DIY sous vide cooking using a sestos PID

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speedy23

42 posts

Geek

Topic # 111400 1-Nov-2012 20:42

Hi
I have just purchased a sestos PID with a thermocouple and 25 amp SS relay. Am planning on using our slow cooker (6.5 L, 320 W) as the heat and water source. Has anyone any experience with this type of set up and can offer any advice to save me falling into what I suspect are simple traps. Thanks.....

Pock

156 posts

Master Geek
+1 received by user: 1

Reply # 711413 3-Nov-2012 16:11

I built one of these ~ 1 year ago using this PID controller:

http://www.lightobject.com/JLD612-DC-12V-Dual-Display-Fahrenheit-Celsius-PID-Temperature-Controller-P443.aspx

It's all pretty simple, feel free to ask questions!

Did you get a heatsink for your SS relay?

speedy23

42 posts

Geek

Reply # 711435 3-Nov-2012 17:09

Brilliant - thanks for your reply, and yes, I have questions!
As I see it, the main difference between our two PID devices is that the Sestos takes 240 AC and puts out 12v to the SSR. Have I got that right?
No, I didn't buy a heat sink but thought I would follow the advice on another site and use one from an old PC I have here. Is it really necessary? I plan on placing the whole assembly - PID, and SSR in a sealed clear plastic box (ex Jaycar) so is a heat sink still going to work?
Did you use a cooker of some type or hook up an immersion heater system in an insulated box/chilly bin. Wondering whether my slow cooker is deep enough.
Did you use a circulating water pump of some kind? I plan on using vertical stainless racks (over a horizontal rack at about 2 cm from the bottom of the cooker) to separate food packs and hope that convection will be enough. Any thoughts?
The thermocouple (k type - K2M) has a threaded "bolt" at the business end - should that go in a protected tube of some sort or is it Ok to just dangle it in the water?

Thanks again. I need to get into town to visit Jaycar and pick up the necessary bits and pieces next week so will keep you posted on progress. Any other advice gratefully received!
Speedy

Pock

156 posts

Master Geek
+1 received by user: 1

Reply # 711725 4-Nov-2012 13:30

speedy23: Brilliant - thanks for your reply, and yes, I have questions!
As I see it, the main difference between our two PID devices is that the Sestos takes 240 AC and puts out 12v to the SSR. Have I got that right?

Yep. I didn't want to import the 240v version in case it wasn't certified for NZ and got picked up by customs. So I used a 12v transformer. Also, I wasn't confident in the quality, and wasn't comfortable wiring up 240v to it.

No, I didn't buy a heat sink but thought I would follow the advice on another site and use one from an old PC I have here. Is it really necessary? I plan on placing the whole assembly - PID, and SSR in a sealed clear plastic box (ex Jaycar) so is a heat sink still going to work?

Yes, it's necessary. I also have mine in a sealed plastic box, and the heatsink works well. I think it spreads out the heat more, which then radiates out through the enclosure. Your PC heatsink will probably do the job, I just thought it would be easier to get one designed for the SSR, and it was only $6 - $7.

Did you use a cooker of some type or hook up an immersion heater system in an insulated box/chilly bin. Wondering whether my slow cooker is deep enough.

I used a rice cooker, it works really well. I unscrew the handle of the lid, and it's the perfect size for the probe.

Did you use a circulating water pump of some kind? I plan on using vertical stainless racks (over a horizontal rack at about 2 cm from the bottom of the cooker) to separate food packs and hope that convection will be enough. Any thoughts?

I designed mine so that I could use it on whatever I wanted (rice cooker, slow cooker, plug in immersion cooker), so it just has a controlled hotpoint on the side of it.

I think that weather or not you need a circulating pump, depends on how big the container is. Do a test! Once you've built it, heat up whatever you intend to use, and move the probe around, see if there is a difference in temp, and by how much. Because Sous Vide relies on precise temperature control to make food safe to eat, I'd be more comfortable using a water pump in a large container.

The thermocouple (k type - K2M) has a threaded "bolt" at the business end - should that go in a protected tube of some sort or is it Ok to just dangle it in the water?

Not sure. The thermocouple that I got cant be fully immersed. My one has a stainless probe, then the bolt and then the lead. I keep the bolt out of the water. I'll take some pics to show you what I mean.

Thanks again. I need to get into town to visit Jaycar and pick up the necessary bits and pieces next week so will keep you posted on progress. Any other advice gratefully received!
Speedy

No problem. I had heaps of fun building this, and to be honest I have only used it a handful of times. I should use it more!

Pock

156 posts

Master Geek
+1 received by user: 1

Reply # 711733 4-Nov-2012 13:54

Thermocouple probe:

https://lh3.googleusercontent.com/-LVkaASwqmRs/UJW6lSlUDiI/AAAAAAAABh0/YKDAKJHI1y4/s512/20121104_133501.jpg

The rest of it:

https://lh3.googleusercontent.com/-BxnJctZqrL0/UJW8GmKjP9I/AAAAAAAABik/_H8uqVUOQOA/s640/20121104_133726.jpg

speedy23

42 posts

Geek

Reply # 711891 4-Nov-2012 20:28

That's very useful thanks. A picture paints a thousand words!! Will keep you posted.

Pock

156 posts

Master Geek
+1 received by user: 1

Reply # 718463 16-Nov-2012 20:13

How you going with this?

speedy23

42 posts

Geek

Reply # 718531 16-Nov-2012 22:53

Slowly! Still getting things together. Bought some stuff at Jaycar but not quite what I wanted so went on line and found much better range of goods and also prices. Now wondering about a pump or bubbler...... Also my K type probe just has the securing nut and the probe tip so I am wondering whether to get a pt100 probe with a 100 mm probe to dip in the water. From my reading I also think the pt100 may have a better/more precise temperature control. Looks like buying online from the US is cheapest option. Hopefully the rest of my parts will arrive next week or I may give it a try before I get the box and proper heatsink. Hopefully fully going in a week or two anyway.

speedy23

42 posts

Geek

Reply # 725612 1-Dec-2012 22:59

Success first time!! I set up the pt100 probe (100mm waterproof tip) and plugged in the crock pot with it's controller set on high. Set the PID to 50.0 degrees and it heated the water to 51.5 for a while (maybe an hour) then dropped back to 49.7 and stepping +/- 0.1 degrees now. Checking temp with my digital thermometer and my IR one, they all read within 1 degree so that seems fine. Will try some food tomorrow. Very happy with progress.

Pock

156 posts

Master Geek
+1 received by user: 1

Reply # 726378 3-Dec-2012 18:45

Awesome!

Let me know how it goes with food.

speedy23

42 posts

Geek

Reply # 733342 17-Dec-2012 07:33

Have not used this much since I got it set up. Coked a couple of fillets of snapper which were nice but may as well cook in the pan, then another day cooked a couple of nice T bone steaks. 56 degrees for an hour then into the very hot pan. Lovely taste and texture but slightly overdone for us as we like it a bit rarer. Best thing is not having to worry about timing. I have done eggs a couple of times and they were good and easy, but the white is quite runny when the yolk is still liquid. Great just being able to crack straight onto a slice of toast though and the whole egg just slides out of the shell! And then my laptop dies so attention has been elsewhere! And now Christmas and loads of family home. Not sure what is next, but fun anyway. A cheap cut of steak I think will be a better indicator of it's value.

Have a great Christmas....