Heated Digital Stirplates

[Yob]

Yep that's right.. the best thing since just about ever is upon us.. well.. almost..

I got hold one of the Beta units to test under no obligations and I've gotta say, they are one sexy bit of kit.

Right to the nuts and bolts..

The Unit



The operation of the stir plate is essentially as we all know it, up arrow goes faster, down arrow goes slower..



To access and set the temperature you currently press both the up and down arrows and it switches to heat mode, up and down to set. This operation is currently being looked at and a refinement of how to access the heat cycle is on the cards.. Ive got pretty big fingers so its a little finicky to get them both pressed.. but really is a minor issue, I'd happily put up with it for what this unit does.

So, Once the temperature is set, what it will do is heat the top of the stir plate to the temperature set, the little heating light will be constant on during heating and when it reaches temp, it'll blink. Ive been using this one on 29'c



I played with it and just water for a few days checking the water temps and such, took tap water to temp in a few hours and easily held it there.

Ive gotta say, Im super impressed and totes chuffed that Michael has brought this out, winter starters need not take that extra day because of the cold fluctuating temps, I might actually be able to remove it from the kitchen table now and make them in the brewery without having to be concerned of overnight temps.

It's simplicity is it's brilliance.

No affiliation with DSP other than being a fiercely loyal fanboi of these guys service, initiatives and products.

 

[Mardoo]

Pardon the puddle of drool...

Probably a quickly built little surround of insulating material would be the go for winter in the brewery. I certainly want to get my starters out of the kitchen.

 

[megabyte]

Thanks for the great feedback Yob, I recently completed some new firmware with a "hold the down button when turned off to set the temperature" feature. It should be much easier to use than the 2 button approach. I wish I could post you a firmware update, how are you with a soldering iron Give it hell, let me know if you have any longevity issues. A small batch is under construction so we're still flexible to make minor improvements at this stage.

Mardoo, I've been thinking along the same lines. A "conical cozy" would be cute but we'll have to order a large quantity to justify a custom shape and my main concern is that what works for a 1L flask won't fit a 5L flask. Let me know if you have any ideas!

 

[droid]

pre-order? Please

 

[Blind Dog]

Looks good

Few Qs. How do you tell if the lights are reading temp or speed? Can you switch between readings (I know I'll forget what I've set it to, and will lose the sticky I wrote it down on)?

 

[Mardoo]

Michael Burton, first thing that comes to mind is a cone of neoprene that would fit over a 5l flask with space for stirplate and some kind of support (as the 5l flasks really can use a bit of extra support). That would insulate a 500ml flask just as well as a 5l. Or if you based it on a four sided pyramid with the base being a square the diameter of a 5l flask plus say 5cm to account for stand that might work as well. It would likely need to be two layers of neoprene to be self-supporting at that size. The good thing about neoprene is it could go flat and ship easily and it's relatively cheap. The making would be your biggest cost.

I myself was thinking I'd get something like this from Bunnings and build a box out of it to put the stirplate and flask in. You could also do a flat-pack of something like that designed so the pieces just locked together. Door hinge could be some kind of heavy duty cloth tape.

 

[Yob]

Looks good
Few Qs. How do you tell if the lights are reading temp or speed? Can you switch between readings (I know I'll forget what I've set it to, and will lose the sticky I wrote it down on)?

The lights have different functions, after you've set the temp, 5-10 seconds later it defaults back to rpm so the default is speed.

You can flick between temperature and speed quite easily, in speed mode. All the LEDs are lit up to the rpm selected, in heat mode, just a single led is lit at the temperature set.

 

[Blind Dog]

The lights have different functions, after you've set the temp, 5-10 seconds later it defaults back to rpm so the default is speed.
You can flick between temperature and speed quite easily, in speed mode. All the LEDs are lit up to the rpm selected, in heat mode, just a single led is lit at the temperature set.

Elegant solution. I want one.

 

[technobabble66]

Firstly, Michael, it looks awesome. Fantastic bit of kit!
I totally want one.

Instead of fancy neoprene, could you just use a sheet of packing foam, like some white goods and electronics are packaged in?
Basically you could use a long-ish, wide-ish sheet as packing for the stir plate itself, then the recipient could just cut it to shape to suit their needs.
The foam sheet i have in mind is only a few mm thick, but should be plenty to make a significant difference when combined with the heating plate (and the heat generation of the yeast itself).

Btw, is there any chance of a DIY kit version of this?
Sorry for being the wet blanket, but is there a rough price estimate? (Apologies, v low budget for brewing :-(( ).

 

[Kumamoto_Ken]

Fark...just got my V3 stirplate a week or so ago and have only used it once (and now want one of these).

 

[megabyte]

I myself was thinking I'd get something like this from Bunnings and build a box out of it to put the stirplate and flask in. You could also do a flat-pack of something like that designed so the pieces just locked together. Door hinge could be some kind of heavy duty cloth tape.

Very interesting idea, a hot glue gun and a bit of left over foam could make a nice simple box to sit over the setup and really let the temperature stabilise.

pre-order? Please

Awesome, I love your enthusiasm! We're still working out our costings, as soon as the PCBs land and we know what cut customs wants to take we should be able to get an accurate RRP sorted out.

Instead of fancy neoprene, could you just use a sheet of packing foam, like some white goods and electronics are packaged in?
Basically you could use a long-ish, wide-ish sheet as packing for the stir plate itself, then the recipient could just cut it to shape to suit their needs.

I love it.. so the packaging could double up as a jacket when cut to size. You mean this stuff right? Most of our empty enclosures come in boxes with this packing sheet to prevent scratches, I'm sure we could get rolls of it from a local packaging company:

Btw, is there any chance of a DIY kit version of this?
Sorry for being the wet blanket, but is there a rough price estimate? (Apologies, v low budget for brewing :-(( ).

Ahh, the DIY kit is in a state of flux at the moment. I feel really bad about our prices with the AUD falling over recent years and I want the DIY kit to remain as affordable as possible. Would an On-Off switch suffice, like a gentle heater mat that we use for our fermentors? Maybe a separate knob with a "power" setting from 0 to 10 but without any active feedback? The other question is whether we can include an enclosure into the kit. They only cost pennies in China so if we can work out some efficient distribution channels a full-form kit would make a lot of sense.

 

[Mardoo]

The ability to set and keep a temp is key for me, FWIW.

 

[technobabble66]

Yeah Michael, that's exactly what I had in mind. I use it for shielding of my thermostat sensor on my FVs. Not the greatest insulator, but perfectly adequate for these low-demand/ intensity requirements.
You might need to include some silver paint to suit the likes of Yob & Mardoo and their addiction to bling :lol:

... Or actually ... include a reel of that metallic shiny insulation tape for an extra, say, $5. So the customer can make the jacket using the packing foam, then put a layer of tape over it - to secure it, but maybe add a little more insulation effect. Plus, much much more blingy!!

On the DIY kit, I'd go with Mardoo's comment. The only worthwhile way to do the heat is to do it in a way it keeps a set temp. A set heat/energy input will result in 10*c or 40*c starters after an unexpectedly cold or hot patch of weather. So whatever the price of that is simply a necessity.
I guess the only way around it might be if you could link your own STC-1000/thermostat to the heat function - so the customer basically supplies their own temp control device, you just supply the nifty heating element within the stir plate. Otherwise, would it be possible to simply place a heater pad (like we use w FVs, as you suggested) +STC-1000 combo btw the flask and the conventional V2 stirplate?

 

[megabyte]

The ability to set and keep a temp is key for me, FWIW.

On the DIY kit, I'd go with Mardoo's comment. The only worthwhile way to do the heat is to do it in a way it keeps a set temp. A set heat/energy input will result in 10*c or 40*c starters after an unexpectedly cold or hot patch of weather. So whatever the price of that is simply a necessity.
I guess the only way around it might be if you could link your own STC-1000/thermostat to the heat function - so the customer basically supplies their own temp control device, you just supply the nifty heating element within the stir plate. Otherwise, would it be possible to simply place a heater pad (like we use w FVs, as you suggested) +STC-1000 combo btw the flask and the conventional V2 stirplate?

Great feedback guys, I sincerely thank you. I think you're both referring to the kits, but the theory applies to our completed stir plates as well. Nobody wants a starter that goes out of whack when you're not watching it. I'm so tempted to add a WiFi -> Pushover option so you get a notification to your smart phone whenever it hits the fan but I'm probably the only one that would get off on that stuff :lol:

I'll hold off on heated DIY kits until we have a proper temperature controlled design. The control parts cost should be less than an STC 1000 so it makes sense for us to handle that in our circuits.

Your comments are very relevant to the prebuilt heated stirplates (Yob's prototype) as well. On one hand, I like having a stir plate that can simply keep my yeasties warm(ish) on cold nights because that's already way better than my old uncontrolled setup. Yob's prototype with a temperature controlled plate should do a good job of it, but when a cold snap is expected it wouldn't hurt to bump the plate up a couple of degrees to compensate.

OTOH, being a perfectionist and wanting to make brewing as easy and predictable as possible, I'd love to be able to set a temperature for my starter and completely forget about the local weather and know it will hold the temperature accurately. That means we'd need an external probe from the stir plate to measure the actual wort temperature. Rubber banding it to the side of the flask with some bubble wrap to insulate it from the air would probably do the trick. The down side is the parts cost, weight, extra programming etc. Probably an extra $10 on the final cost of the stir plate over having it just measuring the heater surface like Yob's prototype. Do you guys think it would be worth the effort?

 

[Mardoo]

Yes. I believe not having an external probe would bring critiques, especially in the US market. Then again, I myself am fine with "good enough". I would buy it as-is, but for another $10 an external probe would absolutely be worth it to me.

A few weeks ago I actually picked up a non-working fridge to set up a temp-controlled starter chamber with an STC. I really want to get starters out into my brewery where I can run them much more often. I'm pretty sure the heated plate will be of interest to a lot of brewers.

You could just include a Digital Homebrew stubby holder to tape to the side of the flask

 

[Blind Dog]

To me, given the only other heated stirplate I've seen seemed to be analogue speed control, and heat either on or off, even measuring the stirplate temp is a big step forward. In fact news of you working on a heated version is the only reason why I haven't already ordered your non-heated version (blame Yob [IIRC] for mentioning it on the other thread). I'd pay the extra $10 for more accuracy, but ONLY if it doesn't add too much to development time. I really want one (kind of now)

 

[technobabble66]

+1 to Blind Dog.

The plate being heated via temp-control is by far the biggest step forward.
(& is the main reason I haven't yet pulled the trigger on a DIY kit)

Hey, have you done a starter where you measure the side of the flask compared to what that current prototype thermostat is set to? And tracked it throughout the fermentation?

ie: how much does the actual flask temp differ from what the setting is; and how well does the plate-thermostat control cope with the heat generation of the main phase of proliferation/fermentation?

What I'm getting at is that if there's little difference between the 2; and it compensates adequately for the sudden generation of heat during the main phase of yeast activity, then there's no need for the external probe on the side of the flask.
So you can keep it simple and stick to the current plate-thermostat!
With the larger volume being at the base of a comical flask, the plate thermostat may well be good enough.

Otherwise, might there be a consistent pattern that can easily be compensated for?
Eg: for ambient temp >15*c, temp is basically what the thermostat is at; for ambient <15*c, temp of flask is ~1*c below plate thermostat. Etc.

Fwiw, I'd definitely stick with the plate thermostat if it checks out well with temp control accuracy. It's just a neat way of doing it!

If possible, could you add a port to plug in an external probe (like a Type K thermocouple), which would override the plate thermostat when plugged in? Then customers can do that as an extra, if they want to.
If this was a minimal additional cost, I'd go with that. If not, and if the above temp comparison test run indicates a good degree of accuracy with the plate thermostat, I'd just go with that.

Decisions, decisions!!

I'd also second BD, I can hardly wait. So whatever's quickest, really :lol:

 

[Yob]

If you do go with an external probe, can it be on a little retractable wheel thing so it just pulls back into the body when not in use

 

[real_beer]

@ Yob.

Your a real PITA Yob! Now we all have to wait maybe months before the final release is available knowing we can't have one now!

Thank you very much for that! (please read this bit with an inflection of heavy sarcasm).

 

[Mardoo]

If you do go with an external probe, can it be on a little retractable wheel thing so it just pulls back into the body when not in use

Ooooooo... :wub: