Horus
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Homemade Rotary Shaker
So I'm working on culturing a fungus for biosynthesis, and I have an agar-plate culture going already, but I don't know how to bulk up.
All of the patents I've read make use of a rotary shaker, an expensive piece of equipment. How necessary is this? How could I make my own? I found
a promising-looking article in Mycologia Vol. 56, but when I went to the university library to copy it I found it wasn't really what I wanted (the
setup was complicated for something described as "homemade", and its primary goal was controlling the temperature of the liquid culture, while mine is
keeping the culture moving/aerated).
I thought of making some sort of crude "oxygen generator" and running a tube into the culture, but besides the fact that this might not produce enough
oxygen, making an "oxygen generator" that wouldn't melt in the pressure-cooker might be a little tricky.
Also just how necessary *is* a rotary shaker for making a simple liquid culture? I know some people who grow psilocybe mushrooms grow the mycelium in
a liquid culture without any special preparations, but Psilocybe Cubensis is a fairly hardy fungus.
Also, all of the patents use large numbers of low-volume cultures (i.e. 50 50mL cultures or whatever). Why can't I just use one larger one, like in
the 100mL+ range? I'm going to need like 20 gallons of the mature culture for what I'm doin'.
Right now I'm envisioning some sort of motor-powered shaking surface, but I don't have any experience with electricity or mechanics and have no idea
how to make such a thing - and I know it's asking way too much for one of you to "design" it for me, I'm just looking for general ideas here.
"Full government control of all activities of the individual is virtually the goal of both national parties." - Ludwig von Mises
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12AX7
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I can't imagine it being very hard. Build a sturdy base: use lots of heavy steel, or cast iron if possible. At worst, a trip to the junkyard should
secure some choice, if rusty, beams for this. Bolts can hold it together just fine, but welding would be quite nice as well. While you're at the
'yard, pick up some medium sized springs to support the shaker table. Obtain a working electric motor, probably 1/8 HP or less, and gear it down.
You can find a gear head motor or adapt a reduction drive to it, or use pulleys. Pulleys are pretty easy to handle, easy to obtain from most any
hardware store. You need at least two pulleys, shaft stock, bearings (usually pillow bearings) and a belt of the correct length. The RPM ratio
equals the ratio of diameters. When you have the right ratio (by pulleys alone, you'll probably need two sets- 1725 RPM down to 60 in one step
(1/28th) is pretty far -- a 1/5 ratio followed by 1/6 would work quite nicely), mount a vertical shaft in the center and add a crank to it. Fix a
point on the shaker table to the crank, so it goes in circles. Optionally, you can also add a really heavy weight (as heavy as the table) opposite
the crank, to reduce vibration.
This can all be done with bolts, hardware store stock (if a bit expensive in total) and hand-drilled holes. A drill press helps making holes, and a
welder helps to stick metal together. A chop saw helps break down stock, but a hacksaw works with some elbow grease. A home foundry allows you to
cast all the heavy or expensive parts (base, pulleys, etc.) yourself.
The only block you have is not having any experience in metalworking. If you think about it, it's just geometry. Really easy stuff. You already
have an intuitive concept of structure, strength and stiffness, just build it as heavy as you think it needs to be.
Tim
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chemrox
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You can make a homemade shaker with one of two readily available devices. One is a paint can shaker. The other is a casing polisher. Both are
available and cheap at Harbor Fright.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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Xenoid
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I would envisage something like a piece of chipboard, suspended from a metal frame by springs at the corners. Screw a bunch of angle brackets on it to
hold your containers (three per container). Mount a slow or geared down motor (I guess you would need something like about 60 rpm) underneath the
board, with it's shaft axis perpendicular to the surface of the board. Attach an offset weight to the motor shaft, so when the motor is turned on, the
motor and board will shake around. It may take a bit of fiddling to get the right speed and degree of shaking. This method is a bit hard on motor
bearings, but if it's going slow and not overloaded it could work!
Don't you wish you had payed attention in metalwork and woodwork classes now... 
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Horus
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| Quote: | Originally posted by 12AX7
I can't imagine it being very hard. Build a sturdy base: use lots of heavy steel, or cast iron if possible. At worst, a trip to the junkyard should
secure some choice, if rusty, beams for this. Bolts can hold it together just fine, but welding would be quite nice as well. While you're at the
'yard, pick up some medium sized springs to support the shaker table. Obtain a working electric motor, probably 1/8 HP or less, and gear it down.
You can find a gear head motor or adapt a reduction drive to it, or use pulleys. Pulleys are pretty easy to handle, easy to obtain from most any
hardware store. You need at least two pulleys, shaft stock, bearings (usually pillow bearings) and a belt of the correct length. The RPM ratio
equals the ratio of diameters. When you have the right ratio (by pulleys alone, you'll probably need two sets- 1725 RPM down to 60 in one step
(1/28th) is pretty far -- a 1/5 ratio followed by 1/6 would work quite nicely), mount a vertical shaft in the center and add a crank to it. Fix a
point on the shaker table to the crank, so it goes in circles. Optionally, you can also add a really heavy weight (as heavy as the table) opposite
the crank, to reduce vibration.
This can all be done with bolts, hardware store stock (if a bit expensive in total) and hand-drilled holes. A drill press helps making holes, and a
welder helps to stick metal together. A chop saw helps break down stock, but a hacksaw works with some elbow grease. A home foundry allows you to
cast all the heavy or expensive parts (base, pulleys, etc.) yourself.
The only block you have is not having any experience in metalworking. If you think about it, it's just geometry. Really easy stuff. You already
have an intuitive concept of structure, strength and stiffness, just build it as heavy as you think it needs to be.
Tim |
Thanks a lot Tim. I had one of my more mechanically-inclined friends read over that and he said it was totally feasible.
Also I don't know why I was thinking earlier that the rotary-shaker would have to fit inside a pressure-cooker (not sure if I even mentioned that in
the original post).
Something else, if anyone runs into this. I had some trouble acquiring a culture of this fungus in the first place, despite the fact that it's legal
and unwatched. It still took a lot of googling and a fake letterhead to get the darn thing from a culture base. Any easier ways geared towards the
hobbyist (instead of university or business)?
"Full government control of all activities of the individual is virtually the goal of both national parties." - Ludwig von Mises
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experimenter_
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This is a very simple rotary shaker made from a rectangular plastic box with lid, five small bearings, one hobby motor with gears and three plastic
"arms" (orange) 3D printed in order to connect all the above.
In the picture it is not used for biochemistry but replaces the classical magnetic stirrer in a reaction sensitive to magnetic fields.
[Edited on 25-3-2022 by experimenter_]
[Edited on 25-3-2022 by experimenter_]
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