Orion PLA Tips

[brbubba]

Any tips on printing with PLA this puppy? I blew through my free ABS spool and have 5lbs of PLA I'm trying to use. Right now I'm trying to print a custom spool holder extender, to fit the 5 lbs spool (Unfortunately can't print a new modified spool holder as it's bigger than the bed). The prints are looking quite nice in every respect except when it's doing a fillet and it starts to curl around the edges. The part still completes just fine but the fillet area looks like crud. Do I just need to get a fan on this thing or is there something else too?

EDIT: Attached the STL file as the latest prototype is working great. That back large fillet is what's causing issues, the top large fillet also seems to have a little curling. Final parts are functional, just not nearly as good as ABS was.

[jmpreuss]

I am still struggling a bit myself with PLA on the Orion. I believe all Orions come with a Peek fan, which is mandatory for PLA printing. You also need cooling fans for small PLA parts or it will turn to mush. My preproduction Orion has a set of accessory wires in the wire bundle so it was easy for me to wire in some fans. I used this design by partdaddy http://repables.com/r/142/ I used two fans wired in parallel as was recommended to me.

So now cooling is fine, still having an issue with inconsistent extrusion (though I haven't had a ton of time lately to puzzle this out, might be something simple I need to change.)

[geneb]

The curling is often caused by the PLA retaining heat for too long. A layer fan is highly recommended. Until you get one, you might try backing off your printing speed a bit.

jmpreuss: what extrusion temp are you using?

g.

[jmpreuss]

jmpreuss: what extrusion temp are you using?

g.

Probably not high enough. Been at 190 for PLA, next attempts will push that up a bit to see if that is the simple fix (I tend to start conservative with temps with PLA, rather jam than burn). As I mentioned I have been a bit busy lately, I just need a day to play around to get to know the machine.

[PartDaddy]

For PLA, I like 0.24mm layer height, using a fixed extrusion width in Slic3r advanced settings, at 200C, bed at 60C, part cooling fan on, cooling auto with min speed of about 5mm/s, and a top print speed of 30mm/s. See http://forum.seemecnc.com/viewtopic.php ... it=owl+2.4 for the large owl print. I share all the setting I used to make it.

Also remember that not all filament is created equal. Different manufacturers may use different resins (resin is what you call the plastic pellets). And different grades of plastic resin will give different results. Many times you're stuck with experimenting to find the right speed/temperature,layer height,etc.

Prep the glass build surface properly. What works for me is cleaning with dish detergent (soapy water) until squeaky clean. While the glass is room temperature, apply a thin layer of glue stick. Wait about a minute, then apply another thin coat at 90 degrees (make a hatched pattern). DONT's: Don't cake it on. Don't apply it hot. The prints never stick when I've apply glue stick to the glass while hot. Don't touch the build surface with your finger when removing a print. The oils from your skin will cause the next part not to stick. A properly prepared glass build surface will yield many prints without apply more.

[brbubba]

Thanks for the tips. Slowing it down to 10 mm/s seems to help a bit, but I think I'm going to need the fan.

Printed out partdaddy's fan and the fit is a bit tight. I used support material but I'm wondering if it sagged a bit as it won't fit. When I have some more time I'll have to figure something out.

[brbubba]

Uploaded the bracket extender to repables. Only issue now is how do you edit it? I accidentally didn't include the word "extender" at the end. doh.

[johnoly99]

brbubba,

i know he's working on making your 'repables' editable, coming soon i hear

[brbubba]

Odd, I did the helical gear set last night and the gears didn't fit, otherwise it printed perfectly. The same thing on ABS fit without any issues... Is it possible that the PLA is shrinking, I thought it was less prone to shrinkage than ABS. Meh, this will take some further exploration.

[Nylocke]

It may be due to the ABS shrinkage that it fits with ABS and not PLA.... Also ABS has a bit more give than PLA and maybe thats playing a part?

[brbubba]

It may be due to the ABS shrinkage that it fits with ABS and not PLA.... Also ABS has a bit more give than PLA and maybe thats playing a part?

Doh, didn't think of that. The part could have been designed for ABS taking into account the shrinkage. Therefore trying to make it with PLA could have thrown the tolerances out of whack. So much to play around with, so little time...

[Nylocke]

I think ABS part shrinkage is about 5% or so... you could scale the part down by 5% or something like thus....

[brbubba]

I think ABS part shrinkage is about 5% or so... you could scale the part down by 5% or something like thus....

I doubled the part size and it worked just fine. Still not sure why the smaller PLA vs ABS worked or didn't work, maybe it had something to do with my PLA settings.

[cope413]

ABS doesn't shrink 5%. It's closer to 1-2% - which is more than enough to cause parts to not fit together correctly, but unless your part has uniform thickness and infill throughout, the shrinkage will not be consistent throughout the part.

maybe it had something to do with my PLA settings.

That's the most likely cause...

[Nylocke]

That did seem a bit excessive, maybe I was told .5%, I dunno