Increasing RepRap Print Quality

So I've been following RepRap and one thing that continues to be a blocker to me taking the plunge and getting started is the seeming low quality of the printed parts. Not to knock anyone's hard work but its very clear when a part is printed by a RepRap/ RepStarp or even an entry commercial 3D printer (like an UP! or uPrint).

Is there any work going into getting higher quality prints? (i.e. less than 0.3mm layer thickness or better than 0.1mm positioning?)

Sorry if there is already a good resource on this out there (please provide the link).

Thanks in advance,
- Scott

Hi Scott,

... the poor quality of the extruder-output is the main reason i haven't built a repstrap or Darwin when joining the reprap-community 3 years ago

As my mostly needed accuracies are below 0.1mm, i'm milling most of my parts with my CNC-mill or lasercutting thin sheets with a 50Watt laser mounted on top of the mill.

I've made some tests with paste dispensing - here i can dispense droplets or continuous tracks with maybe 0.1mm width (depends on material and viscosity). For different high-temp applications i mixed pastes from ceramic dust and sodium silicate (=waterglass), so i could mould and build ceramic parts with up to 1400°C heat resistance! ... dependaing on the size of the dust-particles you can use dispenser needles with down to 0.12mm inner diameter for pastes, but the heighth of a slice can be as low as 0.02mm with 0.01mm big particles.

In the last time i was busy with diode-lasers (1Watt-blue to 5Watts-IR) for cutting/engraving thin sheets of plastic and paper or laser sintering different dusts to solid structures. Here i have focus diameters of nearly 0.1mm with the IR-lasers and maybe 0.07mm with the blue diode (or 0.01mm with my 50Watt-fiberlaser), so the cutting accuracy is mainly defined by the accuracy of my mechanical setup (0.0125mm with the old mill halsfstepping, until 1micron when my finer/sturdier CNC-setup is running).

Actually i'm finishing the first batch of 'comercial' lasermodules and reworking/activating an old lathe, so i can make all the collimators and optical housings at home ... then my plan is to enhance the laser-mill-system and start with laser-sintering, as here i have the best accuracy with all sorts of possible materials - from plastic, lignin (thermoplastic wood-dust), glass, ceramic to metal ...

Another current task i'm running with the GRRF is developing a conversion-kit with an extruder and motherboard or Arduino, so anyone owning a mill can repstrap it easy into a FFF-printer ...

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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]

Hi Victor,
I have been using the reprap and now I am ready to make my own large ceramic printer. 24"x36"x24" is the size Paulusbuild window I am after. Any thoughts on extruders for this process and can the stock reprap board run something like this. That way I can have my students use existing software and be up and running quickly.

Paulus

Hi Paulus,

... the main size limiting parameter ist the instability of the frame, when building very large - this can be overcome with stiffer parts, tweaks like steel-wire-reinforcement for all frames or by building a repstrap with extruded aluminium bars.

For a ceramic dispenser you can look here and read through the linked post ...

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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]

I have been using the reprap and now I am ready to make my own large ceramic printer. 24"x36"x24" is the size build window I am after.

That sounds fun. What are you calling the machine?

I started a wiki page for you here:
http://reprap.org/wiki/ArizoBot
using "ArizoBot" as a code name, and an artist's impression of the machine ...

Unfold and Jonathan Keep have done some nice work here:
http://unfoldfab.blogspot.com/2010/11/englishman-in-antwerp.html

They're using compressed air to put down clay from a syringe.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

it may be just me, but the current extruder technique seems rather wrong in several aspects, and needs improving

it can certainly improve for reliability, although not sure it can improve in quality too much, in the context where every single extruder is made basically only from what is available to a person, rather than best choices mats

heard a nice comment in some movie with austronauts on the lauch pad, one says "do you realize we are sitting on a craft made from 1 billion parts and every single one of them was made by the *lowest bidder*"

i suspect is something like that in our case, except a little more meaningfull

Chuck Swindoll asked an astronaut in his congregation how it felt to be ready to blast off in a spaceship. The astronaut replied,

Quote
Chuck Swindoll
“How would you feel getting ready to blast off in a piece of equipment with over three-million parts and each one made by the lowest bidder?”

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Thanks Sebastien and Viktor, I do not have a name yet. I think that will come when I see the thing working. What I wanted to be able to do is have a large chamber sitting close to the printer that will hold the ceramic mixture and would extrude thru a hose up to print head. One possiblity was a have a linear actuator (http://www.hurst-motors.com/laslbsstepping.html) drive a piston and from here move the material through a tube to the extruder head.
Another is using phenumatics to drive the ceramic mix from cyclinder to print head.
Questions I have are what the electronics would be for either type of hookup and can the same reprap v2 board I have drive this. I have seen the exsisting versions on the forum.
I have a device (31 cm3) we made to currently extrude ceramic and rubber, with an air actuator. So some modification of this device perhaps could work. See pics here- [reprap.org]
What the extruder head would look then, if extruded material is coming from a hose on the side of the machine?
What electronics have to happen?
Paulus

Looks like with some work you can get 0.2mm thickness. This effort should help prevent higher quality causing too much issues with build times: [blog.reprap.org]

If one can get ~0.1mm on a RepRap, the quality is the same (if not better) than UP! and some of the lower end/ lower quality settings on the Dimension line - [1.bp.blogspot.com] (Mendel part from a uPrint) The best quality the Dimensions go is 0.01mm but almost nobody actually prints at that resolution.

After a little digging, I'm much less concerned about positioning accuracy. I mean the belt systems work in inkjet printers to significantly higher resolution than we're dealing with.

I am a little concerned though as to why there aren't better guides/ documentation about improving print quality after you assemble your system since I think this is where most of the quality issues experienced occur.

Probably the biggest possible improvement for quality is improving the mixed print size method in software and then adding a 2nd extruder for detail work. Thinking a combination of the Cartesian Boden style print head in Ultimaker (http://blog.ultimaker.com/) with a 2nd extruder would be the best bet for increasing quality to the level to compete with commercial printers.

Lots of people keep blogs....

Work out who does nice prints.. go read their blogs.

One way to sample all the blogs (and get lots of ideas on print quality is to read one) of the feeds available off the reprap wiki front page.

IRC has some people on it who do nice prints... spend a few hours on IRC...

Unfortunately, since reprap is a place for development... there are so many variables that one can't just write a "do this and that will improve" help page... things are situation specific.. and we are all learning.

But I have found that there is no substitute for spending hours per week reading reprap related texts...

Al...

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[araspitfire.blogspot.com]

"""But I have found that there is no substitute for spending hours per week reading reprap related texts... """"
araspitfire

May I quote you on that?

Years ago there where Spanish made Trials bikes here in the US of A with out Manuel's well English ones any way.
that was before we knew that we all would need to learn Spanish.
but there were "What works book's" like gold if you could copy one.

Last I checked RepRap could produce higher quality prints than some commercial systems, so your statement "Not to knock anyone's hard work but its very clear when a part is printed by a RepRap/ RepStarp or even an entry commercial 3D printer" is incorrect.

Please read here:
[blog.reprap.org]
[groups.google.com]

Edited 1 time(s). Last edit at 05/25/2012 04:40PM by WildBill.