3d printing - what is the purpose of filament guides and should I print one?

[2DPrinter]

What is the purpose of having a filament guide? I am not talking about a book guide to filaments or anything, I mean one of those 3d printed things with a hole in it that helps feed your filament. Example: https://www.thingiverse.com/thing:1764285
What can happen if you don't have on of these? Filament jams or something??

And should I print one? I am not having any issues relating to this, just looking for printer upgrades for my Monoprice Select Mini Pro and came across someone with one of these. 

[Hackentosher]

So these often help straighten the path the filament has to take to get to the extruder. They also increase the bend radius it has to take. These adjustments together make it easier for the extruder to pull the filament. It may prevent a snag, but unless your filament has to take a crazy path from spool to extruder, it's probably not necessary.

[2DPrinter]

Just now, Hackentosher said:

So these often help straighten the path the filament has to take to get to the extruder. They also increase the bend radius it has to take. These adjustments together make it easier for the extruder to pull the filament. It may prevent a snag, but unless your filament has to take a crazy path from spool to extruder, it's probably not necessary.

Cool thanks. Increasing the bend radius, is that a good thing or bad thing? Or does bend radius even matter? 

[manikyath]

just helps the fillament not get snagged up on things. 

[trag1c]

12 minutes ago, 2DPrinter said:

Cool thanks. Increasing the bend radius, is that a good thing or bad thing? Or does bend radius even matter? 

Think of it this way. The larger the bend radius the closer it is to a straight line. The smaller the radius the more likely you are to damage the filament as it is being pulled into the extruder. It's also easier to pull off of a reel if your pulling straight from the reel rather than trying to tightly arc it over something else.

[Hackentosher]

16 minutes ago, 2DPrinter said:

Cool thanks. Increasing the bend radius, is that a good thing or bad thing? Or does bend radius even matter? 

Lol that's just technical speak for making the filament not turn as tight. The shallower the turn the easier it'll be to pull.