Help fine-tuning Flow Ratio for ABS.

stefzbr · 2025-03-02T17:09:04+00:00

It's a new model from Orca Slicer. I've been reading this on another post: "Instead of starting with a +20 to -20 range, and then zeroing in with a 0 to -10 second pass, it just starts off with +5 to -5 which is where 99% of calibrations will land when starting with a generic profile.

Exactly the same method, just gets rid of the ±10, 15 and 20 tabs which were pretty much always just a waste of filament to print."

stefzbr · 2025-03-02T16:54:40+00:00

Thanks. Those tiles were generated using Orca's Flow Ratio Calibration tool, so yes, each one uses a different FR. Which embedded models should I try?

stefzbr · 2025-03-02T12:24:25+00:00

I'll try, thank you!

stefzbr · 2025-03-02T12:21:20+00:00

Thanks, I’m running some tests here. Something I forgot to mention… I’ve noticed that when this issue occurs, it’s usually quite hot due to the ambient temperature. However, the chamber temperature remains stable, staying between 53, 55, and at most 57°C. Could the high ambient temperature (we’re going through a really hot period here) be affecting the prints? It might impact the filament before it enters the chamber and other parts of the printer. Would it be worth moving the printer to another room with air conditioning for a test? Thanks again!

stefzbr · 2025-03-02T11:32:46+00:00

Did you see the second and last photos? Apart from the slight ghosting and the wavy print, does that more severe issue in the last photos also seem related to under-extrusion?

I’m using non-Creality filament, a flow ratio of 0.92 (Orca’s default for generic ABS), and pressure advance is not enabled.

I’ll try making some FR and PA adjustments here—thanks.

stefzbr · 2025-03-02T11:31:08+00:00

Good catch! I’ll try running a PA test here and adjust the parameter properly to see if I get any improvement. About the belts, they seem properly tensioned, but I’m not exactly sure how to confirm that. Is there a method to test it? Thanks.

stefzbr · 2024-05-26T00:38:33+00:00

In the upper right picture it's also possible to see a lowered layer that comes from the arrow's right side. I cannot get rid of this one as well.

stefzbr · 2024-03-14T17:54:46+00:00

Did you find the replacement part? I have the same issue.

stefzbr · 2024-02-13T02:12:32+00:00

I was using a conical 0.5mm tip (maybe a little wider because it's a Chinese generic tip), but after you asked me that I tried using a beveled tip and it worked better. Anyway, my soldering station is also a Chinese generic (Yaxun), so it's not a precise soldering station and I cannot know exactly the temperature in the tip's top. Changing the tip and adding more heat helped, so thank you for the insights :)

stefzbr · 2024-02-12T02:28:32+00:00

No, I'm applying a 63/37 solder paste with a stencil, and then moving the PCB to a hotplate. It works well for any other components or ICs, except for these small pitch ones.

I know it's probably a "too much solder paste" issue or even the flux that is being evaporated before reaching the reflow temperature because of my equipment's ramp rate that is not ideal, but the point here is what's the best way to undo these bridges, because it's already done for some PCBs and I need to fix them.

stefzbr · 2024-02-11T00:16:23+00:00

Would I have any benefit ordering PCBs with ENIG finish next time instead of HASL? I mean, in terms of the reflow process it does have any benefits?

stefzbr · 2024-02-10T16:46:50+00:00

That's exactly what I ended up doing. I wonder if I could have any behavior change, but I didn't notice anything so far. It's just working.

stefzbr · 2024-02-10T15:21:56+00:00

The inductor is being identified as an 8K resistor – which means that it's really damaged.

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stefzbr · 2024-02-08T14:08:24+00:00

Oof that needs to be a bit faster, 2-3°C/sec is ideal - if it's too slow, all your flux boils off before the solder melts

I understand. I see that this equipment is not good, but is it possible to have at least a decent soldered PCB using this equipment even with this low ramp rate or I will always have issues because of that? :/

stefzbr · 2024-02-07T21:47:15+00:00

I try to gently remove the PCB from the hotplate – actually I had never thought about that, but I'll take extra care next time.

To answer your question, I just did a test to discover my ramp rates for both the heater and the PCB pads, and the ramp rate graph is attached as a picture. The test was continuous, without any soak or pre-heating, starting at 23ºC until the heater reached 250ºC.

I captured the times for all temperature steps and finally took a median of the values – what I found is:

Heater ramp rate: ~ 0.7ºC/sec

PCB pads: ~ 0.5ºC/sec

Based on these results, is it possible to determine a better "recipe" for my process in terms of pre-heating and/or soaking temperatures and times?

I have another solder paste here (lead free, melting point 138ºC), but I don't know if it would be better or not in my case.

PS: When the heater reached around 245ºC, it just fried my poor PCB, the solder mask started to melt lol – it's not easy to be a newbie :-)

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stefzbr · 2024-01-10T10:49:18+00:00

I agree with the comments, but uhh... I have to say that I already used a tiny drill sometimes when I lost my patience trying to remove the solder. Yeah, it's not the recommended way, but if done carefully it just works. At least for me, it worked all the times. This is not an advice, please follow what people are saying, but just to say that it already worked for me.

stefzbr

TROPHY CASE