I reckon i can strip down a flashforge mk8 extruder with my eyes closed.

Stick some flexible filament in there and print it just a smidge faster than it wants and it will wrap itself round the extruder and jam.
And the only way out is to take it apart and remove the filament.

I've finally had enough - lol
By rights if setup correctly the ff should be able to print flexibles almost as fast as rigids.

Bought some cheap flexible pla this week. And I have to say it's pretty impressive stuff. Maybe a tad stiffer than polyflex and at least as strong. £22 a KILO ! and comes in lots of colours. So a proper polyflex killer. I keep asking polymaker to mak more colours of polyflex and they just offer to make me a custom bulk batch up. Which isn't the point at all :-)

I started a print off with the sienoc stuff, the same settings I use for esun flexible pla. Started great, got about 4 or 5 layers in before I started to hear that dreaded clicking noise.
Turns out the sienoc is a smidgen less firm than the esun. Not enough for a human being to tell, but clearly enough to jam an extruder !

Now sebastien told me he'd just inserted a short length of ptfe tubing and that had sorted his problems out.
For that you have to drill out the current feed holes to fit the tubing and then insert from top and bottom till there is no gap between the top and bottom of the bolt and bearing.

I don't want to drill my original extruder - just yet.
So currently I'm printing out this: https://www.thingiverse.com/thing:169086
On Alexa - the ff is in bits.
I'm hoping this will work with the existing metal parts, if not I'll go the drill and tube route.

I do have the extruder from the right side (which currently only boasts a plastic print of a stepper motor) as a backup if i bollox this up.

More later