I want to build a centrifuge for projects and kitchen stuffs, I've got a few options over spending $300-$3,000 on a professional one.
I'm not skilled enough to buy the rotors and circuitry so this is a superficial DIY- buy something that spins like a dremel or blender, and either botch it or in the case of the dremel, create an attachment.
I can do the attachment part myself, some tips and ideas are welcome but my main thing is I have two concerns:
leaving a dremel on for 5 or more hours at 20,000+ rpm, good or bad?
Dremel has less torque than drills and maybe blenders; is overloading it going to amplify any issues I might have with leaving it on for hours?
I probably won't load it beyond 300 or 400 ml, 100 x 3 arms vs 100 x 4 arms
pic related seems to have viles at maybe 10-15 ml x 6. I'd be quadrupling that volume.
>>920322
400ml of fluid is over half a kilo to spin. With a dremel or the like that means balancing needs to be done properly. Try to figure out an attachment and balance it very well maybe with the cell phone method where you run an app and adjust the rotor accordingly.
Using falcon-sized centrifuge tubes also means the tubes need at least to run at an angle, preferably with a pivoting attachment so that whatever you are centrifuging won't wash out from the bottom when the centrifuge stops.
And with larger tubes the speed is much lower but this was no news to you. Eppedorfs can easily take 40000rpm when they rest on their bottom instead of hanging like in your pic
>>920355
I'm not sure what the cell phone method is but thanks for the info.
I didn't like the 3d printed version because it has no pivot and doesn't allow for the vile to rest, which are both safer and more efficient.
if you could help me out one more time before I hurt myself, I was wondering how a string or chain would fail to balance perfectly, so long as the speed was adjusted slowly enough for it to not wrap around whatever the spindle would be?
in other words, viles A and B were attached to one another across a string, and sufficiently tied to the spindle at an exact midpoint.
I'd use braided steel wire and not string, not sure how I'd harness the vile but this seems to take care of both the free floating and balance in one shot.
Somehow I'm thinking the spindle might travel faster than the viles via air friction and cause it to tangle after a certain rpm.
>>920497
Try searching for it. Balancing cell phone app rotation or whatever you know the drill. There is at least one instructable about it.
I got seriusly drunk between posts so I'm trying to follow your train of thought before I forget this thread.
One problem with a string/wire approach might be turbulence or wobbling. The centrifuge tube might wobble during rotation in a way that you can't see/measure it.
I'm not sure if this is an issue but consider it. Wobbling would prolly reduce the effectiveness of the g's you are trying to achieve.
A fixed stand for the vials might eliminate the risk of problems like this. I'm a molecular biologist so I have hands-on experience with these machines but no clue about designing of them.
Off to sleep, fuk I'm fukt.
>>920516
well I thank you for getting through the post, I see the wobble but I'll try to work around it. A braided steel basket centrifuge sounds too good to not give a shot
speaking of shots, see you on the other side
>>920322
I really really dont recommend a diy centrifuge. at those speeds if/when something breaks it will fly at a very high velocity.
My uncle works in a lab, centrifuge broke and severed his colleagues legs. bled to death in a few min.
They are now typically armored to provide some protection in the event of a misalignment causing a break away component flying off.
>>920570
that sounds like the rotor and the cradle were one part, where the misalignment made the whole thing into a vehicle of death
the rotor here is a inside of the dremel machine, the vials and cradle are separate and much smaller components. just as in the pic I'll be using a steel drum in case of any failures but I don't expect to lose any body parts. The worst scenario would be having a vial projectile like a paintball 300 times heavier traveling 30 times faster, that could kill my if it hit my throat or eye but not if it's secured in a drum with a lid.
crazy to hear a man lost his leg, his family should be made now though.
