Problem with HT-LW-PLA

[plush dawn]

So i got some problem with my new HT-LW-PLA after printing a wing i noticed that the wall was 2x the size that i def. in creo. I did change the flow rate (that i calculated via the tests given by the producer of the filament colorfabb) and it seemed to have worked for 1/2 the height of the wing. Its just all in all weird.

-3d printer: A1-mini
-printing temp 250 °C
-https://colorfabb.com/lw-pla-ht-black

Not sure about anything else that is important to it. If there is a need for the CAD model i can also give that

[ember tusk]

AI Help

It seems like you are experiencing an issue with over-extrusion, which is causing the walls of your print to be larger than intended. Here are a few troubleshooting steps you can try:

1. Check the filament diameter: Ensure that the filament diameter setting in your slicer software matches the actual diameter of the filament you are using. It should be around 1.75mm for most PLA filaments.

2. Calibrate the extruder steps/mm: There might be an issue with the extruder steps/mm calibration. You can find guides online on how to recalibrate it for your specific printer model.

3. Retraction settings: Check your retraction settings in the slicer software. Proper retraction can help reduce the amount of excess filament being oozed out during travel moves and minimize over-extrusion.

4. Print temperature: While the ColorFabb website suggests a temperature of 250°C for their LW-PLA HT filament, it might be worth experimenting with slightly lower temperatures to see if it improves the over-...

WARNING: This response is AI generated and may contain errors.

[next valley]

"For printing thin structures such as RC plane parts we recommend printing the first layer at 100% flow using 200C printing temperature. Then increase the temperature for the second layer (around 235C) to activate the foaming and reduce flow to 50-60%."

From their page.

Lightweight PLA is foaming, ie it expands

[plush dawn]

that is what i did. It only starts to be weird at around half the size of the wing.

[next valley]

I think you need to do a flow calibration

[plush dawn]

i did. thats how i found the 65% and 250 °C

they had a excel sheet

[next valley]

But as it goes up the structure gets thinner, you might be running into lower layer times and need to reduce the temperature

Smaller object will mean slower printing speeds and more dwelling toward the top vs the bottom

[plush dawn]

Hm, is there a gradual temperature option?

[next valley]

Not afaik, another solution would be to change the print speeds so that it stays at the same speed throughout

[plush dawn]

It’s a solid wing so I am not sure. The size stays the same

[next valley]

The wing is thinner towards the top isn't it?

[next valley]

Or rather, smaller?

[plush dawn]

Nope

[next valley]

Oh nevermind

[plush dawn]

Stays the same

[next valley]

Hmmm.

That is peculiar, unfortunately I am not really sure then

[plush dawn]

Here are the calibration cubes. 260-210

(they are a bit burned since i tested how high the temperature could get before they start melting. 110 °C if curious)

[light maple]

Pay attention to your printer’s behaviour at the point where the change happens

It could be that your gcode is suddenly asking your printer to revert to its previous non-60% flow

Not too sure though

But Bambu A1 with creality?

[plush dawn]

creality?

[light maple]

Sorry, I mean cura

Bambu a1 mini with cura???

[plush dawn]

yeah, is that a problem?

[light maple]

There’s a vase mode in Bambu Studio’s advance mode

[plush dawn]

yeah picked that one

[light maple]

Nono, there’s nothing wrong with it

I was just curious because even I can’t find printer profiles for Bambu in cura

[plush dawn]

The reason i use cura is just laziness. Don't want to learn a new program i started with a ender 3.

[plush dawn]

made my own lol.

[light maple]

🤝🤝

[light maple]

That’s fair enough

Any extra per model settings?

Or is it just a pure vase mode with a temp and flow change on the second layer and that’s it

[plush dawn]

but yeah is there a way to inspect the g code for flow changes

[light maple]

Unfortunately I don’t delve deep enough into gcode to know that, but I believe your answer is yes if you’re tedious enough

[plush dawn]

thats it. 0 retractions (because that forms bumps which are aerodynamically problamatic)

[light maple]

I really want to say try doing it in Bambu Studio

But if you insist that you don’t want to, I’m outta ideas too

[plush dawn]

good point. I just have to make sure this time it actually works since the filament is way too expensive unfortunatly.

[light maple]

Are you aware if it “reverts” at a set height (i.e. have you tried printing this part multiple times and the error happens exactly at the same spot)?

[plush dawn]

first time printing it and i unfortunatly did not watch it that closely. Just made sure it did not turn into spaghetti and then left

[light maple]

Fair enough

I’d say take some cheap ass filament you have lying around and redo it in bambu’s slicer

Maybe like a 80% flow instead of 60%

So that it still prints out and has structure

And if you see the same fail, then you can rule out slicers

[plush dawn]

will that damage anything? I did not play with it until now

[light maple]

The cheap filament?

I doubt that anything bad will come from it

[plush dawn]

the lower flow rate in combination with cheao filament

[light maple]

Naw

It’s just gonna be flimsy

[plush dawn]

ok, yeah will try and see in 5h

[light maple]

I’m not asking this to be a final part, but rather as a dry run to make sure the gcode isn’t faulty

Because it seems to me that using that expensive filament is… well… expensive

🫡 good luck, I’ll be interested with the results

[plush dawn]

yeah, unfortunately. I wished LW pla would be cheaper.

[light maple]

Are you okay with it being hollow though?

You could always try aligning your z seam to the trailing edge of your wing

That should ensure the rest of the body is smooth

[plush dawn]

it has to be hollow or else the plane will end up too heavy.

[light maple]

Aaaah alrighty that’s fair enough

[plush dawn]

i did some calculation and max tension that i can expect are 10 MPa so it should be fine

[light maple]

10MPa on plastics with non-homogeneous material properties is abit yikes for me

But I’m not the LW filament maker so I can’t say for sure 😭

[plush dawn]

they advertise it as 30 MPa at 250 °C printing temp so it should be fine

honestly a bit of experimentation on my part

[light maple]

Aah that’s fair enough then, SF of 3 should suffice

Actually, genuinely curious - how’d you calculate stresses around your parts?

Atleast I’m assuming you’re not just hand calculating all the Bending axial and moments

[plush dawn]

ik the lift and approximate drag force then i put that into the FEM module of creo. Unspectacular i know but its the easiest way.

[light maple]

Aaaah

[plush dawn]

oh god no. I had enough of that in Uni

[light maple]

I’m assuming it’s a shelled model with the same approx thickness as your line width then?

[plush dawn]

2 line widths jup

[light maple]

I apologize I was just curious because I can’t really find any software that can take infill into account 😭

So I’m stuck assuming a thick shelled hollow part is handling all of the stresses that way 💀

[plush dawn]

https://www.youtube.com/watch?v=QJjhMan6T_E&embeds_referring_euri=https%3A%2F%2Fhackaday.com%2F&source_ve_path=MjM4NTE&feature=emb_title

i gotta admit i used this video for it

[light maple]

Oooo

No shame in using videos

But that looks extremely cool regardless

[ember tusk]

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[plush dawn]

@light maple did not fix it, ill troubleshoot later

[light maple]

Aaah shoot, any visual references?

[plush dawn]

the diffrence is not really visible since its only 0.2 mm or so. (thats also why i did not include a picture) I assume it has to do with the model

[light maple]

Probably a good luck at the prepared gcode in the slicer world show and thickness inconsistency

[ember tusk]

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[plush dawn]

found the issue and its incredibly stupid. It was the nozzle i used the same one from when i got the printer and well it was a bit degraded from carbon fiber filaments but i did not expect that much

switched it and now it prints fine

i did not expect carbon fiber to be so corrosive to basically kill my nozzle with 2 rolls

[light maple]

I assume you were using a stock A1 mini

but god damn that's good to know

time for a hardened steel nozzle I guess

[next valley]

Yep, glow in the dark and glass fiber will do it… in about 50g.

Carbon fiber in about a spool

[plush dawn]

i used a hardened steel nozzle

[plush dawn]

is glow in the dark that much worse?

[next valley]

So, so much worse than carbon fiber.

[light maple]

😭

actually, where can I find a hardened steel for the A1?

[plush dawn]

amazon.

or aliexpress

[light maple]

I was gonna say that I don't live in North America but Aliexpress' fair

[plush dawn]

i live in Germany but yeha aliexpress is fine

just a bit cheapish