FolgerTech Kossel 2020 Printing above build plate

I'm wondering if anyone can assist me with the problem I'm having with my Folgertech Kossel. I've followed instructions to the letter, everything runs and moves around as it should, but when it comes time to print its always above the plate. I did some separate testing in PronterFace and i found that after the G28, and G29 codes are executed no matter where on the plate i try to go down to 0 for the Z axis I'm always about 5-7mm too high. I've messed with the Z Probe Offset and a couple other variables but i keep getting the same results.

Is there something fundamental that I'm missing and just not seeing?

Any help is immensely appreciated, I've spent lots of time on this one, and i still can't figure it out...

After the initial G28, when you brought the tip down to the plate and read the position, did you remember to subtract it's value for the Z max in Configuration.h? If so, a G1 Z0 F1000 should put the tip at the surface of the plate . . . If not, don't proceed to setting up probe offset and such, you need to get this right first. And regarding the instructions, I did the procedure once and it worked, so the doc is good as written (although I have yet to screw with auto level - I get decent prints with just a G28, G1 Z5 F4000, and run . . .

- Tim

Hi Tim,
I have gotten the Kossel setup to where it does come down all the way to the build plate with the G1 Z0 command by modifying the Z_Max as you stated, Although i have not tried printing without having first setup auto-level. What i find strange is even when I'm changing Z_Probe offset anywhere from -1.4 to -5.2, i'm not seeing any changes as to the distance from the nozzle to the bed after executing G28 then G29. To be clear, after executing G28, and G29 and then doing a G1 Z0, that's when i begin to be too high off the build plate, where if i were to not run G29 command I'm able to come down to the build plate all the way.

When the Z probe activates, and you check M119 (or is it M114?) what value do you see for Z at that point?

I have to admit, I didn't bother setting up auto level on the old Marlin that Folger supplied - I jumped to the 1.0.3 tree, and the height has been good (I just have some problems getting it to compile with the needed Y offset value, but that is a different issue. I'd go downrev and test, but am 30 mins into a 9 hour print which I need ASAP, so can't stop to test at the moment . . .

Can you post your Configuration.h file, or at least the mechanical/auto level part of it?

- Tim

Edited 1 time(s). Last edit at 05/14/2015 05:01PM by tadawson.

When the Z Probe gets activated the Z value that i see is 5.2 which then in turn i set Z_PROBE_OFFSET to -5.2, is that the correct way of doing things?


-Samuel

Looks good from here . . . I wonder if the offset somehow got set in your EEPROM? Perhaps try M502 and M500 to reset defaults . . .

Hopefully someone who has set this up with the Folger supplied Marlin version will jump in as well . . .

- Tim

Tried M502 and M500 before homing and running G29 yet i still have Z0 above the bed by about 5mm. Am i supposed to run M502 and M500 before or after G29?

So I've got it all figured out now, everything is running as intended (running Marlin 1.0.3 dev)....... But now the extruder cant push the filament through, apparently there are a bunch of metal shavings that are lodged inside the heatsink piece that the heater block mounts to. I've knocked some it out with a RC metal push rod, but i can't get an angle on the last bit. I didn't see this earlier since i was "printing" without filament.

Edited 1 time(s). Last edit at 05/15/2015 02:19PM by websuser.

Out of curiosity, what was the solution? 1.0.3-dev?

- Tim

Edited 1 time(s). Last edit at 05/16/2015 02:12PM by tadawson.

I simply flashed 1.0.3 dev, kept settings pretty much the same, i just re-calibrated and it worked.

I finally unclogged the extruder and was able to print last night, although some fine-tuning needs to be done because the 1x1x1 centimeter cube i printed was off by a bit in each axis.

Any good places to check out for fine-tuning? i see there are differing methods as to how to do it.