Solder paste dispensing screw pump

[Alexander]

Here is the design of the paste dispenser. Instead of extruding directly from a syringe under pressure, a mechanical drive system will allow much more precise control of the amount of extrusion. The idea is that the solder paste is pressurized into an Archimedes screw. To squeeze out the paste, the auger rotated and squeezed the paste into a needle. The body is made of  POM by milling. 

[bert shivaan]

that is really nice looking!

Did you make the tip also?

How about a video of it working?

what is POM?

On Mon, Aug 2, 2021 at 1:47 AM Alexander <785...@gmail.com> wrote:

Here is the design of the paste dispenser. Instead of extruding directly from a syringe under pressure, a mechanical drive system will allow much more precise control of the amount of extrusion. The idea is that the solder paste is pressurized into an Archimedes screw. To squeeze out the paste, the auger rotated and squeezed the paste into a needle. The body is made of  POM by milling. 

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[Adam Donovan]

Pom is a type of plastic that is very good to machine.  

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[Alexander]

The machine needs adjustment, I will post the video later. This is what the prototype looks like now.

понедельник, 2 августа 2021 г. в 12:10:28 UTC+3, adamjj...@gmail.com:

[Mike Menci]

You will need pressure -compressed air as well to push the paste from syringe into auger screw chamber!

Mike

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On 2 Aug 2021, at 16.08, Alexander <785...@gmail.com> wrote:

The machine needs adjustment, I will post the video later. This is what the prototype looks like now.

To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/1b1db010-1c5d-4d6d-9326-1745fa34a474n%40googlegroups.com.

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[Mike Menci]

my test from 5 years ago - https://youtu.be/w3fm-gYnoMY

Mike

[Shai]

POM is essentially Delrin and the tip is an airbrush tip commonly available. But how do you plan to get this working on OpenPNP if it doesn't support paste extrusion?

[Alexander]

OpenPnP Dispenser  from Erich Styger  and other links.

OpenPnPDispenser - YouTube

Paste Dispensing · openpnp/openpnp Wiki · GitHub

Paste Dispensers setup (google.com)

3D Printed Precision Paste Dispenser | 0x7D.com

вторник, 3 августа 2021 г. в 00:19:23 UTC+3, Shai:

[Shai]

@Alexander, read your 2nd link again. It was removed in OpenPNP 2.0 . It's only supported in 1.0 unless that is what you plan to use? the 0x7D.com link looks pretty cool, but that's not OpenPNP from what I read briefly.

[Alexander]

Shai Hello, I did not write that the screw pump for solder paste supply will work in OpenPNP 2.0. The third link at the very end in bold type contains the text that was previously read before the publication of your message.

Paste Dispensing · openpnp/openpnp Wiki · GitHub

Note that currently (Apr 2021), this feature was removed from OpenPnP 2.0 as it was too burdensome to support in relation to the small number of users who used this feature in 1.0. It's currently looking for a sponsor to pick up this development again.

четверг, 5 августа 2021 г. в 04:24:39 UTC+3, Shai:

[ma...@makr.zone]

Hi Alexander

The classic Archimedes' screw only works, because the water is constrained to one side of the screw by gravity, as the screw is laying at an angle:

https://en.wikipedia.org/wiki/Archimedes%27_screw

I do assume that the viscosity of the paste will also work against it just worming back up the screw, however this has to compete against the resistance through the tight nozzle (and perhaps even against sucking from the syringe?), where that same viscosity works against you. I guess it can work if the screw is long enough to multiply that worming-back resistance. But that would then probably not strictly be an Archimedes' screw principle, would it? ;-)

Have you tried it in real life?

_Mark

[Alexander]

Hi Mark. 

I believe that here it is necessary to select the air pressure supplied to the syringe with the paste at which the paste is fed into the auger but does not come out of the needle / the longer the auger, the less dependence on the precise maintenance of the pressure in the syringe / it is easier for me to calculate the hydraulics of the heating system. In the course of preliminary experiments, a small air pressure is sufficient, which can be taken from an air pump that is not used at the time of applying the solder paste. During operation, the pump heats up; additionally, a heater can be connected. Other options for supplying air to the syringe are possible. The motor can be collector mounted preferably with an encoder or a brake clutch. There is a special solder paste for the Metering Auger, which I do not have in stock. In principle, this is an experiment. I may be wrong about something.

четверг, 5 августа 2021 г. в 09:48:22 UTC+3, ma...@makr.zone:

[ma...@makr.zone]

Hi Alexander

I'm sure there is a good reason, so this is just out of curiosity: why does very slowly actuating the plunger of the syringe not work? Like with a very fine threaded lead screw?

One could probably use a simple M2/M3 threaded rod, as it moves very slowly and the numbers of cycles is few.

_Mark

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[Alexander]

Hi Mark. 

 The solder paste application process will be more stable with the screw feeder. I see the advantage of a piston dispenser in its simplicity of design, but I would use a short nozzle for the solder paste, but I may try it later. I think the disadvantage is the unstable application of the pale paste.

Технология дозирования материалов.pdf (ostec-3d.ru)

  The main negative parameters of a pneumatic dispenser is a change in the dispensing result with a change the viscosity of the material and the level of the material in the syringe. Diagram below shows the change in the parameters of the paste dose when the level of the material in the syringe changes.

четверг, 5 августа 2021 г. в 14:59:01 UTC+3, ma...@makr.zone:

[tony...@att.net]

I would think you would want a positive displacement pump so you can control the exact amount of paste being dispensed.  As Mark pointed out, a single screw does not give you positive displacement.  However, two counter-rotating intermeshed screws (one righthanded and one lefthanded) can be used to provide positive displacement and the housing shouldn't be much more difficult to machine.  If you make the pitch of the screws large enough, you may only need to drive one of the screws as the other will be driven by gear action.

[Shai]

This may be of interest to you guys: https://www.exxoshost.co.uk/forum/viewtopic.php?f=35&t=3536 I stumbled upon this thread yesterday while researching how Voltera does their paste dispensing and aside from how to dispense it, it would appear it's very difficult to not have the nozzles get blocked at such a small orifice. You can read that thread about all the issues with the Voltera and how it dispenses paste.

Further reading the links Alex provided (thank you!), all the professional high resolution dispensers that are use for various liquids use an auger like Alex wants to do. I would agree with him. The last link he shared here has good pointers: https://0x7d.com/2014/3d-printed-precision-paste-dispenser/

However, I would also be concerned with finding a tricky balance of auger screw design vs air pressure as you don't want the solder paste to get pushed/slide around the screw while it's not moving. But, like mentioned on the Voltera thread, I think the bigger issue you might realize eventually is how frequently this stuff jams.

[Wayne Black]

I actually made this clay extruder once to try and print solder paste. I followed the directions as outlined in the PDF and was shocked that it worked. For about 5 minutes that is. Then it died. The issue was that the pressure generated using T5 paste through a narrow gauge needle caused excessive heat and the auger to cold weld.

Was interesting little project.

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[Michael Anton]

The machine I have that supports solder dispensing has a little heater that heats the lower part of the syringe.  It worked very well with down to a 23ga needle, using T3 paste, and air dispense (not an auger).  Make sure you use paste that is meant for dispensing.  The paste for stenciling doesn't work well at all, and plugged tips are usually the result.  I suspect that heating the paste would make it much more reliable.

[Alexander]

We are slowly moving forward, today we have installed the pump on the car.

пятница, 6 августа 2021 г. в 02:23:14 UTC+3, Michael Anton:

[Alexander]

First experiments in applying solder paste.

пятница, 6 августа 2021 г. в 08:16:46 UTC+3, Alexander:

[Dave Park]

I have also been experimenting with paste dispensing.

My contribution here is that I have a 30% lower rework rate for bridging on QFP and SOIC pins if I simply stagger my blobs on the pins so they're not in a straight row.

Dave

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[Shai]

@Alexander, how did you control the paste extruder - via OpenPNP?

[Alexander]

It is possible for another.

суббота, 28 августа 2021 г. в 18:50:00 UTC+3, Shai:

[Dave Park]

This alternating pattern is exactly what I did. Reduced bridges greatly.

Dave

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[Alex]

понедельник, 30 августа 2021 г. в 20:15:21 UTC+3, pla...@plasticuser.com:

[Alex]

First test of the auger solder paste dispenser.

понедельник, 7 июля 2025 г. в 09:25:03 UTC+3, Alex:

[bert shivaan]

Alex, I have recently become interested in this tech. Did you make these yourself? Where did you get the tips?

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[Slavko Kocjancic]

Little late but I think the Moineau pump should be best for that purpose. Especially layered pump.

The pump is positive displacement and linear flow. 

https://en.wikipedia.org/wiki/Progressing_cavity_pump

https://www.thingiverse.com/thing:1915577

[Alex]

Shank dispenser test, needle diameter 0.3 mm, housings TQFP-100, QFN-32, 0201, paste type 4: 20-38 µm.

вторник, 15 июля 2025 г. в 22:47:01 UTC+3, esl...@gmail.com:

[Alex]

A 3D printer for applying solder paste.
Repurposing a 3D printer for dispensing substances from a syringe online, here :   https://mariosgit.github.io/SolderPasteDispenser/

пятница, 25 июля 2025 г. в 11:33:23 UTC+3, Alex: