Another DIY Rotary Controller

[m00dawg]

Curious what folks are using to heat a water bath automatically? Playing human computer by keeping the temperature controlled manually ends up taking quite a bit of time for me, particularly if I have multiple runs I need to do and given the changing temperature of my tap water.

I know lots of folks recommend an aquarium heater. I have one I actually did use in an aquarium (it's an Aqueon) but it's sealed due to being fully submersible and alas only goes to about 85F. Others I've found so far also do not, without modification, get up above 85 or so either. I was looking at one of these (https://www.amazon.com/Portable-Electric-Immersion-Element-new/dp/B01A3ER4MY/ref=sr_1_8?ie=UTF8&qid=1515259589&sr=8-8&keywords=Heater+coil). Seems like it would work if I can rig up a means to make sure it doesn't touch the sides or bottom of my container (currently an ice chest) and will get quite hot so I could use it for mixing temperatures too. These look super sketchy though. Anyone tried these?

I know I can just buy a Sous Vide for temperature and circulation and, in fact, almost did, but I got rather deep into Arduino code not only for making a PID based temperature controller, but also for keeping track of development steps and how I could go about building a DIY rotary as well. Most of that code is written as a proof of concept and I just ordered a motor and H-bridge controller board to test it out, though that will take some time (and probably 3D printing) to figure out. Doing all that may take a while but using my own controller lets me iterate on features and potentially end up with a controller that handles a lot of what would otherwise be done separately.

Code is available here if anyone wants to take a gander at it: https://github.com/m00dawg/devdawg

[John Layton]

Years ago I cobbled together a plywood/epoxy tank as a temp. jacket for doing E-6 - and was able to maintain temp. to within 1/10th F with a device such as you've linked to above (small submersible heating element) plugged into a Photo-Therm unit (small temp. controller box with a submersible sensor) plus a submersible recirculating pump. I think I've still got this stuff lying around someplace - and if I find it I'll try posting some images.

[m00dawg]

Ah yeah, this guy (http://www.phototherm.com/bath.html)? A shame it still isn't available. Good to know a submersible heating element will work! From what I've read, you need to keep the top end of it out of the water correct? A lot of these on Amazon look like they have a high potential to introduce electric current into the water which seemed rather concerning.

[Robert Tilden]

Make sure you use a GFI outlet to minimize chance of 'concerning' events.

[Leszek Vogt]

You could dial in stable temp (in digi sense) using propagation mat (for seeds). The mat is waterproofed, but the hookup may not be (?). Some of the read out controls come with a probe, so reaching and keeping consistent temp shouldn't be an issue.

Les

[m00dawg]

Hah I didn't know those existed until now. Clever idea! I ended up ordering this (https://www.amazon.com/gp/product/B074K98XR7/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1) to see how it may work. It has a threaded top which should make mounting it much easier compared to the other immersible heaters I found.

[photonsoup]

I got an Anova http://https://www.amazon.com/s/ref=nb_sb_ss_c_1_5?url=search-alias%3Daps&field-keywords=anova+sous+vide&sprefix=Anova%2Caps%2C443&crid=192TVIPNTUMUU that holds water temp to within 1/10of a degree once it stabilizes. If the controller goes out in my Jobo goes out I'll just drop this in!

Incredible steaks by the way

[m00dawg]

Haha yes indeed! Friend of mine has a Sous Vide though I forget which one and yes the steaks were quite fantastic! We're on a smoker kick right now (got one for Chrstimas) but definitely something I want to try as well.

For film dev, I've seen videos of a few folks using it and it does indeed seem to work rather well and I woulda probably gone down that road if I didn't already have almost all the parts I needed to make my own lying around. Plus I hadn't worked with Arduino code for a while so it was nice to go back to that. It's a very fun microcontroller platform and is DIY friendly in that you can make things using through hole or SMD parts and it's quite easy to make your own purpose built boards once you settle on a design you like.

And they are hearty, though most uC's are. Chances are good that controller in your JOBO will probably outlast all the mechanical parts. At worst you might have to swap out some of the electrolytic capacitors - those are cheap and usually simple to replace with basic soldering skills. Point is, I'd be surprised if you had to start using your Sous Vide over your JOBO anytime soon!

[m00dawg]

Update for the more grand plans, I implemented and tested a proof of concept to control a motor for handling tank rotation. It uses a DC motor and an H-bridge so nothing special there. It does go through the motions, as it were, during a development cycle on the controller. The heating element is coming tomorrow which should resolve the most tear term practical needs I have (keeping the water at temperature) while I figure out how I might design a means to rotate a tank (preferably in the same water bath as the chemical bottles).

[EdSawyer]

I have one of those Phototherm Model 14 baths, it's quite nice and useful, works well even though it's an older unit. They show up on ebay from time to time.

[Greg]

I have one of those Phototherm Model 14 baths, it's quite nice and useful, works well even though it's an older unit. They show up on ebay from time to time.

For the longest time was looking for a JOBO TBE-2/12 Tempering Box. Finally gave up and found a Brinkmann IC-2 unit and constructed a home made tempering box. Can 100% recommend the Brinkmann IC-2 unit

[TroyG]

I use a NuWave Induction Cooktop (https://goo.gl/otqgBN). It is useful for maintaining water at 100°F as well as an additional burner during the holidays!