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SoliForum - 3D Printing Community → Solidoodle Discussion → spliting ABS work
big or small it splits,
should I :
-slow down the machine
- put a fan on the work while its being made?
any ideas?
here is a video.
I have an SD3 with heated bed, running a glass bed on mine over my heated bed.
195*C on extruder
bed is at about 95-100*C
thankyou,
Ryan .
Did you enclose the machine?
Did you enclose the machine?
no not yet
will that fix this for sure?
is there a thread somewhere on how to enclose the machine nicely?
http://reprap.org/wiki/Print_Troublesho … oo_Cold_01
Bookmark above.
on this note what does the fan on the extruder head do?
People do all kinds of random things to enclose. I used cardboard at first till i had time to scope out some cheap plexiglass. Some use magnets, some use weather stripping. I used painters tape and weather stripping. Just search for case mods. There are lots of links.
As far as i know the fan is for cooling when layer times are really short. If you print small things and the layers go on to fast it gets all gel like and out of whack.
As far as i know the fan is for cooling when layer times are really short. If you print small things and the layers go on to fast it gets all gel like and out of whack.
That is sorta correct for a PRINT Fan - but the EXTRUDER Fan is to cool the Stepper Motor so it doesn't cause the filament to soften and start escaping between the extruder and the drive-cog - at normal operation the stepper can get >50° which can cause the filament to soften and not feed. The fan on the Extruder Stepper should *always* be operating.
The primary reason for a PRINT fan is actually for Bridging, but yes, it also helps on small layers - however adjusting "Cooling" under Slic3r config to slow down print speed to 10-15mm/s if layer time is under 20seconds usually solves the 'small layer melt' issue - but when it gets to really small layers (loops on the top of Yoda's head for example) then yes, a fan really helps.
But the main 'i really need a Print fan' reason is Bridging - both long sections, and wide sections...
Anyway - to the OP:
The reason ABS splits often is too rapid a cool down causing uneven contraction across the model. This is also why 'tall' prints in unenclosed environments can cause splitting as the top contracts relative to the bottom.
To solve it can be any one of the following, or a combination depending on circumstances
- Lower you print bed temps (yes, it makes a big difference 5°)...
- Ensure there is no open windows or other 'cross-ventilation' occuring - moving air will rapidly cool the part...
- Enclose the printer
- Don't just turn the heatbed off - ramp it down (this is why I like ceramic - it does this naturally, where as glass and alu just dump their heat very quickly)...
- lower the heatbed to 70°, let the part soak for a bit, then remove it.
Ultimately - the more of an equilibrium you can achieve across the entire part, the less cracking, warping or splitting you'll experience....
thankyou for all the help
this is so great that people are actually helping.
a lot of forums love to read stuff but never feel the need to help when asked.
thankyou again,
hope I can return the favor some day.
Adrian, what is this about lowering the bed temp?
How would that reduce the temp difference? I believe that would increase the temp difference from nozzle to print piece.
Lowers the delta of the base decay rate relative to the mid band of the print relative to the upper print changes. The nozzle to ambient decay rate is a constant vs the delta of bed temp to upper print which is cooling at a different rate to the lower part of the print held at the temp of the bed. If bed is 100, mid print is somewhere between that and ambient, and the freshest layers are at 2.5 times the bed. All of these are changing temp at different rates to one another and different temp curves relative to each other. Given the extruder is a constant, the only other adjustments are lowering bed temp to get it closer to ambient so the delta is smaller, or, increasing ambient to do the same but to the mid band.
Its quite accepted in printer designs that do not allow an easy enclosure....
print still split in one spot.
6hrs of printing left to go.
and I even enclosed it almost fully.
there is a standoff gap at the top enclosure of about a half an inch.
is that corner of the bed maybe too low?
I don't know how to figure out how to modify the federate either.
im printing at .2mm
any ideas now?
I would increase extruder temp as well as that was my issue with adhesion and
had given me similar results
big or small it splits, 195*C on extruder bed is at about 95-100*C
Run the head at 200 (with the starting gcodes for safety), maybe up the extrusion rate if you are going to do finishing later anyway and really want to drive it home. Enclose it with cardboard, reflectix or what have you if you are going big and solid.
Try another brand of filament. Or maybe try natural and spray paint it later so you get all of the stickiness and no dilution. YYMV.
ryan-mm85 wrote:big or small it splits, 195*C on extruder bed is at about 95-100*C
Run the head at 200 (with the starting gcodes for safety), maybe up the extrusion rate if you are going to do finishing later anyway and really want to drive it home. Enclose it with cardboard, reflectix or what have you if you are going big and solid.
Try another brand of filament. Or maybe try natural and spray paint it later so you get all of the stickiness and no dilution. YYMV.
how much should I increase the extrusion rate?
how much should I increase the extrusion rate?
A little at a time, say 10%, so from 100 to 110. Another tip is to find the simplest use case you can to reproduce the problem. Scale it down by 50% and see what happens. Or more, at least then we know what the printer is capable of and if we are just dealing with problems with the materials or the environment.
ryan-mm85 wrote:how much should I increase the extrusion rate?
A little at a time, say 10%, so from 100 to 110. Another tip is to find the simplest use case you can to reproduce the problem. Scale it down by 50% and see what happens. Or more, at least then we know what the printer is capable of and if we are just dealing with problems with the materials or the environment.
wow cant believe I didn't think of that last part. lol
thankyou ill give updates as I get them
thankyou again.
****oh is it flow rate or feed rate I adjust?
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