PSU and Extruder problems
Posted by wes1007
|
PSU and Extruder problems April 03, 2015 06:47AM |
Registered: 9 years ago Posts: 43 |
Hi guys
I'm looking for a geared extruder design that doesnt use a hobbed bolt. I have 2 drive gears and id like to use those if possible. Unless anyone can link me to a guide on creating my own hobbed bolt.
Secondly Im having problems with power delivery. Recently just added my 650w power supply to the printer and all the motors stutter. Upon closer inspection the 12v line drops to 9.5v with the heated bed+heaterblock and drivers are all working.
ATM I am running the heated bed off the 650w psu and everything else off a 350w and its running fine. The voltage is still dropping right down on the 650w though (heated bed measures roughly 1 ohm and the 650w psu has 2 rails with 18A each.)
What I'd like to know is should I go with a mean well or similar dedicated 12v PSU or do ATX supplies actually work okay? Id like to still have a 5V rail for running my RaspberryPi off of.
Any help would be appreciated
Thanks
I'm looking for a geared extruder design that doesnt use a hobbed bolt. I have 2 drive gears and id like to use those if possible. Unless anyone can link me to a guide on creating my own hobbed bolt.
Secondly Im having problems with power delivery. Recently just added my 650w power supply to the printer and all the motors stutter. Upon closer inspection the 12v line drops to 9.5v with the heated bed+heaterblock and drivers are all working.
ATM I am running the heated bed off the 650w psu and everything else off a 350w and its running fine. The voltage is still dropping right down on the 650w though (heated bed measures roughly 1 ohm and the 650w psu has 2 rails with 18A each.)
What I'd like to know is should I go with a mean well or similar dedicated 12v PSU or do ATX supplies actually work okay? Id like to still have a 5V rail for running my RaspberryPi off of.
Any help would be appreciated
Thanks
|
Re: PSU and Extruder problems April 03, 2015 08:35AM |
Registered: 9 years ago Posts: 286 |
Is the psu thats not giving 12v a pc power supply as well?
As they use the 5v line to regulate power. Unless you put a load on the 5v supply it will not supply a good 12v.
[reprap.org]
Gordon
As they use the 5v line to regulate power. Unless you put a load on the 5v supply it will not supply a good 12v.
[reprap.org]
Gordon
|
Re: PSU and Extruder problems April 03, 2015 08:37AM |
Registered: 9 years ago Posts: 977 |
The motors stuttering probably has nothing to do with the PSU but is caused by not having adjusted the Vref on the stepper drivers.
The voltage drop when the heatbed is turned on is due to poor regulation with an unbalanced load.
The solutions for both problems can be found in the wiki, a quick search will get you to the correct pages.
The voltage drop when the heatbed is turned on is due to poor regulation with an unbalanced load.
The solutions for both problems can be found in the wiki, a quick search will get you to the correct pages.
|
Re: PSU and Extruder problems April 03, 2015 10:14AM |
Registered: 9 years ago Posts: 43 |
Quote
gordonendersby
Is the psu thats not giving 12v a pc power supply as well?
As they use the 5v line to regulate power. Unless you put a load on the 5v supply it will not supply a good 12v.
[reprap.org]
Gordon
Quote
AndrewBCN
The motors stuttering probably has nothing to do with the PSU but is caused by not having adjusted the Vref on the stepper drivers.
The voltage drop when the heatbed is turned on is due to poor regulation with an unbalanced load.
The solutions for both problems can be found in the wiki, a quick search will get you to the correct pages.
Both PSUs have a 50W halogen downlight on the 5v lines. Drawing just have 2 amps. Im sure thats enough load.
The stuttering only happens when Im printing. In otherwords when im running the heatedbed+hotend. Thats when the voltage was dropping to 9.5v. If i move each axis with everything else off it runs fine. Vref is okay on the drivers.
I had the 650W PSU set up with the one 18A rail running just the Heated bed on my Ramps board and the other Rail ran the hot-end+drivers. Thought that running them on separate Rails would be the same as running them on separate PSUs (which is working fine right now)
|
Re: PSU and Extruder problems April 03, 2015 10:26AM |
Registered: 10 years ago Posts: 14,672 |
Quote
wes1007
I had the 650W PSU set up with the one 18A rail running just the Heated bed on my Ramps board and the other Rail ran the hot-end+drivers. Thought that running them on separate Rails would be the same as running them on separate PSUs (which is working fine right now)
It's not quite the same thing, because most ATX PSUs have only one feedback loop, so the two 12V and the single 5V output are not independent of each other. Still, I would have expected that arrangement to work, provided you had sufficient minimum load on each rail.
I ran a single-head 3D printer quite successfully from a single 550W ATX PSU for a while and later from a 430W PSU. I was using the ATX12V connector to power everything, and both PSUs had a single 12V output current rating. I'm wondering how the ATX12V is wired in a PSU with multiple 12V outputs. Maybe it's independent of the other 12V outputs and also needs a minimum load?
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
|
Re: PSU and Extruder problems April 03, 2015 10:32AM |
Registered: 9 years ago Posts: 43 |
Quote
dc42
Quote
wes1007
I had the 650W PSU set up with the one 18A rail running just the Heated bed on my Ramps board and the other Rail ran the hot-end+drivers. Thought that running them on separate Rails would be the same as running them on separate PSUs (which is working fine right now)
It's not quite the same thing, because most ATX PSUs have only one feedback loop, so the two 12V and the single 5V output are not independent of each other. Still, I would have expected that arrangement to work, provided you had sufficient minimum load on each rail.
I ran a single-head 3D printer quite successfully from a single 550W ATX PSU for a while and later from a 430W PSU. I was using the ATX12V connector to power everything, and both PSUs had a single 12V output current rating. I'm wondering how the ATX12V is wired in a PSU with multiple 12V outputs. Maybe it's independent of the other 12V outputs and also needs a minimum load?
My understanding of the rails is that they are completely independent. If you have a high end GPU and it strats to draw a lot of amps this wont affect your harddrives ruynning on a different rail.
Sadly I have no idea why I'm having problems with it. It is an old PSU and maybe its seen better days. Will look at fetching a new one from work and hooking it up to test.
I found a way to make a hobbed bolt: http://www.thingiverse.com/thing:23717 Provided you have a rotary tool like a dremel. busy printing half the parts out... still has a few hours to go.
|
Re: PSU and Extruder problems April 03, 2015 10:51AM |
Registered: 10 years ago Posts: 14,672 |
Quote
wes1007
My understanding of the rails is that they are completely independent. If you have a high end GPU and it strats to draw a lot of amps this wont affect your harddrives ruynning on a different rail.
Sadly I have no idea why I'm having problems with it. It is an old PSU and maybe its seen better days. Will look at fetching a new one from work and hooking it up to test.
If the ATX12V output really is independent of the other 12V rails, then it will almost certainly need a minimum load, just like the 5V output,.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
|
Re: PSU and Extruder problems April 03, 2015 12:10PM |
Registered: 9 years ago Posts: 977 |
Nope.Quote
My understanding of the rails is that they are completely independent.
Two things again:
1) Power supplies with two rails almost always mean they have separate overcurrent protection on each rail, but both rails actually derive their voltage from the same secondary circuit.
2) Old power supplies sometimes have bad regulation of the +12V rail even if you provide a significant load on the +5V and +3.3V rails. This is why (among other things) I strongly recommend in the wiki to avoid using old ATX PSUs. Buy a new, good quality one and avoid many headaches and possible accidents. Recommendations are in the wiki.
Finally, "Vref is okay on the drivers." is not good enough information. Exactly what drivers do you have, what is the Rs on them and what is the voltage you have set them to?
|
Re: PSU and Extruder problems April 03, 2015 05:51PM |
Registered: 10 years ago Posts: 469 |
I see no reason to not use a server psu. While cheap used. They are one trick pony with usually 50+ amps 12v rails.
My Personal Blog. Build blog.
[engineerd3d.ddns.net]
Modicum V1 sold on e-bay user jaguarking11
My Personal Blog. Build blog.
[engineerd3d.ddns.net]
Modicum V1 sold on e-bay user jaguarking11
|
Re: PSU and Extruder problems April 03, 2015 06:04PM |
Registered: 10 years ago Posts: 14,672 |
I am very happy with Chinese LED power supplies. Like ATX PSUs, they are short-circuit protected; but unlike ATX PSUs, the voltage is adjustable - which is handy if you have a heated bed that struggles to get hot enough for ABS printing - and they don't require minimum loads. The downsides are that they are probably not as reliable as top-brand ATX PSUs (OTOH you can buy 2 of them for the price of one branded ATX PSU), you need to do mains wiring and make an enclosure to protect it, they don't give you a 5V output (which modern printer electronics boards don't need anyway), and they don't have a standby function.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
|
Re: PSU and Extruder problems April 03, 2015 06:15PM |
Registered: 9 years ago Posts: 43 |
Quote
AndrewBCN
Nope.Quote
My understanding of the rails is that they are completely independent.
Two things again:
1) Power supplies with two rails almost always mean they have separate overcurrent protection on each rail, but both rails actually derive their voltage from the same secondary circuit.
2) Old power supplies sometimes have bad regulation of the +12V rail even if you provide a significant load on the +5V and +3.3V rails. This is why (among other things) I strongly recommend in the wiki to avoid using old ATX PSUs. Buy a new, good quality one and avoid many headaches and possible accidents. Recommendations are in the wiki.
Finally, "Vref is okay on the drivers." is not good enough information. Exactly what drivers do you have, what is the Rs on them and what is the voltage you have set them to?
OKay ive got some A4988 drivers. I've manually set the Pots on them and actually haven't gone into any calcs. Basically the procedure of turning it up till its too hot and noisey then toning it back down. I plan to upgrade them to a newer form of driver (the model eludes me right now
Quote
jaguarking11
I see no reason to not use a server psu. While cheap used. They are one trick pony with usually 50+ amps 12v rails.
OOOH yes. a 1U would be nice and compact but oh too pricey..
Quote
dc42
I am very happy with Chinese LED power supplies. Like ATX PSUs, they are short-circuit protected; but unlike ATX PSUs, the voltage is adjustable - which is handy if you have a heated bed that struggles to get hot enough for ABS printing - and they don't require minimum loads. The downsides are that they are probably not as reliable as top-brand ATX PSUs (OTOH you can buy 2 of them for the price of one branded ATX PSU), you need to do mains wiring and make an enclosure to protect it, they don't give you a 5V output (which modern printer electronics boards don't need anyway), and they don't have a standby function.
Ive debated getting some of these...however i do plan to run my heated bed off 24V sometime so having the adjustable voltage isn't really necessary for me. could always have a "standby" mode by running the LED power supply through a relay.
|
Re: PSU and Extruder problems April 03, 2015 07:31PM |
Registered: 10 years ago Posts: 14,672 |
Quote
wes1007
Quote
dc42
I am very happy with Chinese LED power supplies. Like ATX PSUs, they are short-circuit protected; but unlike ATX PSUs, the voltage is adjustable - which is handy if you have a heated bed that struggles to get hot enough for ABS printing - and they don't require minimum loads. The downsides are that they are probably not as reliable as top-brand ATX PSUs (OTOH you can buy 2 of them for the price of one branded ATX PSU), you need to do mains wiring and make an enclosure to protect it, they don't give you a 5V output (which modern printer electronics boards don't need anyway), and they don't have a standby function.
Ive debated getting some of these...however i do plan to run my heated bed off 24V sometime so having the adjustable voltage isn't really necessary for me. could always have a "standby" mode by running the LED power supply through a relay.
You can get 24V LED PSUs too. Using modern printer electronics, you can run the entire printer from 24V and benefit from increased maximum stepper motor speed. Probably the trickiest part to source cheaply is a 24V hot end fan, but you can use always revert to using a 7812 regulator to drive a 12V fan.
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
|
Re: PSU and Extruder problems April 04, 2015 03:28AM |
Registered: 9 years ago Posts: 43 |
Quote
dc42
Quote
wes1007
Quote
dc42
I am very happy with Chinese LED power supplies. Like ATX PSUs, they are short-circuit protected; but unlike ATX PSUs, the voltage is adjustable - which is handy if you have a heated bed that struggles to get hot enough for ABS printing - and they don't require minimum loads. The downsides are that they are probably not as reliable as top-brand ATX PSUs (OTOH you can buy 2 of them for the price of one branded ATX PSU), you need to do mains wiring and make an enclosure to protect it, they don't give you a 5V output (which modern printer electronics boards don't need anyway), and they don't have a standby function.
Ive debated getting some of these...however i do plan to run my heated bed off 24V sometime so having the adjustable voltage isn't really necessary for me. could always have a "standby" mode by running the LED power supply through a relay.
You can get 24V LED PSUs too. Using modern printer electronics, you can run the entire printer from 24V and benefit from increased maximum stepper motor speed. Probably the trickiest part to source cheaply is a 24V hot end fan, but you can use always revert to using a 7812 regulator to drive a 12V fan.
Maybe I'll pick up a 300ish watt ATX PSU and a 24v meanwell psu to run the heated bed. I don't plan to change my controller just yet.
|
Re: PSU and Extruder problems April 05, 2015 06:33PM |
Registered: 9 years ago Posts: 43 |
Did some experimenting today and it looks like its a problem with the ramps board.
Heated bed measures a bit over 1 ohm, Its drawing a total of 6 amps and doesn't trigger the over current protection when plugged directly into the 12v line on the PC PSU however when its plugged into D8 on the RAMPS board the PSU goes into over current protection.
If I unplug the heated bed and set a tempreture for it on RAMPS the light comes on and everything seems to work. It seems that any load on D8 causes this problem. even a smaller load such as a 12v downlight but with no load everything works fine.
Anyone got any ideas as to what I can do? Where should i be looking?
Edited 1 time(s). Last edit at 04/05/2015 06:34PM by wes1007.
Heated bed measures a bit over 1 ohm, Its drawing a total of 6 amps and doesn't trigger the over current protection when plugged directly into the 12v line on the PC PSU however when its plugged into D8 on the RAMPS board the PSU goes into over current protection.
If I unplug the heated bed and set a tempreture for it on RAMPS the light comes on and everything seems to work. It seems that any load on D8 causes this problem. even a smaller load such as a 12v downlight but with no load everything works fine.
Anyone got any ideas as to what I can do? Where should i be looking?
Edited 1 time(s). Last edit at 04/05/2015 06:34PM by wes1007.
|
Re: PSU and Extruder problems April 05, 2015 07:37PM |
Registered: 9 years ago Posts: 977 |
|
Re: PSU and Extruder problems April 05, 2015 07:57PM |
Registered: 9 years ago Posts: 43 |
Quote
AndrewBCN
Check the resistance between the D8 terminals with the RAMPS disconnected from everything. If it's zero you have found your short circuit.
Nope no short between terminals with everything unplugged and off.powered up is the same story. When powered up and a tempreture is set for D8 i get 12v on that line.
If it was the mosfet surely id have problems regardless of having a load on it or not.
|
Re: PSU and Extruder problems April 05, 2015 08:52PM |
Registered: 9 years ago Posts: 977 |
|
Re: PSU and Extruder problems April 06, 2015 02:10AM |
Registered: 9 years ago Posts: 43 |
|
Re: PSU and Extruder problems April 06, 2015 06:50AM |
Registered: 9 years ago Posts: 977 |
I am repeating myself, but here goes anyways:
- Old ATX PSUs usually have problems with the unbalanced loads presented to them by RepRap 3D printers.
- New, "noname" ATX PSU are not recommended for RepRap use either. They have poor designs and use the cheapest possible components, and rarely work even at half their specified wattage.
- A new, good quality PSU with the correct power rating from a recognized brand is the best choice for an ATX PSU to power a RepRap 3D printer.
|
Re: PSU and Extruder problems April 06, 2015 07:11AM |
Registered: 9 years ago Posts: 43 |
I get that. The new PSU I used is a 450w proline PSU. They are pretty decent quality.
However the fact that the heated bed runs fine when powered directly off a 12v line from the psu and not via the ramps board makes me believe that there's something wrong on my ramps board. I might try running the heated bed of d10 as a test. With nothing else rubningm if that's worjig I might take the MOSFET from D9 and put it on D8. Of that works then I know the MOSFET is faulty
Sorry for the possibly horrid English . replying from my phone as the internet is down in my town.
However the fact that the heated bed runs fine when powered directly off a 12v line from the psu and not via the ramps board makes me believe that there's something wrong on my ramps board. I might try running the heated bed of d10 as a test. With nothing else rubningm if that's worjig I might take the MOSFET from D9 and put it on D8. Of that works then I know the MOSFET is faulty
Sorry for the possibly horrid English . replying from my phone as the internet is down in my town.
|
Re: PSU and Extruder problems April 06, 2015 07:58AM |
Registered: 9 years ago Posts: 977 |
|
Re: PSU and Extruder problems April 06, 2015 08:08AM |
Registered: 9 years ago Posts: 43 |
I can't remember exactly but I'm sure on my board the traces went different sizes... I'll double check that. The heated bed only draws 6 amps. I'm sure the rise for D9 and 10 is bigger than that? All I'm wanting to test is that the heated bed alone on one of the channels works. I'm not going to print like that.
Not in front of my board right now but when I am I'll have a look. I'll need to see if anyone locally stocks those MOSFETs. I might get one or two and run them off a different ardunio pin and have them on their own 24v line. Then use D8 as a chamber heater in the future. Sure it can be done with a little tweakig in Marlin. Sure beats replacing the caps and fuses on D8
Oh and I live in the sticks in south Africa... So parts arnt always easy to find.
Edited 1 time(s). Last edit at 04/06/2015 08:09AM by wes1007.
Not in front of my board right now but when I am I'll have a look. I'll need to see if anyone locally stocks those MOSFETs. I might get one or two and run them off a different ardunio pin and have them on their own 24v line. Then use D8 as a chamber heater in the future. Sure it can be done with a little tweakig in Marlin. Sure beats replacing the caps and fuses on D8
Oh and I live in the sticks in south Africa... So parts arnt always easy to find.
Edited 1 time(s). Last edit at 04/06/2015 08:09AM by wes1007.
|
Re: PSU and Extruder problems April 06, 2015 10:17AM |
Registered: 10 years ago Posts: 869 |
RAMPS 1.4 doesn't have different size traces for D8-D10.They're all the same. (unless someone redesigned the circuit board). The 11A fuse though still holds true why you can't switch to a different output.Quote
AndrewBCN
The heated bed from the D10 connector: DON'T!!! The large current traces and the 11A fuse on the RAMPS are only for the D8 connector.
|
Re: PSU and Extruder problems April 06, 2015 10:35AM |
Registered: 9 years ago Posts: 43 |
|
Re: PSU and Extruder problems April 06, 2015 11:26AM |
Registered: 9 years ago Posts: 977 |
Quote
cdru
RAMPS 1.4 doesn't have different size traces for D8-D10.They're all the same. ....Quote
AndrewBCN
The heated bed from the D10 connector: DON'T!!! The large current traces and the 11A fuse on the RAMPS are only for the D8 connector.
As far as I can see the islands (marked as dotted lines) for the 11A circuit path provide a lot more copper than the traces for the 5A circuit path. And they are shorter, too.
Edited 1 time(s). Last edit at 04/06/2015 11:27AM by AndrewBCN.
|
Re: PSU and Extruder problems April 06, 2015 04:09PM |
Registered: 9 years ago Posts: 43 |
Quote
AndrewBCN
Quote
cdru
RAMPS 1.4 doesn't have different size traces for D8-D10.They're all the same. ....Quote
AndrewBCN
The heated bed from the D10 connector: DON'T!!! The large current traces and the 11A fuse on the RAMPS are only for the D8 connector.
As far as I can see the islands (marked as dotted lines) for the 11A circuit path provide a lot more copper than the traces for the 5A circuit path. And they are shorter, too.
Yeup that is the case...
I've been following the schematics and checking for bad connections and such but so far everything on the D8 channel seems fine? I've switched the FETs around from D9 to D8 and I'm getting the same thing.
|
Re: PSU and Extruder problems April 08, 2015 04:07PM |
Registered: 9 years ago Posts: 43 |
So after being fustraded by this stupid heated bed problem i gave something else a try.
After being told not to use D9 for the heated bed i looked into what other options i had. It was still D9, however not directly. I have set up a relay to run off of D9 Which is hooked up onto a separate rail on the psu. This seems to be working well so far. Did a test heat to 40 degrees and it overshot a little then came back down. There is clearly something wrong with a trace or something on the D8 channel.
Im going to order a new Ramps board as well as those Mosfets. Will swap the heated bed ones with the new ones as soon as it arrives
After being told not to use D9 for the heated bed i looked into what other options i had. It was still D9, however not directly. I have set up a relay to run off of D9 Which is hooked up onto a separate rail on the psu. This seems to be working well so far. Did a test heat to 40 degrees and it overshot a little then came back down. There is clearly something wrong with a trace or something on the D8 channel.
Im going to order a new Ramps board as well as those Mosfets. Will swap the heated bed ones with the new ones as soon as it arrives
Sorry, only registered users may post in this forum.