Suggested donation per cm/in of PLA used?

[Lokkju Brennr]

Do we have any sort of suggested donation to pay for the cost of 3d printing materials used?

I'm planning on doing a bit of printing, and if we have a guideline, it'd be useful.

Loki

[Eric Miller]

Printrbot is still having their sale, http://printrbot.com/shop/1kg-3mm-pla/

The reprap is dangerously low on PLA plastic.  I'd suggest an ad-hoc fundraiser to buy a 1kg spool.

The remaining PLA is this https://ultimachine.com/content/pla-3mm-green-translucent-1lb so the cost can be calculated based on weight of the printed object.

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[Eric Miller]

Also it's $12 shipping for that green PLA from Ultimachine.

[Eric Miller]

And actually, come to think of it we approved $20 back in November that I don't believe was ever spent: http://wiki.hacdc.org/index.php/Regular_Member_Meeting_2012_11_13

The total for the Printrbot plastic is $50.58 shipped.  So perhaps we can get the Board and Treasurer to approve a $30 expenditure for the full cost of the spool.

[Lokkju Brennr]

Yeah, weight does seem like the best measure

/me starts hunting for a scale

In lieu of that, as the printer software gives an estimation of centimeters of PLA to be used, it seems:

PLA is 1.24g/cc

3mm diameter == 7.06858mm2 x 1cm == 0.87650392g per cm of 3mm PLA

The ultimachine plastic, including shipping, comes out to about $0.07/g, making the PLA come out to ~6.2c/cm

gives me a ballpark to start with, at least.

As for ordering more, mirage in now in charge of the 3d printing stuff, right?

Loki

[Paul Fields]

I sent something a few weeks back that never showed up about a man that built a $250 extruder and won the Desktop Factory prize for doing so. With the extruder you can make spools from cheaper pellets that can be colored and various labs are working on color changing materials that can be used to print various test apparatus.

The normal pellets are cheaper than spools and somebody figured the extruder pays for itself at 10 pounds maybe kilos.

Combined with a grinder mistakes be recycled further increasing economy and return on investment.

[Lokkju Brennr]

I saw that, and it looked like a decent project idea.  Not too complicated either...

Loki

[Eric Miller]

The length cost calculation will be really helpful.  The Lyman extruder only works for ABS from what I saw so unfortunately it's not something we can use.

[Justin Myers]

We have that bucket of mistakes, rafts and other scrap printed plastic underneath the drill press table in the workshop (next to the Cupcake), which would be really handy for something like this.

On Thu, Mar 21, 2013 at 5:49 PM, Paul Fields <evilrob...@gmail.com> wrote:

[Matthew Hines]

Anyone willing to work on building a Lyman extruder please volunteer explicitly now. The Lyman extruder should work with PLA, and most other plastics. Having our own extruder is probably the best way for us to go. Besides our own use, we could probably buy it back renting it out to other hackerspaces (and earn some PR).

At least 20m of PLA is available at the space, and most print jobs use <2m. At only a few jobs per week, that filament may last a while. $0.50/m is a reasonable donation for consumption.

By the way, what about Project 3DP? It might be wise to allocate some Project Awesome dividends to finance plastic, or a filament extruder.

Some other options:
*) We could probably trade some ABS for PLA through juri. AFAIK this would be at an ~0.5x exchange rate.
*) There is a lot of ABS at the space. Fairly trivial modification to our extruder may enable us to use it.
*) Nylon filament, in the form of weedwacker line, is about 3x cheaper than PLA/ABS filament. Not sure about quality issues though, and the extruder would need to be modified (same as for ABS).

[Eric Miller]

On Thu, Mar 21, 2013 at 6:37 PM, Matthew Hines <spamfree...@gmail.com> wrote:

Anyone willing to work on building a Lyman extruder please volunteer explicitly now. The Lyman extruder should work with PLA, and most other plastics. Having our own extruder is probably the best way for us to go. Besides our own use, we could probably buy it back renting it out to other hackerspaces (and earn some PR).

I don't believe any plastic is infinitely recyclable, and I think PLA is more difficult to recycle even once.  I have not heard of anyone recycling PLA but maybe you can find some evidence.

At least 20m of PLA is available at the space, and most print jobs use <2m. At only a few jobs per week, that filament may last a while. $0.50/m is a reasonable donation for consumption.

It's generally better to plan early rather than wait until it runs out and then have the printer be unavailable for weeks while someone tries to organize a purchase and UPS trucks up more plastic.

 

By the way, what about Project 3DP? It might be wise to allocate some Project Awesome dividends to finance plastic, or a filament extruder.

There should be another acrylic tip container for the 3D printer.  Previously all donations have been allocated as "general income" so anything people have put towards 3D printer usage hasn't been earmarked back to 3DP, which also has never had funds allocated due to zero votes.

 

Some other options:
*) We could probably trade some ABS for PLA through juri. AFAIK this would be at an ~0.5x exchange rate.

I'd rather do business with someone that doesn't try to undercut the value of the material by 50%.

 

*) There is a lot of ABS at the space. Fairly trivial modification to our extruder may enable us to use it.

It's not trivial to soak the hot end and hobbed bolt in acetone and thoroughly clean it.  ABS is caustic to human health and is worse for the environment.  We should only use PLA.

 

*) Nylon filament, in the form of weedwacker line, is about 3x cheaper than PLA/ABS filament. Not sure about quality issues though, and the extruder would need to be modified (same as for ABS).

WWS is often contaminated with fiberglass to strengthen it, and it is hydrophilic so it must be baked in an oven at 300deg for 4 hours before use, and cannot sit unused for any length of time.

Conclusion: Buy more PLA.

[Julia Longtin]

Buy more PLA, but if you run out, I can show up with a bit of it. There's no reason for a 3d printer to go un-used. :)

I already dropped off some small samples at the space, and will make an effort to drop off another few meters (black, this time) when I get back into town. If the space runs out, I can arrange with someone to drop off my spool of green.

-- Juri_

--

[Philip Stewart]

///////// ABS is caustic to human health and is worse for the environment.  We should only use PLA. ////////

Echo that.

/////// Conclusion: Buy more PLA. //////

& echoed.

[sound of zen exercise of someone trying to kick himself in the butt to chip in for more PLA. When some horridly time-intensive things are done here, I will do exactly that.]

Phil

Mar 21, 2013 07:49:40 PM, Bla...@hacdc.org wrote:
On Thu, Mar 21, 2013 at 6:37 PM, Matthew Hines spamfree...@gmail.com> wrote:
>
>

Anyone willing to work on building a Lyman extruder please volunteer
explicitly now. The Lyman extruder should work with PLA, and most
other plastics. Having our own extruder is probably the best way for
us to go. Besides our own use, we could probably buy it back renting
it out to other hackerspaces (and earn some PR).
>
>I don't believe any plastic is infinitely recyclable, and I think PLA is more difficult to recycle even once.  I have not heard of anyone recycling PLA but maybe you can find some evidence.

>
>
At least 20m of PLA is available at the space, and most print jobs
use

>It's generally better to plan early rather than wait until it runs out and then have the printer be unavailable for weeks while someone tries to organize a purchase and UPS trucks up more plastic.
 
>
>
By the way, what about Project 3DP? It might be wise to allocate
some Project Awesome dividends to finance plastic, or a filament
extruder.
>
>There should be another acrylic tip container for the 3D printer.  Previously all donations have been allocated as "general income" so anything people have put towards 3D printer usage hasn't been earmarked back to 3DP, which also has never had funds allocated due to zero votes.
 
>
Some other options:
>
*) We could probably trade some ABS for PLA through juri. AFAIK this
would be at an ~0.5x exchange rate.
>
>I'd rather do business with someone that doesn't try to undercut the value of the material by 50%. 
>

*) There is a lot of ABS at the space. Fairly trivial modification
to our extruder may enable us to use it.
>
>It's not trivial to soak the hot end and hobbed bolt in acetone and thoroughly clean it.  ABS is caustic to human health and is worse for the environment.  We should only use PLA.
 
>
*) Nylon filament, in the form of weedwacker line, is about 3x
cheaper than PLA/ABS filament. Not sure about quality issues though,
and the extruder would need to be modified (same as for ABS).
>WWS is often contaminated with fiberglass to strengthen it, and it is hydrophilic so it must be baked in an oven at 300deg for 4 hours before use, and cannot sit unused for any length of time.

>
>Conclusion: Buy more PLA.

 ;
>
 ;
>
 ;
>

[Julia Longtin]

phil,

repeat those statements for nylon, as well. caustic, nasty stuff.

-- Juri_

[Philip Stewart]

[assumes form of spheroid reflector]

[leaves out ye olde tales of toxicity for sake of time]

Between a susceptibility to chronic bronchitis and experiences exploring sites I might have opted not to explore, I am keen to keep the air (etc.) clean if I can!

[David McInnis]

I've been wondering how to re-pay the space for my own (minor so far)
PLA useage. Weight seems to be the best route, to me.

Just to make other views known.. I'm all for using ABS.
There are times when ABS just makes more sense. I'm hoping to find
some time eventually to work out the extruder issue. (I'm also hoping
to experiment with nylon and maybe finding some form of soft material
to work with, maybe silicone or some form of foam)
-David Mc

[Matthew Hines]

We should support at least occasional use of non-PLA plastics for
specialty parts (eg. weather-resistant). The tiny quantity of hydrogen
cyanide produced by melting ABS is probably equivalent in toxicity to
the alcohol fumes from an open beer bottle.

However, I do agree that ABS is less desirable than PLA for most parts,
especially if they have a short lifetime. We have at least 2kg (200m,
~$100) of ABS in the space. Selling half that for PLA would be wise.

[Peter Edworthy]

AFAIK the difficulty with recycling PLA / converting pellets to filament is drying it first. This guide gives some idea as to exactly what is required:

http://www.natureworksllc.com/~/media/Technical_Resources/Processing_Guides/ProcessingGuide_Crystallizing-and-Drying_pdf.pdf

So I don't think that it's practical for us to think about manufacturing PLA filament from pellets.

That's not to say that we couldn't produce a recycled B grade filament. What we would need to know is:
- What is the minimum quality needed for 3d printing. It obviously doesn't need to be perfect as filament that has been left out still works, at a reduced quality owing to ooze.
- How much have we degraded the PLA by printing with 'damp' filament.

It would be interesting to experiment but there is a real chance that we would discover that the PLA scraps have been degraded too much to be used.

We could also go another way and put our PLA scraps into boiling water and then bury/compost them and find out how long it takes for them to breakdown.

Thanks,
Pete

[Philip Stewart]

Actually quantifying the fume toxicity, whether by literature review or by experiment, would be preferable to guessing.

In any case, we ought to have a fume extractor in our sights if we are going to do this stuff. Right now any fumes -- whether simple respiratory irritants or serious toxins -- will hang in the air without sufficient ventilation.

Situating a fume extractor and the equipment it serves near a ventilation point at a window is another story.

All materials we use involve trade-offs of various sorts. Where we strike the balance will be nonlinearly influenced by our desire, our personal habits of risk-assessment, and whether we have a stock of stories of mysterious illnesses and toxic exposure. So, minimally: quantify.

Phil

[Matthew Hines]

AFAIK, there is a donation offer for a fume hood, offers to build a fume hood, plans to accommodate it, and significant demand for it far beyond 3D printing. Fume hoods are technically trivial.

My (unprofessional, don't sue) understanding of cyanide is that it chokes cellular metabolism in sufficient quantities. Acute exposure insufficient to cause histotoxic hypoxia would seem harmless. Notably, dangerous forms of the cyanide ion occur naturally, in such things as cherry pits. Cherries pits are commonly consumed accidentally without incident.

Finally, it is burning ABS produces cyanide, and that can be mostly avoided. Specifically, not leaving the extruder idling at 220C for 15 minutes or more is wise.

[Philip Stewart]

Well, cyanide, as I understand it, is not the only thermal degradation product from ABS that is toxic. A more thorough look at ABS is appropriate.

"...styrene, various nitriles, aldehydes, acids, and a significant aerosol factor" are cited as thermal oxidative degradation products of ABS in one article I've looked at. I'm not a chemist, so I'm not the right person to assess the studies I am looking at for methodology and inferential soundness -- this is just to note that cyanide, while notable for its potential as a toxin, does not exhaust the mix of stuff that the useful polymer can break down into (the article quoted here does not appear, in the preview excerpt, to address cyanide). I can acquire a much broader sample of the toxicology literature with the time to devote the appropriate keystrokes, but this isn't the right weekend for me to undertake a lit review.

Anyway, +1 to installation of a fume hood / extractor. :)

Phil

[Matthew Hines]

It seems highly doubtful even the most extreme use cases for ABS
filament at HacDC would present a hazard on account of those organic
volatiles.

Looking at "Acrylonitrile Butadiene Styrene Copolymers (ABS): Pyrolysis
and Combustion Products and their Toxicity - A Review of the
Literature", it seems styrene is the dominant organic volatile,
occurring as <10mg per gram of material pyrolized. Supposing 10% of our
plastic pyrolyzed into vapor as 1kg was printed, approximately 1g of
styrene vapor would be produced. If this vapor remained within a 27m^3
area, and the air had a mass of 1kg per meter, styrene gas would amount
to 1 part per 27000 parts by weight, or about 37ppm. The Permissible
Exposure Limit for styrene vapor appears to be 50ppm.

These figures represent a significant overestimation. For starters, we
are highly unlikely to print 1kg of ABS before ambient air circulates
well beyond 27m^3, and the pyrolysis rate is almost certainly far below
10%. Further, styrene gas is heavier than air. Finally, other organic
volatiles appear to be produced at rates one or two orders of magnitudes
lower, pushing them deeper into the very low ppm range.

Ultimately, we *have* been using ABS with the makerbot for some time
now, without issues.

Disclaimer: Unprofessional, don't sue.

That said, a fume hood is still a good idea, if only on the off chance

[Philip Stewart]

It still merits more of a look (which I will give it, first via the paper you cite).
The permissible exposure limits are worth investigating for the history of influence that led to them -- strong political-economic forces operate on the establishment of the limits. They may be reasonable -- they may be wishful.
As for using ABS without issues -- issues are cumulative and not necessarily accurately attributable.

Doubt can cut both ways -- as I say, this is a high-order nonlinear issue. If you've suffered unaccountable health problems potentially attributable to a workplace toxin or hazardous waste that has caused a building to be condemned, then the picture shifts. Desire plays in. "Hazard" likewise is a slippery term. Caveat user.

Phil

Mar 22, 2013 04:15:36 PM, Bla...@hacdc.org wrote:
It seems highly doubtful even the most extreme use cases for ABS
>filament at HacDC would present a hazard on account of those organic
>volatiles.
>
>Looking at "Acrylonitrile Butadiene Styrene Copolymers (ABS): Pyrolysis
>and Combustion Products and their Toxicity - A Review of the
>Literature", it seems styrene is the dominant organic volatile,

>occurring as plastic pyrolyzed into vapor as 1kg was printed, approximately 1g of

>styrene vapor would be produced. If this vapor remained within a 27m^3
>area, and the air had a mass of 1kg per meter, styrene gas would amount
>to 1 part per 27000 parts by weight, or about 37ppm. The Permissible
>Exposure Limit for styrene vapor appears to be 50ppm.
>
>These figures represent a significant overestimation. For starters, we
>are highly unlikely to print 1kg of ABS before ambient air circulates
>well beyond 27m^3, and the pyrolysis rate is almost certainly far below
>10%. Further, styrene gas is heavier than air. Finally, other organic
>volatiles appear to be produced at rates one or two orders of magnitudes
>lower, pushing them deeper into the very low ppm range.
>
>Ultimately, we *have* been using ABS with the makerbot for some time
>now, without issues.
>
>Disclaimer: Unprofessional, don't sue.
>
>That said, a fume hood is still a good idea, if only on the off chance
>
>On 03/22/2013 06:00 PM, Philip Stewart wrote:
>> "...styrene, various nitriles, aldehydes, acids, and a significant aerosol factor" are cited as thermal oxidative degradation products of ABS in one article I've looked at. I'm not a chemist, so I'm not the right person to assess the studies I am looking at for methodology and inferential soundness -- this is just to note that cyanide, while notable for its potential as a toxin, does not exhaust the mix of stuff that the useful polymer can break down into (the article quoted here does not appear, in the preview excerpt, to address cyanide). I can acquire a much broader sample of the toxicology literature with the time to devote the appropriate keystrokes, but this isn't the right weekend for me to undertake a lit review.
>

[Matthew Hines]

>>>unaccountable health problems potentially attributable...
Strongly agree. At the same time, ABS presents a very minimal risk,
particularly given the extreme pessimism of the estimations I made, and
that pyrolysis is probably not actually occurring.

At the end of the day, it would be nice if HacDC had a fume hood setup,
along with new shelves and less junk. In the meantime, I think we should
still move forward and support PLA alternatives. Nothing stops us from
opening the windows as we go into summer, and by winter we will surely
have fume hoods.

[Matthew Hines]

The PLA stock at HacDC has absorbed significant moisture, and the
problem seems to be getting worse. We would benefit from a controlled
environment for 3D printers regardless of filament type.

[Philip Stewart]

What is the sign of the absorption of moisture? Has it swollen? (Swollen unevenly, e.g.?) Frayed at the outer surface? (ick if so...)
How about a controlled environment for storage of the plastic stock? (A de-humidor?)

[Paul Fields]

Metal box with a big bag of dissecant?

[Timothy Reuter]

Does anyone here have access to a SLS printer, such as a powder printer or a light polymer printer (like Form 1 or B9 Creator) that I might be able to use for an evening or afternoon? I have a project I am working on that could benefit from being able to use one. Thank you. -Timothy

 

[Lee Ciereszko]

I think the other maker space in Reston/Herdon has one. He is only open on Thursday evening last time I was there and he seemed nice enough; offering to print something out without compensation. 

Lee  N4TCW

Where's Lee?

http://map.findu.com/n4tcw

On Mar 25, 2013, at 1:52 PM, Timothy Reuter <ti...@yahoo.com> wrote:

Does anyone here have access to a SLS printer, such as a powder printer or a light polymer printer (like Form 1 or B9 Creator) that I might be able to use for an evening or afternoon? I have a project I am working on that could benefit from being able to use one. Thank you. -Timothy

 

--

[Eric Miller]

Karl hosts an "open hack night" just about every Thursday from 6-10PM, with an announcement of the planned activities to their mailing list on Tuesday (tomorrow).  The location is Cortona Academy in Herndon.

[Timothy Reuter]

Hi Lee,

Thanks for the tip. Are you referring to Reverse Space or is it another hackerspace?

Timothy

---

From: Lee Ciereszko <n4...@yahoo.com>
To: "Bla...@hacdc.org" <Bla...@hacdc.org>
Sent: Monday, March 25, 2013 3:05 PM
Subject: Re: [HacDC:Blabber] SLS Printer

[John Yang]

I use one of those extra large ziplock bags to store my filament with a bunch of large desiccant pouches thrown in there with the reels.  Otherwise I've heard that you can dry out a reel in an oven at warm setting (usually below 200F) for 2-3 hours.  I've never tried this, since my ziplock bags with desiccant has worked ok for me so far.

[Peter Edworthy]

Hi,

To dry out PLA it needs to be below 60C / 140F to avoid the water starting to degrade the filament. Lots of desiccant and leaving it for a long time would be simpler.

[Lee Ciereszko]

Reverse Space

Lee  N4TCW

Where's Lee?

http://map.findu.com/n4tcw

[Matthew Hines]

Steam is frequently emitted from the nozzle when extruder is used, and in increasing quantities. Further, some bubbling and other defects have been getting increasingly worse.

Nothing major for now, but ideally we would eventually create a small dehumidified, heated, vented chamber for the 3D printers and their filament. Some have built 3D printers into such enclosures.

Storing extra filament in a dehumidified environment will not resolve the problem, since a single spool is likely to remain loaded for months at HacDC.

We could also bake our filament periodically, if we had a temperature controlled oven around.

[Philip Stewart]

/////// Storing extra filament in a dehumidified environment will not

resolve the problem, since a single spool is likely to remain loaded

for months at HacDC.////////

Hmm. Could keep a spool by the printer for small runs of plastic, & run lengths that seem appropriate out to the dispenser spool from the storage spool...

Steam. Heh. That's got to produce anxiety about one's creations, to be sure. Eek!

Phil

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