Building an "Airtight" case with carbon filter.

So i have started work on a almost airtight case. The plan is to have 2 fans pulling a vacuum on the case and exhausting through a carbon filter.

I have the parts listed below on the way or in hand. My wife has recently become pregnant and I don't want to take any chances with stray fumes.
4x8 sheet of fine birch plywood.
http://www.amazon.com/dp/B0067D7DEA/ref … 25410_item - Carbon filter
http://www.amazon.com/dp/B0009JZSKO/ref … 25410_item - 80MM exhaust fans
http://www.amazon.com/dp/B000AYHZHM/ref … 25410_item - door hinge
http://www.amazon.com/dp/B0006N40CK/ref … 25410_item - flush mount handles
Now. While I await all of my parts I have some questions.
I have a QU-BD bed and 30A power supply inbound as well. I'll post more as I complete it.





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How are you handling the cooling of the electronics? the ramps board gets pretty darn hot if its enclosed.

I plan on adding 2x 40mm fans blowing directly on the board.

unless your standing over the machine huffing the fumes i really dont think you have anything to worry about. but a case is always nice for keeping the heat in and drafts out.

and unless your carbon layer is really thin the air might bypass the filter. those fans arent meant to pull air through a "load". they are simple exhaust fans for low resistance applications. air is always going to take the path of least resistance, which might be the area around the blades instead of through the filter.

Attachment 244

It is done.

nice job! i like the filament hanging system!

This is a GREAT idea, since so many people want to over temp the filament, it causes toxic fumes to enter the room where the printer is located. Over time this can become a health problem.

I see no problem in sealing a carbon filter in a way that the air will not be likely to bypass the filter, sure there may be some bypass, but very little.

I congratulate you on your device !

Nice job ^^
I actualy might also create something simulair, Probably in Aluminium since thats what i can find atm alot more easily ^^

My printer is atm in my bed room, Since you sleep 1/3 of your day in that room it wouldnt be the best thing as health goes (Atm i do try to get as much air circulating during prints, But still health is a sacred thing)

Well that or i just move my printer to another room. ;)

I really like the filament concept. Do you leave the filament hanging all the time? The reason I ask is that I read all the time about filament absorbing moisture and contributing to jams and pops in the print. I've always kept my filament in nearly zero humidity containers and never leave it out when not printing. I don't do this based on any prior experience. I do it only because of what I read. It would be nice to know if some of that fear-mongering about moisture was misleading.

Just curious how you deal with it and what problems, if any, you've had.

Thanks for all the kind words!

RobH2 - I have a golden rod in the bottom of the box. It keeps the humidity aound 16% so it stays fairly dry in the box. That is a secondary reason I built the box! It works very well and keeps my nylons dry enough for printing.

Can you explain what a "golden rod" is? That's a new term for me? It sounds interesting enough to get me going on building my own box based on your nice design.

Rob have you ever experienced moisture problems? I ask as I am newish to the print world and we are approaching our humidity season in the NE so far I have not had any moisture problems with ABS stored out in the open.

No I have not but I think I mentioned in an earlier post, I've been hyper vigilant to keep mine in a sealed bucket with desiccant. I have a professional hygrometer in it and it's always around two or three percent humidity. I've never just left ABS out for couple of weeks and then printed with it. The longest mine is ever out is about two days.

When I got started I did a lot of reading and kept reading that ABS really liked to soak up moisture and that could cause jams and gassing or popping gas bubbles in the print. So, I've just always been a good boy and kept it dry. I figured that the more things that I could control and keep from being a variable, the better luck I'd have learning to print. That way if something was not going well, I'd know it was not due to moisture. Plus I kept reading about guys baking their filament over and over in the oven. That doesn't sound very fun.

Its a dehumidifying rod http://www.amazon.com/GoldenRod-18-i.../dp/B005FRFSIM

Our print room is currently 65% and its printing fine. I like to debunk myths if they are truly myths..

I like the idea of the Golden Rod, the cost and the watts too. It cheap and efficient. That's an inexpensive solution for sure. Thanks for the myth debunking Steve. I'm going to help you debunk more and leave some ABS out for a few weeks to see what happens.

In the name of debunk I have a few meters soaking in a bucket of H2O ill let it soak till tomorrow night then run a print.

http://i113.photobucket.com/albums/n...pscgajqgmu.jpg

ABS I am not worried about even at 65%. Nylon on the other hand prints like crap when its got any moisture in it. Print with nylon at 65% and your going to have a bad day!

Good luck myth busters!

Quote:

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Originally Posted by beerdart

In the name of debunk I have a few meters soaking in a bucket of H2O ill let it soak till tomorrow night then run a print.

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Awesome test. Good thinking...

Ok ran the marinated ABS last night and it appears to have some filament out-gassing on the finished edges. Then ran the same filament @ room humidity of 55% and you can see the difference. So conclusion do not soak your ABS in H2O but I dont think high humidity will bother it much. Ill post back in the summer when humidity hits in the 90% range..
http://i113.photobucket.com/albums/n...pseqkndzqa.jpg

http://i113.photobucket.com/albums/n...ps579srajn.jpg

http://i113.photobucket.com/albums/n...psq2xk66vb.jpg

Ah, marinated ABS. Let me get my fork and knife out and tie my 3d printed bib around my neck....

Yes, I figured it might not go too well but you don't know until you test it. That's the whole tenant of science.

Great test. It's good to see a good photo of what severe "out-gassing" looks like. If for nothing else, the test gives us a good image of that so when it happens we'll know.

I'm a little confused about what you are saying about the same filament at 55% and 90% humidity. What are you doing there?

What I need to do (and I will when I get some time) is leave a piece of filament out for 1-day, 1-week and 1-month and then print the same object against fresh and humidity-free filament. Then examine them closely and see if I can tell which is which. In a perfect world, you would not be able to. That test will take some time as I'd need to take the "month" piece out now and then wait 3-weeks to take out the next piece....etc. I will do this one day soon.

Explain the next step was confusing and report back with the results. Nice work...

What I mean about 50% that is my current room humidity and in the summer it will be 90% so Ill post back when the humidity is high to see if I get any out gassing.

Ok, I gotcha. That makes sense. You are just saying that right now, with your filament always out, you don't have problems in a 50% humidity environment. If that's the case, that's good to know. I have AC so I don't really ever get much more than 50%. So, I maybe should not worry about it too much. I've printed on a roll for 3 or 4 days but then I always put it away. I haven't had any moisture problems that I know of. I need to do the test I mentioned earlier. Maybe I'll stop and do that tonight.