@fcwilt said in recent issue heating bed..funny smell:

@gnatman

Did you tighten down those screw terminals every now and then?

They can loosen slightly to the point where the increased resistance of the connection can start to create some serious heat.

That may have happened to you.

Frederick

I have, I also installed a replacement board which did the exact same thing. I have a Duet wifi 1.02 and now a replacement wifi which has the blade style fuse between the two terminals. This one also would smell on bed heating and also I mentioned the blade fuse getting pretty hot. (new to me as my old board doesn't have the blade fuse there)

@jay_s_uk Thank you for the quick reply. hopefully this resolves the issue otherwise I'm not sure what else to do.

after going strong for a day, it started to smell again, this time I was not home but my wife was and she stopped the printer. I purchased this mosfet https://www.amazon.com/dp/B08YZ4W4LN?psc=1&ref=ppx_yo2_dt_b_product_details

Based on the image, how do I hook this up. My heated bed has a pos/neg wire plus wires for the thermistor. I don't want to be wrong here but are the blue wires in the image supposed to be the thermistor wires or are they trying to show there is no polarity on the wires coming off the bed going to the mosfet. Im just confused slightly by the blue wires in the diagram.

@jay_s_uk
Thanks,

The last piece is going to be trying to figure out what caused it to short in the first place. I will mention that I was plugging in the bltouch. Not sure if that was it or what. (was on) as soon as I noticed, it was too late.

Below is my current drive setup. If I were to change M569 P2 S0 to something like M569 P8 S0. Would that be all I need to change? Along with changing the "2" on my M584 to match. so it will now read M584 X0 Y1 Z5:6:7:8

; Axis Drives
M569 P0 S0 ; physical drive X goes forwards
M569 P1 S0 ; physical drive Y goes forwards
M569 P2 S0 ; physical drive Z1 goes forwards Left Front
M569 P5 S0 ; Drive 5 Z2 U Motor goes forwards Left Rear Duex 5
M569 P6 S0 ; Drive 6 Z3 V Motor goes forwards on Duex 5 Right Rear
M569 P7 S0 ; Drive 7 Z4 W Motor goes forwards on Duex 5 Right Front

M584 X0 Y1 Z2:5:6:7 ; Drive X-0 Y-1 Z-2&5&6&7 Z2=U5 z3=V6 z4=W7

@Phaedrux said in Zstepper issue / fried chip?:

What makes you think that?

I saw the magic smoke, and I get an error "short to ground reported by driver(s)2"

That depends if you have a free driver on the Duex5 or not. If you have a spare open, yes it's easy to move over.

I do have 2 spare spots, I also have 1 spot available now on my extruder too on the duet2. Maybe I'll use the duex5 so that all my z steppers are on that. Will I have to do anything with the jumpers, do they just stay there. Are they needed anymore once I do the change.

I think I have an issue. I was trying to clean up my wiring after changing out some stuff on my printer. I have a Core xy (hevo) using quad z steppers. I have a duex5 board also. Anyway I think I fried the stepper chip on the z thats on the duet. I currently have z1 stepper on ZA and the jumpers on ZB, and the other 3 steppers are on the duex5. Can I take the stpper from ZA and move it also to the duex5 or am I out of luck?

@jay_s_uk Thank you for the quick reply. hopefully this resolves the issue otherwise I'm not sure what else to do.

after going strong for a day, it started to smell again, this time I was not home but my wife was and she stopped the printer. I purchased this mosfet https://www.amazon.com/dp/B08YZ4W4LN?psc=1&ref=ppx_yo2_dt_b_product_details

Based on the image, how do I hook this up. My heated bed has a pos/neg wire plus wires for the thermistor. I don't want to be wrong here but are the blue wires in the image supposed to be the thermistor wires or are they trying to show there is no polarity on the wires coming off the bed going to the mosfet. Im just confused slightly by the blue wires in the diagram.

@phaedrux said in recent issue heating bed..funny smell:

@gnatman said in recent issue heating bed..funny smell:

@jay_s_uk said in recent issue heating bed..funny smell:

@gnatman said in recent issue heating bed..funny smell:

16" x 16"

looking online thats going to be about 500w.
This would equate to 21amps so you're above the recommended rating for the bed mosfet (18amps).
Best to move to an external mosfet

I've been printing this way for like 3 years or more. I don't think that is the issue.

Says the man who's printer smells like burning.

I think it was just a cable being loose. I was able to resolve it once I replaced all the wires

@jens55 said in recent issue heating bed..funny smell:

You are exceeding the current capacity of the Duet. Go to an external relay or mosfet!
Yes I realize you might 'just' be inside the limits (didn't bother to verify) but you are no longer in a comfortable operating range.

I'll look at adding a mosfet, do you have one you would recommend. I'm 95% sure it was just one of the neg cables screws being loose on the terminal. I didn't replace all the ends or wires the first time, I just did one side of one neg wire. then swapped the board. This time I did all of the wires.

I swapped out all power wires, and so far it seems to be ok. not sure if there was still some issues going on with the ground wire that has the duex5 ground or whatever but I think all is good.

I will keep checking the wire to make sure it's still going strong and not too much current on the wire. I swapped the 12g that was the pos/neg from the vin to 14g. that same 14g is on the duex5 too.

@fcwilt said in recent issue heating bed..funny smell:

@gnatman

Did you tighten down those screw terminals every now and then?

They can loosen slightly to the point where the increased resistance of the connection can start to create some serious heat.

That may have happened to you.

Frederick

I have, I also installed a replacement board which did the exact same thing. I have a Duet wifi 1.02 and now a replacement wifi which has the blade style fuse between the two terminals. This one also would smell on bed heating and also I mentioned the blade fuse getting pretty hot. (new to me as my old board doesn't have the blade fuse there)