New roaster (600k of photos)

[Mark]

Re: New roaster (600k of photos)

Yup, just a piece of aluminium. Melting point of Al is 660 degC, so it shouldnt be a problem.

Looking forward to the pics. Good luck.

[AndyCJ]

Re: New roaster (600k of photos)

Thanks for that Mark - Ive managed to wezel a freebee 12v battery from a guy at work, so Ill test out the motor, and then attach it to the pot next weekend (with a bit of luck).

Will experiment with a heatgun and extension tubeing when I get the rig setup.

Did you use an alloy strip for the stirring arm? Whats the melting temprature on alloy anyhow? Im assuming its not showing any signs of melting.

Picks up as I build it I think - so perhaps some next week.

[nunu]

Re: New roaster (600k of photos)

Hmm...does an evaporative cooler work well for beans?

My relatives tell me to put on a jacket when the temp drops below 20 degrees. I miss home, and havent been back since January 2001.

[doxhead]

Re: New roaster (600k of photos)

a solid point well presented.

[Mark]

Re: New roaster (600k of photos)

Cooling beans is far more important than cooling visiting relatives though ;D

[doxhead]

Re: New roaster (600k of photos)

Nice one Mark, Im well impressed.

Im getting grumpy doing 100g batches every 2-3 days so I might have to have a crack at your design myself.

Luke

p.s. I recognise that fan, that beautiful lovely fan.

[Mark]

Re: New roaster (600k of photos)

Could you tell me if youve had any firther luck with a PC power supply? Thats what Im going to try using next week, before I build it, just to see how it powers the motor? What are your thoughts? Where did you get that battery youre using to power the motor?? And does it just use a standard 12volt charger?

I havent really looked more into a PC power supply, but Ive used them for other things before and there are a few gotchas. For one, most ATX supplies dont have a power switch so you need a way of turning it on. Also they tend to not like being turned on without a load, so it can be a good idea to put in a load resistor so it always draws some current even if nothing else is connected. If this sounds like too much work maybe stick to batteries?

The battery I have was just one I had already, but its just a standard 7Ah gel cell lead acid. You can pick them up at Dick Smith, or any other electrical store for about $30-$40. Your mechanic friend might even be able to give you an old car battery or something? The charger is just a standard lead acid 12V charger, again, Im sure you could pick one up at Dick Smith or Jaycar.

Also - howd you go with heatproof piping, or exaust extension pipe? Did you try any of those??

My wooden holder thingy is working fine, I doubt Ill be changing it any time soon.

Cheers,
Mark

[nunu]

Re: New roaster (600k of photos)

Most of the damage was centralised around the caps. The lid and most everything else was still functional. This biggest loss was time cleaning up the mess. Being a simple thing like a power supply, replacing parts isnt too expensive compared to other pieces of equipment in the van. The power amplifier (klystron) was undamaged, and that part was like $5000usd on its own.

[Dimal]

Re: New roaster (600k of photos)

That must have been very exciting nunu :P, but very expensive .

I bet the tech involved didnt perform that little trick for anyone again... not the best way to impress someone ,

Mal.

[nunu]

Re: New roaster (600k of photos)

I remember an instance where one of the technicians replaced one of the capacitors in a high voltage power supply (5000v output). They fired it up, and shortly thereafter we heard a boom and saw smoke coming out of the exhaust vents. The capacitor had been installed backwards (polarities reversed). The power supply was blown out of the rack, and the lid was blown off as well. The inside of the equipment rack was coated with electrolytic goo. Each of the six capacitors had blown its top simultaneously (each was the size of a soda can).

Ended up having to re-train that technician, and as lead tech, I bore most of the responsibility. Luckily no one was injured. You turn on the power supply, and wait about 5 minutes before you can fire up the power amplifier. During that 5 minutes, everyone went outside the van to have a smoke and a chat. Good thing too... :-[

[Dimal]

Re: New roaster (600k of photos)

240v however is quite dangerous, although not as deadly as 120v for some reason (mainly I think in part to 120v being quite adept at stopping your heart). You shouldnt have to open the power supply at all, so most danger is avoided, but just keep it unplugged when messing with your wiring.

Hi nunu,

All mains power supply should be considered to be dangerous when above 32V AC. The higher the voltage the worse the situation becomes since with everything else being equal, more voltage translates to more current flow, and the more current flow there is the more significant the effect is on ones vitals. In short, as you suggest... always make sure that mains powered appliances are unplugged before opening up the covers. Some devices, like TVs and Computer Monitors for example, can even be dangerous for quite a while after the plug is removed so unless you know what youre about, play it safe at all times.

After all, we dont want any of our CS brothers and sisters coming to grief now, do we. ;D All the best,

Mal.

[nunu]

Re: New roaster (600k of photos)

If you go scouting around on council cleanup day, youll probably find quite a few computer carcasses, often with power supply still intact. If I remember correctly, however, the PC power supply only supplies +12, -12, +5, -5, and +2.5 vdc. The power supply should have a label with the corresponding colours and voltages. PC power supplies are often in the 250 - 400W range, so they should have no problems driving a 12v motor without much modification. 12vdc is nothing, and youre unlikely to even feel it. 240v however is quite dangerous, although not as deadly as 120v for some reason (mainly I think in part to 120v being quite adept at stopping your heart). You shouldnt have to open the power supply at all, so most danger is avoided, but just keep it unplugged when messing with your wiring.

Im no expert, but I do have a background in electronics, and communications equipment (mainly microwave and satellite).

Now that I think about it, electronics, communications, atmospheric science, and commercial cookery; Ive done way too many things in my relatively short life. Now Im stuck into coffee as well. "Jack of all trades, master of none."

[AndyCJ]

Re: New roaster (600k of photos)

Just wanted to liven up this post again - mostly to ask Mark about his setup again.

The reason is simple - because it rules, and Im going to copy it!!! ;D

Mark. Ive got myself a large pot ($12 from junkshop) and I went to the local mechanic who gave me a windscreen wiper motor for FREE! Yep, hed literally just swapped one out, so he gave me the other one from the wreck he was working on! Sweet deal so far...

Could you tell me if youve had any firther luck with a PC power supply? Thats what Im going to try using next week, before I build it, just to see how it powers the motor? What are your thoughts? Where did you get that battery youre using to power the motor?? And does it just use a standard 12volt charger?

Im a bit hopeless with wiring etc. Ill be lucky not to electrocute myself, but Ive been assured from colleages at work that a 12v shock is a lot more forgiving than the 240 from the power socket, so Ill try not to fry myself in the process.

Also - howd you go with heatproof piping, or exaust extension pipe? Did you try any of those??

Good work to you for coming up with a great idea... Ill see how I go.
Andy

[chrisk]

Re: New roaster (600k of photos)

lol thats the coolest roasting setup ive ever seen. ;D

[andy]

Re: New roaster (600k of photos)

Nice work Mark,
very even roast and half a kilo to boot... sweet!

I like the simplicity and ergonomic height of the cooler too.

Well done! [smiley=thumbup.gif] [smiley=thumbup.gif] [smiley=thumbup.gif]