Printing a Full-Size Car

Here's an interesting article I came across, about a group of engineers who are using 3D printing to manufacture their car, called the Urbee 2:

[www.twincities.com]


Are there any projects for building 3D printers with large build volumes? Could something like this be built using a shipping container? I'm imagining large plastic cabinets or credenzas being printed with smooth glossy finishes. Or maybe just simple lawn furniture.

One pretty large scale 3D printing project I saw was:

[rs20.abstractdns.com]

Kinda cool I thought.

Bobbitay Wrote:
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> One pretty large scale 3D printing project I saw
> was:
>
> [rs20.abstractdns.com]
> ing/
>
> Kinda cool I thought.

Yeah, I've read about that Contour Crafting stuff - pretty cool.
I wonder if it wouldn't be better implemented by taking their concrete print-head and adapting it for use with traditional concrete boom pumps:

[www.youtube.com]

Concrete pumps were first invented in 1927, and concrete boom pumps were invented in 1958, so they're a well-developed and well-established technology in use all over the world. If the newer invention of the Contour Crafting printer head could be adapted for use with that existing technology base, then it could probably be brought into the marketplace much more quickly.

Imagine having the Contour Crafting printer head attached to the end of the hose dangling from the boom, while also being further attached to a cable or track system mounted near the point of use. Or imagine a very tall version of the rostock deltabot design, enabling you to build upwards to create a taller multi-story building.

I wonder how scalable the rostock design is?

The machine I am putting together right now will have an 18" cube work space. I have an extra axis slide, so I could create a 36" X axis very easily. With some replacement slides of the same type currently on Ebay I could get a 78" X axis for about $650 extra, and a 36" Y and Z axis for another $650. See my Ifactory thread to see the start of what I'm building.

Gary H. Lucas

While I totally "get" the idea of using extruded concrete, I have to ask if the strength and weight (actually lightness is a better term) of plastic printed objects (by printed I mean reprap-prusa.mendel style wet extrusion) equals or even approaches that of conventionally cast or vaccu-formed objects. My limited experience is that while printed parts display reasonable strength in two directions, in the third they are generally as weak as a paper doll.

Edited 1 time(s). Last edit at 02/13/2013 02:36PM by xiando.

Nice thread on large format printing. I want to share the work my team has been doing in the development of Goliath, a printer with 600 x 600 x 600mm print volume. You can read more about the group re:3D here: re3d.org the printer is of a straight forward and solid design. I am currently printing @ 80mm/ sec and rapid travel of 200mm/sec.

The printer will be offered on Kickstarter later this month. I will just say that it is really nice having such a big work surface

Best,
@chief_hacker @re_3d

xiando Wrote:
-------------------------------------------------------
> While I totally "get" the idea of using extruded
> concrete, I have to ask if the strength and weight
> (actually lightness is a better term) of plastic
> printed objects (by printed I mean
> reprap-prusa.mendel style wet extrusion) equals or
> even approaches that of conventionally cast or
> vaccu-formed objects. My limited experience is
> that while printed parts display reasonable
> strength in two directions, in the third they are
> generally as weak as a paper doll.

A good rule of thumb is that properly printed things have half the strength in the weak direction compared to the strong directions. If the thing crumbles when handled, it was just printed badly.

Just out of interest, I grabbed the closest printed thing I had, an ABS truss structure test thing that weighs 50 grams, and it supported a load of 100 kg just fine. I propped it up only at the ends and put the load on the center and it didn't even budge.

chief_hacker Wrote:
-------------------------------------------------------
> Nice thread on large format printing. I want to
> share the work my team has been doing in the
> development of Goliath, a printer with 600 x 600 x
> 600mm print volume. You can read more about the
> group re:3D here: re3d.org the printer is of a
> straight forward and solid design. I am currently
> printing @ 80mm/ sec and rapid travel of
> 200mm/sec.
>
> The printer will be offered on Kickstarter later
> this month. I will just say that it is really nice
> having such a big work surface
>
> Best,
> @chief_hacker @re_3d

Can you post some pictures of this thing? Does it once again print mainly in ABS/PLA/etc?

I used to work for DuPont in their Engineering Polymers division, and they had thermoplastics containing reinforcing fibers, like glass fibers or kevlar fibers, which could radically increase the stiffness and significantly reduce that "weakness in the 3rd dimension" issue.

Does anyone make a filament with glass or kevlar fibers in it? Perhaps that could be of great use for larger format printing involving thermoplastics.

Is there any experimentation going on with filament composition? What's the bold new stuff?

@Tssalo, the question stands:

I have to ask if the strength and weight (actually lightness is a better term) of plastic printed objects (by printed I mean reprap-prusa.mendel style wet extrusion) equals or even approaches that of conventionally cast or vaccu-formed objects.

EDIT: the point being that making a car out of printed plastics kinda needs to be strong, no? So aside from the novelty, I'm not so sure that it's a matter of apples vs apples.

Edited 2 time(s). Last edit at 02/13/2013 07:10PM by xiando.

@sanman

You are correct, our large format printer does use ABS, PLA, PVA, nylon ect. There are a couple of things that set this machine apart from everything we have seen for the home market. The size is much larger than anything else available. With a 600mm cube of print volume it is amazing how that opens up new possibilities that were previously not possible. The frame is built to be extremely rigid and at this size it is much easier to work on and around so we envision it to serves as a platform for new extruders and feed-stock materials well into the future.

I think your ideas of strengthening the materials with additives is spot on. When I think about the future possibilities of this hobby we are all working in I can't help but to get excited all over again.

Some of the boldest and most interesting developments to come will be in medical and micro biology research fields.

xiando Wrote:
-------------------------------------------------------
> @Tssalo, the question stands:
>
> I have to ask if the strength and weight (actually
> lightness is a better term) of plastic printed
> objects (by printed I mean reprap-prusa.mendel
> style wet extrusion) equals or even approaches
> that of conventionally cast or vaccu-formed
> objects.

What I meant with the example of the 50 g object taking 100 kg load is that the somewhat lesser strength in one direction doesn't by itself prevent using FDM-made objects in any specific application. It's just one issue among many that you have to take into account in the design phase. Sometimes you may end up needing to use more plastic to compensate for the weaker direction, sometimes less because FDM allows making a complicated part in a single piece whereas conventional methods would have required assembling several subcomponents with fasteners. Try injection molding this!

Tsalo, fair enough. I was forgetting that serious players (like stratasys, etc) aren't subject to quite as many of the delamination issues that the hobby printers seem to exhibit, so the inherent weakness the bending forces in many of the amateur prints are probably not evident in more professionally printed items (compressive strength isn't something I'm questioning at all, for all the obvious reasons, it's peeling of the layers...).

You're right...no doubt, that something like the image you present simply isn't practical for injection molding as a single entity, but were I to print this on a large number of the printer people make, I could probably peel tit apart with a reasonable degree of ease...Were it a car hood, could a minor surface defect lead to catastrophic delamination while at speed on a highway? I think it could.

Anyway,. I wouldn't be here if I didn't believe the technology wasn't promising, so I don't mean to be negative, just "cautious".

Thanks for the reply and explanation.