Hey All,

I believe one deficiency that still exists between reprap and commercial machines is a good support structure. It looks like little has been worked on in this area or maybe I am looking in the wrong areas. Commercial machines have soluble support structure or a easily broken away structure. The material they use is a dark brown plastic similar to the model material. Does anyone know abouts this material?

Another approach might be to use an elevated temperature to unlock the support material - if the support and model material were both thermoplastics but one had a significantly lower melting temperature... at least something to think about.

Thanks,
Thorp

Hi Thorp,

... this 'brown', soluble material is a sort of longmolecular sugar - the main problem with the support-material seems to be the adhesion to the printed material

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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]

Interesting information about support material here: http://ifeelbeta.de/index.php/support/quest-for-support-1 and here: http://ifeelbeta.de/index.php/support/quest-for-support-2

The workings of this chemical solution is impressive, but do we really want to pour such solutions down the kitchen sink?

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Sodium Hydroxide is sold as drain cleaner for doing exactly that!

Not sure what else they are using as they are keeping it secret for now.

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[www.hydraraptor.blogspot.com]

Even if this solution were plain water, you'd at least pour the plastics into the environment. This isn't even allowed in Gemany and likely not in the whole European Community.

Did nobody try to build break-off supports, yet? They're widely used in Stereolithography and even with the 3D Systems ThermoJet process (wax printing with an inkjet-printer type toolhead).

See the red surfaces:



Picture taken from here: [computer.howstuffworks.com]

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Yes you can do break off supports with Skeinforge but I don't think they work particularly well because it is a single material. I believe commercial machines use a more brittle plastic for the support to make it easy to remove. PLA might work as a break off support. You could also put it in hot water to make it go jelly like. I expect that would make it easy to remove if you can get to it.

Newer machines have moved to soluble support though because it is a more complete solution as you can remove it from places you can't access.

Does anybody know what commercial machines do with the soluble waste?

Edited 1 time(s). Last edit at 06/20/2010 02:56PM by nophead.

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[www.hydraraptor.blogspot.com]

> Even if this solution were plain water, you'd at
> least pour the plastics into the environment.

PLA is biodegradable, so that shouldn't pose any problems. As long as it wont solidify at a later stage, and clog up some piping or pumps of course. But then, you could just dump it in your garden instead.

> Did nobody try to build break-off supports, yet?

Of course. Everything in the same material, and it may require quite a lot of post processing.
A few examples:
http://www.thingiverse.com/thing:2164
http://www.thingiverse.com/thing:3130

We had both an alaris and dimension elite at my place of work. The dimension works very similar to these printers and it used a soluble support material. After the parts were complete, we would wash them in a bath. The bath was a solution of water and lye and the bath used ultrasonics to further break away the support. Also, fairly interesting, is that the dimension uses disposable trays to print on. The surface is fairly coarse and it would always lay down several layers of support material before starting to build material support.

VDX- is this support material that same thing that you are talking about- a 'longmolecular sugar'. If it is, has anyone tried to extrude it? The support material is handled in the same manner that the model material is and the heads are identical, though I don't know about temperatures and such.

The alaris used a gummy clear solution that was later removed with a high pressure washer, but that whole process is completely different than what we have here.

Hello Thorp,

Sorry, this is slightly off topic. I see that you have an Alaris and a Dimension Elite.

We currently have an Eden 333, which is the same type of printer as the Alaris, just a few years older and has some more advanced features. We are starting to have some issues with the Eden, specifically, it breaks down too often and is very expensive for us to keep running.

We are seriously considering replacing it with a Dimension Elite. I'm aware that we will loose the ability to build rubber prototypes and the resolution won't be nearly as good. That said, I have not seen any models built on an Elite yet.

If you don't mind, could you please send me a brief email about the pros/cons of Alaris vs Elite.

I thank you in advance.

David

I still believe in my “Fixturing” process.

[probersideas.blogspot.com]

Ever see how they build a building etc from concrete? They buid a form and/or add rebar for a strong build. It works, so buy some cheap toothpicks and use them as support. They can be used internal or external.

... some ten years ago we had some brainstorming how buildings or smaller objects will be built in some years - my idea was a swarm of small robots, building 50mm high hollow boxes representing the later walls ... and other bots pour hardening material in this boxes, so they solidify to the building-structure.

You can embedd some inner structures/tubes for wirings, other support or water, and so on ...

One problem was the support vor overhangs and ceilings - here some temporary columns or elevated plates should do the job ...

Now imagine something similar in a micro-range, where a head placing prefabbed parts in position and the other welding/moulding them together ... much faster than building/curing the complete volume out of a single fluid material

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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]

Prober and Viktor, part of the allure to a 3D printer is the ability to choose a stl file, hit go, and out your part comes sometime later. In my opinion, when much human interaction is required to make a print, that benefit quickly diminishes.

Cepdave, My experience with both printers has been quite different and I think they excel in different areas. I have printed boxes and boxes and boxes of parts on the elite but only had the chance to print a few parts out on the alaris . This is because we have had the elite for much longer than we have had the alaris but also because the alaris print heads seem to clog often. The alaris is picky in that I think it needs to be continually run to keep the print heads clean and unjammed. One or two prints a month for us on the alaris wasn't working and the tech support cost something like four grande per year. The alaris will create a much higher resolution because the technology is different. So one of it's strongpoints is getting a nice, accurate, high resolution model. The main drawback with extruding thermoplastic as the elite does is the z height- .009 thou layer resolution I believe? It makes for a jagged surface- similar to a topographic map. The alaris Z resolution is much finer but this also can significantly add to print time if you have a tall part. Another advantage of the elite is the material properties. With the ABS, we were able to drill and tap holes without issue. We have a industrial designer that builds quite a few prototypes by hand. He's able to melt our models to modify them- he can work with the abs material in this manner but not the alaris. Then there is the serviceability aspect. We have have had problems with our elite, but not many and most of the time we are able to fix them ourselves. The technology is not advanced compared to the alaris and so it is not so intimidating. Hope that helps.

I have a friend in Taiwan with a Uprint. Last we talked, he was interested in cracking the system so that he would be able to supply his own material and would then avoid the inflated cartridge cost. If he goes down this route then he will be in search of raw support material and I will be sure to inquire.

I don't have time at the moment to look through the patent but I thought it best to pass the information on.

Stratasys' solution:
patent 6,790,403

I am unclear of the implications a patent has on an open source project such as reprap. Anyone know?

The implications of patents is a whole different story, but I could see benefits for the open source hardware world. As you're free to build and use patented technologies for your own purposes self-builders and accordingly GPL-addicted people have a boon which can't be copied by the commercial guys.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I suspect nothing unless it effects the sales of stratasys and if it does and there are patents which have been crossed, expect a world of pain.

But then I am not a lawyer

Interesting that when they discuss the requirements that PLA ticks a lot of the boxes. The base monomer is an acid, so can be dissolved with alkali. Also it explains why PLA sticks well to a lot of things (e.g. glass, copper, ABS), apparently this is also because the monomer is an acid.

The only problem I see with using PLA for this role is that the glass transition is a bit low so you can't have your chamber as hot as Stratasys do. Mind you we can't anyway because the machine is made from plastic instead of metal.

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[www.hydraraptor.blogspot.com]

According to the MSDS sheet for Stratasys' P400SS soluble support material, it is an "Acrylic Copolymer Thermoplastic". Unfortunately, they don't have a specific CAS# (just says 'mixture). The SR-30 soluble support material is a "Terpolymer of Methacrylic Acid, Styrene, and Butylacrylate", CAS # 25036-16-2 (oddly, they list the percentage as 'mixture')

All of the support material MSDS sheets are here: [www.fortus.com]

It may be worthwhile to look up the MSDS sheets for the HP branded Stratasys units now being sold in Europe to see if they offer any additional clues (though they probably have nothing more than the above information).

Edited 2 time(s). Last edit at 07/02/2010 12:05PM by Have Blue.

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[haveblue.org]

Interesting thread this is

I took a closer look at the Statasys patent for water soluble support material (#6070107). At the end is reads:

Specific examples of water soluble plasticized PEO compositions that can be extruded into flexible filament and successfully extruded through a Stratasys FDM head are presented below:
______________________________________
EXAMPLE I
Calcium Carbonate* 22.3 wt. % PEO (200K MW) 65.0 PEG (600 MW) 8.6 Grilamid L16

So, as far as I can tell it is basically 'just' as mixture of:
1) filler material (Calcium Carbonate), basics material
2) Stratys patented material PEO , known as Aquazol (CAS #25805-17-8) but freely available through ISPCorp and others
3) PEG, polyethyleneglycol, marketed as 'carbowax' by dow chemicals, dont know if there an non commercial alternative
4) Grilamid, polyamide

Shouldnt be that hard to get a hold of these, mix together and replicate the water soluble support material. Off course pricing could be a problem in the end, but may be worth further investigation

hey just a thought

Thorp Wrote:
-------------------------------------------------------
> We had both an alaris and dimension elite at my
> place of work. The dimension works very similar to
> these printers and it used a soluble support
> material.
-------------------------------------------------------


how similar. what i mean is would it be possible to buy support material direct from dimension and either test it to see what it is or use it directly? how much would this cost?
dont really know if this is even viable
cheers
Mevo

All my searching had let to this. This is the ultimate solution. PVA sucks, we have to come to with something else. I have a HYREL "engine " that can do 4 extruders no problem, but there's boo reasonablw super material out there.

My dept just got a mojo and I saw this material (looks like already in 1.75 mm filament). I'll try it and report back. It's super expensive, I want to say like 300/kg because it comes with an extruder (and because they can), but I'll give it a short.

I want to follow up with this. The support material from stratasys (SR-30, [www.amazon.com]) may cost an arm and a leg, but it's totally usable in most 1.75 mm extruders. They use 0.05" filament diameter (1.27mm) so it's a good deal smaller, but it worked in my Davinci 2.0 with NO MODIFICATION! It's $400/80 in^3 (~1.3kg) but it works and I've found plain water will dissolve it slightly enough to get it loose, although technically, you need to use their tablets that help degrade/dissolve it (http://www.amazon.com/Stratasys-Ecoworks-Tablet-Cleaning-Agent/dp/B00MC1G3B0). Smaller is better for filament IMO as long as you have good quality control/tolerance, I'd actually like to see a transition to 1.27 for all extruders, but it might be worth make a modified extruder just for this stuff.

nicksears - I have a Dimension Elite at work, typically have lots of left over filament once the machine says it's actually empty, frustrated about the waste, I've been trying to figure out how to make use of that extra support material. What temperatures do you set your Davinci extruder and bed to? Do you find it plays nicely with PLA? Thanks!

Don't have a davinci anymore, but it should work on any open source printer. I used the same temps as I use for ABS (240/110) but didn't do much testing, so I'm sure it could be optimized. I also only tried with ABS.

I'm excited about DOW's new universal support material (says it works with ABS/PLA/PETG/TPU) although it is a bit expensive (https://taulman3d.com/buy-direct.html) Anyone try it yet?

Thanks for the info, tips - will give it a try.

Hadn't heard about USM - I'll be interested to hear how it compares with Verbatim BVOH that I'm using now if anyone posts - I find the BVOH leaves stringy deposits behind that require manual removal, rather than completely dissolving away - appears I'm not the only person experiencing that. I haven't tried PVA, but the comments/reviews that I read when I bought my printer sounded like BVOH was the superior of the two.