Build plate adhesion on my gMax 2.0 w/ heated bed

#1
Having a strange issue with bed adhesion. Z height is perfect in some places, but in quite a few very small places it will not stick or the build plate has a high spot and nothing extrudes. Have a Heated build plate. these spots are about 3-4 mm wide or square. In most bed leveling setups I have seen there is a Fade Height adjustment. I can not seem to find one on my gMax 2.0
 
#2
follow the steps to level the bed again and use ABS and acetone combo , i was having the same issue and thought my bed was off but once i had the bed leveled with this glue like mixture im getting great prints. i use rubbing alcohol on top of the surface and let it sit for a while so that i can remove any other chemicals and dirt that may have been on my bed. once after i wipe off the alcohol and use the abs acetone mix on the bed.
 
#3
I find it also helps to level the bed *while the bed is hot* - this means the measures are taken while any thermal expansion has already taken place.

Also, I tend to print my first layer 150% or thicker, which especially seems to help when doing layers only .1mm thick.
 
#4
I am printing at a .8mm nozzle and .32 layer heights. I Also always level the bed with the bed hot. I know that it is a common mistake made. Thank you both for the suggestions. I think I figured out what the problem was.


As it turns out the build plate cracked while removing a print one day. Custom ordered a piece of Borosilicate (spelling?...) glass and a Geckotek Hot build adhesive pad. Build adhesion no longer a problem, unless you want to consider having a hard time getting it off a problem. I had to drop heated bed temp down to 50C. Was still having issues with bed leveling though. Seemed like random spots on the buildplate had High a low spots that the Printer was not compensating for. Not that I blame it, the spots were very small. what gave me a clue though was that they were close to the same places as the previous buildplate had them. That is when I noticed that the hardware for the build plate frame to carriage were hitting the bottom of the Heat pad pushing against the glass. Took spare washers from removing the feet of the printer and put 2 under each side of the screws for the build plate clips and tightened gingerly as to not stress the glass. I can easily tell if my Z axis needs leveling now.

there were a few other quirks that the printer had that I also resolved, but I am not stressing over them as this is a Hand built Machine that was pieced together in house with some great parts and it printed excellently out of the box.

The issue I am having now is I seem to be getting heat creep up the nozzle.... When I retract and make long distance moves over the model and it Starts a new layer. I get a gap at the begging of the layer. Only after a long move as the nozzle has time to ooze...

I have lowered nozzle temps, Sped the acceleration up, slowed it down.., Increased and Decreased jerk...., Increased Retraction prime amount, Slowed the printing speed down to 15mm/s.... Nothing seems to help. I either get a huge zit from to much reatraction prime amount or a gap...