The Peopoly Heater problem

#1

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.

peopoly%20heater%20power%20brick%20AC%20(hot-gnd)

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.

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#2

thanks for the feedback. We are replacing power supplies that are faulty.

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#3

I hope this is a problem that can be fixed by changing the power brick for the heater because now my prints look like this.

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PeoPoly heater problem, analysis and solution
#4

and with heater off, everything is ok?

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#5

I will print the same object and post picture. I have not printed without my heater on, because the temp in my workshop is around 20c. I will print with the heater power brick unplugged and plugged in with heater off.

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#6

Just a point to acknowledge the OP, I had posted an image in another thread related to this a while back and had also found that the heater was causing this issue.

However since our printer is in a government funded laboratory, everything has to be CSA approved (which the power brick for the heater was not.) After replacing the power brick, as well as locating the fan further from the galvos, all lines have disappeared.

image

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#7

There’s also a problem caused by some wobble in the z-axis that is being addressed by a new part that Peopoly is selling (or the DIY Project Tripod).

I got inspired to check things out electrically after seeing someone report good results by adding a ton of EMI shielding to their printer.

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#8

How can we identify a faulty power supply? Is there a model number or serial number to look for on the brick?

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#9

it is not all the power supplies as in design flaw. this is more a QC problem on the supply side. So if you don’t have problem, then don’t worry about. if you do, email us.

@Whazaa please email us about the power supply

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#10

I will check the test prints printed without heater - if they look better I will mail you regarding changing my power supply.

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#11

posted this on the FB group. have mailed the heater and PSU back to Peo for diagnostics.

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#12

And I’m back with the verdict

With heater on

and with heater off

Peopoly is shipping me a new heater + power supply. Everything went smoothly with Peopoly Support.

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#13

I’ll bet you anything that a new heater + power supply from PeoPoly does not solve the problem.

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#14

So do you suggest another heater setup?

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#15

Glad this worked out for you, and I’m also happy to hear @peopoly is looking after this promptly for you!

Best of luck going forward, and keep us posted!

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#16

THAT is a stunning print.

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#17

Hello @Whazaa!

I have had similar wave movements on my print and I think I have found the cause :smiley:

But I do not want to lean further out of the window :zipper_mouth_face: and finish the last series of experiments. Tomorrow I will present the results and most likely suggest an alternative heating solution …

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