Cefiar Wrote:
-------------------------------------------------------
> Sounds a bit like it.
>
> That PSU has dual 12V rails internally (according
> to the page you linked). Each rail will have a max
> current rating, and if all your electronics are on
> the same rail, then it this might be the issue.
>
> You should try using one rail specifically to run
> your hot end/motors/fan, and the other to run the
> heated bed. I don't have the same PSU here, so I
> can't tell you which one is which.
>
> Note: The fact that it works again after being off
> for a short while usually means it's tripped an
> over-current limit. It switches off to avoid
> dumping a lot of current into a possible short
> circuit, and the only way to get it back is to
> disconnect the power and leave it till certain
> internal currents have discharged (time will vary
> depending on the PSU, and the nature of the
> over-current issue).
Ah.. makes sense.
I haven't looked at the circuit diagram of my RAMPS (because I probably won't understand it even if I did LOL), but there are two connectors each of which I connect each of two 12V output from the PSU. So, I would assume the designer of RAMPS made sure not all electronics are using one rail...
Having said that, I think I probably have connected my fan to the rail which the heated plate is connected. The fan runs all the time, as soon as I turn on PSU. Then when I turn on the heated plate, then I can hear the fan slowing down.
Even though each of the rails have separate max current rating, I wonder connecting too many electronics/devices will make them compete for the power and affect each other, even among the ones which are connected to different rails...
As I have stated, when I added a fan to my print, I believe I ended up adding more load to my PSU than what this fan draws, because the fan would have made the hot end to use more electricity for heating.
Now I am having a new problem, which I never had before. Near to the end of a big printing job (yeah, it really sucks!), my printer started shifting in Y direction. It created a quite nice looking (but useless and unwanted) even steps.
Ever since that, I keep having this issue with all my prints, sometimes it starts right away and other times it starts happening after 5-10 minutes.
I tried to adjust the potentiameter in Y motor Pololu. It seems to work better when I increase the current. However, I still haven't had a successful print - I am increasing the current by very little at a time, so I basically keep increasing the current ever so slightly and trying over and over, until I no longer have this shifting issue.
Anyway, I never had this shifting problem until now, and I haven't changed my Y motor Pololus setting for quite a while. So, it really makes me wonder if my Y motor Pololu is not getting enough share of the current, that now it cannot drive the motor properly..
I really need to insulate my hot end nozzle...
-------------------------------------------------------
> Sounds a bit like it.
>
> That PSU has dual 12V rails internally (according
> to the page you linked). Each rail will have a max
> current rating, and if all your electronics are on
> the same rail, then it this might be the issue.
>
> You should try using one rail specifically to run
> your hot end/motors/fan, and the other to run the
> heated bed. I don't have the same PSU here, so I
> can't tell you which one is which.
>
> Note: The fact that it works again after being off
> for a short while usually means it's tripped an
> over-current limit. It switches off to avoid
> dumping a lot of current into a possible short
> circuit, and the only way to get it back is to
> disconnect the power and leave it till certain
> internal currents have discharged (time will vary
> depending on the PSU, and the nature of the
> over-current issue).
Ah.. makes sense.
I haven't looked at the circuit diagram of my RAMPS (because I probably won't understand it even if I did LOL), but there are two connectors each of which I connect each of two 12V output from the PSU. So, I would assume the designer of RAMPS made sure not all electronics are using one rail...
Having said that, I think I probably have connected my fan to the rail which the heated plate is connected. The fan runs all the time, as soon as I turn on PSU. Then when I turn on the heated plate, then I can hear the fan slowing down.
Even though each of the rails have separate max current rating, I wonder connecting too many electronics/devices will make them compete for the power and affect each other, even among the ones which are connected to different rails...
As I have stated, when I added a fan to my print, I believe I ended up adding more load to my PSU than what this fan draws, because the fan would have made the hot end to use more electricity for heating.
Now I am having a new problem, which I never had before. Near to the end of a big printing job (yeah, it really sucks!), my printer started shifting in Y direction. It created a quite nice looking (but useless and unwanted) even steps.
Ever since that, I keep having this issue with all my prints, sometimes it starts right away and other times it starts happening after 5-10 minutes.
I tried to adjust the potentiameter in Y motor Pololu. It seems to work better when I increase the current. However, I still haven't had a successful print - I am increasing the current by very little at a time, so I basically keep increasing the current ever so slightly and trying over and over, until I no longer have this shifting issue.
Anyway, I never had this shifting problem until now, and I haven't changed my Y motor Pololus setting for quite a while. So, it really makes me wonder if my Y motor Pololu is not getting enough share of the current, that now it cannot drive the motor properly..
I really need to insulate my hot end nozzle...