Can't get the printbed to heat up to 110 degrees


I’m trying to make a go at 3D printing again with my old AO-100 3D printer. I haven’t used it in 7 years.

My problem now is that I can’t get the printbed to heat up to 110 degrees (I only have ABS reels). It reaches slightly below 105 degrees and stays there. I waited 40 minutes with no change. During this time, the power supply (the big one with aluminum sheet metal casing) became quite warm, and its fan started 3 times. I don’t remember it ever running the fan when I was using it in 2013. Reaching 110 degrees would take 15-20 minutes back then, if I recall correctly.

What could be the issue? The PSU, or the PCB Heatbed Mk1 ?


If the temp reaches 105 degrees and stays there, the bed heater is fine, as is the the thermistor. Have you verified the temperature? I’m guessing that if the temperature is correct, the heater’s not getting enough power. I’m not familiar with the printer you mention so can’t offer anything else


The AO-100 is an old 3D printer from 2012, I doubt many of them are still in use! It’s based on the old Mendel Max design with a gantry made of 20x20mm aluminum extrusions and printed parts, and has what are now quite obsolete components (PCB heatbed Mk1, Arduino AM2560/RAMPS 1.?).

I don’t have anything to check the temperature. While Printrun specifies 110 degrees for ABS, the AO-100 manual actually says to heat the bed to 100 degrees. I decided to start my first print (the old Lulzbot octopus) at 100 degrees. By 90% completion the bed had managed to heat up to 109 degrees. The print came up fine, so I’ll keep doing that for now.

Sounds like you are able to manage :slight_smile: Is the AO-100 a Lulzbot machine? Do you have a cooking thermometer that you could lay on the bed covered with some kind of insulation, blanket or whatever to check the temp?

Yes, it was the second 3D printer made by Aleph Objects/LulzBot, after the Prusa Mendel. Both were based on open source designs from the RepRap community.

They made the AO-101 next, an evolution of the AO-100, then they developed the TAZ which was an entirely new design.

I don’t have a cooking thermometer, but it’s something I should have anyway. Thanks, I’ll give it a shot!

Thanks for the info. Looks like your printer has a nice rigid frame which is a bonus

Yeah, but the drawback of the A-frame is that the inclined front posts get in the way of accessing the print bed. They also limit the print height to 100 mm, because there’s not enough space between the upper horizontal extrusions for the extruder and stepper motor to rise in between.

I would like to move them behind the X-axis and straighten them up vertically. Kind of like the traditional Prusa i3 design. See attached design inspired by the i3, but with aluminum extrusions (made by StephS many years ago, I doubt it’s ever been built). Because the X-axis rods are horizontal rather than vertical, the posts would have to be farther back. Not sure if it would compromise stability…

But all this I should have pondered and done (or not) 7 years ago!