So all the sudden I can’t get my heated bed past 80ishC°. I’m running a QU-BD12x12 silicone bed with a ramps 1.4 from ultimaker.
This combo has been working for months without fault. I have had to put a fan on the poly fuses though. Do they degrade over time? Thus is super frustrating.
OMG GET RID OF THE POLYFUSES.
Seriously, they’re the part that causes the most problems on the Ramps. That being said, they are not intended for a 30cm bed anyways and are already undersized for a regular 20cm one. Still, get rid of them and use for example automotive blade fuses. They’re cheap, available in all amperages (~ 25A for your bed?) and you know when they’ve tripped.
I’ve heard that if the power supply fails, USB will get you to 80C, but not higher.
Check the wiring to the bed and the connectors… Excess heat means excess load. if the wires are hot that current isnt making it to the bed. I had a similar issue, shifting the fan to blowing across the fuse instead of directly at it also helped.
I’m pretty sure you misheard that, @Carlton_Dodd . USB is always current-protected and will shut off if the device draws any more than 500mA (up to 3A on newer devices). It would instantly trip if you tried to run a heated bed from that.
@Thomas_Sanladerer
Yeah, I knew the current limit, I just never correlated it. I should have realized that statement was incorrect.
Ok so I swapped out to an SSR controlled by the ramps. Guess what. Still maxing out at 83 after an hour of being powered on.
I re-ran the PID auto tune and all that jazz. My bed FEELs hot though. Like full temp. Im trying to find my temp gun now to see with its sitting at. Im wondering if the integrated thermistor has gone bad…
It’s the silicone pad I think. I’ve found the same thing with my one from Ali Rubber (they make the QU-BD ones) try plugging it directly into your PSU and see of there’s any difference. My suspicion is that one of the nichrome runs within the silicone has a short. There are several loops in those things so. if you loose one, it wont get as hot.
Yea, Im wondering about that too
Well I think it might be my ramps. I can’t get my nozzle to temp now either. I have an extra ramps I can try tomorrow but I’ll need to replace the controller with something.
Anyone have recommendations for something that can run a large bed and d dual extrusion? I wanted to get an acreage
Axteeg x3 but it seems like you can’t buy them any where