My nozzle just crashed into the bed for no reason  

Re: My nozzle just crashed into the bed for no reason

This has happened to me as well.

Re: My nozzle just crashed into the bed for no reason

Not sure what is happening, but in the short time I've had mine, I too damaged the bed. 100% my fault (power cable got lodged in x-axis).

You would think if the x-axis got bound up, the z-axis cal is OK. NOT TRUE. After the x-axis got stuck, z-axis right was out of alignment, didn't see it and then the damage, mine's a large scar 12mm long.

Still works OK, just need to avoid the scar when slicing.

So now, if any element of the motors X, Y or Z binds up, unexpectedly runs into limit (slider error?) or anything weird, I do a Z reset / cal by running the head all the way up to limit until the motors starts to slip. This aligns the to Z motors (I'm thinking may the root issue for me) then I do a Z cal.

No issues after implementing this protocol (so far).

Replacing the PEI is easy (assuming similar to TAZ5). They said I could buy a replacement sheet for about 10$US.
I gonna "let the new wear off" and just avoid the damage when printing. After I get all the bugs worked out, I'll replace / repair mine.

Happy Printing

Jim

Re: My nozzle just crashed into the bed for no reason

Don't worry too much about these dings on the PEI surface. I have several little craters like that and an inch-long gouge right in the center of the print bed. It causes a slight obtrusion on the bottom of the prints, but other that, that there is no visible impact on prints, so it's really not a big problem. I know it's not nice to see damage to your expensive new printer, but it's like a scratch on a new car, it'll happen eventually so don't stress over it.

Re: My nozzle just crashed into the bed for no reason

I too have a situation like David, although my scratch is near to the front left of the bed.

Again, it does not affect the adhesion and there are only very small marks on the first layer.

Peter

Re: My nozzle just crashed into the bed for no reason

I have that too but it's not causing any issues. I stopped calibrating "hot" though to avoid this if it should happen again. If you go that route make sure the nozzle is clean when calibrating so you don't have any loose filament between nozzle and bed.

Re: My nozzle just crashed into the bed for no reason

Martin

There is a problem calibrating cold - the bed is not heated/expanded so after heating the nozzle gap will be too small and id there is a piece of plastic on the nozzle it will hit the bed and again be incorrectly calibrated.

Peter

Re: My nozzle just crashed into the bed for no reason

Martin

There is a problem calibrating cold - the bed is not heated/expanded so after heating the nozzle gap will be too small and id there is a piece of plastic on the nozzle it will hit the bed and again be incorrectly calibrated.

Peter

Huh, I haven't noticed those issues at all. I make sure there's no filament on the nozzle before I calibrate but I'm doing the calibration while heating the bed and it's been good so far.

Re: My nozzle just crashed into the bed for no reason

Hi guys, thanks for your feedbacks.

I don't mind having scratches or impacts as long as it is my fault, which is not the case here 👿

Still don't know what happened... 😕

By the way, I have a problem with the card reader too, moving the switch on its side doesn't have any effect and the reader is (obviously) stuck into "read only" position. I had to use my camera SD card which can only be a temporary solution.

I am half happy with this purchase. The printer seems to print pretty well (when it does not crush into the printing bed 😀 ), but I preferred to buy from the official prusa shop rather than from Aliexpress in order to get a good after sale service and so far, I have not been truly impressed by how these issues are handled. 😐

Re: My nozzle just crashed into the bed for no reason

Hi Sylvain

Have you ever tried to buy from AliExpress? It's rather hit and miss (mostly miss for me...). Believe me when I say that you really don't want a Chinese clone printer. I have one (it cost half the price of the Mk2 "original") and it does actually manage to print 3D objects.

But that's about as far as it goes. No support, no spares, poor print quality, relatively small build size. Worst of all it requires maintenance after every print.

I do think that you will appreciate your "original" when it starts to really work for you.

Yes, there are a few niggles and minor issues, but the guys at Prusa Research do listen and they do address problems. This is a new printer that has only been on the market for a few weeks; there will be issues. Now I have learned to use the printer it is running like a dream with no failed prints, no maintenance and superb results.

Peter

Re: My nozzle just crashed into the bed for no reason

Hi,

I just faced quite an annoying issue with my MK2 printer and I would like to share it with you.

I started a print as I always do, but before I started, I used the "stop print" option as I wanted to check something.

The printer still started its calibration process but after checking the first point, it just ignored the following ones and crashed into the bed...

Then, I started the print once again and everything went fine....
.

One piece of advice ive learned from experiance (on my mk1's and 2)

instead of using the stop print option, just use the reset button (the X button) this stops any motion and immediately. And resets the printer. When you use the stop print command in the menu, it will continue running any commands that are still in the buffer (this can be a few seconds worth) , this may have been why the Z kept going down (cant be sure im no expert)

Using the reset button doesn't do any harm to the machine at all, and will stop all movement immediately.