Thinking About Getting a 3D Printer

The biggest changes I made to my machine were

• MicroSwiss direct-drive conversion + hot end - this is tagged for the Ender3 but is compatible with the V2 if you also replace the cooling block (which I did)
• Cut all the wires leading to the tool-head and solder in JST/Deans connectors
• Self-printed 5015 Satsana cooling block with BLTouch bracket (This is not the exact model I printed, I have the STL file on an old hard drive though). Mainly upgrades the part-cooling fan to a 5015 turbine style fan with two nozzles. I ran a cooling block with TWO 5015 fans for a while, but it was absolutely overkill. One is a big upgrade from the stock 4010 blower fan, and more than enough.
• BLTouch Z-Probe (open box clearance rack item at MicroCenter)
• MRiscoC "Professional Firmware" - Lets you do a lot of advanced bed leveling and calibration procedures which aren't available in the stock firmware. Allows you to tune speed/acceleration/jerk to much more extreme settings if you're willing to spend time tuning it. Allows you to tune "linear advance," which is especially useful for flexible materials like TPU. It adds a PID temperature control algorithm for the hot end and bed. It also adds support for some more advanced G-Codes, so certain motions like "Z-hops" can be adjusted on the machine without being baked into the G-Code.
• Magnetic textured (not smooth) PEI build surface (absolutely fucking fantastic). Sticks reliably while warm and completely releases by itself when cool, without needing to chisel and pry your prints off the plate (thus, preserving your bed leveling). Stick can be restored periodically by washing with dish soap. Allegedly TPU will permanently fuse to PEI, but in my experience, the textured surface allows it to release. The same sheet works for PLA, TPU, PET, and (kinda) ABS. Mine is Creality branded, but the brand isn't very important. If you get one of these soft/flexible build surfaces, you PROBABLY want a Z-probe, because these things are never as flat as the glass/steel plates.
• Stiffer springs and fancy knobs - you can find a million listings for items like this on Amazon / AliExpress / wherever. The stiffer springs reduce drift in your bed leveling, and provide better support for large prints. The knobs were purely for vanity and not necessary.

A lot of wear and tear components have been replaced along the way (nozzles, wheels, pneumatic couplers). Before I deleted the bowden tube, I replaced the stock one with a Blue Capricorn tube (tigter tolerances, much stronger couplers - the stock couplers inevitably break, especially the one attached to the extruder). Also, the cooling fan now has pro gamer RGB lighting.

This isn't the order I installed these parts in. I generally replaced things as they broke. Switched firmware pretty early, got a really shitty flexible magnetic plate and started doing mesh leveling with a piece of paper very early by necessity. Eventually got the BLTouch, then I went trough a couple custom cooling blocks before doing the direct-drive conversion and soldering.

When I did the direct drive conversion and replaced all the wheels, I ended up taking enough of the machine apart that I basically gave it a full tune-up as I was putting it back together, and now it remains level for months at a time. I don't print nearly as often as I used to, but when I do I can just start it up, run the tramming procedure out of habit (automated by the custom firmware), and typically not have to make any adjustments before printing.

This thing still struggles with ABS (it has no enclosure), but prints PLA and TPU faster than any of the commercial 3D printers at my job, and does PETG... competently.

I also recommend playing around with different nozzles. If you don't need extreme detail, a 0.6mm nozzle can lay down thicker layers and infills than the standard 0.4mm nozzles, making prints quicker (and stronger). I even ran 0.8mm for a while to print several LARGE parts for a hydroponics system, though here you will begin to hit the limits of how quickly a stock/drop-in replacement hot end can melt the plastic.