Hacking the electronics of a juicer to run slower - making a stirrer

[SamBell]

I'm modifying a juicer to be a magnetic stirrer for making up feed. Below a vessel of water/feed is a magnet (from a hard drive) on a motor, and in the feed another hard drive magnet (glued to a plastic stick, wrapped in PTFE tape). When the outside magnet spins, the inside one does too, mixing up the feed.

But the appliance I am hacking spins way too fast, and I don't know what I'm really looking at inside. The juicer has two speed settings and off, just lowering the speeds two would probably be fine.

Here's a load thumbnails linked to decent res pictures if anyone can say WTF is going on in this machine.

I think it's an AC motor. The power comes in, through the controls and two safety switches (already glued on), and into coils on a horseshoe of metal. The core of the motor is then inside the horseshoe. From some Googling it seems the frequency needs control, not the voltage like with DC, and I guess that is what the electronics behind the switch do?

The juicer was 3UKP from a charity shop, whilst the kind of thing people do to control grow room extract fans might work, me just finding a different applicance with fine speed control might be cheapest answer.

Any ideas appreciated

[craigfjyp]

would you not be easier just getting a cheap air pump for mixing the nutes mate?

[Guest mrtibbs]

Even a maxi jet pump?

[Inspiration101]

Dimmer on the plug to slow it down ?

[SamBell]

 

would you not be easier just getting a cheap air pump for mixing the nutes mate?

D'oh, of course it is! I might even have a working one in the piles of junk I've acquired. Cheers for pointing that out!

 

Even a maxi jet pump?

I guess that's a water pump? This'd mostly be used in a big water cooler bottle, at the moment, so an air pump outside might be better. Cheers though.

 

Dimmer on the plug to slow it down ?

I'd thought of that, but wasn't sure if it works or not. To be honest craig's reminder of how the rest of the growing world does it makes the most sense.

I've used magnet stirrers in labs, and they are very cool, so was on the path to recreate something like that. Bubbles'll do

[Bud Wiser]

Not quite sure what a magnetic stirrer for making up feed is, but I clicked 'like' anyway ... turning old junk into something useful is to be applauded in my book.

There's nothing quite like a project to get the brain-juices flowing, good luck and I'm curious to see where this goes.

[Guest mrtibbs]

 D'oh, of course it is! I might even have a working one in the piles of junk I've acquired. Cheers for pointing that out!

  I guess that's a water pump? This'd mostly be used in a big water cooler bottle, at the moment, so an air pump outside might be better. Cheers though.

 I'd thought of that, but wasn't sure if it works or not. To be honest craig's reminder of how the rest of the growing world does it makes the most sense.

I've used magnet stirrers in labs, and they are very cool, so was on the path to recreate something like that. Bubbles'll do

You crazy man

[Aurora Ruderalis]

A lot of water pumps offer the venturi style intake. It's usually for air. The same principal could be used perhaps with a simple solenoid liked to an e.c. meter.

The type of engine required to run this would be at least 160bhp and would fall off if glued on...

[sinbad!]

Ive always used an air stone just cause they are cheap, but also any spare pump you have lying around (depends on the size of your reservoir) a maxi jet 500 pulling from the bottom of your tank and with a bit of tubing dropping the water onto the top. if you drop the water back into the tank it also creates oxygen as it hits the surface, so good all round.