[Kevan]

I've been printing with CF-PETG for a year and love it, prints nice, is rigid and grinds and files easy and takes a M2 tap without a hitch.

I've started using the roll of Prusament PLA that came with the printer, it's silver and looks great and prints nicely but as I found out yesterday is a swine to tap a hole in...as the PLA seems to weld together again and ultimately snapped my M2 tap trying to remove it...the 1.6mm drill for the next hole welded in also and required destruction of a body post to free the drill.

PETG is somewhere in between.

I've not tried any other filament, have any of you guys tried PC or ABS?

[JMay]

Filaments vary widely in performance and quality from brand to brand and type to type and sometimes from batch to batch. Historically I have used PLA mainly, and currently using the EONO brand which is a good all rounder for chassis' and bodies for under £20. 

I have dabbled with ABS using Sunlu and Aystkiniet brands which I found OK for making chassis and wheels but some issue with thin wall body shells delaminating or warping or both. Building a booth to contain the printer along with pre-heating the bed to warm the whole booth helped but couldn't rely on it 100%. ABS I found will take a M2 thread to secure wheels if you treat it like soft aluminum, where as PLA works OK for grub screw axle travel stops but not effective for wheel holding grubs screws as you cannot apply sufficient force to the grub screw to secure the wheel from rotating. 

Recently as shown elsewhere been using the Ziro carbon fibre loaded PLA filament which is better than the ABS for bodyshells as tougher and doesn't warp/delaminate on thin sections and makes very rigid lightweight push fit front wheels for racing. I haven't tried putting a thread in it yet so will give that go. 

PETG have used to make guides and rear wings where there are thin sections and it needs to be flexible without snapping. PETG though suffers from stringing which means a lot more post processing to remove the stringing which is a pain.

One thing I have found, is that adjusting the printed hole diameter in 0.02mm steps for M2 threads helps to dial in the best performing thread and you need to repeat this process for each type of filament as the shrinkage varies. 

Cheers
               JMay.

[Bazzer]

I've been printing with CF-PETG for a year and love it, prints nice, is rigid and grinds and files easy and takes a M2 tap without a hitch.

I've started using the roll of Prusament PLA that came with the printer, it's silver and looks great and prints nicely but as I found out yesterday is a swine to tap a hole in...as the PLA seems to weld together again and ultimately snapped my M2 tap trying to remove it...the 1.6mm drill for the next hole welded in also and required destruction of a body post to free the drill.

PETG is somewhere in between.

I've not tried any other filament, have any of you guys tried PC or ABS?

Kevan

I get good tapped threads at M3 size in the Protopasta CF PLA, using that as aileron torque rod arms on 130mph RC aircraft.

B.

[MrFlippant]

I generally just leave a hole undersize and let the screw do the work.

[Kevan]

...PETG though suffers from stringing which means a lot more post processing to remove the stringing which is a pain.

Have you tried playing with retraction settings?  I like PETG, great layer bonding and tough as old boots prints but as you say needs post processing.