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bdocs84
(@bdocs84)
Active Member
Crash detected mk3s

I've run out of ideas what to try here.. just bought a new mk3s got it setup passes the calibration no issues. But regardless what I try printing, after a random period it'll stop and say crash detected. I've tried several of the default provided models, and printed them multiple times, it'll stop at different times.

So far what I've tried:

-FW is updated to 3.8.0-2684

-belt status x257 y272

-made sure there was some grease on the x/y/z, everything does move freely

-loosened the back plate on the extruder (the part holding the bearings), and redone the tie wraps to make sure they weren't tight

-tried to slow the print speed down to 60%

-the last print failure says crash x 5

-I tried to disable crash detect, that definitely didn't help

I'm out of ideas what is causing this or what else to try, if it's something I've missed or did, or if I recieved a defective device?

Any help would be great! Thanks.

 

Posted : 25/09/2019 11:44 pm
rmm200
(@rmm200)
Noble Member
RE: Crash detected mk3s

Kit or prebuilt?

Turn power off and manually move X and Y in both directions. Is it smooth or do you feel binding?

Watch from behind. Are cables or zip ties anywhere they can be hit?

Grease on the rods is not what is needed. You need grease inside the bearing, and the bearing shields keep it there.

Never put grease or oil on the threaded rods. They must be clean, or you damage (dissolve) the Delrin nuts.

Posted : 26/09/2019 12:17 am
bdocs84
(@bdocs84)
Active Member
Topic starter answered:
RE: Crash detected mk3s

@robert-rmm200

Hey Robert, it was the kit I purchased.

With the system off/unplugged moving the bed and gantry they do move full motion without any binding. I'll try taking the bearings off and try adding grease to the inside see if it rides any smoother after that. You're correct adding grease to the rail was pointless it was all cleared off to the sides in a pile.
As far as clearance the zip ties do clear the bed or any of the sides.

Oddly the Z when first built would not go the full height and kept failing during the caibration, greasing the screw rods fixed that issue. But it's good to know it should not be on there though, don't recall seeing anything about that in the manual.

Posted : 26/09/2019 1:45 am
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(@)
Illustrious Member
RE: Crash detected mk3s

PINDA should be 0.8 to 1.2 mm higher than the nozzle. Yours looks really low in that last photo. You may want to measure the clearance, just to be sure.

Posted : 26/09/2019 8:23 am
rmm200
(@rmm200)
Noble Member
RE: Crash detected mk3s

And now that you have the oil / grease off the threaded rods - loosen the screws in the Delrin nuts.

Move Z  bottom to top a couple of times.

Tighten the Delrin screws again. This helps them center themselves. May help with any Z problems.

Delrin is much like Teflon. It wears in. My cross threaded nut fixed itself with a little use. And twisting.

Posted : 26/09/2019 3:15 pm
bdocs84
(@bdocs84)
Active Member
Topic starter answered:
RE: Crash detected mk3s

Yup took the z apart to remove as much grease as I could from the screw and the delrin nuts (that wasn't fun, lesson learned). I've moved it up and down the z a few times before tightening the delrins again.

The pinda to bed height is 1.11mm

At no point during the print does the pinda, nozzle or anything hit, at a completely random point in the print it just stops saying the crash detected

This post was modified 5 years ago by bdocs84
Posted : 27/09/2019 12:42 am
rmm200
(@rmm200)
Noble Member
RE: Crash detected mk3s

At least your printer is in better shape now than it was...

Something is giving a resistance bump in Z travel. Some cable hitting something...

One thing we have not tried is raising the Z motor dust covers a bit. They should not touch the motors.

Posted : 27/09/2019 4:44 pm
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(@)
Illustrious Member
RE: Crash detected mk3s

When it crashes, what does the LCD report for current print?

 

ps: 

This post was modified 5 years ago by --
Posted : 27/09/2019 9:30 pm
bdocs84
(@bdocs84)
Active Member
Topic starter answered:
RE: Crash detected mk3s

Tim I'd agree 100% that does look low.. not sure why at that angle it looks so low. But I triple checked that.

That's a better shot.

I did move the covers up a bit, initially I did have them far too low

.

The fail status for the last print says power fail 0, failam runout 0, crash x 5 (this is usually under 10) y 0. When it does fail, it will home again and retry to print, but when it tries to home the z after it gets to the last y position it will keep looping the homing,  but won't even try to continue past that z home and goes back to crash detected and if I want to continue.

Well this is interesting, one suggest I seen in the book was to try disable to crash detect... This is the result of that. Definitely looks like it's an x axis issue

Posted : 28/09/2019 12:39 am
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(@)
Illustrious Member
RE: Crash detected mk3s

So the crash is X, not related to Z.

Usually, this is dry bearings or a crushed bearings.  X should slide side to side with absolutely NO friction, stickiness, or snags from stop to stop.

If you tilt the printer, the extruder should slide from the uphill side to the downhill side as you approach 45 degrees.  

Another test is to look at the mislabeled "Belt Tension" numbers on the LCD.  Anything below 250 is problematic and shows very high friction.  I worry about numbers below 260, since a lot of people with X crashes have numbers below 260. 

The MK3s extruder housing has been known to crush the bearings if screwed tightly together. Especially self printed parts. Loosening the screws near the bearings a quarter to half turn is usually enough to relax the fit and free up motion.

 

Posted : 28/09/2019 6:29 pm
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(@)
Illustrious Member
RE: Crash detected mk3s

After rereading everything - post a photo of the entire printer, front, side and read views.  That last image of the frog being condensed into a 1/8" bar is a sure sign your X axis is snagging, probably something is hitting, or your X belt drive gear is loose, and when it does catch, it flags a crash. A loose gear can also explain why the slowest part of the print seems to work, but fast moves derails it.

Posted : 28/09/2019 10:07 pm
bdocs84
(@bdocs84)
Active Member
Topic starter answered:
RE: Crash detected mk3s

Hello again Tim, thanks again for all the help.

I've check the belts again to verify they were a bit tighter, unfortunately still crashes.

I tried the tilt test, it does seem to move free, however a few random times it did stop at a random spot. I could try take the x apart and add a bit of grease to the bearing, just to make sure

Posted : 29/09/2019 3:42 pm
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(@)
Illustrious Member
RE: Crash detected mk3s

The four views look reasonable enough, but the video is most telling.  Whatever that cable is dangling off the side of the printer extruder looks like it can easily snag on the bed and cause the problem you are having; and the cable tie looks like it will also limit X range. I'd completely remove the extras and try again.

This post was modified 5 years ago 3 times by --
Posted : 29/09/2019 6:53 pm
bdocs84
(@bdocs84)
Active Member
Topic starter answered:
RE: Crash detected mk3s

In the clips the thing dangling from the extruder or on the left of the x rails is the belt.. I removed it partially so see how it slid without the belt hindering it. it slid smoothy but did stop randomly every few slides I did, the belt while sliding didn't catch when it stopped.

I have an odd feeling the bearings are where the problem might be, not sure how easy this will be but I'll try swap the z bearing with the x and see if the x moves better or if then the z starts having an issue.

Posted : 29/09/2019 7:16 pm
rmm200
(@rmm200)
Noble Member
RE: Crash detected mk3s

When you have the bearings in your hand - clean and grease them. No telling when you will get another shot.

Posted : 29/09/2019 10:06 pm
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