One of the essential steps to learn to do is to make the printer's bed, the surface prints are made on, both level so that the movement of the print head either in X or Y is always perpendicular to the Z axis (up down). The movement in a 3D printer is different from that in a CNC mill. The printer head is mounted to the X-axis, and the Z axis moves the X-axis up and down. The Y axis moves the print bed forward and backward in the frame. I can see why they do it this way, it's just... different from what I'm used to.
The system controller is that little box on the right. It has a nice little LCD, but it takes some getting used to. I'm used to a 17" LCD monitor on a PC so much more information can be displayed and the keyboard allows more input options than the little knob at the bottom of the box. On my PC, in whatever CNC program I'm using I can do immediate commands, like type "G01 Z2.00 F35"; which is telling it to move the Z axis to 2.00 inches (could be up or down depending on where it starts from) and go at 35 inches per minute. On this little box, I scroll through menu selections, find "Move", find Z, spin the knob to 2.0 and click the little knob inward. Say I send the mill to 2" but I wanted it at 3" instead. I can hit a key that gets that entire command back, change the 2 to 3 and hit return. On this box, I go back to Z and then crank from 0 to 3 instead of 2 to 3. A minor thing, but their user interface could be easier to use.
The print bed is that horizontal surface down around the bottom of the clear space in the printer's frame. If you look at the front (closest to the camera), on the right, just below that print bed and above the blue knob, you'll see a large disk-like object. That's the adjustment to level the front right side of the bed. The one for the left front is visible below the left corner of the bed but it's a crowded image. There are two identical such knobs in the back. There is not an overall adjustment, say in the middle of the bed to lift the whole thing up and down. On You Tube, you'll find at least a dozen videos on leveling a print bed; I ended up preferring this one. Like learning to fall off a bike, you'll get lots of practice doing this.
In that post 10 days ago, I mentioned learning to use a slicer program and described how it's the equivalent to CAM software for a printer. After reviewing another handful of videos and websites, I decided to use the Cura slicer software by a printer manufacturer called Ultimaker. They give away a home version of the software and charge for business use. I found it relatively easy to use, but it still does some things that surprise me. Here's a look at Cura's interface with a test design in it.
Conceptually, leveling the bed is like tramming a mill, except I get the implication it has to be done regularly, while tramming is likely good for a long time. The file in Cura is from that video channel I linked to before and the idea is you test your printer by printing a few passes around in that file. You lightly rub the filament with a fingertip (the printer bed is 50C, or about 125F - hot but you're not really leaving your finger on it). This is a pass on my printer this afternoon.
On the lower right side you can see some gaps in the print. It's my understanding that's from having the print head just a little too close to the bed and the fact it's in the front right says to lower that a little. I did that and it did get better but I'm a bit cautious about chasing that around the system. More tests are definitely coming. I don't really understand how I could have two areas of thin printing, extending most of the way across in X, in two different places in Y, given how everything is adjusted.
While studying up on this printer, I find that one of the features some higher end printers are starting to come with is auto leveling. This guy shows how to add it to my printer. The system is called BLTouch, and it doesn't mess with those adjustment knobs, it does the correction in software. The system measures the offset of the printer from level around the bed and then adjusts the extruder height during the print. Given my years of designing control loops, this appeals to me, and adding this to the printer for about $50 sounds good.
All this said, I haven't printed anything useful yet. I had a little adapter for an experiment I want to try on my Webster engine that I designed and ported over to Cura to slice. That's ready to print and Cura says it will take 12 minutes. It might even print properly, since it's a small thing, 1-1/2 by 1/2" and 1/8" thick.