Tool head for thick paints

Hello Everyone!
Im thrilled join this genius community. Im currently designing a circuitry printing CNC machine for my undergrad engineering FYP. For this purpose Im trying to print using a type of graphite paint (its quit high viscous). I tried various methods achieve a evenly coated rectangle shape (it is important that the coatings are even, so using paint brush is ruled out). I tried filling up this paint with a fountain pen, a gel pen refills and some permanent markers like sharpie. But for my dismay I failed to achieve a thick even coating due to the paint's high viscosity. So i came across this airbrush system but it is ruled out due to its high price. When i browsed the toolhead section of reprap website, i came across a syringe based paste extruder. Is it possible for to achieve a even coating using a syringe system? Is there any other toolhead you guys suggest me? please help. Thank u so much....Cheers!

Edited 1 time(s). Last edit at 01/21/2015 02:05PM by vino92.

... if the paint has medium to high viscosity, then this would be perfect with a motor-driven syringe

For low viscous fluids you have to reduce the inner diameter of the nozzle/capillary down to 0.08mm to get it working with good repeatability ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thank you so much Viktor. It would be great if u can suggest me motor driven syringe extruder assembly. To name a few, bowden's, reprap universal or gregs. Which one is easier to make and precise enough for my application. My college doesnt have good 3d printer so it sucks. I canget it printed outside

... read through the links - there are several types and applications around: [forums.reprap.org]

Here images of a type I've built some years ago: [www.reprap.org]

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Hello Vikor,
I made my own syringe extruder. Now having built that, how do I sychronize the stepper driving the syringe and the CNC axis stepper? Any tips with programming?
Thank you so much,
Vino

Edited 2 time(s). Last edit at 02/21/2015 08:06AM by vino92.

Hi Vino,

the syringe stepper is driven exactly like the extruder motor -- you only have to change/adjust the speed relation depending on your nozzle diameter or dispensing volume per X/Y-step.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Have you considered pressurizing your paint, and delivering it via a timed injector (like a fuel injector from a car)? Speed of movement combined with the number and duration of pulses should provide a smooth and accurate product (after some experimentation).

Best of luck!

Dean