Help on PETG print surface.  

RE: Help on PETG print surface.

Looks like filament dripping off the heater block. Worst case, you have a leak due to incorrect hotend assembly. More likely, it's just some filament oozing when the nozzle is heating up. Use needle nosed pliers or tweezers to remove any filament that's oozing while the nozzle is heating up after mesh bed leveling. PETG is more likely to ooze than PLA, plus it likes to curl up to the nozzle, so you also want to use a soft wire brush to clean the nozzle and the bottom surface of the heater block (just don't shorten out the thermistor).

RE:

Okay I take back everything I said. I just realized this is the inside of a cylinder. For some rest I thought it was the bottom layer. That's what you get for not having enough coffee before you look at posts. These zits are quite common with PETG. Some brands seem more prone than others. Make sure the filament has been dried thoroughly. 

RE: Help on PETG print surface.

Haha no worries! My bad for not mentioning.

this filament is brand new actually just open.

RE: Help on PETG print surface.

That may not be enough. You don't know how long it's been sitting on a shelf with a distributor. Not saying that humidity is necessarily the root cause but my first stab would be drying. 

RE: Help on PETG print surface.

Posted by: @fuchsr

Looks like filament dripping off the heater block. Worst case, you have a leak due to incorrect hotend assembly. More likely, it's just some filament oozing when the nozzle is heating up. Use needle nosed pliers or tweezers to remove any filament that's oozing while the nozzle is heating up after mesh bed leveling. PETG is more likely to ooze than PLA, plus it likes to curl up to the nozzle, so you also want to use a soft wire brush to clean the nozzle and the bottom surface of the heater block (just don't shorten out the thermistor).

Going through things in my head, how would you shorten out the thermistor? Isn’t everything insulated?

RE:

Going through things in my head, how would you shorten out the thermistor? Isn’t everything insulated?

There have been reports of shorting the thermistor or heater wires to the heatblock when cleaning the nozzle with a wire brush. Too often this has resulted in a fried component on the Einsy board.

Search the forum for instances. Use extreme caution if you use a brass or other metal wire brush to clean the hotend.

Cheers

RE: Help on PETG print surface.

You can also use something like this https://www.printables.com/model/69467-nozzle-brush-no-supports-or-bridging-needed    

It's good for the quick swipe between prints but every now and then you'll need the wire brush. 

RE: Help on PETG print surface.

I have been using just a small piece of maroon scotch brite pad.

RE: Help on PETG print surface.

So stupid question, do you have the nozzle at temp when using those furniture pads?

Posted by: @fuchsr

You can also use something like this https://www.printables.com/model/69467-nozzle-brush-no-supports-or-bridging-needed    

It's good for the quick swipe between prints but every now and then you'll need the wire brush. 

RE: Help on PETG print surface.

Not a stupid question at all! Yes, to have to clean the nozzle at temperature, so the filament can come off. The felt will indeed begin to melt after a while. Make sure you work quickly and just give the nozzle a couple of rubs. But after a while you will have to replace the felt pads.

RE: Help on PETG print surface.

I find it best to clean at a little below print temp, where the plastic is still soft, but it isn't hot enough to ooze.  Generally it's something I try to do after a print finishes and the hotend is starting to cool down.  Between that and using Bobstro's start G-code, I haven't had any issues at all with hanging bits of filament messing up my prints in months.

RE: Help on PETG print surface.

I have taken to using a nylon brush for a couple quick swipes at the nozzle as the hotend is coming up to temp during pre-heat.

I only resort to the brass brush when it’s clear I need to, and then with great care. Once the brass brush starts to get worn and bristles begin sticking out every which way, it’s time for a new brush. 

Cheers

RE: Help on PETG print surface.

The tricky thing is to avoid contacting, or worse, breaking, the small wires connecting the heatblock heater and thermistor.  Those cannot take a joke!

Having said that, since I've had the machine I regularly brush off the tip of the nozzle with a soft brass (not steel) brush, yes, particularly when using PETg, as that filament tends to be quite oozy.

I am always very careful to contact the nozzle only and not the associated wiring of the heatblock.

RE: Help on PETG print surface.

I am always very careful to contact the nozzle only and not the associated wiring of the heatblock

This… and a new(ish) brass brush with no stray bristles to wander off and wreak havoc.

RE: Help on PETG print surface.

For the new guys in the room (like me) are you referring to this start-up G-code?

I had to research it to find it, but man am I glad I did!

Posted by: @netpackrat

I find it best to clean at a little below print temp, where the plastic is still soft, but it isn't hot enough to ooze.  Generally it's something I try to do after a print finishes and the hotend is starting to cool down.  Between that and using Bobstro's start G-code, I haven't had any issues at all with hanging bits of filament messing up my prints in months.

RE: Help on PETG print surface.

Yes, a lot of us use this or a variant of it. 

RE: Help on PETG print surface.

That's the one.