Nozzle stops spraying about 1/3 of the printing

For any Plan B specific topics
Post Reply
Ben8781
Posts: 6
Joined: Fri Jun 24, 2022 7:58 pm

Nozzle stops spraying about 1/3 of the printing

Post by Ben8781 »

Hi, we have make the PlanB printer working so far with Gcode. We are using customized sugar powder and modified the cartridge with sake. The only problem we are having right now is that the nozzle we gradually extrude less binder and eventually stops spraying. We are printing a simple cube (0.8cm height) with 0.15mm layer height, 400% print density, 100% infill and it will have about 54 layers. When the printer reaches between 23-28 layers, the nozzle will start spraying less binder until almost no binder extruded when it hits about 28 layers.

The nozzle will extrude again when we stop the printing and start over from the first layer. The problem will still persist whenever layers 23-28 has reached. May I know is that anything that I can adjust in the printing or nozzle tab of the firmware to fix this? For your information we are using the same model of the cartridge that you uses.

Thank you for your help and have a great day.
Ben8781
Posts: 6
Joined: Fri Jun 24, 2022 7:58 pm

Re: Nozzle stops spraying about 1/3 of the printing

Post by Ben8781 »

Update:
We have tried it with another model with 5mm thickness, which will yield 33 layers (0.15mm layer height). The printer still suffer with the same problem, it stops spraying when about 13 layers reached.

The formula Ezrec provided works just fine for us, below is the partial printing result of 13 layers.
Attachments
E29DFA0B-2304-4159-BFF0-12AADB7CF54A.jpeg
E29DFA0B-2304-4159-BFF0-12AADB7CF54A.jpeg (128.48 KiB) Viewed 72070 times
User avatar
dragonator
Site Admin
Posts: 599
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Nozzle stops spraying about 1/3 of the printing

Post by dragonator »

I sadly missed your message, therefore the late reply.

Slowly getting worse sounds like a heat issue, where the printhead heats up too much. Are the pauses between you printing again long, or is it right after. You can try slowing down the printer to make the head absorb less heat, or try lowering the voltage on the printhead, either by bypassing the boost converter, or by modifying it.

I do not have any more detailed help sadly. Plan B was a long time ago for me.
Ben8781
Posts: 6
Joined: Fri Jun 24, 2022 7:58 pm

Re: Nozzle stops spraying about 1/3 of the printing

Post by Ben8781 »

The pause between my printing is not long, I tried it right after and it will gradually got worse, most probably caused by heat issue as you said. I have slowed down the printer by 50% and it stops at about 1/5 of the printing. I tried to sped up the printer by 150% and the effect is the same as slowing it down with slightly less print accuracy.

Plan B code is in ideal option to make significant faster print that would avoid the heat issue, but the converter is not converting the Gcode properly. Is that any modifications I can make on the printhead, boost multiplexer or the firmware to lower the voltage of it? I really appreciate your assistance, thank you.
User avatar
dragonator
Site Admin
Posts: 599
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Nozzle stops spraying about 1/3 of the printing

Post by dragonator »

Towards the end I had a Plan B running with an Arduino Due, but this was a really custom machine, which was difficult to be shared. It did print 3x faster though.

In any case, we are trying to fix symptoms, not the issue. I never had a Plan B cut out half print (besides mechanical failure). Can you verify the voltage of the booster, and whether it stays stable during printing? This is the first place I'd look.
Ben8781
Posts: 6
Joined: Fri Jun 24, 2022 7:58 pm

Re: Nozzle stops spraying about 1/3 of the printing

Post by Ben8781 »

Hi, I sincerely apologize for the late reply. I was busy for the past week. We have tested the voltage of the printhead, it was stable throughout the print, the boost demux really does the job of boosting and maintaining the printhead voltage around 19.8V even when the ink stops spraying. By hoping the issue is caused by some connection problem between the demux and printhead, we changed a new ribbon cable today and the problem still persists. Overheating might still be the main reason for the issue.

Interestingly, we tried out 34 layers of printing today. The very first print went furthest, 23 layers before the ink immediately stopped spraying. Then we stopped the print immediately and tried out another print twice, both times it stopped spraying immediately when 7 layers reached, which could be caused by overheating we guessed. Then we paused for about half an hour and printed again, it slightly improved to 11 layers. We will highly appreciate it if we could get some suggestions on handling this overheating issue, we have already hit this bottleneck for quite some time, thank you.
User avatar
dragonator
Site Admin
Posts: 599
Joined: Fri Aug 14, 2015 4:48 pm
Location: The Nethelands
Contact:

Re: Nozzle stops spraying about 1/3 of the printing

Post by dragonator »

At this point all I can offer is suggestions as to what you can try. I have never had these issues, and I don't have the hardware to try and reproduce.

The thing I'd try is lowering the voltage. If you have a DC-DC converter, you can hook the boost demultiplexer to it (after removing a few of the components that pass the voltage for the boost circuit. With this or any other variable power supply you can see if lowering (or raising) the voltage helps with the times.
hsnbas
Posts: 6
Joined: Sun Oct 31, 2021 2:22 pm

Re: Nozzle stops spraying about 1/3 of the printing

Post by hsnbas »

The maximum firing frequency of the C6602A is 1.5 khz. You should not exceed this speed. The frequency increases as the print density increases. If you want high print density, lower the print speed.
Post Reply