A possible Ender 3 Pro fillament snapping solution

Having had a Creality Ender 3 Pro for a few years, I had never had a problem with fillament snapping.

One day it decided to snap the fillament, breaking where the extruder stepper-motor pulls it through with the toothed gears, meaning fillament was left in the main boden tube, but not able to push anything to the hot-end.

Tried it again and it worked for maybe another print, but, shortly after it snapped again. This happened near the end of a reel of fillament, and with the start of a new reel of the same.

After a bit of searching I found "mostly disapair". People trying various things including:

• Adjusting the tension of the spring which grips the fillament between the stepper motor. Most of the discussion about this was to increase the strength to help fix under-extrusion. Not relevant to me.
• Trying new reels of fillament (maybe the old one had gotten old and brittle, exposed to high moisture levels, etc) or different brands of fillaments etc. These stories mostly resulted in no success, and given it happened to me with two separate reels, most definitely not the issue in my case.
• Some discussion of stuff jamming up the pipes in extruder motor area - I couldn't find any obvious jams etc

However in playing around, I was checking to see if the fillament would feed smoothly through the extruder-feed assembly. It didn't - if the fillament was coming from above, it was a bit hard to pull through. If I pulled it more in line with the output, much better.

One of many possible solutions

Just move the fillament reel to have a smoother feed-in angle.

I had the holder for the fillament mounted on top of the frame. I think the instructions said to put it there, and that's where it is on most images of the printer (including Creality's website)

However, the fillament has to turn about 90 degrees from here. I had printed a little adapter to help guide it in, which I'm not sure did much.

A much simpler solution is just to mount the holder on the vertical pole, like this:

So far, this seems to be working - I've done a bunch of prints with no snappage.

Quite why this only started being a problem, I don't know - maybe the angle has always been "almost too much", and as the printer has gotten older and more used the friction has pushed things over the threshold.

Update (Aug 2021)

This simple change did appear to help - however I still had some snapping problems sporadically.

However I think a major part of the problem was:

1. The snap at the end of the old reel of FlashForge fillament was possibly a coincidence - maybe something jammed (or maybe I am mis-remembering and it ocurred after I changed fillament?). I had used many reels of FlashForge fillament without issue.
2. The new reel of fillament was a brand I had never used ("Comgrow"), bought as an experiment as it was the cheapest one available on Amazon AU.

There was likely some form of problem with the new Comgrow reel. It started off fine, but after a few prints it started snapping in very unsual places - a print would complete, then the next day the fillament would snap halfway between the extruder and the reel! Maybe like there was some twist building up in the fillament as it unspooled

To complicate things: for various reasons I changed the extruded to a "Direct Drive" extruder. This didn't make any change to that Comgrow fillament.

I ordered another reel of the FlashForge branded fillament and since then I've had no issues since.

So: I'm not too sure moving the reel to the side helped - it definitely didn't make things worse, but the whole issue might just be "bad fillamant is bad"!