Wow super fast reply, thanks I appreciate the help! I finally printed my first error-free ABS model last night, after upping my VREF to about 1V for both the X and Y axes.
1. Although I’ve got a fan blowing directly on the A4988s, I’m planning on buying some DRV8825 drivers soon to help improve movement. 32nd stepping should make designs twice as accurate as 16th steps right? Also, I’m using 20t pulleys and I might move down to 16t for better performance, but I don’t think they are the reason I was missing steps.
2. A helpful note for people like me who couldn’t find 1.25″ bolts for the middle assembly bearings: You can use 1.5″ bolts however they will scrape up against the plastic when tightened and bend inward, creating a Vulcan death grip on the conduit pipe. I’ve found it’s better to leave them a little loose (or just use proper sizes).
3. I might’ve found another culprit for those skipped steps: lack of speed bearings. I couldn’t find any in local stores and decided to loosen the fender washers to help the belt bearings slide better, however this causes the roller motor mounts to wiggle at higher speeds and potentially jump over belt teeth. After tightening them down, the bearings might not move as freely but it’ll keep the motors and belts from bouncing around.
TL;DR Note to self (and others with skipped steps): Don’t skimp on the parts! Use what’s listed, follow the guide, and the hardware should work nicely.