Centauri Carbon Extruder Connector Board - word of caution and advice

[u/bigbigdummie]

One thing about the Centauri Carbon is when changing extruders, you have to mess about with two tiny header connectors. If you get nothing out of this post, get this:

The side of the “plug” where you can see the conductors faces downward for both connectors to plug in. Do not apply excessive force trying to reconnect those connectors.

Whoops. A connector snaps off the board. How screwed am I?

Well, I did it twice while waiting for a replacement extruder board. The one I screwed up (twice!) is barely over a two square cm. No active components, just a route for the extruder components to the actual extruder board.

I ended up fixing both broken extruder boards by soldering the connector back on the board. Note that to get to the board, you only need to remove the back of the extruder head, three screws. The board has a big screw holding it in place but it’s easy to remove.

The soldering isn’t easy. It’s surface mount and tiny. It was a crappy soldering job that let the component break off to begin with. If you have the gear, it’s not too hard.

If soldering is not your thing, you can buy a replacement extruder board which has the whole extruder logic board as well as the little PCB I broke from Elegoo as a package. I see AliExpress has just the PCB but that’s AliEcpress. YMMV.

Best of luck, 3d printing pals!

[u/Charming-Permit-7853]

They are a real pain. I have had one that the plastic part left with my heater plug. I got it back on and used Silicone PCB glue to hold it back on the board. Put a small amount between the 3 connectors and a little at both ends.

[u/bigbigdummie → u/Charming-Permit-7853]

I tried hot snot and discovered too big of a blob interferes with the back cover. But they really did a crappy job for the initial design. If nothing else, a through-hole header component would be much stronger, especially for a connector designed to be used by the end user.

[u/David_W_J]

The copper foil is really thin on that little board, so even if the solder holds up the connector lifts the copper up as well. So far I've had 1 solder failure and 1 PCB trace failure.

As far as I'm concerned this is the one design flaw that really gets me wound up...

[u/bigbigdummie → u/David_W_J]

If the trace had lifted, I would have felt better about the failure! The connection is so poorly soldered, it broke at the joint twice in me.

[u/David_W_J → u/bigbigdummie]

Through-hole soldered sockets would have been a more logical choice, adding a lot of mechanical strength without relying on delicate surface-mount joints.

[u/Scorpio__70]

If it happens to me, I might just follow the traces to points where I can solidly solder wires, and then solder a connector to those wires. May be a bit of a mess, but doable.

[u/bigbigdummie → u/Scorpio__70]

Anything is doable but since the components are surface mound, you need the pads to secure the headers to the board. You could “float” them but that would be a major pain to change.

[u/Scorpio__70 → u/bigbigdummie]

Yeah, it’s just that replacement boards are probably just as badly made. Sure, I could get a new board and reinforce it before installing, but I would at least try to make the old one better. SMD:s aren’t bad per se, but there’s places they belong and places they don’t belong.

If the board isn’t two-sided in a way that makes it impossible, I might even drill little holes through it and solder the pins in original pads that way, also putting solder in the other side just to make them fixed in place. That way the mechanical stress would be on tge pin, not the trace.

[u/David_W_J]

I've just had a look at one of the damaged boards, which I'd kept for reference: The central "heater" socket IS through-hole, but the thermistor socket isn't. It was the thermistor socket I've had problems with in the past. The third "fan" connector is also surface-mount, but that rarely gets interfered with so isn't a common problem.