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How can I deconstruct this project in a safe way?

How can I deconstruct this project in a safe way?

How can I deconstruct this project in a safe way?

(OP)
Disclaimer: I am a C.S. engineer and not a mechanical so that is why I am asking the following.

What I would like to do is teach my kids how to be resourceful but in a thoughtful / safe way.

The project I am thinking about is to make a ball that will screw onto the end of an air hose and can be used to clean out our very long clothes dryer duct.

I know I can buy an item like this for cheap like http://shop.air-care.com/fg0001 but that is not the point. I want to use this "easy" project to show my kids how to think and learn more myself in the process.

I found where someone did what I am looking to do with a foosball at this site http://www.instructables.com/id/Reverse-Airflow-No... but they used little to no science.

What I would like to do is look at air flow rates from my compressor and then try to calculate and comprehend the "pressure" that will come out of X number of 1/16th inch holes in some object attached to the air hose.

I would like to start off with some materials that will fail in a semi safe way to bring in the topic of material choices. I was thinking of a potato then ping-pong ball then racket ball then something stronger but with not enough threads, or something with enough thread holding strength but the material blows out the top, etc.

What I would love to eventually get to in this process is an attempt to 3D print some of their designs and have them test out or experiment with design options. We don't have a 3D printer but we do have a STEAM Lab in our small town where we can work with printers. I think the printers are MakerBot ABS printers but not 100% on that.

I realize this is actually a big project to do correctly in a safe manner so that is why I turned to you all.

If this is not the right place for this topic would you please redirect me?

Regards,

Pippin

PS: here is the compressor I have: http://makitatools.com/en-us/Modules/Tools/ToolDet...
which does have an adjustable regulator on it.

RE: How can I deconstruct this project in a safe way?

Compressed air and kids?
Dangerous combination.
Frankly, I'd try to come up with activities that don't involve stored energy.

Mike Halloran
Pembroke Pines, FL, USA

RE: How can I deconstruct this project in a safe way?

(OP)
Mike, I appreciate your reservations but feel that I would much rather be around and with my kids while they learn these things than leave this up to someone else or just trial and error. I learned most things the hard way and would like to at least give my kids options ;)

Regards -- Pippin

RE: How can I deconstruct this project in a safe way?

How about starting with a vacuum cleaner in reverse? That should be safe and I suspect that you may be better with volume rather than pressure.
I was blowing up an air mattress with a very small vacuum cleaner once when I .. uh .. blew up the air mattress. No collateral damage done and not particularly dangerous, I just had to sleep on the floor of the cabin that night.
By the way, welcome to the hobby forum.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: How can I deconstruct this project in a safe way?

Pump on a balloon until it bursts, that will demonstrate the energy of compressed air.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: How can I deconstruct this project in a safe way?

Concurring with the points about safety above - and I'd like to comment on the ball+hose idea.
Have you tried this before? I've fished a lot of cables through a lot of conduit. Some things work better than others.
Dryer ducts can have some pretty tight corners, and even if you can bend the air hose at that radius, it may be pressed hard on the duct walls. Those joints aren't very smooth either.

STF

RE: How can I deconstruct this project in a safe way?

What size hose is it? From your potential ball selection, 3/4" ID to 2" ID?

If it were me, I'd wad up a plastic grocery bag, tie fishing line to it, pop it in the inlet, vacuum on the outlet.

Fishing line in case it gets stuck somewhere in the middle, you can pull it back out.

Of course there is a lesson to be learned in spending a lot of time on design details, manufacturing something, and having it fail the first time you use it, because you never tested a prototype. A rigid 3d printer ball doesn't seem like a good choice.

RE: How can I deconstruct this project in a safe way?

Could end up teaching your kids, "if you need something done, hire a professional".

RE: How can I deconstruct this project in a safe way?

(OP)
bigsmile monkeydog - that is not only very funny but rings of wisdom and truth! Thanks for the chuckle.

That being said I am one of those goofy folks who got cursed with OCD perfectionism and I "think" I do better work than most pros. It usually takes me 10 times longer then a pro would take and I am guessing that the "extra" I do makes almost no real difference other than making me feel like I am imbued with special powers.

That being said I am sure I have already taught my kids to NOT do what I do and never call me if something needs fixed, but I STILL want to at least think about this problem in an educated way.

I do respect all of the comments and really want to be safe so lets just make this theoretical but with good science. If nothing else I would like my kids to have used the scientific principles to think through a problem.

Specs:
Ball: The diameter of a foosball is 35mm so lets just go with that dimension.
Hose: 1/4 in. x 50 ft. polyurethane air hose
Duct: 4 inch x 45 feet with 2 45 degree bends

Thanks again to everyone! -- Pippin

RE: How can I deconstruct this project in a safe way?

I assume that is intended to be a humorous comment. That would be a very sad lesson, indeed. Although I see that attitude a lot here.

RE: How can I deconstruct this project in a safe way?

(OP)
Sorry Compositepro, I am not sure which comment you are referring to.

RE: How can I deconstruct this project in a safe way?

I was responding to "hire a professional". Your post was one minute before I completed composing my comment.

RE: How can I deconstruct this project in a safe way?

(OP)
Compositepro - I am actually quite surprised at the reluctance here. Are folks worried about liability or is it that I am not a ME???

I am a life long learner and always curious so if there is a better forum for this discussion would you please let me know.

Regards,

Pippin

RE: How can I deconstruct this project in a safe way?

I expressed reluctance because you gave no hint that you are familiar with even basic precautions related to use of compressed air. See, e.g.:

https://www.bwc.ohio.gov/downloads/blankpdf/Safety...


Mike Halloran
Pembroke Pines, FL, USA

RE: How can I deconstruct this project in a safe way?

Frankly, I'm a little surprised by the reluctance, as well.

Honestly, guys, he's not asking how to make a high-pressure tank here. The safety factor on this is hardly more than someone at home using the hose end of a pancake compressor sold at Sears. Yeah, some basic safety items should be kept in mind, but we're not talking about some half-wit wondering how to make a bomb. It's a hose with a wiffle ball on the end. I'm sure most here have done more dangerous stuff clearing a toilet clog.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: How can I deconstruct this project in a safe way?

It took a while to find a reference, probably because it's so un-PC, but in an industrial setting, one of the first things you should be taught is that even an OSHA-approved blowgun can do serious damage to a colon. Example:

http://www.whio.com/news/news/crime-law/police-stu...

It's the sort of thing that teenagers will think of doing, very soon after they are left unsupervised near a compressed air source.

Here's a more general safety bulletin, watered down too much for my taste, that only hints at the blood and gore that can result from horseplay:

http://www.t2center.uconn.edu/pdfs/T2TT_AirSafety....

Mike Halloran
Pembroke Pines, FL, USA

RE: How can I deconstruct this project in a safe way?

(OP)
Guys, I actually appreciate the caveats and even more so, the links to help heed your warnings. I have taken the onus for my family's wellbeing and followed Mike's link which then lead me to these as well;

http://www.ehs.ufl.edu/programs/os/shop/compair/
https://www.bwc.ohio.gov/downloads/blankpdf/Safety...
https://www.youtube.com/watch?v=g99a1c_FlpU (Warning this video is VERY gory and does show how serious compressed air is!!!)
https://www.youtube.com/watch?v=Qt7Vdz-EPCg
https://www.youtube.com/watch?v=KVP_A7eGYxw

I honestly did not know how powerful compressed air could be and thanks to Mike and this forum I and my family are better off.

Regards - Pippin

RE: How can I deconstruct this project in a safe way?

Before the thread dies off, I think it's worth pointing to two of the posts in particular:

1gibson has a practical suggestion about another way of achieving the aim of clearing the duct. Should be plenty of opportunities for education (and more opportunities for letting the kids take the design lead) here.

waross makes a really good point about volume Vs pressure. The application you're describing is really one for a blower rather than a compressor. You absolutely don't need 90 psi to clear fluff from a drier duct, but you might well be interested in more than 3.3 cfm.

Where were you hoping all the fluff was going to go? Is there any mileage in engineering some sort of extension to the suction end of a vacuum cleaner (with brushes and nozzles designed to dislodge and capture fluff)?

A.

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