Print Head doesn't seem to be descending to the Bed

[WizarDru]

I have a Printrbot Simple Metal. Recently I purchased the heated bed upgrade and last week I purchased SImplify3D. I think it's great, but I'm still in the dialing-in phase of the software and printer.

A problem I seem to be having is bed adhesion, which I used to have working. Earlier this week I printed the '3DBenchy' tugboat in PLA. It had some errors, but those seemed like settings issue. The next day after that, I couldn't get the printhead to get homed on the Z-axis correctly, despite not even closing Simplify3D or changing the Process. I recalibrated and rehomed the Z-axis, but it doesn't seem to be getting closer to the printbed, despite my changing the G-code for the Z-axis to go lower. Is there some limitation that prevents it from getting closer than a certain point?

I'm afraid of setting it TOO close, but I'm having a hard time figuring out how close it should get. When I home Z, it's close enough that it almost catches a piece of paper, but it's still loose beneath it. I believe my bed is level.

Any suggestions?

[CompoundCarl]

All of the options you can use are outlined here: https://www.simplify3d.com/support/prin ... to-the-bed

[WizarDru]

Thanks, I'd seen those. The real problem is identifying WHICH one of this is the correct problem.

To wit: I can't tell if the print-head is close enough or too close, likewise if the temperature of the extruder or the bed is either too hot or not hot enough.

My main confusion has been figuring out why my prints have become so unstable since I added a heated bed. I change the G-Code off-set, but it seems like the extruder isn't actually getting closer to the bed.

One thing I try, for example, is to home the Z-axis on the bed and then use the jog controls to lower the head. It lowers, but I can't get it to go past a certain point. Since I can still slide a piece of paper underneath it, I don't know if that is something with Simplify3D, the sensor, the printrbot or something else.

I'm going to try and work with it again tonight. If I could just get the settings dialed in, I think it would work great. When I attempted to switch back to Cura just to compare I realized exactly how good Simplify3D is.

[CompoundCarl]

It's usually pretty easy to tell if the nozzle is too close or too far away. Either no plastic is coming out because the nozzle is too close and there is no space, or the plastic is extruding but doesn't stick to the bed since it's too far. There's good pictures in that link I posted that should also help you identify the problem.

Or if you want to post some pictures of the first layer being printed, perhaps others could also provide feedback.

But it's really common to need to make slight adjustments to the first layer positioning, so if you plan on doing more 3D printing, it's probably a good skill to learn

[WizarDru]

Oh, I've learned it. A LOT. I guess I didn't expect that I'd need to keep recalibrating the Z-axis over and over again.

The real issue for me is that there seem to be a dozen different factors that can screw up first layer adhesion and I'll have to bull through until I figure out which one I screwed up THIS time.

In this case, it turned out to be an issue of both the Z-axis needing to be rehomed AGAIN and temperature settings.