Part splits in the middle of printing

[apostoly]

My first print using KISSlicer seemed like it was going great will printing the Tool Tray designed for the Max V2. Even with the splits in the part, it is the best quality i have probably seen in any of my prints. Ill just attach the photos which will show the issue clearly. I do know that my printer on Y side going up towards X tends to print a little high, even though i have each tower dialed in the the exact same spot. The rafting i notice actually became unstuck on the right hand side of the print which is where the first small split occurred, then over time it grew and others followed. So looking at these pictures, would you say the little corner of the the raft unsticking from the plate would have caused this?

[img]http://i1110.photobucket.com/albums/h451/apostoly1/Mobile%20Uploads/IMG_20140614_160720.jpg[/img]
[img]http://i1110.photobucket.com/albums/h451/apostoly1/Mobile%20Uploads/IMG_20140614_160739.jpg[/img]
[img]http://i1110.photobucket.com/albums/h451/apostoly1/Mobile%20Uploads/IMG_20140614_191738.jpg[/img]
[img]http://i1110.photobucket.com/albums/h451/apostoly1/Mobile%20Uploads/IMG_20140614_191754.jpg[/img]
[img]http://i1110.photobucket.com/albums/h451/apostoly1/Mobile%20Uploads/IMG_20140614_191801.jpg[/img]
[img]http://i1110.photobucket.com/albums/h451/apostoly1/Mobile%20Uploads/IMG_20140614_214344.jpg[/img]

[bdjohns1]

I've had a beast of a time getting larger thin-walled parts to stay together as well. I designed an iPhone landscape charging cradle to put my phone on a bedside table and use as my clock, and it's got a big thin wall like that. Keeping your build area enclosed and warm will help (apparently, >70C is the place to be), but even that's no guarantee.

I'm starting to become more of a fan of PET filament for stuff like this - it's a bit more expensive, but it has similar mechanical qualities to ABS except for not shrinking appreciably. I haven't tried it yet, but apparently you can acetone-smooth it. The stuff I have is from MadeSolid - printing at 250C with the bed at 70C seemed to work well.

[apostoly]

I've had a beast of a time getting larger thin-walled parts to stay together as well. I designed an iPhone landscape charging cradle to put my phone on a bedside table and use as my clock, and it's got a big thin wall like that. Keeping your build area enclosed and warm will help (apparently, >70C is the place to be), but even that's no guarantee.

I'm starting to become more of a fan of PET filament for stuff like this - it's a bit more expensive, but it has similar mechanical qualities to ABS except for not shrinking appreciably. I haven't tried it yet, but apparently you can acetone-smooth it. The stuff I have is from MadeSolid - printing at 250C with the bed at 70C seemed to work well.

hmmm. so its a heat issue?
Ill try and wrap the printer with something and give it a go, or maybe try the garbage bag trick even though its ugly as hell haha

Ill need to organise a chamber soon too

[bdjohns1]

I have 3 out of 4 sides walled in with acrylic right now - built a box from OpenBeam. Just need to cut and drill for the holes for the hinges and rig some magnetic catches.

The one thing I'm still thinking about is moving the extruder out of the build volume. 70C is probably not good for the extruder stepper.

[Polygonhell]

Generally the issue with ABS is it needs to be hot enough to bond effectively, and that's usually significantly above the temperature at which it can be extruded. Your forming a weld and the only heat is in the piece you are laying down, so it has to be hot enough to heat the joint enough to form a good bond.
Generally that's in the 245+ range, but verify your thermistor is accurate before you go that high.

[apostoly]

I have 3 out of 4 sides walled in with acrylic right now - built a box from OpenBeam. Just need to cut and drill for the holes for the hinges and rig some magnetic catches.

The one thing I'm still thinking about is moving the extruder out of the build volume. 70C is probably not good for the extruder stepper.

Would you mind taking a photo? the more designs the easier to decide what to actually end up going with and building.

What about placing a heat lamp abver the build plate will printing.. Would that help at all??

Paul

[bdjohns1]

Photos are hidden in plain sight!

http://forum.seemecnc.com/viewtopic.php?f=41&t=4565

[apostoly]

Photos are hidden in plain sight!

http://forum.seemecnc.com/viewtopic.php?f=41&t=4565

Thanks for that, looks awsome!!

I ended up printing another tool tray but changed the orientation and dabbed on some wurth super glue with a ear bud as i saw little cracks appearing

95% better result but still not workable solution for these lenghy prints ... obviously haha

[snoman002]

I think polygonhell hit it, your printing too cold. It can extrude at a low temp (relative temp) but does not have enough heat in it to weld itself to the next layer, hence the splits.

Once you get the splits to stop that stress is going to go onto ripping ng your piece off the build plate, the heated chamber should help there as it will minimize overall shrinking.

[apostoly]

I think polygonhell hit it, your printing too cold. It can extrude at a low temp (relative temp) but does not have enough heat in it to weld itself to the next layer, hence the splits.

Once you get the splits to stop that stress is going to go onto ripping ng your piece off the build plate, the heated chamber should help there as it will minimize overall shrinking.

Hmm ok, not sure how acurate my temps are at them moment, i have a feeling they are way off but i cant really check that at the moment.

I have been printing with the same filament at different temp ranges.. From 210 up to 230

This first tray that split really badly was at 215 and the last one i did which wasn't too bad with the help of glue, was at 225

I just notice that once i start going above 225, the filament seems to be burning and blowing out a burnt smokey smell

Paul

[Polygonhell]

You can print ABS at 250+ without issue, it turns black if you print it too hot, even 230 is cold for ABS.

[apostoly]

You can print ABS at 250+ without issue, it turns black if you print it too hot, even 230 is cold for ABS.

ok so what about the burning smell and visible smoke coming from the tip of the extruder?? is that normal?

[notarat]

You can print ABS at 250+ without issue, it turns black if you print it too hot, even 230 is cold for ABS.

ok so what about the burning smell and visible smoke coming from the tip of the extruder?? is that normal?

I print ABS at 233°C-235°C with a Heated Bed at 95°C-100°C (and PLA at 230°C on my Replicator 2 ) and I see no smoke, but I do get a very minor "smell" when using ABS. It almost sounds like the filament has some contaminants in it. Also remember that the ingredients used to achieve that particular color can change the temperatures required to achieve the same performance as another color. 230°C may be great for Gray ABD from Toy Builders Labs but you may need 235°C-240°C if using Neon Green ABS from Octave (or vice versa)

If I'm printing ABS, I never go below 233°C but I'm pretty certain my temperatures are accurately being reported...

[Polygonhell]

You can print ABS at 250+ without issue, it turns black if you print it too hot, even 230 is cold for ABS.

ok so what about the burning smell and visible smoke coming from the tip of the extruder?? is that normal?

ABS smells somewhat unpleasant when printed, smoke is usually a sign of water or something else in the filament, but you really need to verify your hotend temperatures are being reported accurately, especially if you push the temperatures much higher. It's not unusual for the thermistors to be off by a significant margin.