Paste flow rate

[sim]

I have an issue that I think is similar to How to modify / correct the solder-paste flow rate?
When my voltera starts dispensing paste, it does it correctly:

However, as the dispensing goes by, I end up having almost no paste per pad:

Or not as expected:

If I manually increase the flowrate, then I can have my board with the right amount. Is there a parameter that increases the paste flow with time?
I tried the rheological setpoint, which for my “DramaticGoose” paste defaults to 0.16, but with a value of 0.20 didn’t notice any difference.

Thanks for your support,

Sim

[mewertow]

Hi Sim,

I’d check two things:

1. What is the ‘print height’ setting for your paste?
2. Is your nozzle in working condition? See this article to compare: https://support.voltera.io/hc/en-us/articles/115005831867-Broken-Nozzle
3. Is your bottom-z limit switch clean? If there’s any residue, this will lead to height issues.
4. Is there paste leaking past the piston in the cartridge? If the piston seal has broken, you’ll see dropping flowrate.
5. Increasing the ‘rheological setpoint’ parameter will increase the flow rate over time, but if your problem is any of the above it may not help much.

I think it might be a height-related issue, based on the incomplete paste deposits.

• Matt

[sim]

Thanks for your help. As of the things to check:
1.- I have tried the default 0.14 and also 0.16 ‘print height’, with the same results.
2.- The nozzle appears to be ok
3.- I have cleaned the bottom-z switch several times, so this should be ok.
4.- There is no paste leaking past the piston
5.- I can try with other values for ‘rheological setpoint’, just to check.

Is there any other thing I could try? Maybe you have a file with a test pattern, to check against?

Thanks,

Sim

[mewertow]

You could try the ‘Hello World’ pattern - you can load this by just clicking the ‘Load Hello World’ button in the Solder Paste step. I’d also suggest upping the rheological setpoint to 0.22 to see if you still have this problem.

How long does it take for the V-One to finish the board?

[Steven_Hines]

I’m having the same problems with Dramatic Goose dispensing correctly at the start and then slowly falling behind.

I’ve worked around this for the moment by carefully watching the paste dispensing job and when the paste appears to thin, increasing the flow rate. Yesterday I had a job that started at +0 and ended at +48 about 5 minutes later.

[cborn]

+48 is a lot of boosting! On my last board I got up to +16 and was worried about how far I had to take it. But that was only a 14-pad board, not a 5 minute job.

[jazozaya]

Hi everybody,

So I got a chance to do some solder paste testing this afternoon. I first tried printing with our default settings and also found that the amount of solder paste diminished over time. This behavior is not intended. I started tweaking the printing parameters and I think I’ve narrowed in on some settings that should improve this for everybody.

In the settings window, I invite you to try the following settings:

Dispense Height: 0.10 mm
Feedrate: 500 mm/min
Trim Length: 10mm
Rheological Set Point: 0.22

Remember to change the settings for the particular ink lot you are using! Each profile can store different settings so if you feel like nothing changed, double check your ink profile.

With these settings I was able to get consistent dispensing on longer prints.

Feedback is welcome!