So, I don't remember if I told Oppo that we had whole sheep's milk this year, to feed bottle lambs and supplement lambs with inadequate mother-provided-milk as opposed to the usual powdered formula. This is great from a nutritional standpoint, but bad from a usage and storage point.
We bought ~1000lbs (about 120 gallons) of milk from a sheep dairy that had failed it's well inspection and could not sell the milk (or milk products) for human consumption. It came frozen in giant food-service dispenser bags that hold ~5 gallons.
They take roughly three days to thaw in this tray.
As we do not have an appropriate dispenser for these bags, we are transferring the milk to 6-gallon beer bottling buckets for storage in our basement fridge, and dispensing. As I know I have mentioned sheep milk has extremely high fat and protein content, and this is whole, raw milk. Unpasteurized and unhomogenized. It will separate to cream/fat and whey if left still in the bucket.
Each 5 gallons lasts about 3 days, taking the bucket out of the fridge to slosh it and stir it is a PITA, also we only access it every 6 hours, which is plenty of time for separation to have occurred, requiring extensive stirring to recombine the milk, and leading to the formation of unwanted fat globules... The solution is to stir it often... Like a bulk tank agitator....
So I made one.
An arduino nano, a DRV8825 stepper driver, a beefy NEMA 17 stepper, a 1amp 12v wall wart from an old router, a cheap plastic stirring paddle, a 3D-printed arm, a heavy-duty servo pushrod, and a bit of 2x4, some deck screws and ingenuity later and I have a device that stirs the milk for two minutes every half hour without any input from us!
Initial tests look promising. We'll see if it solves our milk separation issue long term over the next couple of days.
jminer last edited by
@jawzx2 very nice and ingenious looking fix! I love solving problems with Arduino and the like.
WhoIsTheLeader last edited by
@jawzx2 Now that's some ingenuity!
frinesi2 last edited by
SilentbutnotreallyDeadly last edited by
One idly wonders if a magnetic stirring solution might be cobbled together. There's quite a few DIY recipes and it would be potentially less fiddly in dealing with equipment swapping from one bucket to the next since you'd only be dropping a stirrer bar in the bucket. Of course, the unique properties of the sheep milk might present more than a few design challenges to such an idea...
barnie last edited by
Damn, @Jawzx2, yer a hero. Lamboing, developing new tools and time to post stuff. Good on ya. How many little ones now? How many are are getting bottle fed? Supplemental or momma dry? How are the 2 house lambos? Sorry for Qs, Birds are singing love songs around me and spring flowers are popping. This season of renewal, birth, beginnings..
What driver for the stepper? Constant or intermittent on? Is 12watts enough for the stepper? What printer are you using? (I'm looking to get or build one)
@silentbutnotreallydeadly I had considered magnetic stirring, but we have no local source for the stir bars, I would have had to mail order them. I had most of the parts on hand, and was able to acquire all other parts for this design locally. Also, I read some scientific papers that asserted a "sloshing", or ideally "dipper" agitator was more effective for milk container volumes under 10 gallons due to the possible formation of a stable vortex that does not wander and has no excess surface area to pull in from and create a circulatory current.
Shop-Teacher last edited by
@jawzx2 Very cool!
@barnie 49 lambs now. Births are going to slow down significantly at this time, as we have yearlings and/or otherwise first-time pregnant ewes left. They usually get pregnant later in the time with the ram and give birth later.
We have 6 regulars at the nipple bucket (and two more occasional), the two house lambs, who are now living full time outside, and four who's mothers are not necessarily dry, but aren't producing enough milk to meet thier needs, oh and we do have an almost totally dry momma too...
Using a DRV8825, 2 amp-per-coil capable, but I've got the current limited down to ~400ma-per-coil, so we're never drawing more than about 10watts and the stepper is outputting sufficient torque for the job. I'm running it in full-step mode for max torque, as this job really doesn't require the precision or reduced noise you get from running microsteps. Though I will admit it is quite loud this way...
It's only running for 2 minutes every 30, so the power supply is plenty adequate for the task. The motor could put out more torque if I had more power, but I just don't need it for the speed and load It's running.
My printer is an extensively modified Anet a6. An older cheap-chinese kit printer. It's got uprated power transistors, higher wattage power supply, custom firmware, modified axis pulleys and end stops, a bi-metal titanium heatbreak on an e3d clone with a custom direct-drive short-throat filament feed, high-temp heaters and conversion to a high-temp-capable thermocouple from thermistor... It can print Nylon, polycarbonate and POM, but doesn't quite have the heater snot to print PEEK... I mean, the control board, display, input panel, and most of the frame and the z-axis lead screws and steppers are all still the parts that came in the box from china, but the rest is pretty much bespoke.
DipodomysDeserti last edited by
@jawzx2 I’d be interested to know what was in their groundwater.
@dipodomysdeserti bacteria. Nothing that would get a residential well condemned, but the requirements for a commercial dairy production facility are a bit more stringent. They may end up having to install either a UV treater or chlorine injection system to pass.
barnie last edited by
@jawzx2 Wow! Thank you for the completeness of your reply. Hit all points and as busy as you are, I appreciate this all the more.
When you first mentioned stirring, I saw an Arduino controlled MOSFET to control power to a drill with the trigger ziptied. This is a lot more elegant and cost effective. Particularly since you already had the parts and know-how.
Old Jewish fellow introduced me to 3d machines (engraving) about '80. He had a sign on his desk that has stuck with me ever since. "If you want a good job done quickly, give it to a busy man." You seem to embody that spirit.