So I spent the weekend looking at my peopoly moai with my rigol 100mhz oscilloscope. I think I’ve come to the source of the “waves” in prints (other than loosey-goosey z-axis). The AC-DC power brick included that’s supposed to output only 24vdc is also putting 46VAC 60hz (and a poor sine wave at that) into the signal.
The heater is definitely radiating this AC into space. I can pick up quite a strong AC signal a few inches from the heater while it is plugged in - even if it’s OFF.
Here’s a screnshot.
I’ve got a bench power supply, I’m going to connect that to my heater and see if things work any better.
In short, I think peopoly got a batch of junk power supplies from the manufacturer.
Measured at the fins of the heater, there’s 24vac when the heater is off and 26.5v when it’s on.
The AC is present between earth (common/ground) and the DC Positive tip of the power supply. The heater isn’t dealing with the 46VAC probably because it’s not expecting to get AC input in the first place.
The main power supply for the MOAI puts out a nice clean DC signal. While the MOAI isn’t using all of it, my heater draws 4.5a, so I guess I can’t combine the power source.
@peopoly please take a look at your heater power bricks with your own test equipment to confirm. It’s either a design flaw (most likely) or a very high failure rate in these things since many people have problems with ripples while heater is installed.