A3S V1 - Must Tighten Screw for Leveling Position 1 to the Maximum Amount, and Z Degreasing

poikilos

I have community firmware for board and for LCD.

Problems I can solve myself (probably)

1. I plan to tune the drivers, but print quality is usually excellent after using the "baby-" feature of the community board firmware and LCD firmware. I got the printer from eBay AS-IS, and after a long time I realized that the z stop connector was not connected. It may have been pulled out due to all of the cables being loose inside, but I'm not sure why they were loose. The printer was returned to a store. I re-routed the wires and fastened the wire tie-downs. I plan to get improved wiring to the stepper motor and add a drag chain, with PTFE tube to make it move better as recommended--If you know the length of drag chain to get such as on Amazon, let me know (I asked JGAURORA tech support just now). I plan to eliminate the need for babying by using mesh leveling. If you have any concerns about the above, let me know. I hope I haven't damaged or pushed my z stop sensor downward by jamming it so many times!

2. I assume the better bearings (linked from https://jgaurorawiki.com/essentials) work on my version of the A3S, so I plan to replace the stock bearings.

The problems that remain:

3. For the rear left (position 1 for leveling), I have to tighten the screw all the way down--the other 3 seem to level fine. The bed is slightly bowed upward in the middle, but I suppose I can tighten the other 3 then use mesh leveling to compensate for that purposeful extra tweak downward. However, I cannot get the rear left one any lower. It is tightened as much as I possibly can tighten it just to make paper fit between it and the bed. The bed assembly is seated in the gantry as tightly as possible. Are there any concerns, or should I just leave it and do the above (make others extra low then use mesh leveling)? Should I get a shorter spring and live with it?

4. As I said, I plan to tune the drivers. After running the z up and down many times, it started moving smoothly, but I'll replace the gummy grease (it stutters occasionally, and on jogging only if moving in 10mm increments--it seemed to start after changing to community firmware). I have wax&grease remover but it will be really messy using brushes or paper towels in place (I don't plan to disassemble)--I can try rags or old socks. If you have any tips for removing the stock grease let me know.

poikilos

This problem is apparently solved.
1. The Z stop sensor is working fine apparently (see #3 below for real solution)
2. The stock bearings are working fine apparently (see #4 below for solving biggest issue).
3. The used 3D printer was missing the (4) 4mm screws that attach the gantry to the main body. Adding them fixed the problem adjusting the rear left corner being so different. I found 4 of these screws on an old HP dc7900sff, since that is the size of bolt used for mounting a monitor (you could also find them on some old monitors if the stand is screwed on, but they are usually clipped in a proprietary way from the factory), though they are a bit long and I plan to replace them so they don't interfere with the (moving) wires going to the bed.
4. Tuning the stepper drivers made the Z axis movement sound and work much better, such as when jogging by 10mm. It was difficult, but using a mini flat head screwdriver helped me see how far I was turning the adjustment screw (drawing lines on a ceramic screwdriver would be safer though).

My version of A3S: V5 maybe V6 according to https://jgaurorawiki.com/a5/info since there is no drag chain and y axis support was 3D printed; but filament sensor was broken off entirely so I don't know if that means it was the unreliable kind that would indicate it is a V5.

The first layer is looking really good now. See also https://jgmakerforum.com/discussion/931/a3s-v1-air-prints-from-z-at-which-temperature-is-set-unless-g28-home-extruder-is-added-manually#latest

For degreasing, I got some brushes from the dollar store and cut them smaller. I got a baby bottle brush for getting in holes and cleaning/dishwashing brush for the rod. I talked to a mechanic: I will use the automotive degreaser a.k.a. metal prep (he also recommends laquer thinner) and then I decided I'll spray some tar remover spray for touch-up since the grease is so thick (he recommends "gum off" spray from an automotive store such as NAPA for touch up after scrubbing). I got an oil drip pan from an automotive supply store (NAPA) as well. :edit: Use skin and eye protection and adequate ventilation (and respirator rated for the chemicals) when using chemicals.