Auto level weird problem

First the stats.
Marlin
Ramps
Pronterface
Boro Silicate heated glass bed
ATX Power

I installed bed leveling using a micro switch and servo. Before the install I got really good prints, but had to level bed after about 2 or 3 prints using a paper shim. Hence, auto bed leveling.

All seems to work well. Everything homes as it should and then does it's bed leveling thing. I use 2 points. The numbers come up as I would expect. I can also see the z axis compensating for the bed tilt.

The only thing after G29 is a G0 E25 to prime the extruder. The other thing I don't have is the G90?? to set to absolute coordinates. Should I have that??

The weird part. A small part, say 30mm x 30mm does OK. But, on one that uses say 150mm of the x axis the left side does fine, but the right side is too low. The skirt on the right side is mashed out much flatter that the left and the when printing the part the nozzle pushes the previous layer and also leaves "blobs" here and there. The left side prints fine.

Leveling is fine on the printer itself and on the x axis. It's just got me stumped. This is not random. It happens on every print.

Does anyone have any suggestions?? I need help here. I am at the end of my knowledge base.

Thanks for any replies.

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes

probe more points on the bed, 2 is probably not enough

Thanks for your response.
It actually probes 4 points, Marlin is set to 2. I have tried 3, which is actually 9 probes with no success. Same result.

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes

Make sure to run g28 and then g29 when your bed is up to temp.

Sounds like your print surface is not completely flat, maybe a little bow to it or something or one corner doops. I have the same trouble. The bed leveling feature can only compensate for a completely flat plane, it doesnt compensate for a print surface that has a bulge in the middle for example. This is why its really pointless to probe more than 3 or 4 points.

Edited 1 time(s). Last edit at 04/18/2015 08:57PM by GITRDUN.

krwynn and GITRDUN. Thanks for your replies.
G28 is always run first then G29. As to the bed flatness, using a machinists straight edge I can see no light anywhere I place it. Don't have a setup to dial it yet, but may have to make one.

Thanks again. I've moved back to the 2014 pronterface. Seems a little better. Don't know what that has to do with it, BUT ?????????

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes

Agravation!! When I start a print I have to force the left Z motor down about 3 steps and the right up about 3 to 4 steps. Then all prints beautiful. But, it is agravating to have to do this. No start and walk away. When I do another print I have to do the same thing.

Anymore thoughts??

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes

You know, it's like the matrix is being put in reversed from left to right! What would cause that??

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes

Well, it's not backwards. I just tilted the bed a lot. It is following along right, but still about 3 steps high left and 3 low right.

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes

Are you sure you set the x and y offset correctly? paying attention about the sign?

Victorjung-Ummmmm? Not sure,but I'll check it soon.

---

Not such a NEWBEE anymore
Thanks,

Bob Keyes