Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
Sir,
The printer is a MK3S and is about 18 months old.
Printing with Prusa PETG Orange
Because of the BLACK LAQUER which continually develops on the nozzle, I clean it between EVERY PRINT with a brass brush. Otherwise the BLACK LAQUER flakes off and ruins the print.
The HOT END is on and heated to allow the material an any filament residue to be brushed away.
Unfortunately, today while running the brass brush AROUND AND OVER the nozzle, SPARKS OCCURRED from the mother board case.
As viewed from the printer FRONT the SPARKS were generally LOW and LEFT from inside the box.
So, it’s obvious the wire bristle shorted the hot end wire to the metal hot end causing this SPARK and failure of the system.
There is NOW a MINTEMP error and the HOT END temperature on the LCD reads 0.
Does anybody have GUESSES on what to look for or possibly what has failed?
The printer still moves using octoprint but of course will not print or access ANY other menus.
Thank you for ANY information you may have to help me REPAIR the printer.
Kevin Dudley
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
if you're lucky, the hotend thermistor is gone and to be replaced.
I'm not an expert. Ma parlo anche italiano 😉
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
Have you checked the 5amp fuses on de Einsy board.
Maybe you got lucky and the fuse saved your board. I have read on the forums that some fried their board cleaning like this.
I do it like that too, but you really should power the printer off after heating and before cleaning.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
If the one of the fuses is blown, take out the extruder thermistor plug and the extruder heater plug from the board. One of these can have a short, and should be checked.
If the fuses are OK. Take out the extruder thermistor plug and plug the heatbed thermistor in its place. Don't plug in the extruder thermistor for now. (you don't want to plug in a broken thermistor and maybe do more damage to other parts of the board)
When you power on the printer now, does the heatend temp show a reasonable value now? If it does your extruder thermister is broken and needs to be replace. If it still shows 0 it looks like you board is broken.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
@baklin
Pretty sure it got the board.
Fuses, good, thermistor good.
Just ordered a board. Also ordered a new hotend for safety.
If other is "all good" then I'll have spares.
Fortunately I'm print farming so "cost of doing business" but I hate it anyhow!
Thanks for the responses, much appreciated!
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
Throw that brass wire brush back in your tool bag and print yourself a felt brush handle and get yourself some felt floor protector dots. The felt does a great job cleaning the lacquer off of the nozzle.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
@dan-rogers
Sounds like a good plan.
Thanks!
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
And never, ever, clean the printer with the power on! Heat it up, switch off the power then clean. Brass brushes are good for cleaning nozzles and hotends, used them myself.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
Hope all is okay but I find it odd you need to clean so often. It's not something I ever think about with my MK3S
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
@3delight
I thought the hot end needed to "cool by the fan" when turned off to prevent heat creep and clogging?
I thought it problematic to not allow the hot end to properly cool on shutdown.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
A few of us had this problem. Lesson learned.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
I suspect you only clean the nozzle for a couple of seconds, so heating up and turning off the power, cleaning the hot end, and restoring the power immediately does not usually cause heat creep.
and heat creep, if it does happen, heat creep is easier and cheaper to correct, than a board replacement
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
Glad I saw this thread and the linked thread from @5D-concepts.
i regularly clean the nozzle with a brass brush while the nozzle is heating. I didn’t realize the risk this poses. I think I’m not going to do that anymore!
Thanks to all who shared their experiences and for posting a viable work-around if the worst does happen.
Always learn something new here. Much obliged.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
You can also buy similar brushes but with nylon bristles. These work just as well. The short stroke time used for removing stuff is not enough to melt them and its electrically safe.
Or the field expedient option is to cut some 1 inch wide strips of corrugated cardboard from an old box and use the edge of those to scrub the nozzle. Works surprisingly well and is free.
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
@neophyl - Thank you for the tips, good info to have!
RE: Prusa MK3S SPARKS from controller case while cleaning nozzle. Printer now down!
Very sensible advice about never cleaning the nozzle with the power on. Careless of me, I never thought of it until now.
In my case, I installed time ago a silicone sock, so no real chances of shorting the wires with a brass brush, only the tip of the nozzle is exposed. All the same, I’ll keep that in mind : Power off-Clean-Power on. Better safe than sorry.
Anyway, I think that pliers (thin and long nosed ) are he best way to remove filament from the nozzle. No need in most cases to scrub with a brush. I use the pliers when a print has just finished and the filament is still soft. I use them too before the mesh bed leveling starts, if I see a brim of filament dripping from the nozzle.