We have a Snapmaker A350 that, at the time the problem started, wasn’t even a year old. The problem is that the nozzle will not stay hot enough to melt the filament even though the software says it’s at the correct temperature.
For example, we set the nozzle temp to 200C in the little Android interface device and, using our bench calibrated temp sensor gun, we can see the nozzle is only getting to about 160C.
We finally got a support rep to send us a replacement part (a board I think) for the print head which fixed the problem for maybe 35 hours of printing but now the problem is back.
Anyone else having this problem where the nozzle refuses to get to the set temperature?
I didn’t have any issues, but when running too fast too much. It can’t keep up with temperatures.
Maybe update the firmware and use new 109 code params. to see if it helps?
We use a Hikmicro B20 thermal camera when we need to see how hot something is (or isn’t) getting. Check out the comparison between what the B20 says the nozzle temp is (151.7C) and what the A350 interface says it is (205C).
After leaving the A350 turned off for a couple days and then this morning do a firmware update on it I attempted the same print again. It got a little further this time but it had bad layer adhesion and after 3-4 hours it again started air printing because the nozzle wasn’t hot enough to melt the filament.
I have the print speed set to 60 mm/s and earlier it was only printing at 65 mm/s, so not that much faster.
What are the “new 109 code parameters” you mention?
I assume you’re referring to the main cable the plugs into the connector at the top of the print module. If yes, then yes, we make sure it gets inserted securely. It doesn’t click though - just pushes in and stops. I checked and all pins are the same length except for one (circled in blue) of the larger ones, which I’m guessing is the ground pin.
Good idea about the thermal grease on the thermistor. I have some standard Arctic Silver 5 in by desk drawer here but the specs on that top out well below 200C, let alone higher temps.
From the Arctic Silver website for Arctic Silver 5:
Extended Temperature Limits:
Peak: –50°C to >180°C
Long-Term: –50°C to 130°C
I’m printing with plain 'ole black PLA from Sunlu and 200-205C is the recommended temperature so far as I understand. We’ve never had a problem with that temp range until recently.
When this problem starts happening I can tell the nozzle to go to 275C and while the screen on the device SAYS it’s at 275 it only gets up to maybe 200C or so in reality.
True, the thermal camera is at an odd angle in the picture I send but that’s because I took it while the machine was still thinking it was printing. When we tested this the other week we had the print module well above the bed (which was cold) and isolated from other heat sources. The readings then were the same as they are now.
I tend to lean towards the thermal camera being accurate because it reinforces the theory that the print head is indeed not reaching the melting point of the PLA.
By “spare hot end” do you mean the nozzle itself or a large assembly?
I’m not quite following what you’re asking me to measure, or how. How would I measure the resistance of the thermistor? What do you mean by “ambient and same temperature”?
Did you take a close look at the hotend to see if the thermistor is actually in it? Also, check the wires going to the heater. This is where the majority of issues lie. If the thermistor has popped out, reroute the wiring to ensure that it stays in. Be extremely careful though, as the thermistor wires are extremely fragile, and so is the glass bulb.
This is normal because the temp displayed on the screen is the temp of the thermistor, not the nozzle tip. This is why each machine needs to individually calibrate temp for the filaments. That is the nature of thermodynamics and thermal conductivity.
CNC-Maker - The thermistor was inserted into the hot end as it should have been. I removed it to take these two pictures. See anything amiss or is that how it’s supposed to look?
Mxbrnr - The thermistor is only a couple of centimeters from the nozzle tip and of course is inserted into the same aluminum block the nozzle is attached to, so the difference in temperature shouldn’t be that much. I can accept a few degrees in difference but not 40 as I’m seeing here. We’ve never calibrated temps for filaments and we’ve been using this printer successfully for a year straight. We always use 200-205C for the Sunlu PLA. The problem is the gap in temp values between the screen and the nozzle and not that we don’t have the temp setting correct for the filament we’re using.
You should have a spare hotend with thermistor, heatresistor and nozzle in it, change it and see if it helps.
Check the hotend connector before assembling the new hotend.
Grizzly thermal paste is good, there are some users who use this.
We’ve already swapped out hot ends, twice if memory serves, and the problem persists. This tells me the problem is likely not with the hot end itself. We also swapped out the little circuit board that’s accessible from one side of the print module. That swap out fixed the problem for 30 hours or so of printing but afterwards we were right back where we started.
When I get the thermal paste in I’m going to get as much as I can in the hole with that thermistor and see what happens. Not sure what else to do.
Good news is that SnapMaker says they’re going to send us a replacement print module so with any luck that’ll make everything work for at least another year.
Yes, it really can be that big of a difference. When I have printed PETG comparing a copper nozzle to a standard brass nozzle, the difference in displayed temp is in excess of 50 degrees between the two. That’s how much difference just the nozzle material can make in that short distance between the tip and the thermistor. I use that to show that the absolute temp of the nozzle tip is irrelevant so long as it is printing properly, which you have to base off the displayed temp (the reason temp calibrations are a necessity for true reliability). PLA has a melting point between 150 to 180C, depending on the manufacturer formula and additives, and yet the machine typically needs to run at 200C displayed in order to achieve that at the nozzle tip. Change out the brass nozzle for a copper one like I did, and the thermal conductivity is so much more accurate that you will find for some filaments you actually can’t set the printer at a low enough temp for it to work (firmware sets a minimum sensed limit of 170C). Swap to stainless steel, and suddenly that displayed number needs to 40 degrees higher than standard in order to achieve that same melting point at the tip.
So yes, that short distance of separation between the thermistor and the nozzle really is that different in sensed/displayed temp vs actual.
That is good news. After reading your first paragraph it sounds like a bad connection, which could be rather difficult to find and fix, as it is most likely thermally and/or movement related.
If you want to look into it further and take apart the module, I would look at all the connectors and soldering joints between the board that the module connector plugs into and the glass bulb itself. It could be multiple bad connections and not just one.
