I had a few issues with adhesion in the corners of the bed, so i thought I will check it out with my IR gun. setting the bed to 80’C and letting it sit for 10 mins, i was getting about 72’C to 74’C in the centre of the bed. then a looked at the corners and it was in the low 60s , this came about after printing this model - https://www.printables.com/model/1033831-computer-side-wall-mount-brackets
and it kept warping / lifting away from the bed. ( this was at 80’C set bed temp , clean plate, with 10mm brim)
so now for my PETG profile i have had to set the bed temp to 90 to get somewhat good corner adhesion. For ABS with the panda heated chamber I’ve had to set the bed to 110 and chamber to 65 to get good results.
The printer’s heated bed has its temperature sensor right in the middle. This means the temperature you see on the screen is only for the exact center of the bed. Because heat naturally escapes from the edges, the four corners are always colder. Usually, the corners are 5°C to 12°C cooler than the center. If the room temperature is low, this temperature drop gets even worse.
This also explains two features of the official printer cover when printing materials like PETG, ABS, or ASA:
Extra Wait Time: The printer automatically adds a 3-minute preheat time to give the whole bed a chance to warm up.
Internal Fan: The internal fan turns on during printing. While it does filter the air, it also pushes the heat around so the entire printing chamber stays at a steady temperature.
Both of these features are meant to improve this temperature problem.
Hey @Zoe_M ideally the temp difference shouldn’t be more than 5’C from Centre to edges. ( Ideally ) , so if you are printing a large model that is touching the edges, but not much happening in the centre it should compensate for that.
also there should be more sensors than one in the centre of the bed. we don’t just print in the middle. at the moment whatever you do , due to the bed heat sink design , there will always be a massive difference between the centre and the edges. which is not good when you are printing thinks like the link above.
Thanks for the updates. I will check whether the engineers have any further suggestions.
I am also curious about other user feedback. While searching our internal support records, I found one user reporting notable temperature difference between the left and right sides of the PEI sheet (10‑20 °C). According to the video they submitted, the temperature gap between the bed center and the far‑right side was around 5 °C.
I was printing a shelf bracket like the one below and noticed lifting in the bottom left corner, and this is why I started looking into it ( this one was a success, but I had to set my bed to 90’C )
Yeah I wouldn’t be at all surprised if its a standard oven heating element?
In fairness the SM, despite advertised bed sizes from all 3d printer manufacturers they tell you ideally to keep 10mm away from the edges if possible!
The lefthand side isn’t helped by the 2 z axis being open IMHO I did print a cover for the right hand one when I modified the fans - really need to see if theres a double version for the left
Let’s not forget the price point of this printer (the U1), and that we’ve all bought it for having four tool-heads not the evenness of the bed heating. If a better bed heater is on people’s wish list, I’m sure there are people out there willing to produce third-party upgrades. Having more temperature sensors seems like pie in the sky – you would need more inputs on the controller, and then what exactly would you do with the information?
As with any other printer, learn its characteristics, limitations, and how to make the best use of it.
If this were another manufacturer, you would just have to take it or leave it. I don’t think Snapmaker making themselves accessible to the community means the community should treat them like a whipping post.
I am simply sharing my findings and reaching out to see if anyone else has the same issues. I will be avoiding the bottom left corner from now on if possible.
There is a 3rd party upgrade out there already, which I will be looking into as I already have it on my K1 Max.
It’s good to balance out product critiques, but I didn’t really see the OP as poorly intentioned. I’m guessing most of us are aware that many consumer printers have some heating variance across the bed. Snapmaker’s still made an incredible product overall. @Zoe_M We applaud you all for bringing it to market.
I’ve had a few minor printing inconsistencies on the ends of long diagonal parts myself, and plan on testing the temps in different areas over the weekend the best I can with a cheap IR gun. Not that it really changes my opinion of the machine, but maybe I can make some small adjustments.
If there are third party options, that’s great to know for anyone that wants to go that route. @nikolarun if you end up trying it we’d, of course, be happy to hear back from you on your real-life experience.
Did a little bed temp testing. Could it be overkill? Yes. Is it totally scientific? Not completely. I used a cheap IR gun. However, it was within 1C when testing ice water. Also, I measured off of 9 2"x2" pcs of electrical tape to have a known emissivity, and when measured cold they were all within 0.3C of each other. So appears to be fairly accurate.
This was just one machine, of course, and it’s in an indoors loft room that runs a bit warm. No drafts. Take it for what it’s worth. Just to state again - I think the U1 is a great machine, so the post is done in that spirit.
All side and corner measurements were about 1" in from the edges of the build plate.
A few patterns did seem to emerge. 1) Left side runs slightly cooler. 2) Corners might be run around 1-2.5C under set temp for 55C, and 4-5C under set temp for 80C. (These could improve even more with more time). 3) The whole center of the bed plus right center is very close to set temp.
Anyway, since I took the time to write them down for myself, I thought I’d share.
thanks for the testing. reminded me to buy another IR thermometer. it will be here tomorrow and i will try to replicate your test.
Just out of curiosity , when you say you tested ice water, how did you know what temp the ice water was ? as as far as I know ice water can get down below freezing , but not be frozen.
It doesn’t really matter what the absolute precision of the temperature reading is, the important thing is repeatability so that the temperature differences are recorded properly.
