# Figure out max bed temperature

I have a Tronxy X8 (yes, I know, poor choice but I didn't know better) and after some years printing PLA, PETG and TPU, I am considering trying ABS, since I got myself a second hotend which can go up to 300 °C.

But I am not sure if my bed can handle the required 110 °C.

According to the manufacturer, 110 °C is the maximum on the bed, but they also claim their teflon-lined hotend can go up to 275 °C, so I don't trust their claims at all.

How can I safely determine the maximum temperature that the bed will go?

I have a MOSFET mod for the bed (and also a Bigtreetch SKR v1.1 Mainboard). The only original parts in the chain, which I don't trust, is the PSU and the heatbed.

The bed looks like aluminium, the surface is a Buildtak clone.

What could happen if I just crank up the heat?

• Have you found a solution to your issue? Did the answer help? If it did, don't forget to mark it as the accepted answer, otherwise, please post the solution that you found yourself. Thanks. Jul 14 at 9:40

The firmware has a fixed limit for the bed, this is also the maximum value you can set through the LCD interface, the default is e.g. set in the configuration file for Marlin, it contains the following constant definition:

#define BED_MAXTEMP      150


But, you will most properly never reach this value, even worse, most beds won't even reach 110 °C. At some point the losses become too high and the heat input is too low to compensate. This is discussed in a previous question that I will link when found. To mitigate the heat loss, you can insulate the bottom of the heated bed and place the printer in an enclosure, this allows for reaching higher bed temperatures. Printing ABS should preferably be done with an enclosure anyways.

To find out the max temperature, just schedule the bed to go to 140 °C and see where the bed temperature takes you, or where the safety features kick in.

• The firmware that I have is not the original anymore (since I have a new mainboard). So the original limits don't apply any more. Can anything go fatally wrong if I crank up the heat? I really don't want a burning printer. Jun 13 at 20:05
• You should test to see how far it goes, if it doesn't reach 110 °C you cannot even set the bed at that value. You can heat up the bed from the LCD, take it to the max value (firmware limit) to see what you can get. That is not dangerous, it will not burn your printer, the hotend is something completely different, it requires Thermal Runaway Protection.
– 0scar
Jun 13 at 22:26
• I want to add that smaller (say 75 x 75 mm footprint or less) ABS prints can be done on an 80 C bed with some "extra super hold" type hairspray.
– Davo
Jul 14 at 11:47
• @Davo User FarO has similar experience he also uses a skirt shield to create a mini climate. Thanks for sharing!
– 0scar
Jul 14 at 13:46
• @0scar nice - we do that for some of our PEEK prints. :)
– Davo
Jul 14 at 13:50