Getting the basics out of the way…I’m relatively new to 3D printing and this will be my first post so please forgive me when I inevitably do something wrong.
I designed a small gear (internal workings for a vintage turntable) using OnShape and after the print, the piece seems to have a reverse elephant foot thing going on (narrower at the bottom)…it isnt a huge amount but it may impact the ability to mesh the teeth.
Are there any settings I could try to get more square edges?
I hope the following will be enough info, and I can supply more if it will help with troubleshooting:
P1S with AMS, standard PLA (12% humidity), .2mm nozzle, .1mm layer height, random seams, have tried speed of 120mm/s down to 30mm/s
*I have a pic, but cant see a way to attach it to this post
Pretty sure you need to turn on advanced settings to access this. It isn’t turned on in the picture because I have developer mode enabled which does the same thing with a little more features.
Running with @Impeller_Warehouse’s idea currently and for @Bullocks, here is a 3pack image of one of the test prints…hand for scale, profile, bottom surface
Bottom looks like your first layer Z is pretty close to perfect. Additionally, the teeth are getting messy pretty far above the first layer, so elephant foot probably isnt in play.
On super small parts like this it might be a lot of things.
My thoughts:
It looks like it might be curling up on each individual tooth, which might be remedied by less plate temp / nozzle temp, extra fan if not at 100% already, or using a non-textured sheet. Those gears teeth are basically the same area as the speckles in PEI, so like… hmm. Smooth plate (with glue) if you have one?
Try arachne wall generator, it can maybe make those tiny extrusions even tinier…
Pressure advance calibration, but if you said it happened even at 30mm/s this might not be the relevant issue.
Ran the print again with the elephant foot compensation setting and this is the result (didn’t change much), but it did provide more info…according to the new pics, it looks like the teeth are not curling up but just not laying down material.
The pic of the bottom has a small black dot for reference, those teeth seem to be fully formed.
The two side profile pics show one where the edge is more “square” vs the one where the edge looks angled.
**sorry for the quality of the pics…hard to shoot something so tiny up close
OH…the black speckles are coming from a piece of foam I am using to shoot against, it isn’t a print plate (and unfortunately I only have the textured plate…will buy a smooth one eventually)
I’ll give it another try with the arachne wall generator setting…luckily it is a really fast print and takes about 3 cents of material
And thank you for the advice, I appreciate your (and everyone’s) time
You can try to MacGyver a “smooth” area on your textured plate by smushing it with gluestick and evening it out with a wipe. I think it’s telling that some of the teeth seem to retain shape, and some do not, - and the ones that do not, look like they are pulling up. If you’re available to be bored to death, it might be interesting to visually watch it as the first layer goes down. Make note if the teethies are adhered after layer 1 finishes, and then check back at the end of the print and see if they exhibit the same pulled up look.
Might want to slow down those print speeds and turn the part cooling and aux fan all the way up. Seems like the filament isn’t cooling fast enough in time.
To me, it looks like you have some warping to the print. This translates to thinner top layers and hence increasing overextrusion of layers as the height increases.
There are a few relatively easy fixes and a number of more intricate ones (which you’ll not need for PLA though).
First and foremost: That 12% humidity is relative air humidity. It has nothing to do with filament moisture unless you have dried it yourself. After weeks at sea in bags that slow but do not stop water uptake…
And remember that as little as 2g of water per kg filament can have severely detrimental effects on rheology and cool down behavior.
So give the filament a good drying cycle. Filament Drying Recommendations | Bambu Lab Wiki
If that has not on its own resolved the issue, run a flow dynamics and maybe flow calibration. It is not needed for anti-warping, but you want those teeth to be sharp and precise (do you use the “Arachne” wall generator yet?).
Next, note your build chamber temp. A cheap thermo-/hygrometer in the build chamber, strategically placed where the camera can see it is enough. For PLA, you want to be in the 30 to 35°C range. Colder is possible, but beware of heat creep above 35°C. Just print in a closed condition and prop the lid up to limit heat chamber temp as required.
I’d be surprised if you need more anti-warping measures for PLA, but just in case:
If you still get slight warping, consider using a brim.
For a part this size, that should be more than enough. But there are more options such as reducing speed and/or layer height to reign in warping and its follow-on effects.
The 12% humidity is the filament, not relative humidity…dried it myself.
I have not run it with the arachne walls yet, that is the next test.
Would adding a brim not foul the formation of the teeth? I get that there might be some post processing needed, but having to cut a brim away from all those teeth would be a lot of extra work.
I’ll set up a hygrometer in the chamber (I picked up a bunch recently)…and since I got the same results running at 30 mm/s, I’m not sure how much slower I can run it
Not quite. 120g of water per kg filament would be dripping
But
that is the important information!
That is the second most important item regarding warping. Keep PLA nice and cozy between 30 and 35°C during printing. Maybe closer to 30 than 35 with the .2 nozzle.
That very much depends on the brim gap. The smaller the gap, the better for adhesion but it’ll be more difficult to remove. But with dry PLA printed in a warm chamber, I find brims are rarely needed.
Yes, that is surprisingly slow for PLA. Even for a 1st layer. You could of course further decrease the layer height, but with a .2 nozzle and .1mm layer height… it is rather puzzling.
I assume that is Bambu PLA Basic white? How long did you dry it at what temp? The reason I am asking again is that in my case, I always give them a full treatment when unboxing as I have found that to be neccessary.
Furthermore, when did you give the Textured PEI its last good brush in a nice hot bath? The Textured PEI is well known for its excellent tack for weeks … until it suddenly stops. Then, it requires a really vigorous scrub. Or two…
And just in case I am riding the wrong horse: @Impeller_Warehouse mentioned cooling. I have not had much luck when playing with cooling due to the number of interconnected variables.
But I have found increasing the layer times by simply printing 2 or more pieces simultaneously to help a lot in the rare cases where this can be a problem (layer times in the preview should be the same as max fan speed layer time in the filament settings). I did not spot the telltale signs of this in your pics though.
If you can post the 3mf or screenshots of your settings maybe one of is can spot something.
HUGE improvement with this last run. For best troubleshooting, I will only change one parameter at a time so it is easier to determine what worked…“I changed 11 things and now it works, but I have no idea what fixed it” is something I learned years ago.
This last run was with the aracne walls and the teeth are much more crisp and defined with verrrry little of the angled “lifting”.
Going to do one last test with all the fans maxed out…I noticed the parts fan would not spin up when I manually turned it on, the connector may not have been fully seated after swapping the nozzle.
I think I’m in the home stretch here…thanks again to everyone
**and I sat there with my nose pressed against the door watching the first few layers…now I need to clean the glass
& 
