Panda and the A1-Mini - too many Knomi's?

[NicPlays3D]

Learned something new today.

One of the printers I run is an A1-Mini with a single AMS-HT attached.

I have a Panda Branch and a Panda Branch Plus attached to handle the accessories.

I attached several Panda devices to the Mini and ran into some issues.

Panda Aura

Panda Lux

Panda Knomi mounted on the Z-axis front cover

Panda Knomi in a screen holder mounted next to the screen in the vacant indentation area

First, it wouldn’t run the devices with stable power. There was a bit of a flicker in the Lux.

So I powered down and removed the Lux from the chain.

It powered on stable but the AMS-HT did not behave - it wouldn’t feed the filament.

So I powered it all down again and removed the Knomi mounted to the front of the printer in the vacant indentation area next to the screen. I also put the Lux back into the chain. I also removed the Panda Branch as it was not needed.

Everything is working fine now.

For some reason, it doesn’t want more than one Knomi attached to the printer?

Or perhaps it doesn’t like the Branch and Branch Plus attached?

Not sure, but it definitely didn’t like all of the devices attached.

Any ideas on the “why” or “how”?

I’d like to run all this, but as of now, I don’t believe I can.

For the curious -

I had some issues with my original Panda Knomi 3D and reached out to Biqu/BigTreeTech. They weren’t helpful and I finally figured it out (it was not anything logical, but it worked). By the time I got it working, I’d already purchased a second Knomi and it had made it here (which is why I have two).

[lion7718]

I looked at the Panda when it was released for the Mini, I also looked into the Branch.

But this picture confused me because reading all the info it seemed like the Branch couldn’t power the Panda & the AMS Lite. I emailed Biqu & they replied that I was right, there is only 1 input port & all the others are output. Things might have changed since then, I don’t know…I’m just posting what they told me.

[NicPlays3D]

But the BigTreeTech Wiki says it’s specifically built for the Knomi.

That’s the reason I purchased it.

Not sure what to think.

Why would they state it’s for the Knomi and then state it doesn’t have the power for it?

This one is really bugging me.

[MaxThreeD]

I don’t know anything about the Panda stuff, or even the A1 really (so I should probably just shut up… lol), but from looking at that board, I can tell you it doesn’t “power” anything. Maybe you already knew that… But it’s just a port expander and 5V converter. Meaning all the actual juice still has to be delivered by whatever is providing the 24V input (the printer?). So if that source can’t deliver enough power (Amps) for all the attached devices, there will definitely be issues, like you describe (or worse, for the supply end).

To determine total draw you’d have to add up the power draw of each attached device (including startup power surge) and compare that to the total power which the source can deliver (and ideally stay under ~80% of that).

The screenshots don’t say anything about AMS HT, and I don’t know what the power draw of that is compared to the “AMS/AMS Lite” listed. Might be something to look into.

HTH,
-Max

[NicPlays3D]

FIGURED IT OUT!

The Knomi ALSO works via USB-C.

The Panda Branch Plus has a full on external power source and plenty of USB-C inputs.

I can connect several Knomi’s to the Branch Plus via USB-C and they all work with no impact on the printer.

This took me WAY too long to figure out.

I do appreciate y’all weighing in on this.

It was a bit frustrating and it’s good to know there are others I can turn to.

Thanks again.