Strange smell after enabling performance mode on steppers

I added a fan for my steppers a while ago and was going through my printer.cfg and saw the section for improved performance for the drivers. I commented out the previous driver section and uncommented the "cooled" section. I tried a PA test print and everything went smoothly except there was a new weird smell. It seems like it was coming from the motors. The motors also are more "musical" now. Not bad, they just sound different. I had just run the same test the previous day with no smell so I assume it is due to the stepper config change. I have a V-Core 3.1 500 that is largely stock. Should I be worried? Is this just a "new config smell"? Trying not to burn the place down...
16 Replies
TheTik
TheTik9mo ago
As long as the drivers are cooled, you should be fine. I also noticed the more musical steppers. They'll run a bit hotter, probably just smelling whatever gets volatile at the new temp. I didn't notice that, as I don't have a sense of smell anymore 😦
ADSRMedia
ADSRMediaOP9mo ago
drivers appeared to be relatively cool to the touch during the print. Motors also seemed to be just above room temperature so nothing concerning there either. I was just hoping to get a more informed opinion from this experienced community regarding whether or not I'm about to burn my house down.
TheTik
TheTik9mo ago
it'd be real hard to burn your house down from steppers. It's the heaters and bad AC wiring that is way more likely 😛
ADSRMedia
ADSRMediaOP9mo ago
That was definitely the most nerve racking when I first set it up but it's been going good for a while now.
TheTik
TheTik9mo ago
Glad to hear it. Happy printing!
ADSRMedia
ADSRMediaOP9mo ago
Update: I found the source of the smell. I went to do more testing on it and wasn’t able to connect. So I physically went to see what was wrong and everything seemed to be running. I figured I’d just reboot everything and flip the power switch. The switch is normally easy to flip but now it was very difficult. I found that suspicious and managed to turn it off and I unplugged it to investigate. That’s when I noticed that the corner of the plug was melted. Apparently it couldn’t handle the increased amount of amperage that the printer was drawing due to the updated settings. So I guess I need to replace the receptacle with a better one. It was supposed to be rated at 15 amps so I figured I would have tripped the breaker before melting it. Any advice on what receptacle to get?
ADSRMedia
ADSRMediaOP9mo ago
This is the one I had installed: https://a.co/d/fhA5YW6
3Dman 15A 250V Rocker Switch On/Off Power Socket Inlet Module Plug ...
3Dman 15A 250V Rocker Switch On/Off Power Socket Inlet Module Plug 10A Fuse Switch with 18 AWG Wiring 3 Pin
TheTik
TheTik9mo ago
Get one from a reputable source. I went with one from Digikey https://www.digikey.com/en/products/detail/schurter-inc/4304-6071/2645659, but https://www.amazon.com/gp/product/B09X1VZ852 is another popular one I trust Digikey to supply items that meet their specification. Going cheap on high power stuff isn't wise
Oskait
Oskait9mo ago
Uff that sucks. Especially because the 10A fuse should have tripped long before 15A are reached. As far as I know the amperage your bed heater pulls is far higher than the stepper motors in performance mode. Are you on 100 or 230V? Could you post a picture of the melted Socket? Would be interesting were it failed as I have a similar one (on a 120W load, not my printer, but still).
ADSRMedia
ADSRMediaOP8mo ago
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ADSRMedia
ADSRMediaOP8mo ago
The amps I measured from the bed were 9-9.5 amps. Overall draw was about 10.5. Thought it’d be higher considering the drivers are set up to draw 1.1amps each unless I’m reading the config wrong. The performance setting bumps them up to 1.6amps which is why it melted. Didn’t kill the fuse though. I’ll be upgrading to a C20 inlet with a 15amp breaker shortly. That should be able to tolerate anything I should be throwing at it. I’m in the US so it’s 120v. I have no idea why the fuse didn’t blow. I’ve gone back to my old config with a spare switch/inlet and salvaged the 10amp fuse from the melted one since it shipped with a 5amp fuse for some reason. 🤷🏻‍♂️ You can even see in one of the pictures the fuse is still intact.
TheTik
TheTik8mo ago
That's a scary failure. The fuse is there to stop things from melting 😕
Vitamin G
Vitamin G8mo ago
On the Amazon page it says it comes with 18 AWG wiring. I used a similar switch from Amazon but replaced the wiring with 14 AWG copper wiring
Oskait
Oskait8mo ago
Oh wow. Yea that is scary. Your drivers will pull 1.6 amps but on 24V DC (or 48V if your running that). So that would equal to roughly 0.32 Amps at 120V (5x the voltage -> 1/5 of the amperage, ignoring losses from PSU) that each stepper needs.
OldKingHamlet
OldKingHamlet8mo ago
Makes sense the fuse didn't blow: It doesn't look like current overdraw, but an arc fault issue. The other joyful cause of house fires. The hot lead on the AC wiring looks like it might have been loose (either internally in the switch or on the paddle of the connector) and over time, it degraded itself more and more. Could have arced just a little bit each time it was turned on. Running the steppers slightly higher may have just accelerated the process a little bit (if it was a loose connector and not a bad switch), but I think it was something already in progress and the stepper change made you more sensitive. So count yourself lucky. Also, thanks: I'm here cause I got a used Rat Rig off someone, and I was not incredibly happy with the AC line but haven't prioritized it. I'm thinking I should now. I have my printer in my garage, and my garage is GFCI only, which would not prevent this either 😑
ADSRMedia
ADSRMediaOP8mo ago
I've since replaced the inlet and switch both rated to 20 amps. I'd already been using 14AWG for the 120v wiring. I've added a 20A breaker and monitor as well. The house will trip before that does and everything is rated well enough to handle what I can provide it so I think I'm good now. Thanks again, everyone.

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