Bed connector going hot
Hey everyone,
Happy New Year to all of you. Unfortunately 3d printing didn't start so well this year.
I noticed my bed not getting hot again after a failed print. After investigating a bit further I noticed that the connector that is used on the Electronics board has gone hot a bit. See attached images for an impression.
Not only has one of the pins overheated but the whole plug seems to have been hot enough to also melt the plastic covers of the crimp connectors crimped on the cables.
Luckily I had one of these connectors from another project to test if this was the only issue and it seems like it was. Even though I wonder how this could happen.
It's definitely not a general temperature problem on the board as the Extruder connector next to it still looks like new.
Any ideas?
Overall that doesn't increase confidence in the machine. Anyone else seen this happening?
Thanks,
Frank (@helmi)
P.S. Sorry for the bad image quality, only had my iphone handy at the moment and it's not that easy to shoot closeups of smaller parts with it.
Re: Bed connector going hot
Hi Helmi,
This happens when the connector is not fully plugged in or the wire harness from the heated bed is not perfectly secured to the RAMBo cover and connector wiggle with every bed movement.
This is the connector http://www.molex.com/molex/products/datasheet.jsp?part=active/0395300002_TERMINAL_BLOCKS.xml which is rated at 18AMPs, well above the currents flowing to the bed. The connectors are self extinguishing so melted connector is not fire hazard.
New female connector on cables will not solve the problem as the male part is oxidised. Permanent solution is to solder the heatbed wires on the back of the RAMBo, then everything will work 100%. Alternatively you can buy a new RAMBo which is wasteful or replace the part on the PCB.
This is unfortunately not covered by warranty on kit MK2.
Re: Bed connector Melted ...
Just had the same problem as well, seems bad design if wiggling will cause it to melt you didn't run a connection that didn't wiggle loose, I will be solding mine as you suggested BUTI would Like to change to a Bit Longer Wires because I have them break a couple of times from them flexing back and forth, First I was thinking of using silicone more flexible wire, is this ok and What Gauge wire do you use for your Heated bed now, So I can get the same or maybe a little bigger for protection