fuses popping constantly

Here's where you can find the official (and unofficial too) things like assembly instructions etc...
Post Reply
Cale
Printmaster!
Posts: 50
Joined: Mon Jul 14, 2014 1:12 am

fuses popping constantly

Post by Cale »

Recently a small fuse popped on my MAX v2.I wasn't sure what caused it but I replaced the fuse anyway.Today I tried cleaning the hot-end.While I was getting the tip off,the same fuse blew.My dad thinks there is something wrong with the heater.I checked the wires at the hot-end,but none of them are touching.At the board everything checked out ok.So what is wrong?I also noticed during the latest heatup of the hot-end the extra filament inside came out as weird little droplets.What is causing that?
Can you please tell me how to solve this.
Thanks,
Cale
User avatar
teoman
ULTIMATE 3D JEDI
Posts: 1783
Joined: Sat May 24, 2014 5:43 pm

Re: fuses popping constantly

Post by teoman »

You could be shorting the resistors on the hot end.
When on mobile I am brief and may be perceived as an arsl.
User avatar
Eaglezsoar
ULTIMATE 3D JEDI
Posts: 7185
Joined: Sun Apr 01, 2012 5:26 pm

Re: fuses popping constantly

Post by Eaglezsoar »

I agree with teoman.
You need to have your meter set to measure 12 volts and measure the voltage going to the hotend while jiggling the wires around
that run to the hotend. There should be shorts while jiggling and detected on the meter because the voltage on the meter should
drop to zero instead of 12 volts. Something in your wiring is shorting out and blowing the fuse.
“ Do Not Regret Growing Older. It is a Privilege Denied to Many. ”
User avatar
teoman
ULTIMATE 3D JEDI
Posts: 1783
Joined: Sat May 24, 2014 5:43 pm

Re: fuses popping constantly

Post by teoman »

Or you can put your multimeter to continuity mode (beep beep) and put the ends on to the 2 wires at the rambo side. While fiddling with the hotend if you hear a beep then you have a short.

You may want 2 people for this.
When on mobile I am brief and may be perceived as an arsl.
guanu
SeeMeCNC Staff
Posts: 397
Joined: Mon Mar 26, 2012 1:54 pm

Re: fuses popping constantly

Post by guanu »

with the power OFF! never mess with the hotend when the machine is on... the 12v rail is always on, and the grounds are what are switched.. so never mess with it while the machine is on

Guanu
Earthbound
Printmaster!
Posts: 458
Joined: Sun Sep 07, 2014 2:39 am

Re: fuses popping constantly

Post by Earthbound »

Continuity checker may be fooled by the low resistance of the hot end circuit and be unable to distinguish normal from shorted.
"Trust no quote from the Internet." - Abraham Lincoln
User avatar
teoman
ULTIMATE 3D JEDI
Posts: 1783
Joined: Sat May 24, 2014 5:43 pm

Re: fuses popping constantly

Post by teoman »

And indeed the flukeing continuity checker is fooled by the low resistance. Well then you have to set it to ohm (resistance meter), and look for a sudden drop in resistance while fondling the hotend. My hotend is 4.4 ohms.

And having the machine off is how you should be doing your tests. Or your testing could burn more fuses or damage the machine or cause injury to yourself.
When on mobile I am brief and may be perceived as an arsl.
Cale
Printmaster!
Posts: 50
Joined: Mon Jul 14, 2014 1:12 am

Re: fuses popping constantly

Post by Cale »

Thanks everyone for all the help.I've solved why the fuses popped both times. :D :D
After a lot of thought I remembered it occurred when I was taking off the nozzle for the hot-end.It is very likely I accidentally touched a wire with the wrench I was using. :roll: My little mistake.

Cale
User avatar
teoman
ULTIMATE 3D JEDI
Posts: 1783
Joined: Sat May 24, 2014 5:43 pm

Re: fuses popping constantly

Post by teoman »

Do you mean that you were changing the hotend with the power on? Or that you sqished the hot end resistors' open wires to touch the aluminum heater block, and experienced shorts thereafter?
When on mobile I am brief and may be perceived as an arsl.
Cale
Printmaster!
Posts: 50
Joined: Mon Jul 14, 2014 1:12 am

Re: fuses popping constantly

Post by Cale »

What I mean is that the power was ON(to make cleaning the nozzle easier).I was using two wrenches (one to keep the main hot-end from moving,and one to loosen the nozzle).It is very likely the first wrench touched one of the resistor wires and blew the fuse.

Cale
Post Reply

Return to “Rostock MAX Official Docs”