Workhorse Bed is not level after bed levelling

Hi All, I am very new to 3DPrint. I have a Workhorse, purchased back in November. The only mod is that I added a Build Tack mat and then adjusted the offset on Marlin.

I THINK that there is a problem with levelling the bed. In some areas of the bed, parts have a “smooshed” first layer, and when I watch that layer go down the material is almost non-existent, extremely thin (This is the front of the bed)

At the back of the bed, the first layer is thick and I have adhesion issues. Please see the image below. This was a failed test print… two cubes, one in the front left corner and one at the back left. The cube at the back left pulled away halfway through and killed the print. But you can see the differences in initial layers.

Any ideas on how to deal with this? I get no errors from the bed levelling process.

EDIT: OK, I just watched it do the levelling 2X… when it does the second contact with 3 out of 4 of the corners, it’s a very light contact, almost imperceptable.

When it contacts the left-front corner, instead of a light touch, it’s pressing the whole plate down a couple mm. So if it “thinks” this corner is lower, it’s going to press further into the plate.

What could be causing this? If the left front is not electrically connected, will it not error?

EDIT2: OK, I did some significant cleaning of the contact pad and the nozzle, and the levelling procedure looked much better. Re-running my test routine and we’ll see how it goes.

Zojo I’m having a similar problem. I’m having warping issues and I don’t know why (I’m Using Polylite PLA). I notices the same anomaly when the printer calibration proses starts on the first contact point. I thing the problem could be related to the Z offset. What’s your current Z offset (Mine is -1.05)?

If the nozzle noticeably deflects a corner of the bed during the leveling process, either that corner or the nozzle is dirty enough that electrical contact could not be made. Clean the corners with Isopropyl Alcohol and/or a Scotch-Brite pad. A very light sanding with 600+ grit sand paper (I use a 3200 grit pad very, very, lightly).

The nozzle should be heated to the high end of the last used filament’s range and then carefully (i.e. don’t burn yourself) cleaned with a non-conducting tool such as a Scotch-Brite pad. If you wish to use a conducting tool such as a brass wire brush, TURN THE POWER OFF after heating the nozzle. Failure to do so could damage the electronics.

If the software you use to connect to the printer allows, use its console feature to manually execute a G28 followed by a G29 V4 which will print out the raw Z values at each corner.

Enter “G29 V4” in this forum’s search for a list of topics with more information.

I went ahead and really cleaned it all up… and now there is no deflection during levelling. But there is still a very intense difference between 1st layers printed at the center and corners.

Lulzbot have asked me to remove my build tak mat and to try on the bare plate. I’ll give that a shot and respond.

Thanks for the tip ! worked perfectly… Have another question… I’m having constant warping on my parts with polylite PLA. What could be causing this ?

PLA generally doesn’t have warping issues. For ABS (which does have warping issues), the solution has to do with controlling the environment (i.e. an enclosure for the printer). If your printer is located in a very drafty or cold environment, you may need an enclosure for printing PLA.

Without any additional information, that’s the only thing I can think of. Pictures and a description of your environment might help.

I’m planning on getting some kind of enclosure. The problem is that my house tends to be really hot… Around 28 to 33 degrees Celsius. Could this be a problem ?

For as much as ABS loves heat, PLA loves cooling. Try adding an additional fan blowing across the bed. Leave it off for the first layer or two and then let 'er rip.

Strange as it may sound another member on here just mentioned that their part cooling fans were blowing backwards because they were somehow installed that way. Wouldnt hurt to just verify that your fans are blowing ON the part and sucking from the outside.
Strange you are having warping issues with PLA though. Is your PLA dry? Are you sure its warping and not just layer adhesion issues?

I had similar issues with the 1st layer being inconsistent across the bed area, documented here: Z offset irregularities across the build surface - General / LulzBot TAZ - Lulzbot

Ultimately I gave up on the printer. Personally I would not buy a printer without mesh leveling with some kind of sensor, which is a common feature on printers nowadays. I spent a huge amount of time coming to this conclusion, and I hope I can save someone else time, money and frustration.

Your hot end is likely gummed up with plastic preventing a solid zero. see: