extruder fault problem and upgrade to 24v.
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I have a mini Kossel v1 with duet 0.8.5 electronics and a V6 hot end.
I have just upgraded my heated bed from 170mm to 220mm to prevent heating problems at edges of bed. All worked really well printing PLA at 210 and 65 degrees C.
However when printing ABS at 235 and 100 degrees C I get extruder heater faults saying the temp has varied by more than 15 degrees and the printing completely stops. I think it is because the power supply is the original Dell 12v 15A one and it is now struggling when extruding, moving the carriages and heating etc. all at once.
If this is the case I will have to update it, maybe to 20 or even 30 amp supply. Should I consider going to 24v ?I presume this mean changing the fans and the heater cartridge, is there anything else? -
@Dave-Parry said in extruder fault problem and upgrade to 24v.:
Dell 12v 15A
it depends on the heater on the bed, but in this case i would say yes the power supply is not enough.
if the duet 0.8.5 switches on the negative (not sure about the duet 1 but the duet2 does) then you can use a buck converter to make a 12v signal from 24v and use the fans with that.
heater cartridge should be changed for 24v
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Thanks for reply. I think I will go for a 24v system. I have 3 x 30mm fans on the system so will change them, just looked on amazon and they are cheaper than I thought. Just need to decide on a power supply. There is a big cost jump from 15 to 20 amps, but do you think that 15A at 24v would be ok. will keep the power supply external as I don't think I can fit it under the bed, even though I have doubled the height of the bottom part. Only problem is the heated bed. I ordered a 12/24v version and received a 12v only one. Have raised the issue with the seller so will have to wait for his response.
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@Dave-Parry said in extruder fault problem and upgrade to 24v.:
15A at 24v
it really depends on the power draw of your bed. can you tell us the rating?
also consider buying a high quality power supply from e.g meanwell
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Cant find any info on heater bed power, but measuring resistance when cold gives 1.9 ohm which at 12v gives 6.3 amps which doesnt sound right. Neither of my multimeters go above 10a so their no use. Looking at similar square beds they seem to be about 200w. which would be about 15A
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@Dave-Parry
can you link the heater? -
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@Dave-Parry said in extruder fault problem and upgrade to 24v.:
Looking at similar square beds they seem to be about 200w.
yeah that sound like a good guesstimate
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so say bed = 9 A,
v6 40w = 1.6A
nema 17 Stepper motors = 1.6A x 4, 6.4A
Thats about 17A, so I think I need 20A. does that sound about right?
I know the motors wont draw that much in realitity, but I think 24v 15 A is a bit low. -
see
https://duet3d.dozuki.com/Wiki/Choosing_the_power_supplyyou need to calculate the nema differently
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So does that mean 2.8v x 1.68A = 4.5A per motor?
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My Bad, just read again and its 1,68A + 50%= 2.5A x 4 = 10A
So thats 20 A + other bits.
So probably 25A or 30A is going to be the required current.
Thats a lot, no wonder 12v 15A is having problems. -
Definitely consider a meanwell supply from a reputable supplier like digikey or mouser.
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Next problem is a power connector. 25 amps is a lot for a connector to handle.
My present one is a 8 way one, 3 for +, 3 for -, and 2 I think are for power switch.
Not sure what type they are but I think they are molex ones. What type do other machines use? -
@Dave-Parry said in extruder fault problem and upgrade to 24v.:
Next problem is a power connector. 25 amps is a lot for a connector to handle.
My present one is a 8 way oneI'm not sure what you're referring to? Photo?
