breakaway ooze wrecks auto-level

[jones007 1]

I'm not sure if this issue has been addressed before - if so, perhaps someone can point me toward the appropriate thread. I have an older u3 and a couple of S5s, and the S5s have been driving me crazy with auto-level failures due to ooze on breakaway support material. The U3 suffers from a similar problem, but it is easily remedied by carefully cleaning the tip with the breakaway material before active leveling begins. On the S5, no amount of cleaning fixes the problem. Here's what is happening:

 

• The printer is ready for a new print, either still warm from the previous print, or completely cooled after a rest period.
• I make sure both nozzles are clean.
• I start a job with a build material plus breakaway support.
• The S5 starts to heat the nozzles and build plate. As the nozzle with breakaway material heats, some material oozes from the nozzle. I clear it.
• It moves the head to the back right and appears to try to squish any material on both nozzles on the build plate.
• It then re zeros x,y and then goes through the leveling for nozzle 1. As it does this, breakaway material starts to ooze out of nozzle 2.
• It re zeros x,y then switches nozzle 2 to the down position. By now there is a glob of breakaway material that has oozed out of nozzle 2 and cooled.
• It hits the 3 level check points, but incorrectly measures the depth of nozzle 2 due to the cooled glob.
• It then starts the print, but the breakaway material is emitted too far from the build plate and does not stick.
• A short time later I check to see if the print is working and discover a huge rats nest of breakaway material floating around the build plate.
• I abort the print after screaming some profanity at the printer and repeat.
• After about 3 or 4 tries at this, apparently the nozzle has oozed enough and the print succeeds.
• This entire sequence requires about 30 to 45 minutes of babysitting the printer to make sure the jobs actually start correctly.

[Adri-an 1]

I can confirm the issue @jones007 mentioned, I have EXACTLY the same problems with our UM S5 right now, driving me cazy. 
From my point of view the bed leveling process on the S5 does the following:

1. heat bed
2. heat core1 and core2
3. z-level core1at one point, switch to core2 and z-level core2 at the same point
4. switch to core1 and "scan" the whole bed. During that (time consuming) process, core2 cools down.
5. switch to back (to cooled down) core2 and measure 3 points of the bed.
6. start print.

The issue: at 5.) the bed is beeing measured by a material blob on core2 that can't be pressed flat (like at 2.)) and you can cancel the print --> error distance between core1 & 2 sizing that materialblob.

 

So now my question: How can let UM S5 keep core 2 heated during the whole leveling or better: heat it once again before measuring the 3 point of the bed?! 

Thanks in advance for quick reply, I practically can't use the S5 right now at all.  
 

[Sk7500 2]

I have the same problem with my S5. I've been having some success with flipping the support to nozzle 1 and material to nozzle 2. Hope this helps.

 

I totally understand the frustration of spending hours watching as print after print is unusable.

[Super_paulie 10]

years later, but the only way i can get a successful print due to the above issue is inbetween jobs i heat up the nozzle to 250 and let the remaining filament "ooze" out of the nozzle. After maybe 2 minutes i wipe the nozzle and then send the print. It works almost all of the of the time, its just tedious. If i dont do the above then its almost a 100% chance the job will fail at the bed leveling stage followed by the frustration and anger at this stupid machine.