Sciencemadness Discussion Board - Is it cheaper to buy or make hot plate magnetic stirrers?

Is it cheaper to buy or make hot plate magnetic stirrers?

Draeger - 10-2-2020 at 14:29

I was searching for hot plate magnetic stirrers for a long time already, and for professional stirrers, the price range for used (and debatingly slightly broken) ones was around 110€, while new stirrers were around 200-900€. The only cheaper options were sketchy looking offers that had no ratings and no CE marking, yet still cost 40€.

So, I don't really know if I just don't know where to look or if that's just generally what to expect. So, I was wondering if it would be cheaper to buy or make a hot plate stirrer? And, if still relevant after the answer for that question, where do I find cheaper hot plate stirrers?

[Edited on 10-2-2020 by Draeger]

monolithic - 10-2-2020 at 17:20

The cheap Chinese/Indian ones are mostly garbage that can barely boil water. You can build one yourself but I really doubt it could be done for cheaper than the cost of a used hot plate.

Twospoons - 10-2-2020 at 17:56

Building your own has got to be more fun though.

dome13 - 10-2-2020 at 18:08

About 4 years ago i bought a cheap magnetic stirrer with hot plate from ebay. Now I found it again, same price. I really recommend you this, because I never have any problem.

Here is the link:

https://www.ebay.com/itm/SH-2-Magnetic-Stirrer-With-Hot-Plat...

Dr.Bob - 10-2-2020 at 19:29

I would strongly recommend buying a used quality hotplate/stirrer, not sure about Europe, but in the US, you can buy a used one for $100 or so, which is likely less than the cost of building one, and almost certainly better than buying a cheap piece of crap that will break in a week or not work well. I have used ones that are over 20 years old at work, which still work better than the cheap ones when new.

If you buy a good brand, Corning, Heildolph (in Europe), IKA (if you like fancy expensive ones), or even the Thermodyne ones, they should work for years. I have found that the simpler analog ones will outlast digital ones by 5 or 10 times the lifetime, but some people like the digital ones. Just buying the right parts would be hard to get for under $100, but used ones are readily available on Ebay, just make sure it works (ask the buyer for details on how it was tested) before making a bid, and test it well after receipt. Some people sell them for parts or repair, if you can buy several broken ones, you can often combine the parts into one working one, but sometimes, they all have the same flaw. That is a real gamble, since broken ones often cost almost as much as working ones with shipping.

rockyit98 - 11-2-2020 at 00:46

Quote: Originally posted by dome13

About 4 years ago i bought a cheap magnetic stirrer with hot plate from ebay. Now I found it again, same price. I really recommend you this, because I never have any problem.

Here is the link:

https://www.ebay.com/itm/SH-2-Magnetic-Stirrer-With-Hot-Plat...

this link got me LOL only 180W .don,t worry i been thinking of posting my hotplate build.

Is it cheaper to buy or make hot plate magnetic stirrers?

Sulaiman - 11-2-2020 at 03:01

Yes
___________________________________________________________________
You can buy hotplate stirrers of various brands, new, used, abused or scrap value.

You can build a hotplate stirrer from exotic custom made materials or from existing scrap items.

Generic domestic electric hotplates are cheap when new, even cheaper used.
For better heating control use an electronic 'dimmer' module.

Overhead stirring was very cheap for me because the motor was free - from a broken hand blender,
I had clamps, stands, power supplies etc.
(a laptop charger plus pwm module would work)
so I only needed to purchase the shaft coupler, shaftwith ptfe stirrer and stopper/bearing.
Not ideal but it works https://www.youtube.com/watch?v=ziRxiFSaZsA
(a second clamp for the stopper helps when stirring in beakers).

Similarly, a diy heating mantle can be made quite cheaply,
e.g. my cake-tin 500ml heating mantle, almost complete, being tested.
(I enclosed the pwm controller and spray painted the tin grey sometime later.)

DIY or Buy, which is best ? ... depends .......

draculic acid69 - 11-2-2020 at 03:04

I recommend buying one if your not extremely confident that you can make a robust,sturdy and reliable item.making one is quite easy and very possible for cheap.
Adding a stirrer is a little bit harder but still very doable.if u need it quick and you don't have time, effort or money for repairs upgrades and troubleshooting the problems you'll almost certainly encounter just buy one.youll want at least 350-450w anything less for a 1litre and it'll struggle to boil water.

[Edited on 11-2-2020 by draculic acid69]

G-Coupled - 11-2-2020 at 09:59

Unless you're like McGuyver (or Sulaiman there

), buying a used industrial model is the way to go IMO.

B.D.E - 12-2-2020 at 03:34

My advice is to buy a used ceramic hotplate-stirrer from ebay. I checked ebay everyday untill I found the deal of my life on a branded 220/250V ceramic plate. It is a high tech 7*7" ceramic plate with digital temperature and RPM control, that reaches 540C and works perfectly well. cost me 280USD with express shipping + taxes(the hotplate itself was 120USD), but it definitely worth it.

Heptylene - 12-2-2020 at 07:23

It's not worth the time and money to build one from scratch. If you have the knowledge to do so, you'd be better off getting broken hotplates on ebay and repairing them. Almost all of them have either the motor OR the stirrer working. So buy two and combine the parts.

Even redo the electronics completely. A brand new PCB with 5V power supply, microcontroller, 7-segment display, internal + external temperature probe, heater + motor power control, etc. should cost a few tens of dollars to make.

My IKA hotplate has less than $50 worth of electronics inside. The microcontroller itself costs only $5 (PIC16F874A) with a handful of components, optocouplers, triacs, etc.

SWIM - 12-2-2020 at 15:33

The cheap way to a hotplate stirrer.

Buy a thermostatically controlled electric frying pan. One that is aluminum.

It can be used as a hot plate or oil bath and the stirring function can be achieved by putting a magnetic stirrer underneath.

Before I owned any lab heating equipment I used a thermostatic hotplate with a stirrer under it made from a hand mixer motor (many speeds in the appropriate range).

I bought these two things used at some garage sale or charity store. I forget where, but they were mighty cheap.

This setup won't give you temperatures over about 200C, but below that it works pretty well.

mekanochemical - 21-2-2020 at 15:01

i was on this doubt until last week, but i bought one... cost me around US$120

the magnet for stirrer should be heat proof (the Neodimium magnets can be damaged), need some machined parts, thermostat, motor control, power source for the motor, etc

i prefered bought to save some work

G-Coupled - 22-2-2020 at 08:20

Quote: Originally posted by mekanochemical

i was on this doubt until last week, but i bought one... cost me around US$120

the magnet for stirrer should be heat proof (the Neodimium magnets can be damaged), need some machined parts, thermostat, motor control, power source for the motor, etc

i prefered bought to save some work

Sounds like a good deal - what model did you get?

Vosoryx - 22-2-2020 at 08:48

I built one, it sucked, I wasted immense amounts of money on it and it broke within days. But I also learned a ton and had fun doing it. So. I'd say buy one, and don't cheap out. The good ones are good, the bad ones are awful.

vibbzlab - 22-2-2020 at 08:59

I've made one with the help of my uncle. It was fun building one rather than buying. But as everyone say if you have good use to it and have the cash but. Otherwise just stick to making one. Or just use the conventional butane burner or spirit lamp

morganbw - 22-2-2020 at 18:34

Quote: Originally posted by Vosoryx

I built one, it sucked, I wasted immense amounts of money on it and it broke within days. But I also learned a ton and had fun doing it. So. I'd say buy one, and don't cheap out. The good ones are good, the bad ones are awful.

This is pretty much the most informative post in this thread.
nods to your honesty sir.

mekanochemical - 23-2-2020 at 22:25

Quote: Originally posted by G-Coupled

Quote: Originally posted by mekanochemical

Sounds like a good deal - what model did you get?

bought in this site, in my country

https://www.cienlab.com.br/agitador-magnetico-com-aqueciment...

i dont know if they export

OrganicGuy - 2-3-2020 at 00:00

Quote: Originally posted by Draeger

I was searching for hot plate magnetic stirrers for a long time already, and for professional stirrers, the price range for used (and debatingly slightly broken) ones was around 110€, while new stirrers were around 200-900€. The only cheaper options were sketchy looking offers that had no ratings and no CE marking, yet still cost 40€.

So, I don't really know if I just don't know where to look or if that's just generally what to expect. So, I was wondering if it would be cheaper to buy or make a hot plate stirrer? And, if still relevant after the answer for that question, where do I find cheaper hot plate stirrers?

[Edited on 10-2-2020 by Draeger]

I bought mine from China, very high quality for the resonable price (75 to 200 USD depending on size and manufa ture). I can help with email if you need something, they are good people, ship day after you Paypal the money