[JMay]

Interesting article on the Geekdetour webpage.

https://geekdetour.com/3d-printing/blobs...e-problem/

For those of us using SD cards in the printer to print from, then by default most printers will periodically dump information during printing back on to the SD card. Depending on a number of factors, i.e. the model complexity, printer processing power, SD card write times etc, the printer can actually pause in printing and allow a blob to form on the part. This was noticeable on complex bodyshells where a random blob would appear every few layers.

   

Adding the G code from the GeekDetour website, to the Start G code (for Cura, select printer then Machine settings and cut & paste the code in)

   
Added code in red box turns off the write cycle.

Here is another body after doing this and the blobs are gone.

   

Enjoy
John.

[Savage GT]

Although power loss recovery might be something you don't want to turn off. 
Especially if you live in a rural area where short power drops are not uncommon ... ie where I live !

[Kevan]

I'm fairly sure the Prusa printers have that option on the machine itself.

[JMay]

This mod is a coin toss, weighing up the recovery in the event of power failure or print quality. My view is that 9 times out of 10 on thin walled objects i.e. bodies then the print is ruined by having the head ooze filament over the wall and then freeze in position when the power goes out.

Conversely printing large objects with low detail and thick walls (i.e. I made large brackets using a 1mm nozzle for an external light) is recoverable so turning recovery back on is desirable. You can have multiple printers in Cura so one can be with recovery the other with it switched off and these then be selected from the printer box at the top left of the screen.

More recent printers do have this as a menu option so can be selected on the fly, the Creality CR10S and Mini's that I have do not. 

Cheers
John

[Kevan]

That zitty finish can create a lot of cleaning hassle.

[Kevan]

Hey guess what popped up on Youtube just now....

[MrFlippant]

Prusa figured out how to keep power panic on without the memory dump problem, I guess. I never turn off that feature, and never get that kind of problem.