<p>I use OctoPrint on an Ubuntu system with a M3D printer.</p>

<p>Midway through a recent print, the filament just stopped extruding although the motor-functions of the printer were proceeding fine. Since then, every print I attempt has trouble extruding proper amounts of filament. It's always not enough. The output is stringy and not cohesive.</p>

<p>I'm thinking there may simply be a clog in the extruder and wondering the safest way to remove it.</p>

<p>The weird thing, though, is that when I use manual control and extrude at, say, 220C, the filament comes out fine.</p>

<p>You can see the raft definitely isn't printing right. Way too little output:</p>

<p><a href="https://i.stack.imgur.com/M4Ih4.png" rel="noreferrer"><img src="https://i.stack.imgur.com/M4Ih4.png" alt="enter image description here"></a></p>

As noted in the answer to the other question you asked, the Flux Delta steel plate bed will handle multiple layers of glue. The determining factor regarding this particular printer and specific glue is how many ripples, bumps and/or lines you are willing to tolerate on the first layer of your prints.
You'll notice that a print made with a couple layers of glue, freshly applied, will have a relatively smooth surface. Peel off the model, apply glue over the now-cleared areas, and you've created a slightly-less-than-smooth surface for your next model.
I've found that I can apply six to ten layers before the ripples become objectionable.