the fan needs. Its very easy to use and it more safe for the bot.
> Choose the one that can handle about 30 volt in and reduce it to what you want. They are very cheap and very safe to use.

[Joseph Chiu]

Well, if one is determined to use 12v fans, but don't want to worry about efficiency or having to build up a circuit, there are off-the-shelf DC/DC converters out there that do a pretty decent job.

Here's one for about $5:  http://www.digikey.com/product-detail/en/VBSD1-S24-S12-SIP/102-1369-ND/989824

I've used CUI's DC/DC converters before and have been pretty happy with them.  In small volumes (factoring in the engineering time), they are more cost effective than building your own DC/DC converter.

On Mon, Apr 15, 2013 at 8:49 AM, Damian Gto <dami...@gmail.com> wrote:

Well use 24v fans. thats the only simple way ;-)

To use 12v fan you need to reduce the volt to 12v.

The simple way for this is to use a voltage regulator, if you want to rep to be able to control it.

A more simple way is to use external power to it.

More advanced way is to build a circuit that will use external power, but use the onboard control for the fan to switch it on/of or make it with a thermostatic switch that will turn on the fan when it needs to.

But none of this is simple, more then use the right volt on the fan, for the normal user. I can make this without problem, but I have that skill :-P

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[Miguel Alvarez]

I will be using the 24v fans, they just shipped out :D

On Monday, April 15, 2013 10:49:50 AM UTC-5, Damian Gto wrote:

Well use 24v fans. thats the only simple way ;-)

To use 12v fan you need to reduce the volt to 12v.

The simple way for this is to use a voltage regulator, if you want to rep to be able to control it.

A more simple way is to use external power to it.

More advanced way is to build a circuit that will use external power, but use the onboard control for the fan to switch it on/of or make it with a thermostatic switch that will turn on the fan when it needs to.

But none of this is simple, more then use the right volt on the fan, for the normal user. I can make this without problem, but I have that skill :-P

   

On Monday, April 15, 2013 5:38:17 PM UTC+2, Miguel Alvarez wrote:

[Count Spatula]

As per #1 would you be using 2 fans to properly cover the print bed or is it necessary for electrical reasons (or both).

[David Kessner]

I only mentioned 2 fans because the original poster was using 2 fans.  It could just as easily be 1, 4 or 20 so long as they are ran in parallel, the voltage you are driving them with matches the rating of the fan, and you can supply enough current to deal with them.

-David K

[Miguel Alvarez]

2 fans, 1 per extruder. More than two would surpass the current limitation of the mosfet that controls the fan output as stated earlier. I could run 1 instead of 2 if I wanted. They are both going to be 24v

[Miguel Alvarez]

I did a multimeter test as well as a fan test with the 24v fans. The fan runs with the cooling fan manually set off and on. When the fan is set off during a print, the voltage is 18v and when the fan is set on its at 24v. Would anybody else be willing to confirm this on their 2x?

On Friday, April 12, 2013 12:38:21 PM UTC-5, Miguel Alvarez wrote:

When I got ordered the replicator 2x, my main interest wasn't to be able to print with ABS but to be flexible in general with using different materials and also being able to dual extrude to use PVA as support. That being said I still like printing PLA in general because of the reduced warping and start up speed (platform doesn't have to be heated). 

Since the 2X doesnt include an active cooling fan, I decided one of the things I want to do is install my own. This is what I know so far from searching around.

The replicator 2X motherboard has an unused connection which is what the replicator 2 uses for the active cooling fan.

This image was provided by Kobus du Toit in another thread showing the open port 

http://www.flickr.com/photos/92380311@N04/8630148713/in/photostream/lightbox/

After going through some of the replicator 2x documentation. I found this under the "menus" link in their documentation page

"The Filament Fan setting allows you to turn an active cooling fan on and off during a build. Your Replicator 2X does not come with an active cooling fan installed."

This leads me to assume that the replicator 2X allows control of an active cooling fan if it were connected to this open port

I found the model of the active cooling fan from a video of somebody removing it from the replicator 2. http://www.youtube.com/watch?v=shv-ssIgQFY

Here is a digikey link to the part number for the fan which I'll be ordering soon.

http://www.digikey.com/product-detail/en/BFB0524HH/603-1116-ND/1014447

This I believe is the proper connector for the motherboards fan connection

http://www.digikey.com/product-detail/en/XHP-2/455-2266-ND/555485

Once I get some parts in I will test things out and eventually design a mount to attach the fan. Thought I'd post this for other people that might be interested in doing the same.

Miguel Alvarez

[David Celento]

Good luck with this, Miguel!

Have you decided where to mount them?

~Dave

[Miguel Alvarez]

Thanks Dave, 

Its actually really tough. Anywhere on the sides would reduce the build area because the extruder assembly requires the entire sliding space to reach all the platform boundaries. The fans will have to be placed on top. I worked a bit this weekend on a funnel that directs the air around a small gap I found but I still dont have a working prototype yet. I haven't had much time this week since I had a test today. I'll try to get a prototype working this weekend and hopefully some test prints.

Miguel

[Miguel Alvarez]

Alright so while I haven't had much time to work on this since I've been finishing school projects and preparing for finals, I have got a general design for the fan duct. It still needs some adjustments but I think its a pretty good start. Since I am trying to keep it from obstructing any of the extremes of the axis, this is as big as I could make the ducts. They wont have as much airflow as the rep 2 but its still decent. Both sides are split off internally so each fan blows the individual extruders. Also I will probably back off the ends of each duct so that they're not lying right under the extruder heating block. I'm afraid the heat will be too much for the plastic to maintain its form over long periods of time. I've attached some images and I'm open to any suggestions!

Miguel

[David Celento]

Looks promising. Couldn't figure out from photos the source of the air?

[Miguel Alvarez]

On the 3rd picture, the rectangles on the right and left side are the fan slots. Sorry I didnt include the fans in the picture, that probabpy wouldve made it clearer.

[Jake]

On the 3rd picture, the rectangles on the right and left side are the fan slots. Sorry I didnt include the fans in the picture, that probabpy wouldve made it clearer.

What size fan does your design take?

I recently bought a pair of 15mmx15mm fans from Digikey, with the hope that they might make a good, low profile solution for 2X cooling.

I'm not quite sure they will.  They're like 0.1CFM.  just a tiny breeze, and I'm not sure it could push much through a duct.

[Miguel Alvarez]

I'm using 50x50mm fans, the exact same model used for the rep 2. There is a digikey link to it on the first post :)

[Jake]

Ahh sorry about that... Got lost in collapsed threads in google groups.

I've been eyeing these as a potential solution for a compact solution, but I haven't started any real work on designing anything:

http://www.olc-inc.com/CFR1B.html

[camstuff]

Have u put this deign on thingiverse yet? Just to share and maybe have some others possibly help come up with some tweaks in the design?

[Miguel Alvarez]

Damn I could do that but theres a problem. I just drove home today (from college) and I usually leave my desktop on in case I need to access it remotely, but the router is in my room mates room and he turned everything off so I wont have access to the files till next Wednesday (May 15th) when I go back. I'll definitely upload the files when I get there, I just need to make a quick change to it first! :)

[Miguel Alvarez]

Thats a great idea Eric! I hadnt considered this since I havent had problems with the pla jamming from heat creep, but it could be something affecting people in hotter environments. I'll try to implement this in the design. I'll also be uploading the files this week (after some fixes) in case others want to test and modify themselves. Thanks for the input! :D

Miguel

[PhGeis]

Hi Miguel did you manage to have a working electronical setup? could you draw and post a diagram inclusive the electrical specifications? 

Are the parts from the first post still valid and working ?

[Miguel Alvarez]

Hi PhGeis,
As of right now Ive tried connecting both fans from the original post in parallel without any other components. The parts from the original post including the connector are all correct. The only problem I have is that when the fan isnt set to be on, the fan port outputs 18v so turning the fan on and off from the settings just changes the speed, but its always on. Ive had nobody else confirm this for me on their bot and Im thinking it might be a defect on my board

[PhGeis]

Hi Miguel,

I just ordered the fans and teh connector. gone splice them together as soon as i get them and will test that for you. could you send me a pic of the board where the right outlet is located? 
Philipp

[Miguel Alvarez]

AWesome!
Its labeled on the board and its the only connector. You'll see it but if you dont I can get you the picture. Also I hope you didnt forget to include the connector crimps. I didnt include them with the rest of the links since the link for those is provided in the product page

[camstuff]

have you put this design on thingiverse yet? dyeing to try it out.

Cam

[Miguel Alvarez]

Haha probably not till thursday since im barely going back to college tom! Sorry for the wait!

[Miguel Alvarez]

So I finally got to uploading the parts to thingiverse. I wouldve really liked to test it and modify it some more but I promised an upload on thursday so here it is. I cut off the tip of the blower for each extruder tip because I felt it was too risky to have the plastic so close and in risk of melting. If you want the design that is in the pictures let me know. This still isn't completely designed to print perfectly since there will be some sort of overhang in either orientation, but I'm working on it! Anyway this isnt meant to work yet, but at least you can take a look.

http://www.thingiverse.com/thing:90174?save=success

[PhGeis]

Hi Miguel, my crimps and motorts finally arrived, just have to find time to open up the bot and connect. 

Tried to print pla in the meanwhile with that thing: http://www.thingiverse.com/thing:33254

solved the cooling issue as far as finding the problem with the extruder... heat creep like discussed alaround. my plan was now to use the blowers as fillament cooler. any idea how to attach a tube to the cooler? thaought about modifiying your mount to an 6mm tube outlet and than drilliing a hole through my whpthomas extruder upgrade arm to push through the tube... 

Did you find the heat creep issue and how did you solve it?

[Miguel Alvarez]

Hi Phgeis,
I could add a slot or extra arm that would provide cooling to the plastic. The only problem is that this might reduce printing space. The heat creep problem seems to depend on the temparature of the area where you're printing. I did not have the problem (Printer is in my room) but I have a friend that did with his rep 2. His printer was set up in his garage (no AC). I told him to try it in his room and it fixed the problem. Anyway, I'll try to add an extra slot when I have time (let me know if you need it a specific aize), I'm also worried though that this might greatly reduce the output air flow on the extruder tip considering its not that high at the moment.

Miguel

[Eric Weber]

My blowers should arrive this week. Has anyone tested the prototype the 2x yet?

[PhGeis]

try to get a separate version running.. right now i fight with bubbles in my fillament and poor print quality, maybe resulting from that?!? 

Did not measure the output voltage yet.. maybe 2morrow morning..

[Miguel Alvarez]

Hi guys,

I'm sorry if some of you have been waiting impatiently for updates. I've been working on some school projects which have had my printer running non stop. Hopefully my printer will have a break within a week so I can continue on the active cooling project. 
Thought I'd give an update for those of you wondering whats going on.

Miguel

[Eric Weber]

Thanks for the update. I just received the fans and plan to print the prototype during the week.

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[Jake Dambergs]

I don't see a response ever on this, I had the bottom off mine tonight so I tested.  I get 0 vDC when filament fan setting is off and 24 when filament fan setting is on

JakeD

[Miguel Alvarez]

Thanks Jake,

I'll have to contact makerbot about mine then. Must be faulty

[Jetguy]

Yes, you are supposed to get 0 volts when off. the MOSFET is an N channel device. The power source is always on, the FET turns  on the ground return path. So if you have a fan or any device connected that has some conduction through it, OFF both terminals will be 24 volts compared to power source ground. ON one side will be ground, one side will be 24V thus 24 volts across the device.

 

It's working normally, you just didn't know the details on how to test.

[Jake Dambergs]

Right, I tested across pins. Testing using a true ground yielded the results you described - thanks for the explanation.  FWIW, I saw 21.6 on the "ground" pin and 23.4 on the other with the port "off", no load attached. 

-JD

[Miguel Alvarez]

Jetguy,

You mightve missed what my problem was which I posted a while back on the thread. Jakes test is what is expected, but my results are different. When the fan is set to off, the voltage across the fan connector pins(not the MOSFETS drain and source pins) on my printer is about 17V, and when its on I read 24V. I've connected my fan and theres never a point where its off. Its either moving slowly (17V across) or fast (24V across). I'm not sure if the FET is messed up or for some reason the gate voltage is higher than it should be when its off. I could probably look into it more but I wouldnt want to mess up my warranty in any way.

[Jetguy]

Sorry I was responding to Jake, not you.

 

Yes, there are reports of MOSFET failing, when they fail, they fail on or shorted.

BTW this is why EV (Electric Vehicles) have a huge problem. You think Toyota had it bad with uncontrolled acceleration, MOSFETS in an EV can blow and since they short on, the EV runs wide open out of control until the batteries are dead.

 

This is not the first report of that fan MOSFET failing. MOSFETS are voltage sensitive devices so any static or worse, any inductive load sends back towards the MOSFET a huge voltage spike that blows them up. They should have a reverse biased diode on the output to shunt and disipate any excessive voltage but Mightyboard one doesn't (Replicator 1) and from all pics Ive seen, mightyboard rev G in the 2 series doesn't have them either.

 

This is kinda why I warned folks about adding or changing fans on these boards, we knew rev. g was not open source so we don't have schematics and therefore coudn't verify such things like diodes in place. Basically it's not surprising, cost seems to be the biggest factor in the design, leaving out a diode saves them maybe 2 cents.

[Miguel Alvarez]

Ah alright, well the board actually seems to be the exact same one that the replicator 2 uses so I dont see a problem in adding a fan especially if its the exact same one. Since this board was used for the 2x though, who knows if they even test the fan port.

[TaErog]

Sorry, but this is a bit of a pet peve as it is one of those "common knowledge" or conspiracy theories deals that also happen to be more fiction then fact.  (not a bang on you or anything as allot of people go with the headline not the facts here and I ended up doing some real research here)
"BTW this is why EV (Electric Vehicles) have a huge problem. You think Toyota had it bad with uncontrolled acceleration" -Jetguy
To date there is no cases of a uncontrolled acceleration in a production model EV (if there is and you have real documentation send it along).  All of the Toyota uncontrolled acceleration problems where with "normal" cars and due to mechanical problems (+1 at least, electrical).  The only Prius recall had to do with the breaks (a uncontrolled deceleration problem :) really)  re-tuned anti-lock brakes fixed this (this has been a more or less common anti-lock break problem across car lines/makes) for some reason people think/feel acceleration but it is not. This has been researched to death and found that people where breaking at the time and slowing  - just not as fast and smoothly as wanted, the strange studder felt to some as acceleration and had caused a few crashes. Other cases where all out fraud and even prosecuted.
Also, real uncontrolled acceleration in other makes again tended to be mechanical problems or mats (ie Ford etc ), though a few had throttle problems (ie Honda etc) and at least one a short circuit (Camry)

Sorry, after researching this to a great extent to see what was up, (I may have been effected) I found the controversy was almost all news drama with some real but few true problems, nothing to ignore but blown way out of proportion..

Back to the scheduled program:
I am working on just a quick attach blower fan with just a simple 12v wall power-supply, to cool the block and plastic . . . I do not think there is much need for MB control.  I might even add a fan control to vary the speed - whatever I can find in my PC MOD leftovers, and a printed duct? . Should be simple and effective.  Not crazy hot plugging more into that board. Though I would be interested in how things go.

[Bottleworks]

On the EV stuff...  I can speak first hand that the Allison Hybrid electric system's DPIMs use IGBTs.  Can't speak on other EV systems. 

On the Mightyboard fan FETs....  I had one fail for my heatsink fan (rep 2).  They are finally sending me a replacement Mightyboard.  It took a long time for the tech to understand what's going on.  I think I was giving too much data at once. 

[Jetguy]

 I only mentioned jokingly about Toyota since everyone in the world heard about it as an example of controlled acceleration. Sorry if that was confusing I halfway just meant to relate something everyone had heard about since there are very very few real production EVs, and therefore not publicly widespread reports of uncontrolled acceleration of real EVs

 

A PRIUS is NOT an EV, it's a hybrid. There are NOT many production EVs. http://en.wikipedia.org/wiki/List_of_production_battery_electric_vehicles

Toyota DID find a problem and that was that the potentiometer used for the throttle (they are drive by wire) was made with ROHS compliant components and zinc wiskers could and were proven to be growing and shorting the terminals. This could easily cause real uncontrolled acceleration and was proven. NASA did the study http://nepp.nasa.gov/whisker/reference/tech_papers/2011-NASA-GSFC-whisker-failure-app-sensor.pdf     also found here http://newenergytimes.com/v2/sr/WL/slides/20120124LatticeEnergyDoc.pdf  Yes, there were folks who commited fraud and that was proven as well. The Zinc wiskers thing was real and did get recalled.

 

Most EVs are self built, or kits, compared to the numbers of real production EVs. I was studying how to build one and it's in every instruction I've ever seen to have a secondary safety shutdown because the controlling devices FETs, IGBTs, whatever, generally fail shorted. This is true in RC cars with FET based controllers as well and is well documented in industry.

Proven discussion of EV failures

http://www.diyelectriccar.com/forums/showthread.php/run-away-ev-38794.html

"

notmrwizard

Re: Run away EV PS. I had a curtis go about 9 years ago. I was still new to ev's so it had the controler right behind the drivers seat. Luckly I lived and learned. Anyway I can't remember slaping it in neutral but I was out and on the pavement fast. Second luck was it happened in my drive way. Lots more details than any of you want to hear. Third luck was I have over speed control so as soon as I collected my wits I hade time to climb back in and shut it down. Whats it like you ask? BIG BOOM!!! Lots and lots of smoke.     FETS are known to fail shorted in almost every industry. The causes are known and so are the protection methods.   So the problem is the Replicator 2X folks asked if they could just plug in a fan to the motherboard. The problem is, the mightyboard rev E used in the Replicator 2 and 2X is NOT open source. This means that of the several certified engineers poking around in the forums, NONE of us can verify the schematic for best pratices, specifications, layout problems etc.. MakerBot will not provide information on specs or rating either. So again, the question was asked can we just plug  fan into the motherboard. Rather than just say yes, us engineers KNEW we cannot say yes to that question because we have no idea what the capabilities for current are for that port. We could not verify if a diode was in place. Fans are motors made of coils of wires also known as inductors. Inductors produce a voltage spike each time they are turned off. If you PWM (Pulse Width Modulate) you effectively turn on and off the inductor rapidly and create huge amounts of voltage spikes at the FETs.   So, someone did attach a fan and based on the assumption it would just work, blew the FET. Then, there is one other report of the same FET blowing. All I'm trying to relate is that FETS are known to blow when pushed out of spec or by inductive loads. We do not know how much the baord can take and MakerBot will not tell us. Even plugging in the exact same model of fan used on the Replicator 2 could be risky. The point is, there are proven failures and therefore this thread and failures should urge folks not to randomly go attaching any willy nilly fan to the port as it could cause the FET to fail.   If you want to use a fan, you probably should power it externally or build a suitable opto isolated drive circuit. http://hades.mech.northwestern.edu/index.php/Using_Opto-Isolators_to_Prevent_Interference  Note, in that circuit, they used a 330 Ohm resistor to limit current in the LED portion of the opto-isolator. You would need to adjust that up to a larger value for the 24 volts the mainboard supplies. I'm thinking a 1.8 k resistor is correct. The original circuit assumed 5 volt on the logic input side so 5V / 330Ohms is 0.015A, 24 volts / 1,800 Ohms is 0.0133A. That way, you are properly limiting the current through the LED section of the opto isolator to nearly the same current at before (slightly less for a margin of error).   Of note in that circuit, it does show a proper diode on the FET for protection of the output. You could also add a similiar diode to the output on the board now, but it requires you to make sure it's installed the correct direction as incorrectly installed it would short the MOSFET and likely blow it. Basically, we re back to unknowns. I'd love to show you pictures and a mod to add such protection but I cannot verify the schematic and therefore cannot tell you correct direction on those pins. Further, I don't know what FET is used and there appears to be no properly rated fuse or overcurrent protection other than the main fuse which is just an "ah crap" function. Therefore, I have show legitimate reasons not to just willy nilly plug in any fan off the shelf, evne one you think will work or someone else said it worked. The risk to blowing the FET seems rather high.

 

 

 

 

 

[Damian Gto]

I think its so funny as soon something is closed source then all thing is impossibly.

Wake up.,

Its not.

There is few things you can not reverse engineer, even iphone or other smart phones has been that.

So the mightyboard is not so special.

Most of what is used is known and easy to rebuild.

Some stuff its harder to figure out, just for you need some equipment for it.

So just stop this nonsense about closed source. 

On Friday, April 12, 2013 7:38:21 PM UTC+2, Miguel Alvarez wrote:

When I got ordered the replicator 2x, my main interest wasn't to be able to print with ABS but to be flexible in general with using different materials and also being able to dual extrude to use PVA as support. That being said I still like printing PLA in general because of the reduced warping and start up speed (platform doesn't have to be heated). 

Since the 2X doesnt include an active cooling fan, I decided one of the things I want to do is install my own. This is what I know so far from searching around.

The replicator 2X motherboard has an unused connection which is what the replicator 2 uses for the active cooling fan.

This image was provided by Kobus du Toit in another thread showing the open port 

http://www.flickr.com/photos/92380311@N04/8630148713/in/photostream/lightbox/

After going through some of the replicator 2x documentation. I found this under the "menus" link in their documentation page

"The Filament Fan setting allows you to turn an active cooling fan on and off during a build. Your Replicator 2X does not come with an active cooling fan installed."

This leads me to assume that the replicator 2X allows control of an active cooling fan if it were connected to this open port

I found the model of the active cooling fan from a video of somebody removing it from the replicator 2. http://www.youtube.com/watch?v=shv-ssIgQFY

Here is a digikey link to the part number for the fan which I'll be ordering soon.

http://www.digikey.com/product-detail/en/BFB0524HH/603-1116-ND/1014447

This I believe is the proper connector for the motherboards fan connection

http://www.digikey.com/product-detail/en/XHP-2/455-2266-ND/555485

Once I get some parts in I will test things out and eventually design a mount to attach the fan. Thought I'd post this for other people that might be interested in doing the same.

Miguel Alvarez

[Jetguy]

Damian,

 

How about just 1 time, you actually post something helpful instead of arguing with me?

 

I posted a suggested schematic. I posted links and explanations of operation, how to test, etc.

 

You have stated at least ten times about cooling and it's easy. When I and others question you about what fan you use, how it's connected whatever, YOU NEVER ANSWER with something meaningful.

 

Either help or stop being annoying!!!!

[Jetguy]

And, BTW, a Good time for that Moderator to step in.

 

I mean seriously, I'm trying to protect customers and educate at the same time here. MakerBot doesn't want you to reverse engineer the board, otherwise they would publish info on it.

 

Again, a customer added a fan and the MOSFET failed, if that isn't an "I told you so" then I don't know what is.

Rather than have others risk the same issue that likely MakerBot is not going to fork over boards on for free let's try to educate on the why, and provide a how so that users can add cooling and not blow the board.

 

Is that so wrong it requires mean hatred from one or two loud and annoying 2X owners?

 

On Friday, June 14, 2013 8:50:16 AM UTC-4, Damian Gto wrote:

[TaErog]

Again I was not raging on you or about joking just the misconception . . and keeping it going :( " I only mentioned jokingly about Toyota since everyone in the world heard about it as an example of [un]controlled acceleration" - jetguy  and that was the problem contrary to popular belief most all are mechanical to the point of a jammed or blocked peddle. 
"he Zinc wiskers thing was real and did get recalled."-jetguy 
Yup that was the Camry I listed (just said a short because most people would understand that - and it effectively was) and yes it did cause the problem. No argument there.  But again it was not part of the big recall people rave about, was not very far reaching, more of a manufacturing flaw that was not uncommon at the time and not a FET failure.
Also I would say hybrid's could fit into that category as they do have completely electric driveling modes and thus similar hardware/electronics.
"True" EV are rare and sure allot of home made . . . so in these these DIY EVs flaws should be abundant. again no argument there.


"So, someone did attach a fan and based on the assumption it would just work, blew the FET. Then, there is one other report of the same FET blowing. All I'm trying to relate is that FETS are known to blow when pushed out of spec or by inductive loads. We do not know how much the baord can take and MakerBot will not tell us. Even plugging in the exact same model of fan used on the Replicator 2 could be risky. The point is, there are proven failures and therefore this thread and failures should urge folks not to randomly go attaching any willy nilly fan to the port as it could cause the FET to fail."  -notmrwizard?
Interesting . . I would be quite interested in continued information.

I did make today the blower out of a NMB BG0903-B044-00S  (12v)  Got a 1 of many wall transformers to try it on and found the one that fits the specs  - and massive overkill that fan is powerful!  Found a 7v transformer and that was much better. (though need to check the draw) or find my 12v fan controller.  Need to make a clip for it (placing it on the back of the case near the filament feed) . . BUT lost the back tubing I was going to use!!  off to the store later!  Prototype is rather crude but gets the air where I want it. and benefit is it is removable and uses a separate power supply! 
Any ideas on a 2x duct for cooling the filament I could mod? do not want to reinvent the wheel here if I do not have to?

[TaErog]

Some people may find you "loud and annoying" ;P  and possibly a bit opinionated? and that you harp on them in turn?  But then again ALLOT of people here are that way . . Argument/discussion is a GOOD thing, attacking and trolling is not.  compared to other threads this is anything but heated or nasty. . . . annoying? well I would expect so as most forums are.

I do have issue on this statement though
" MakerBot doesn't want you to reverse engineer the board, otherwise they would publish info on it." - jetguy
I think you assume too much here.  there are a host of good and rather mundane reasons not to publish info on the board that have nothing to do with purposely stopping customers from "reverse engineering the board".
I am not saying again that you are wrong here (it could be the or even a reason) but your strong opinion/assumption comes out as a absolute statement that in turn you also use as a basis for other opinions/assumptions.  All of which begs the question are these opinions/assumptions even correct? on which you tend to be quite militant on insisting they are all absolutely correct even when sometimes valid conflicting information or views are expressed. and then you/them find the resulting conversation annoying . . things get heated . . 

I for one am not going to plug in a fan to the MB before I get more information! on this we agree fully, but also I do not think it is imposable to figure it out or even wrangle it from MBI.  personally I am just bypassing the issue for now. (to get this desk fan off my table) when printing PLA . .  unfortunately it is going to be just as noisy . .

[Miguel Alvarez]

Ok, I appreciate you guys providing information and suggestions but I would like to get one thing straight.

Whether you guys are referring to me or not about "just attaching a fan and expecting it to work", I did not test the fan before doing a multimeter test. I took precautions to make sure the board on the 2x matched the board on the rep 2 before deciding to order any parts (there is a rep 2 in the research lab in school). I ordered the exact fan used in the rep 2 and before I connected it I took voltage readings of the fan on and off. It was already at 17v for off and 24v for on. When I tried connecting the fan there was no difference in voltage readings. The FET was not messed up by connecting the fan, this is how it was already behaving.

 I'm a junior electrical engineering student and while I feel that I have the knowledge to do a project like this, I dont have the same amount of experience that a lot of the community has which is the reason I started this post. Many people have posted valuable info on right and wrong things to do, someone posted specs on the FET, etc...  

Now as mentioned, using a external power supply would be the safest and simplest way to get this working, and it could get easily done. I however like everything to work for me. I dont want to have to go turn on the fan every time I'm going to print PLA and turn it off every time I finish. If I have the fan turn on automatically just by selecting PLA as my material in makerware, then I find it much more convenient. 

I did contact makerbot before approaching this project and they told me that anything I might do that causes damage to the board they would not cover. I was aware of this from the start and I would not complain to them if what I did had caused this damage. Like I said though, this problem was there before I even connected anything to the port.

Miguel Alvarez

[Jake Dambergs]

I use a Belkin WeMo to control our HVAC, cheap and works like a charm.  I think a self standing unit is an easy non-invasive choice here.  I expect it would be pretty easy to create a circuit to switch on and off based simply reading the voltage drop across the fan port pins, then you get a Replicator controlled fan and no actual draw.

Jake Dambergs > www.lptechsupport.ca

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[Damian Gto]

I use to post things that add to the treads question or subject.

But you keep posting statement that is wrong.

You keep telling people what they can do or not.

You have no clue what people can do or not.

Also where in the OP post did you find any question about cars??

Does any company want there stuff be reverse engineer?

Some will care some do not care.

I do not think MBI would be angry if you add something to the mightyboard or update some stuff, more then your warranty will be removed.

You do not protect any people when you telling lies and stuff that you often do. Its your opinion and others maybe not share them.

Also you keep showing lack of knowledge on stuff and you still keep telling people what they can do. Just stop that and I bet we all get along much better.

So stop posting things you "think" as a fact. they are not. I could post 10+ things you sad as fact that is wrong and most of the time you change your opinion, but you never admit you was wrong.

Back to topic.

I also think it would be nice if you could turn the fan of/on with the gcode. But I also feel its more safe to have an external power to the fan, to be sure it will not mess with the bot. Also you need a a "duct" that blow on the nozzle/print when using PLA, so I do not think it would be much work to turn the fan on. You could easy put a temperature sensor on it so it turn on when it start getting hot, That way it will turn of when the printer is done and cooled down.

[Eighty]

 Guys, I don't know what you're getting all hot and bothered about.  Jetguy is right here.  The Rep2 and 2X boards are the same.  So theoretically, you could add a fan.  The issue, as I understand it, is that someone added the fan and blew a FET.  That potentially means that MBI never tested the board with dual extruders AND a fan AND an HBP.  It could be overloading something.

 

And Jetguy is also right that they've gone closed-source with the circuit design.  We all know why they did this - to prevent the cloners from copy-catting the design.  I can't blame MBI for this, but it makes these kinds of mods a big guessing game.

 

So let's all cool down and focus on the details of trying to make a fan work.  It would certainly be safer to use an externally-powered fan.  Perhaps the blown FET was just a bad FET.  But until I see some more data, I'm probably not going to risk my 2X motherboard by plugging in a fan.

[Damian Gto]

Jetguy is right its closed source, but not that it means you can not see what stuff is and what they are for. Its not that hard to figure that out, so he is totally wrong on that part and its that part he tell all that its impossibly. If someone want to clone the rep2 or rep2x it not that  hard. They clone much much harder things.

I do not agree that one blewed FET will means that MBI has not tried to use one more fan. That is pure speculation.

Also it could be anything that did blow that. Its like to say when 100 people run on a new road and one do tripp, that the road is wrong. :-P

Like I did say before I think an external power to the fan is better and I also think you need 2 or 3 fans to cool it down so you can print PLA.

I did use 2 fan, but I only used 1 extruder. You might even need 2 per extruder if you want to use dual color( both extruder).

I will look into this more as soon I get time. Right now I  working on my project for reinforcement on the arms.

After that I will look at the filament cooler project and add PLA cooling to that.

So I DO try to solve issues as soon I can.

[TaErog]

Eighty Exactly! 

[Jeremy deGuzman]

So I've added the two blowers (albeit temporarily held in place with a liberal application of electrical tape), and haven't had any problems running both of them in parallel off of the motherboard header. I have some (fairly terrible) photos of the setup attached. 

[Miguel Alvarez]

Haha thats awesome! Is the airflow sufficient to make a difference? If you have time I'd love to see a comparison of 2 parts with and without the fan preferably with slight overhang. I've had to temporarily abandon this project because the prints Ive been doing for my projects require ABS, and I havent had time for modifications and testing. Thanks for posting!

Miguel

[David Schwartz]

Any improvement with PLA? Really curious and hoping.....

Best, David

[furicks]

I ran 2 additional fans off the MBI 2x Fan port for active cooling. I used these fans from their web site. 

http://store.makerbot.com/cooling-fan-makerbot-replicator-2.html

So for what it's worth the board can support at least this much current draw. 

[Jakob Öhman]

I just printed and installed "3FPD-Rep2X Cooling Duct". It fits really nice, and so far does a great job cooling the print.

http://www.thingiverse.com/make:53425

Thank you for all the thoughts and experiments with the fan output on the mightyboard. Great findings!

[PhGeis]

How do you turn on the power on the fan outlet via makerware in the rep2x profiles? Does it turn on automatically when you choose pla?

[Jakob Öhman]

Yes the fan will be turned on automatically after the first layer if you choose a PLA profile. You can also change it by creating a custom profile and edit the following settings in miracle.json:

"doFanCommand": true,

"fanLayer": 1,

"doFanModulation": true,

"fanModulationThreshold": 0.5,

"fanModulationWindow": 0.1,

These settings are the default in the standard PLA profiles

More about it here: http://www.makerbot.com/support/makerware/documentation/slicer/

[Jetguy]

Also, if using any other slicer. Simply M126 and M127 are the on and off commands respectively.

Simply edit the start and end gcode to inlcude those commands before sending to X3G (GPX or other tools).

 

That's all MakerWare is doing is adding that command to the gcode when you "flip the switch" in the profile.

 

Before you ask where that's documented, it's not other than in some forum question.

[Jakob Öhman]

Makerbot has great documentation for these commands:

https://github.com/makerbot/s3g/blob/master/doc/GCodeProtocol.md#m126---enable-extra-output

And it's also pretty easy to figure out. Just export it with the PLA profile in gcode format and then view the file. There's even a comment about it:

M126 T0; fan on
...
M127 T0; fan off

[Ryan Carlyle]

I want to add cooling fans to my R2x, but with a speed controller. Anyone know if it would be safe for the board to run two 24v fans through a PWM controller? 

Fans: http://www.digikey.com/product-detail/en/OD6015-24HB/1053-1232-ND/2621137?itemSeq=144067109&uq=635275434218321933 (current rating might be a little high on these, I can drop it down if necessary)

PWM controller: http://www.amazon.com/gp/product/B007TH4EN6

I'm using this PWM board on my fume filtration system and it works great. Here's a custom enclosure I made for it, if anyone wants to use it: http://www.thingiverse.com/thing:244698

I could use the board fan control to run a relay, but it would be nice to save the trouble.

[Jetguy]

In general, NO, assuming PWM to drive electronic brushless fans STILL means the motors see 24V.

All you are changing is the amount of ON time VS OFF time as a very short interval.

Either do it right and use a 12 volt regulator or roll the dice. I could not in good conscience tell you what you are planning is OK. Especially if the PWM controller board has any capacitors on it and the same with the brushless motor board inside the fan. The cap sees the 24V impulse and will blow sky high.

[Ryan Carlyle]

They're 24v fans, sorry if that wasn't clear.

[Jetguy]

I'll give it to you, I just checked the PWM board you linked and it and the caps are 50V rated hence the 40V rating.

I also followed and saw those are 24V rated fans.

Sorry, for some reason I thought you has somehow implied standard computer parts normally rated for 12V only.

My fault, but still good to educate everyone else on why you cannot cheat and use 12V fans.

[Jetguy]

Again sorry Ryan I just read the initial post incorrectly. You did say 24 volt fans. My fault. Your plan works.

[Ryan Carlyle]

Agreed. I learned a long time ago that voltage ratings on electronics aren't just recommendations. 

The PWM board is crazy overkill for controlling fans, to be honest. 10 amps @ 40vdc is a lot. But I'm going to use the same board to drive a small heater and it made more sense to buy a bunch of the same thing.

[Ryan Carlyle]

No issues pulling PWM off the MightyBoard MOSFET or whatever it is? I can't think of a reason, but electronics isn't my specialty.