Automatic Pellet Hop Dropper

So if as if I didn't have enough stuff to work on I decided to start work on a hop dropper system since now the BrewTroller has a profile for it.

My plan is to have a disc with 8 vertical tubes on it that will use a high tourqe servo to rotate and drop the hops. I plan on using a 8 pin microcontroller to read the drop pulse from the BT and advance to the next tube. I am going to use a microswitch to tell the MCU that it's reached the next tube. The disc is 6" wide and the tubes are going to be 1"OD and 6" high. Since I only use pellet hops I think they will be plenty big. I can always make it with taller tubes if needed. This is mostly a prototype and could be scaled up for hole hops.

Here you can see the disc that holds all the tubes, I cut all the pieces out of .220 thick acrylic, they all look foggy because I still have the protective plastic on them.



Here is the base disc that the tubes will ride on top of and holds the servo.



Here is the servo installed into the base disc



And finally the whole thing put together, I'm just waiting for my tubes to come in from mcmaster and then I can build it the rest of the way.

So my tubing finally came in yesterday so I spent some more time working on the dropper.

Of course no project would be complete without duct tape or JB Weld I used some to attach the servo hub to the carousel. I just used a screw to center the hub on the disc.



So here is the whole unit completed, I still have to glue the tubes in place and I think I might cut out another disc for the top of the tubes to give them stability.



Here is one of the tubes aligned with the drop hole



And finally the hop test, the tubes are 6" long so they hold exactly 1oz of hops per chamber.

Some nice almost a year old mead fueling the project




So now all is left to do is build a base for the dropper, put in a hopper so that I can mount the dropper off to the side of the BK to keep the heat from melting it. Then I just have to finish the code for the MCU.

Cool! I was just thinking about how I would go about making one of these the other day. I've been looking into automated brew systems but unfortunately my Level 7 geekiness leaves me weak when it comes to micro-controllers, servos, and relays in general. I'll be interested to see this working!

Quick question, since each tube holds 1oz of pellet hops, can you program it to drop more than one tube at a time? I assume yes, since it will just be turning on a timer/computer contoller

Well if your looking for simple automation check out the BrewTroller, it's pretty easy and all you really need to know how to do is electrical wiring.

Yeah if you really wanted to you could have it drop two tubes. I think though if I found that I needed more than 1oz per hop addition that I would just make it with bigger tubes. I don't think i've ever done more than .5oz per hop addition on my recipes.

DAMMIT ! I was working on this ! Yours came out much better than mine.

Cool toy, I need that next.

Beat ya to it Larry... dammit!

jcdillin said:

Well if your looking for simple automation check out the BrewTroller, it's pretty easy and all you really need to know how to do is electrical wiring.

Click to expand...

Well my looking has been a bit more drooling and dreaming, I don't really have space for such a rig during the school year... But I have some ideas I may pursue.

One question about the brewtoller that I haven't seemed to be able to find explicitly in writing: as a standalone platform, can it be connected to a computer interface with data logging, remote access, etc?

I know that the halfluck, arduino based system (kind of the brewtroller's predecessor) had that ability.... I was wondering if you knew if the brewtroller was the same

If the brewtroller can automate The Pol's brewing system I am building later this summer, I may need to check it out. I love new toys!

Awesome. I love working with plexi/lexan.

Well done jcdillin.

Here is my version, controlled by my program.
Each tube holds a view ounces of hops and is filled before the brew session.
I do three hop additions per brew, each tube has the correct amount.
The drive motor is a 24 VDC gear motor.




More pics

Cheers,
ClaudiusB

khuygie88 said:

Well my looking has been a bit more drooling and dreaming, I don't really have space for such a rig during the school year... But I have some ideas I may pursue.

One question about the brewtoller that I haven't seemed to be able to find explicitly in writing: as a standalone platform, can it be connected to a computer interface with data logging, remote access, etc?

I know that the halfluck, arduino based system (kind of the brewtroller's predecessor) had that ability.... I was wondering if you knew if the brewtroller was the same

Click to expand...

Yes, one of our forum members is currently working on a program that will let you control the BT via a PC or a web interface. It will also let you view that web interface from any PC in the world. It's still a work in progress but I have tried the first version and it's very cool. It will also do data logging. The BT has a serial port that outputs everything that it's doing so writing applications for it is very easy.

Also Matt and I are working on a windows CE touch based control panel that will allow you use a windows CE touchscreen device to control everything.(Matt being the software guy, i'm the hardware end of the BT)

ClaudiusB said:

Well done jcdillin.

Here is my version, controlled by my program.
Each tube holds a view ounces of hops and is filled before the brew session.
I do three hop additions per brew, each tube has the correct amount.
The drive motor is a 24 VDC gear motor.

Cheers,
ClaudiusB

Click to expand...

Thanks!

Your dropper was a lot of the inspiration for mine. Yours is a work of art, like the rest of the system.

I just crack a whip on my wifes back side and she "automatically" drops whatever I put in her hands.

Leave it to Claudius to Uber Geek. What is it with you? did you buy stock in Coke when you were 12 or sumthin?

jcdillin, looks cool man. The lexan/acrylic really makes it attractive. Question though, why didn't you omit one of the tubes? Or does it start at a half step so you can fill all of them if needed. It does have that cool Gatling gun affect quality though.

ClaudiusB, I like the use of the prox sensor. Could make a simple and reliable RLL circuit to index the carriage. don't have to worry about motor calibration.

Someday Brewtroller..... Someday.

Great job.

Now who's going to hack the twitter api to have brewtroller post your mash/brew steps?

I'm guessing Claudius in a controls Engineer their trucks show up to installation sites missing LOTS of pieces! Stupid shipping department!

CodeRage said:

jcdillin, looks cool man. The lexan/acrylic really makes it attractive. Question though, why didn't you omit one of the tubes? Or does it start at a half step so you can fill all of them if needed. It does have that cool Gatling gun affect quality though.

ClaudiusB, I like the use of the prox sensor. Could make a simple and reliable RLL circuit to index the carriage. don't have to worry about motor calibration.

Click to expand...

Yup I designed the holes so that it can stop in-between for filling. Going to have 2 microswitches, one that shows it's reached the tube and the other for the start tube.

IrregularPulse said:

I'm guessing Claudius in a controls Engineer their trucks show up to installation sites missing LOTS of pieces! Stupid shipping department!

Click to expand...

You didn't know, this system requires 4 spares of every component

Your dropper was a lot of the inspiration for mine.

Click to expand...

Cool, you are the only one .

Question though, why didn't you omit one of the tubes?

Click to expand...

CodeRage I did the same thing, four tubes for only three additions.
Should I ever need a forth addition I can fill tube #4 after the first addition is done. My dropper can not stop between positions.

ClaudiusB, I like the use of the prox sensor. Could make a simple and reliable RLL circuit to index the carriage. don't have to worry about motor calibration.

Click to expand...

The motor RPM is around 1 rev/min, no problem with over shooting the target position, no special calibration required.

jcdillin how or what initializes the hop dropper timing in your case?

My dispenser is synchronized with the boiling point.
Once the brew kettle is at the boiling point for one minute, the hop dispenser routine takes over. If I do a 60, 90 or 120 min boil the program automatically
adjusts the dropping based on pre-programmed parameters.
Should the hop dispenser die, the program will let me know its time to put the hops in by hand.

did you buy stock in Coke when you were 12 or sumthin?

Click to expand...

GilaMinumBeerI don't have a girlfriend on the side, no plane or boat, don't play golf, etc.


Cheers,
ClaudiusB

Yeah with the two microswitches I think I will be able to make it very controllable. I'm tempted to use IR pairs but I don't know yet.

jcdillin said:

And finally the hop test, the tubes are 6" long so they hold exactly 1oz of hops per chamber.

Click to expand...

Jeremiah - Was the 1oz/tube limit based on any specific restriction of the tubing (i.e. cost) or the servo? Most IPAs and maybe even some 10 gallon batches of pale ales would probably exceed this pretty quickly. I guess you could refill during the brew, but what fun is that?

Just curious... I was looking at make something similar, but would probably want something that held at least 3-4 (or 5) oz a shot... :rockin:

Nope, I just wanted to build this version cheap to be sure that it worked.

So far the servo seems like it could handle a bigger/heavier carousel I may build another version with 2" tubes but with the same size discs.

The 1" tube from mcmaster was only $5 for 6 feet of it, I think I paid more in shipping than for the tube.

jcdillin said:

Yeah with the two microswitches I think I will be able to make it very controllable. I'm tempted to use IR pairs but I don't know yet.

Click to expand...

I have done a touch of assembly line automation and can tell you that you DON"T want the IR in this application. Look at some ultrasonic stuff.

My app was a little different - filling ketchup bottles - but I think the steam could cause some IR issues if the lens gets foggy. YMMV, AsIsWhereIs, No Warranty expressed or implied, Offer not valid with other coupons.

Good point, I do plan to have this unit mounted off to the side of the kettle with a chute of sorts to keep it out of the direct steam ,but i'm sure it'll still get some.

Looks like microswitches it is.

jcdillin how is your project coming along?


Cheers,
ClaudiusB

Hey Claudius, i'm in the process of rebuilding my rig so this has been put on the back burner for a while. I have been reworking pressure sensors and doing some more plumbing to fix some issues. I'm hoping to get back on this project here in the next couple weeks.

Looks great so far.

My automated system is still in the design/parts acquisition phase, but when I was originally thinking about an automatic hop doser I immediately went to one of those automatic pet feeders. You could probably hack one of those pretty easily for controlled hop additions.

If you build another dropper, I would use a larger diameter. That way the drop hole could overhang your kettle with less heat and steam exposure to your servo.

So I was talking to Larry on IRC the other day and really got a bug to rebuild and actually finish my hop dropper. I decided to scrap the original and go with an all new design with larger tubes.

So the new one is 8" in diameter with tubes that are 8" tall. I'm still using a standard high torque ball bearing servo that I pulled the guts out of and just directly wired power to the motor.

My control scheme for this unit is going to be a bit more simple. My plan is to use a SPDT micro-switch, the switch is going to have it's center pole wired to the servo. One pole is going to be wired to power and the other pole wired to the brewtroller. So that means that the BT will send the hop drop signal and start the servo moving, once the tube moves enough to open the switch then the servo will be powered by the power supply instead of the BT. Once the next tube arrives then the switch will be depressed again and the power will switched back to the BT but by that time the BT will not be outputting power anymore so the hopper will stay in place until the next activation.

This is the first unit I made out of HDPE. This one is going to Larry to play with.




After making this unit I decided I wanted to see how it would turn out making it out of red oak. I love the look of wood and like working with it.

Here is the main rotor with a recess milled into it's bottom for the servo disc. All these pieces are fresh off the CNC, I haven't had a chance to sand them yet.




Here is the servo disk pressed into place onto the hub. It's really stuck in there but I still plan to put some small screws to hold it securely.

Here is the bottom mounting plate with the tube channel milled into it and the hole in the middle for the servo.



Test fitting the 2" acrylic tubing. The tubing is a perfect fit and is held in place very well just by friction. I still plan to glue them once everything is tested.




All tubes in place during test fitting




Here it is all assembled. I'm waiting for the microswitch to come in which I'm hoping is today or tomorrow. I should have it ready for the next brew.

I like the wood look, great project.


Cheers,
ClaudiusB

This looks compact and efficient enough to sell. Approximate guess at a cost? Even without the BT, you could control this with a timer easy enough. Could be a cool "for sale" item.

I think the HDPE one could be done easy for $100

Will the wood be exposed to the steam from the boil? I like the look of wood, but maybe the HDPE would be a better material? I'm sure you have already thought of that, just curious.

Either way put me down for one. Nice job.

Can't the steam problem be solved with a little metal shoot? I drew a quick ASCII diagram. These look so cool. If your going to add wood. Why not "steampunk" the whole rig?

_____/
| BK |
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Well on my system I have a duct that runs from my vortex fan sitting right over the kettle so the steam doesn't have a chance to go anywhere but up the duct. I also have some leftover acrylic tubing that I am going to use to offset the the dropper a bit off the kettle.

If I do end up making a version for sale to everyone then it will be only made from HDPE or LDPE to keep from having any moisture issues. It's also too expensive for the wood. I paid almost $40 in wood alone for mine.

Can you post a pic of the switch setup when you get it done?

I'm thinking of building the same setup for use with a BCS. I like the idea of the short pulse from the controller then onto a transformer. I've been racking my brain all day trying to figure out how do to the increments.

And Claudius, your setup is an inspiration to a bunch of us. Your hop dropper pic started my brain whirring.

B

I built a less sophisticated version of this a few years ago ...manually advanced:



Yours looks great!