This thread is a continuation of a thread originally about heat break clogs. One poster chimed in with this.
Which led to some comments on how to reduce heat creep to be able to use even higher chamber temperatures…
It just occurred to me that the extruder motor, Z axis motor and the “extra MCU” are all INSIDE the chamber and subject to damage from overheating. The Microcontroller on the toolhead board has to be unhappy with a chamber temperature above 40 °C.
What is the highest chamber temp anyone has printed at?
The CAD model at github shows a heat sink on the MCU but pictures I’ve seen don’t show it.
Most commercial grade components (as opposed to industrial or automotive grade) are good up to about 70C. I think the chamber on the Zero will only get up to around 55C or so, which isn’t a lot of margin. But I don’t think it will be a problem in practice.
While heat is the enemy of electronics, I wouldn’t worry too much, they will probably still last more than a few thousands hours, and they are not expensive to replace (let away repair, where possible). In another application, I run commercial grade MPU’s continuously at 80-85C, they crash at 90C, but at a lightly lower temperature they don’t and I’ve been running them for hundreds of hours without any fail so far.
I’m not suggesting to keep the chamber temperature higher than strictly necessary of course, just to not reduce it for concerns of this kind.
By the way, I’m (the one you were referring to, and I’m) heading towards the addition of a second fan to pull air from the left side of the heat break. I looked for 2515 24V fans and they’re almost impossible to find, even on Mouser, Digikey, Farnell, RS, etc… (I’m a professional electronics designer and programmer so I looked at many places to source them), in the end the least expensive and simplest solution was to purchase them directly from Sovol. While for the Zero they only sell the 2515 24V in bundle with a part cooling fan, for the SV08 the 2515 24V is available even alone, and it (ZYT2515H24B) is the same identical fan used on the heat break of the Zero, so I purchased a couple and we’ll see (I will report my findings) if the heat creep is reduced, and how much.
By the way, does anybody know where is the chamber temperature sensor located, exactly?
When I was printing PETG on the Zero with a 255 C nozzle and 80 C bed, the passively heated chamber temperature reached 61-62 C, and that’s probably when the heat break fan pushing hot air was insufficient to keep the heat break cool enough to prevent a clog.
Keeping the front door closed but removing the glass top reduced the chamber temperature to 50-52 C. I was surprised it wasn’t cooler than that.
I had procrastinated but was planning to make 3D printed insulated tiles for the inside of the Zero but I’m now thinking that might be a bad idea. Most materials that could benefit by a heated chamber have a hot enough bed temperature that the passively heated chamber will be warm enough soon after the print starts. The only real advantage of insulating the chamber would be to reach the desired chamber temperature sooner and have enough excess heat that the exhaust fan could maintain a very stable chamber temperature, but I’m now thinking that the electronics on the extruder aren’t going to like the elevated temperature much beyond what a passively heated chamber will reach. The QIDI printers with actively heated chambers only reach 65 C and they print all types of exotic high temperature filaments.
I should finish the front door to complete my SV08 thermally insulated enclosure as the SV08 could use some passive chamber heating.
I noticed that the chamber temperature rises not much because the heated bed, but because of the heat produced by the extruder / nozzle.
In fact if you try to heat the chamber via a M140 S120 command (heat the bed at maximum allowed temperature) it will take forever even just to raise the temperature of 5-10C vs ambient, while printing or even just leaving the extruder hot (not that it’s good practice anyway, if you don’t let filament flow) will make the chamber temperature rise much much faster.
I usually start with a print of a smaller object, if I need one, or abort the print, just to reach the minimum useful temperature (especially for ABS).
Or use a heat gun at low setting to heat the chamber, but carefully of course.
I wondered if a fan blowing on the under side of the bed would force the bed heater to run at a higher duty cycle resulting in more power being delivered into the “closed” chamber.
Glue on heat sinks on the bottom of the bed would magnify the effect.
I’ve been thinking of placing some thin blowers each side of the bed to blow air underside that bed. Doing similar to this. Switch on when the 3D print finishes to save waiting for cool bed down time
Sovol sv08 may at this time benefit from a new under side print to flaten the taco bed. I keep putting it off doing.
