Creality Extruder Idler Tensioner Arm, Ender 3, CR10 (modified)

This is based on the Github stp file here https://github.com/Creality3DPrinting/Ender-3/tree/master/Ender-3%20Mechanical/STP for the extruder idler arm, so that it is able to work without setting in a thread and only using stock screws, with the option for a piece of PTFE bowden tube which I used.

There are two files:

The first file is 4mmidlertensioner_fixed.stl , this now has a smaller 4mm hole which means you can screw straight into it with both the screw from the bearing and the screw to hold it onto the motor which was already initially fine for this.

The second file, which is the one I printed and am using, is idlertensionerptfe_fixed.stl . It’s the same as the first file apart from the larger filament hole which is now 4.4mm so that a piece of 4mm PTFE/Bowden tube can fit straight into it (this is the same as the stock tube, and I just cut a bit of the stock spare that came with my printer), which means the filament goes through easier and also shouldn’t wear a groove.

Another small thing I did on both files is to make the part that protrudes out and fits into the spring a little longer just to make things a bit easier.

The reason I made these is because I had the common issue of filament wearing a groove into the stock extruder over time, and I was getting filament snapping and grinding because of it. The files provided on the Github page also didn’t just allow the bearing screw to be screwed in but would have required a thread to be heat set into it (you could do this with the stock one but it’s risky and you’ll end up breaking the original arm, which is bad if anything goes wrong with this), and I added the PTFE file because I didn’t want to have to drill into it afterwards.

I would also always recommend having a spare one of these arms around (as is the case with all parts) in case it breaks, whether you use the one I’ve modified or any other.