jamming and puff balls

[guitp]

Something is going wrong in my prints and I would welcome suggestions.

I am getting nozzle jams. Resolved them with a blow torch (brass nozzle was glowing red, the stuff inside was on flames).

Using "natural" color ABS, I now get rusty brown layers, esp. the first few layers. And greater inaccuracy - the first few layers seem a bit more squished.

During the early layers, "puff balls" of ABS appear on the surface of the print. After a while, one of these balls blocks the nozzle and prevents any extrusion from happening (I think). See photo.

Any tests I should run?


Details about what has changed since I used to get non-burnt looking prints:

- For various reasons, I haven't used my Orion Delta for over a year. To me, it seems that the ABS is "more brittle" than I seem to remember it being.

- I switched from manual levelling and Repetier to MC. I have "automatically" configured the levelling several times with MC, 7 positions.

- I have up'ed the temps - 235 nozzle, 110 bed.

- I'm using 123D to create .STL files.

- Layer height 0.2mm (0.5mm nozzle).

Thanks in advance for any ideas
pt

[barry99705]

Looks like your filament isn't dry. It's making abs popcorn when the moisture hits the hotend.

[plasma]

Also it looks like your z-height is too close to the bed. If possible measure the first layer with calipers to tune up your first layer. With regards to puff balls you should try drying the filament in the oven to get rid of the moisture.

[guitp]

Thanks! I would never have guessed that it was moisture instead of lack of moisture. (Probably explains the snap/crackle/pops I was hearing). I'm reading up on how to dry ABS...

I'm still fairly new at this - any pointers on the z-height testing? I seemed to have had the machine set up nicely a year or more ago, using the manual levelling procedures. Now, I'm using MC auto-levelling and am not sure if I'm getting that right.

[barry99705]

Thanks! I would never have guessed that it was moisture instead of lack of moisture. (Probably explains the snap/crackle/pops I was hearing). I'm reading up on how to dry ABS...

I'm still fairly new at this - any pointers on the z-height testing? I seemed to have had the machine set up nicely a year or more ago, using the manual levelling procedures. Now, I'm using MC auto-levelling and am not sure if I'm getting that right.

Do you still have the leveling macro in mattercontrol from Gene's build manual? If so, just run it and see if the hot end is about the same level all the way around.

[guitp]

Yes, I still have towers.gco (and the instructions).

I'm not sure about the interaction with MC, though. If I do a manual leveling, should I turn off "automatic print leveling" in MC's options>>hardware settings? Or, should I do auto leveling after I've done manual? Somewhere in the instructions for auto, I remember seeing that Z must be able to go below the glass on an Orion Delta, to get auto to work with it.

[mhackney]

The rusty brown is copper. By heating the brass nozzle that high, the copper has migrated out to the surface. It will eventually wear away. Much better to use an acetone soak to remove ABS jams or CAREFUL heating and a toothpick to pry stuff out the back.

[barry99705]

Yes, I still have towers.gco (and the instructions).

I'm not sure about the interaction with MC, though. If I do a manual leveling, should I turn off "automatic print leveling" in MC's options>>hardware settings? Or, should I do auto leveling after I've done manual? Somewhere in the instructions for auto, I remember seeing that Z must be able to go below the glass on an Orion Delta, to get auto to work with it.

Don't know, I've never used the auto print leveling. I just run the macro and get it close as my eyes can get.