RAMBo Fuses

[Doug]

I didn't like using the fan 1 connector to power both the print cooling fan and electronics fan on my M2.  The part cooling fan wasn't always starting on its own and needed to be "kick" started. So I decided to add header pins to the aux power holes for the Mosfet and connect the electronics cooling fan directly to that.  I know its the full 19V to the 12V fan but think that will be fine.  I solder the header in and went to test with my DMM and accidentally shorted the two pins with the probe.  This blew the fuse for the Mosfets, I've check it and its done.  So I need to get a new fuse.  I found what I pretty sure is the right thing here http://www.digikey.com/catalog/en/search?filters=18667+12821&page=2  Its a NANO fuse from littlefuse inc but what series should I get?  There are fast and slow acting and different voltage ratings.  I would think a fast acting 5A would be the right one but don't know for sure.  It would be nice to get one the same as the original.

Doug

[Jonathan Hirschman]

Doug,

I believe that you have the correct fuse, but you'd need to verify
with MG. I don't think that it matters if it's slow or fast blowing,
because the docs on the RAMBo mention that a 10A fuse may be
substituted (so any 5A is going to blow really quick anyways).

Also: Karen was nice enough to send me a replacement, so perhaps you
might want to ask. I bought a small supply from Mouser anyways (I went
with fast blow, and it seems to work just fine). I used this:

http://www.mouser.com/Search/ProductDetail.aspx?R=0451005.MRvirtualkey57610000virtualkey576-0451005.MR

jh

[Joshua Wills]

Doug - first, I'm not certain how you had your M2 wired, but the intent/"official" way is to have the bed fan by itself on Extruder 0 Fan, and have the filament drive and electronics case fans tied together on Extruder 1 Fan.  This is detailed here: http://makergear.wikidot.com/m2-electronics .  Second, could you clarify what modifications you made to your RAMBo board?  I'm curious as to what you tried.

Third, listen to Jonathan Hirschman on this one - he's already purchased and tested extra fuses.  We haven't received our order of fuses yet, and I don't have another RAMBo board to steal one from, so Jonathan's Mouser link is your best bet.  Matching the specs from Mouser on Digikey should work fine as well.

Good luck getting back up and running.

[Jonathan Hirschman]

On Sep 26, 10:48 pm, Doug <dougcost...@gmail.com> wrote:

> The part cooling fan wasn't always starting
> on its own and needed to be "kick" started.

FYI, I had the same issue with the fan not starting at the "default"
settings in Slic3r. Had to put the minimum cooling up to 90% - and
that wasn't always suitable.

I found this fan:

http://www.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&keywords=603-1405-ND&x=13&y=12&cur=USD

I can't measure the air flow to find out how lower values translate,
but it does start even with values down to 10%. Don't think that it's
as powerful as the fan that came with the printer, but it works well
for unattended prints.

Note: I haven't tested it at full voltage for any length of time, so
proceed at your own risk :)

[Doug]

I guess then I didn't have the fans wired in the official way.  I had the bed fan and electronics case fan wired to extruder fan 1 and the filament drive fan on extruder 0.  So I guess my real problem was trying to run the larger bed fan and smaller electronics fan together.  All i did to the RAMBo was soldered two 0.100" header pins to the aux power holes next to the extruder heat 1 connector.  I just wanted the electronics fan to run constantly and not pull power away from the larger bed fan.  the official way to connect the fans seems like a much better solution and soldering the pins wasn't needed I guess.  I wired everything before the wiki was available so I just had to guess based on the pictures.

I went ahead and got the fuses from Mouser, that Jonathan suggested.     

[Jordan Miller]

if your room is normal temp I haven't found any need for a fan on the mobo. JohnnyR got an amazing design here. My motor chips don't overheat even when sending 2A each to 5 motors (255 voltage setting for my phidgets motors in RAMBo Marlin).

jordan

[Brian Hockenmaier]

Hi Guys-

I know I'm a year late to the party here, but I found this thread when I blew fan fuse (by accidentally reversing the red and black wires when fixing one of my fan plugs) and purchased a couple of the fuses from Jonathan's mouser link to fix the problem.  So I'm just piping in to confirm that these are in fact the correct fuses and they solved my problem easily.

Thanks!

Brian Hockenmaier

[Jonathan Hirschman]

On 9/28/2013 4:29 PM, Brian Hockenmaier wrote:

Hi Guys-

I know I'm a year late to the party here, but I found this thread when I blew fan fuse (by accidentally reversing the red and black wires when fixing one of my fan plugs) and purchased a couple of the fuses from Jonathan's mouser link to fix the problem.  So I'm just piping in to confirm that these are in fact the correct fuses and they solved my problem easily.

Hi Brian,

Glad that you found that link. Just for completeness, I'm now running on a newer rev RAMBo. One of the fuses has been replaced by a blade-style 15A fuse. Too lazy to track down the function right now :) FYI.

jh

[Kamil]

The ATO 15 amp fuse is for the heated bed. The other two micro fuses are 10 and 5 amp for the heated end/fans and motors/logic.