Recommended stir plate for starters

[Lionman]

Well then, a 3 D print, Mr Fancypants eh?!
What material do you use for this? Do they have a generic plastic for it or can you choose?

I usually print in PLA because it's cheap, made from renewable resources and is easy to print with. It does get a bit soft >50 degrees c which is one of its biggest drawbacks.

I can print in pretty much any thermoplastic that comes in a 1.7mm filament. ABS, Polycarbonate, Nylon, Polystyrene, TPU, PVC, PET etc, plus a bunch of proprietary polymers. They are have varying difficulty (read frustration/time consumption) levels and cost.

Not that fancy, it's not a high end machine.

 

[Schikitar]

So I've actually got most of the bits except for the magnetic stir bar, box and fan controller, I was thinking maybe this one - http://www.ebay.com.au/itm/GA102132-Gelid-Manual-Fan-Speed-Controller/142456099132?hash=item212b0b913c:g:hdUAAOSw3ydV6Y4X

...unless @Lionman wants to build a second one and charge me for it!? I'd pay handsomely!

 

[Mat B]

I just made my own out of an old computer fan and some bits and bobs. Pretty basic wiring, a switch from Jaycar, a resistor to give me two speeds, a case, and an old charger I had kicking about. I got the magnet out of an old hard drive. Those magnets are as strong as all get out! Works a treat. If you get the bits and want to do something similar, I can draw up a wiring diagram for you. A few basic solder joints are required.

 

[Mat B]

I don't think a fan controller is a must. An on/off/on toggle switch and a resistor is a good alternative. Not shitting on the controller idea, but just putting it out there if u already have that stuff.

 

[Lionman]

So I've actually got most of the bits except for the magnetic stir bar, box and fan controller, I was thinking maybe this one - http://www.ebay.com.au/itm/GA102132-Gelid-Manual-Fan-Speed-Controller/142456099132?hash=item212b0b913c:g:hdUAAOSw3ydV6Y4X

...unless @Lionman wants to build a second one and charge me for it!? I'd pay handsomely!

I'll build one first and see how I go.

Will a pc fan spin fast enough on 5v? Have heaps of 5v power supplies, as most people do, not many if any spare 12v ones. Haven't used a stir plate before so not sure of the rpm required.

 

[Schikitar]

I sense some builds and experimentation ahead! Okay, I'll push ahead with a build, I have the same HDD magnets above and I'm sure I've got a case fan or two kicking around, also have heaps of power adapters and stuff. I'm not too sure about watts/volts/amps - I have a bunch of old modem power supplies, most of which are 12V/0.4A so that must make it 4.2W? Would that be okay?

I still think a speed controller would be good so I can dial in the right size vortex depending on the volume...

 

[Lionman]

I think 4.2w would be enough for a 120mm fan. The fans here range from 0.16 to 0.32A.

 

[Lionman]

I printed out a basic frame/enclosure thingo overnight. Its a bit shit, but should work as a first iteration. I'll just hot glue this version together to make sure it works and I'll refine the design from there.

 

[Matplat]

I sense some builds and experimentation ahead! Okay, I'll push ahead with a build, I have the same HDD magnets above and I'm sure I've got a case fan or two kicking around, also have heaps of power adapters and stuff. I'm not too sure about watts/volts/amps - I have a bunch of old modem power supplies, most of which are 12V/0.4A so that must make it 4.2W? Would that be okay?

I still think a speed controller would be good so I can dial in the right size vortex depending on the volume...

You definitely want a speed controller, sometimes you need to start slow and build up speed to prevent the stirbar from being ejected.

 

[tj2204]

You definitely want a speed controller, sometimes you need to start slow and build up speed to prevent the stirbar from being ejected.

I'll second this, I never get anywhere near top speed on my DIY job. I used the same speed controller as @Matplat

 

[Schikitar]

You definitely want a speed controller, sometimes you need to start slow and build up speed to prevent the stirbar from being ejected.

Yep, I've ordered two different controllers to play with (the one you recommended and the one I mentioned above) - I agree, I think it's fairly necessary...

 

[Lionman]

Maybe just using a 5V supply could be good enough to keep the speed down so it's stable but still generate enough of a vortex. I might do some testing to compare.

It would also depend on what RPM the fan is you use. I know PC fans can range from 800rpm though to 2500rpm and above.

 

[Lord Raja Goomba I]

I used a lower rev fan and no speed controller. Does 1L to 3L in a 3L flask.

 

[tj2204]

Maybe just using a 5V supply could be good enough to keep the speed down so it's stable but still generate enough of a vortex. I might do some testing to compare.

It would also depend on what RPM the fan is you use. I know PC fans can range from 800rpm though to 2500rpm and above.

Could also use one of those adjustable voltage power supplies as a speed controller.

I'm using 12v, and the fan goes like the clappers at full whack.

 

[ramu_gupta]

I just made my own out of an old computer fan and some bits and bobs. Pretty basic wiring, a switch from Jaycar, a resistor to give me two speeds, a case, and an old charger I had kicking about. I got the magnet out of an old hard drive. Those magnets are as strong as all get out! Works a treat. If you get the bits and want to do something similar, I can draw up a wiring diagram for you. A few basic solder joints are required.

this is what I did too - with help from this website: http://pcbheaven.com/circuitpages/A_Simple_Way_To_Reduce_A_DC_Fan_Speed/

Simple but effective.

 

[Schikitar]

That's basically just two speed settings though, which doesn't quite hit the mark for me. I'd like full control over the RPM so I can build starters of varying sizes and dial in the perfect vortex for that starter rather than a one(two)-size-fits-all approach..

 

[evoo4u]

I've put together quite a few stir-plates, and can highly recommend PWM (pulse width modulation) speed controllers like this one
http://www.ebay.com.au/itm/6-30V-DC...erse-switch-/351600935082?hash=item51dd0c80aa

The bare bones basic models start at around $2 delivered, so they don't come much more cheaply than that!

Or these ones - $3.30 ea if you buy 5:
http://www.ebay.com.au/itm/5pcs-12V...733923?hash=item46403211e3:g:KRQAAOSwU9xUMJHY

 

[homebrewnewb]

thats neat!

 

[rude]

I've put together quite a few stir-plates, and can highly recommend PWM (pulse width modulation) speed controllers like this one
http://www.ebay.com.au/itm/6-30V-DC...erse-switch-/351600935082?hash=item51dd0c80aa

The bare bones basic models start at around $2 delivered, so they don't come much more cheaply than that!

Wouldnt have a link to a power supply & appropriate fan for that by any chance
My stir plate struggles with 4 litres in the flask would love to make a more gruntier one
Cheers rude

 

[evoo4u]

Try searching the GC-Supermarket site. The range of stuff they sell, chip as chips, is amazing:
http://stores.ebay.com.au/G-C-Super...ml?_nkw=12v+fan&submit=Search&_sid=1090683909