Step 3: Heater Block Assembly

To heat up our material sample to printing temperature, we will need to build an equivalent heater block to the one in our printer hot-end.  The heater block noted is 2" x 1" x .5".  It is drilled for two outside support holes where we will install threaded rod to support the block.  It will also have 2 each 0.250" holes.  One for the heater cartridge and one for the test sample.  the test sample hole has a .08 hole to the outside in the bottom to allow material or gasses to vent similar to a nozzle.
  The other end of the 3/16 rods are mounted in a piece of steel or aluminum to balance the heater block and hold it upright during testing.   Make sure it's steady as you don't want it falling against the acrylic at 300C..!
   The thermocouple twisted wire connects under the nut next to the heater cartridge.  This will measure our sample temperature.
   To adjust temperature we use a variac.  This allows us to dial in any voltage needed to acquire a desired temperature from the heater cartridge.   A word on variacs.....they are NOT isolated, so always turn them off before touching the cartridge leads.

  • 2 each 3/16 x 12" threaded rod
  • 4 each 3/16 nuts
  • 1 each thermocouple "K"
  • 1 each Heater cartridge McMaster Carr 120 volt 80 watt
  • 1 each variac or power source for the heater cartridge
<p>good point we shall not accept any dangerous chemical material to safe our people</p>
<p>If interested, my company, 3DPrintClean is developing a 3D <br>Printer filtration system that filters fumes, unpleasant odors and dangerous concentrations of <br>Ultrafine Particles, making <br>it safe to print in homes and offices. In addition, the solution improves print <br>quality by reducing warping, curling and cracking. See 3dprintclean.com for details. </p>
<p>What about this announcement?:</p><p>http://www.3ders.org/articles/20130721-3d-printers-emit-potentially-hazardous-ultrafine-particles.html</p>
<p>You are correct, a-morpheus...while there seems to be a lot of downplay about the gases being released, we SHOULD be paying particular attention to the particulate matter that is. From a recent report (</p><p><a href="http://ecoh.ca/health-safety-hazards-associated-3d-printers-dr-om-malik/" rel="nofollow">http://ecoh.ca/health-safety-hazards-associated-3d...</a>) :</p><p>&quot;A recent study tested a commercially-available 3D printer and found <br>significant emission of ultrafine particles in the size range 15-65 <br>nanometers (nm). When inhaled, ultrafine particles (defined as particles <br> less than 100 nm in diameter) deposit efficiently in the deep parts of <br>the lungs. The study also found that use of the ABS plastic produced <br>approximately 10 times as many particles as the PLA plastic. For <br>comparison, ultrafine particle emission rates from the 3D printers were <br>similar to the emission rates observed during grilling of food on gas or <br> electric stoves.</p><p>Recommendations to reduce exposures to the emitted fumes and <br>particles include mechanical ventilation with dedicated exhaust, <br>enclosure of the printer, filtration, and choice of a lower-emitting <br>plastic.&quot;</p>
<p>I agree that ventilation is best, the level of flow is the concern I have. Keep in mind that you are only trying to prevent outgassing into the breathing space, not operate a high volume paint booth.</p><p>I live in Alaska and it gets cold enough up (try -60 deg F) here that, if you have a high volume fan, you can EASILY overpower the heaters in these printers if you direct vent with outside to outside air (that is, a loop that draws and vents to the outside environment). All that is really necessary is a decently sealed containment (make a box and silicone the edges) with a small hole in the bottom front left side and a &quot;vent&quot; hole in the top right back side.</p><p>Now a small air pump, which will also likely be pretty quiet, can be mounted to the interior of the box and a small vent hose (we are talking like a quarter inch here) can be fed through the vent hole and to the exterior (careful if you drill through a wall...) In a house I would try to vent to a ventilated basement or attic if possible. Mount the pump inside the enclosure to mitigate any minor sound. I like plexi for the front door because it is nice to be able to see inside... If you want a full seal, add some latches to the closing door.</p><p>This will allow a positive draw into the box without making the air exchange at a crazy rate, and allow it to be pre-heated in the room. You only need to exchange the air once an hour or so to maintain negative pressure inside the enclosure without completely cooling off the printer unit. You could have a higher capacity pump if you want to do a true PURGE at the end of a print, but I doubt that would be a big deal. Some projects that take hours to print would probably benefit from a rig like this, for both particulate and suspended gas mitigation. My two cents.</p>
JagPrint Offer a vast selection of ABS, Printing Material Suppliers, 3D Printing with lightening delivery. <br>http://www.jagprint.com
Hi if is doubtful do the right thing build an enclosure with a venting mechanism. I have been a research chemist who has always erred on the side of caution. Wear a mask and wear nitrile gloves. Never approach these thing without protection. In forty years in chemistry I have observed many guys dying at 40 years of age. Inhaling all these wonderful compounds. I am healthy and 80 many of the others expired from all the overdosing in the air. I never take a chance on any unknown product always used caution.
+1 to venting. My printer is located in a 6x12 shed, one of the first things I did was build a vented enclosure for drawing fumes outside. The venting can also be detached and used for extracting solder fumes =)
Really interesting...so it won't kill you outright...but does that mean that it wont give you cancer in 5 years if you're in your bedroom printing with abs 24 hours a day? I know I can barely stand the smell after a few hours and feel like I'm already growing a tumor...so it can't be completely harmless. I'd like to see a study of all the vapor that abs/pla/line gives off..and what exactly the hardness is of each of them, and if there's a difference between american and chinese abs for instance in the qualities. This is really an interesting subject.
Hey,chimera15, sounds like a great &quot;ible for someone who wants all those answers, to actually do. Seriously.
Invaluable information in this not-so-'ible 'ible!!! Thank you for going through the steps. <br> <br>HOWEVER, I do have a question: What is causing me to get a headache when I print ABS after ~20 minutes? I mean, the HCN levels might be of an OSHA-approved level, but I wouldn't be getting a headache if my body was OK with the altered environment.... My room is roughly 20x20x20 feet and i am generally at the opposite corner of the room when i am printing (so my guess is i'm exposed to the lowest PPMs over there).
1200, It's of course difficult to say, however, there are actions you can take to make a determination as to further actions/resolutions: <br>1. If you're not currently vented, then add a simple vent as shown in the two renderings in the ible. A sufficient vent is made up of a standard 100cfm fan (as in most desktop comp) an inverted storage box and some 6&quot; dryer hose to an exit. <br>2. Most overlook the fact that some stepper drivers emit a lot of noise just above the audio spectrum that can still have an affect. Try running a few prints with no heater and no material letting the stepper go thru their routine. <br>3. The material its self. There are suppliers that sell &quot;odd&quot; colors. Our China contact told us that these &quot;odd&quot; colors may be injection house purges and reject remelts. Reputable dealers will only sell virgin material. <br>4. Styrene can be a source of your issue as it does not dissipate easily. You may want to run the same test as noted in the ible and measure for styrene or &quot;combustible gasses&quot;. If so, do a search on materials that emit almost no odor by others in their blog, IRC and wiki comments. <br>5. Long term exposure to levels higher than 1-2ppm of HCN have shown to cause similar symptoms but again, we saw no low level (0.1ppm) readings within proper operating temperatures excluding trimmer line. <br>6. Check out the following link for additional low level emissions that you may be sensitive or allergic to. <br>fire.nist.gov/bfrlpubs/fire86/PDF/f86017.pdf <br>And again, as we say in all of our ible's, one should &quot;vent all fumes and odors&quot; <br> <br> <br>
ah, some awesome points to consider. but yeah, it seems the only real way to make sure youre not harming your noggin is to vent to the outside world...
...and make it someone else's problem? <br> <br>Perhaps the 3D community (that includes me) needs to think this through a bit harder.
So, then, what do you suggest? Charcoal filters on an active exhaust?
That's what I'm looking at, but 'science' must have looked at this already. I'll be looking around some more.<br>ps I wasn't having a go at you, my interim solution is an open door/windows to the outside...
Well here's what I'm thinking -- I agree with you that &quot;science&quot; must have looked at this already, and therefore determined no need to change the status quo, i.e. venting directly into the environment.<br><br>I remember reading a paper that said heating filament to the levels needed for FFF yields insignificantly low outgassing from both PLA and ABS. It'll take some digging to find the paper, I didn't bookmark it.<br><br>I would imagine that this would change once FFF printing becomes ubiquitous (= higher volume of by-product gas in the atmosphere.
Just so you know in the future, Cyanide has that tell-tale almond scent and taste, as do most compounds it's a part of.
@evilddead- about 1/3 of the population cannot smell cyanide, and of those who can, it deadens the nose to it in short order.
pmowers, you are absolutely correct as this 1/3 note was part of every techncal paper we were able to aquire in our research. There were a few technical documents that implied that this had been tested for, as part of larger tests however, these may be paywalled studies. Thanks for your clarification.
My background is laboratory medicine and we used a cyanide compound to measure hemoglobin in blood. There were a fair number of students and techs who could not smell it, while I could tell it across the room. One of the reasons that HCN was used as a chemical weapon (blood agent) was because it would numb out the olfactory nerves, while at the same time stimulating the respiratory centers of the brain. This is the reason that states use it in the gas chamber, you cannot hold your breath, one whiff and you have to breath more.
Thanks <br>You are correct as this is also noted in the able in section 2 as an alternative detection method.
Excellent work. Instructables needs more careful, rational, and scientific work like this. A *lot* more. :)
BobCat, again thanks for your comments! <br>As mentioned in the ible, there were other materials tested along with 3D Print ABS and 3D Print Nylon. The 2BEIGH3 has hot ends capable of temperatures that will accomodate Tin and Bismuth metals. As new 3D Printing materials come on-line, it's our hope that others jump in on test procedures and methods. <br>Today, you can run polymer and co-polymer combinations and calculations and litterally have the combination extruded for you at any one of several houses. We beleive that this is an excellent move forward in 3D Printing and look to others to add their ibles on test and procedures.
BobCat, thanks for your comment!
wait.. you can use weed-whacker plastic in a 3d printer?? <br> <br>sweet!
Ya, go to the reprap page here: <br>http://reprap.org/wiki/Polyamide#Instructions
This is a nice Instructable with better than usual rigor in its testing. However, speaking as a chemist, I also wonder about what other things are outgassing from the hot plastic. HCN and CO are certainly to be worried about, especially since CO is odorless, but as other commentors have noted, there is a smell associated with 3D printing. If you're smelling something, then something is volatilizing from the hot plastic. What?--probably a mixture of a bunch of things, a complete characterization of which is likely beyond DIY science, although I'd be surprised if someone hasn't written up a paper on it already. <br> <br>So common sense would seen to dictate some level of precaution. Venting your work space would be nice, and don't sleep next to a working printer. Is it any worse than breathing in solder flux fumes or sawdust? I don't know.
Makermike, First, thanks for your comment. We agree, in that venting is always the best approch. We do not want to get into a vendor to vendor comparison as those that wish to can use this ible for that. However, with a little research, we did find comments on blogs from those that had found ABS materials that gave off almost no odors. We did not test that specific material but again as you note, some sort of comparison testing would seem like a worthwhile effort for someone in the 3D Printing community. <br>As a technical note, in that the process from solid to melted back to a solid takes place in a volume the size of the eraser on the end of any pencil, it seems that a simple well placed miniture vacume hose/line would all but eliminate most fumes and odors.
Very well organized. I like the &quot;how to do science&quot; instructables in general, but this is really good. Excellent breadth and depth covering the method, materials, regulatory levels, hazards, etc.
magalyean, thanks for your kind comments. It does mean a lot to us as you can see that there is considerable time, effort and equipment involved. But of course, well worth it to the community!
No really, while I truly am excited about the &quot;maker&quot; culture exploding around us, being a nerd/tinkerer myself, there is so much disrespect for what has come before in many cases, and most disturbingly sometimes a seeming disrespect for rational thought itself at times (my young stepson still swears he could build an over unity generator out of permanent magnets; he has it &quot;all in his head, just needs to work out a few niggles&quot;). I just smile and tell him to build a prototype that works and I'd be overjoyed to admit that I, and Isaac Newton, and the entire edifice of human science to date really, is full of crap. It is simply refreshing to see a 'structable like yours that instructs in solid methods of rational thought after watching my son spend hours on the internet ooh'ing and ah'ing over the youtube videos that &quot;prove&quot; he could build one. He just doesn't get that he is getting intellectually punked by either smart-assed pranksters, or by self-convinced nutcases. Hey, I'm glad he is curious. I just want him to be smart-curious, not gullible-curious! :^D
mgalyean, as a side note, you should have seen the look on our taulman3D physicist face when I told him we were going to generate hazardous gasses and watch as we took videos of the process in real-time. There was this long pause and he just said &quot;intentionally?&quot; He then gave us all a quick course on safety!
Yes, I learned the lessons early on, as a young wild-eyed engineer, I was lucky enough to bump into a much older engineer who after gracefully listening to my ramblings of &ldquo;new stuff&rdquo; commented the following:<br>An inventor&rsquo;s dream is the relentless elimination of technical roadblocks and the only successful inventors are the ones that see the &ldquo;law&rsquo;s of physics&rdquo; as a guide, rather than a roadblock!<br>I'm always pleased to see kids actually &quot;doing&quot; rather than watching.
Nice article, thanks.
Thanks for your comment!
Thanks for the great write up and discussion on all of what I would call 'nagging FaQ's' that sit in the back of the mind .. <br> <br>Well done.
fazgard, thanks for the comment! Again, it is our hope that others can use the ible to test new and inventive materials for 3D Printing as it's relativity easy to have extrusion houses mix new polymers.
REALLY REMARKABLE! I had a nagging concern about my 3D printer offgassing some type of &quot;bad-ness&quot;. <br>I print PLA, and I have been told it is completely safe. If ABS is this safe, then I can only (emotionally) feel good about printing PLA. (of course I would have to test to make sure!) <br>This was so comprehensive and such an incredible public service announcement. <br>thank you so very much!!!! <br>
First, thank you for your kind comments. <br>We've only heard good things about PLA. Some quick research would define what gasses to look for if any and what the proper equipment would be to test. <br>Again, thanks for the comment!
Most impressive ! I do not own a 3d printer (sigh !) but the info you put out there is GREAT for those that do - don't let &quot;Mr. Ocean&quot; get under your skin - trolls of all types exist to simply create misery wherever they roam ! Keep up the great work - this is the most detailed and intelligent 'ible I think I have ever seen.
SenKat, thanks for your comments. I think sometimes when we don't know the answer, and after doing research we find to large a swing in probable results, we are to often left with false impressions. As this is important to us all, we believed it was a worthwhile exercise to nail it down for everyone.
Worthwhile is honestly an understatement - you went over the top - thanks for the great info !
P.S. Faved, followed, and 5 starred !
Thank you for this information-full instructable! Good job!
txdawood, Thanks for your comments. <br>
Is HCN the only dangerous off-gas that can be produced by heating ABS and Nylon in the temperature range used by 3D printing?
charlie, HCN and Carbon monoxide were tested due to their toxicity. <br>For a full list of gasses, download the linked Barnes report for Nylon and the following link for ABS. <br>fire.nist.gov/bfrlpubs/fire86/PDF/f86017.pdf <br>Again, most gas emissions begin at much higher temperatures than we use for 3D Printing. <br>However, as we say in all of our able's, one should &quot;vent all fumes and odors&quot;
Testing for HCN and CO combustion products in melting plastic? Shouldn't you be testing levels of things we know are far more likely to escape, such as Butadiene or Styrene from ABS? <br> <br>Staying in a confined room with a 3D printer using some blends of ABS can be enough to make you keel over, so I'd be more concerned about quantifying exposure to those two carcinogens.
Andy, The focus on HCN was due to it's toxicity. Of course there may be additional gasses depending on the source of the material. We found that even though the results were equal for all ABS tests, during our material &quot;sourcing effort&quot; we had to pay attention to the blog and wiki posting to stay away from known problem vendors. For a complete list of known emissions, download this pdf. <br>fire.nist.gov/bfrlpubs/fire86/PDF/f86017.pdf <br>This document will show all emissions of gasses, but you'll also note that most emissions of these gasses begin at temperatures equivalent to fire. <br>However, as we say in all of our able's, one should &quot;vent all fumes and odors&quot; <br>Also, because these gasses are carried past the sensor on thermals, you should be able to use the able to measure for other gasses with alternate sensors.

About This Instructable




Bio: is an Engineer with a background in electronics, optics, mechanical designs, chemistry, plastic injection molding and plastic die tooling.
More by taulman:Is 3D Printing Safe? or  DIY Testing for HCN from ABS and Nylon 3D Print Material 2BEIGH3 3D Printer Update and call for Testers Nylon Printable 608 Ball Bearing 
Add instructable to: