Having a chemistry lab fully stocked with all necessary equipment is the dream of students, teachers, and professors alike, but a lot of that equipment can be prohibitively expensive. Even in universities, labs are often left using old or worn-out equipment due to cost. So one could imagine that in high schools this is even a more pronounced problem. High school student [Aidan Miller] has solved this problem with at least one piece of lab equipment, bringing the cost for a centrifuge down to around $10 USD.
Part of the savings is due to the fact that [Aidan] has put together a smaller sized centrifuge, known as a micro-centrifuge. The function is still the same though, spinning samples to separate them out the constituents by weight. The 3D printed base of the centrifuge houses a switch and 9 V battery and also holds a small motor which spins the rotor. The rotor itself is also 3D printed, and needed to be a very specific shape to ensure that it could hold the samples properly at high RPM and maintain reasonable balance while spinning.
As a project it’s fairly simple and straightforward to build, but the more impressive thing here is how much it brings down the cost of lab equipment especially for high school labs that might otherwise struggle for funding. Of course it requires the use of a 3D printer but the costs of those have been coming down significantly as well, especially for things like this portable 3D printer which was also built by a high school student.
Points for being inventor – but there should not be patting in back and no words “good job”…
Before using it – it should go thro some construction/safety scrutiny.
It is intended for chemical classes – you do not want to spill liquids around.
This is not balanced wheel with centre of mass of it pretty high above
questionable interface to tiny motor shaft.
Here is much better and more impressive centrifuge: https://www.nature.com/articles/s41551-016-0026
Sorry – I take it back – no points for being an inventor.
I have just noticed that it is just a copy of crappy probably sourced from china device.
It would be “good job” if he took the crappy design, do some research, and make it better.
Right now “bravo” for ability to use 3d printer and waste it potential for printing flat panels.
actually there should be negative points for HAD and zero for the builder. this is not even a copy of a china model it is just a download of one of many from thingiverse.
Hack A Day should rise the quality of Hacks presented here. Yet there still should be some entry point for beginners with some simple things. (This article is not that).
Designs like this one should be designated as special type of HAD article – maybe something like “lets benchmark this sh…t out” – to show how this can progress from bad to decent for set conditions.
The only thing that scares me about the one from the Nature link is the fact that the rotating disc with the blood sample is perfectly aligned with the face of the operator in most examples (though there is at least one suggestion of using a fixed end on one side of the string and a sliding handle on the other)
The video does show exactly that if you would like to watch it again.
There is a guy holding one handle with leg – I guess some think that fail into trousers is better than in the face (but lets not talk about sex) ;)
I would not call it full FMEA but at least common sense.
A more helpful piece of advice to the prospective engineer/scientist would be to document the failings of your project, and then to use that to write the goals of the next version before you start work on it. If you have a project portfolio with goals and findings for each, it will make for a great asset come college application time, and especially when it comes to finding an internship. (Speak the engineer’s language, and they’ll hire you.) Also, you’ll get more internet points.
I thought that RESEARCH word means that…
This wasn’t research on how to build a centrifuge…
You’re gonna want to put a stainless steel mixing bowl or something over that thing when you use it. The mass of an eppendorf tube even with liquid in it is not enough to really injure anyone though probably. For reference an el-cheapo one sold on a large online bookseller is $60-$80 so $10 is a huge cost difference especially if you need several for a class.
Gonna have to disagree.
He should put knives/rotors on the spinning part. Make sure shaft is slip fit.
Also two pulsejets, for extra spin and glorious noise.
To put all the load on a 2 mm motor shaft, which is probably only guided by a sintered bushing, is a terrible design. At least that inspires me to make a few videos on how to build lab equipment yourself.
One of those 3D printer = hammer projects when a ready made project box or some wood and masonite would make a better, faster, cheaper, stronger enclosure. If the school has decent metal and wood shop classes the spinny part would have been better made using a lathe or repurposing a small metal bowl.
Or modify a salad spinner. Put some silicone grease on the gears to make them last longer if the modifications extend to adding a motor drive.
Lathe is still out there a bit in “most people don’t have access to one” land.
Congratulations to all who don’t live there!
Metal bowl… maybe.
How many schools have a metal or a wood shop in 2023? Mine didn’t in 1997! (There, dated myself)
I would have been tempted to print the “spinny part” and do something else for the base. But then… given how most people use PLA these days.. and how PLA turns into uselessly brittle un-cooked spaghetti if you keep it too long.. once you are printing one part might as well print everything you can to use up more of the spool.
I will say though that if I am going to make the effort of printing that box I am going to make it worthwhile with embossed labels and decorations, curved edges and corners and definitely a prettier mount for the power switch. But hey, we all have to begin somewhere. Also, this is a school project. When does a kid have only one class to worry about at a time?
The maker should revoke his tutorial on Instructables.com.
To me it falls into the category of “How not to make”.
Take the crappy battery holder thing alone. He could had taken cheap 9V battery clip wit wires.
That works way better & reliably, just inslate the body and contacts, even if it was electrical tape and a drop of hot glue.
Start over. Good luck
Agree except for the hot glue. Hot glue equals a design flaw.
It’s better than nothing, I suppose. Though there is a reason that real centrifuges are expensive, they are made to spin very fast and contain failures of the vials.
One simple improvement would be to shift the motor up so that the CofG of the rotating mass is at the point where the shaft enters the motor, to minimise the bending load on the shaft. (This would require a slightly bigger rotor, or there would be no way to insert the vials.
Don’t forget ability to connect to the internet. :-D
I think that those were gas centrifuges, assuming that this is a Stuxnet-related comment?
Those centrifuges were unhackable though because they were airgapped.
No airgap is a match for social engineering + an USB thumb drive. ;-)
When I saw this article my first thought was huh I wonder how many $10 stages it would take to separate isotopically distinct gases.
No comment about using the most expensive version of disposable battery power indoors to run a motor. Somebody probably had access to free batteries.
“separate them out the constituents by weight”
Should be “density” not “weight”. You probably should also employ a grammar checker
“Should be “density” not “weight”. You probably should also employ a grammar checker”
Like the original text, you are using the wrong term, but both the original and your answer have correct grammar.
You mean one thing, but use the incorrect expression. You should probably employ a terminology checker.
(I can’t wait to see what the next comment says… ^^)
Reply! I meant reply! Not answer!
(Wipes away sweat)
Got to agree with everyone, this looks more like a hazzard than anything usefull. Even unloaded it wobbled violently as it spun up in the video.
If you really wanted to make a budget centrifuge I’d probably start by picking up a dirt cheap mini food chopper. They can be had on fleabay for under £10 or probably most online vendors of random tat. Replace the blades with a 3D printed rotor and hey presto, centrifuge complete with safety (bowl around it) and a motor that’s much more likely to suvive a little imbalance. No idea how fast it would go, but I can’t imagine it’s worse that one of those toy motors.
example food chopper
https://www.ebay.co.uk/itm/194971074364
I have changed my mind about this. Yes, it’s a rubbish centrifuge. But it exists.
The whole class can try to centrifuge a sample, and see what happens.
In that context, any centrifuge is better than no centrifuge.
And extra marks, looked at that way, for being totally obvious in how it works.
Where do we even begin with this one…
1. Building a cheap version of a device that is expensive for safety reasons.
2. 3d printing a literal box.
3. 3d printing parts that need to be strong AND well balanced.
4. No one involved stopping it at any point?
5. Praising it to a wide audience? Both the local news, which probably doesn’t have anyone with the experience not to condemn it, and now Hackaday, which most certainly SHOULD know better.
This is a train wreck…
We’re all supposed to be ‘kind and respectful’.
I for one am very glad there are no ‘kind and respectful’ comments on this mess.
Part of hacker ethos is brutal honesty.
More please. Fire the mods!