I was hoping for a miracle cure; but, unfortunately this wasn't it. The PLA spit out a very long stream of filament that was long enough to make 3 or 4 coils on the print table. Neither of the clogged ABS cartridges fared as well. I think I know the reason why.
First, let's take a look at the print jet housing on each of the ABS cartridges.
|Filament Guide Separation
Eric Albert sent me an image that gives us a clue.
|Filament Block Taken From Print Jet Tip
In this case, the PURGE function is not going to have much chance of unclogging this particular tip since there is filament blocking the path that is not going to be heated.
My early conclusion is that we can probably predict the efficacy of PURGE by first taking a look at the filament guide as it enters the print jet housing. I'd still try it; but, wouldn't hold much hope for a miracle cure.
On the other hand, if we catch a clog by being alert for that dreaded clicking sound, we may be able to avoid a total backup like we see above. In these case, I think we are going to have very good results with purge.
I'll keep testing it. I certainly have some good test cases. An d, I'll let you know the results. At least we now have a shot of recovering a mildly clogged cartridge. And, that is a step forward.