External Grinder Timer
Greetings Avid Grinders of Coffee!
I currently manage a coffee shop in Madison, WI. We use a La Marzocco Linea and 2 Mazzer Super Jolly's to grind our espresso. Teaching new baristas about keeping the doser chamber empty and about the effects of settling vs. leveling before tamping was something I had gotten used to. Then I saw articles online and in Barista Magazine about people building grinder timers to keep a consistent weight of coffee in each portifilter. After doing an online search and consulting with my Electrical Engineer of a father we came upon the 555 Integrated Circuit. This chip had been developed way back in the 1970's but is still used quite often today. Basically the IC is a timer that could be set to count for any amount of time. By hooking it up to a relay which powered a grinder we were able to make an analog grinder timer which could time for anywhere between 2 and 27 seconds. Since then I've managed to reduce the waste at my shop, ensure that every pull has the same amount of espresso in it regardless of barista, and increase the freshness of the espresso in each pull.
In the spirit of sharing I would love to pass on the circuit diagram I used for anyone to use. I've attached it to this discussion. It's just a .jpg file and I kept it pretty simple and specific. The power supply needs to be 12V 15mA. You can wire one of these up yourself, but I just found the power supply for an old answering machine to use. Basically there are 2 buttons and one dial on the final product. There's a start button, a reset button, and a dial which controls the amount of time you set for it.
Hope someone finds this useful!
Yours,
-Eric Tissot
I currently manage a coffee shop in Madison, WI. We use a La Marzocco Linea and 2 Mazzer Super Jolly's to grind our espresso. Teaching new baristas about keeping the doser chamber empty and about the effects of settling vs. leveling before tamping was something I had gotten used to. Then I saw articles online and in Barista Magazine about people building grinder timers to keep a consistent weight of coffee in each portifilter. After doing an online search and consulting with my Electrical Engineer of a father we came upon the 555 Integrated Circuit. This chip had been developed way back in the 1970's but is still used quite often today. Basically the IC is a timer that could be set to count for any amount of time. By hooking it up to a relay which powered a grinder we were able to make an analog grinder timer which could time for anywhere between 2 and 27 seconds. Since then I've managed to reduce the waste at my shop, ensure that every pull has the same amount of espresso in it regardless of barista, and increase the freshness of the espresso in each pull.
In the spirit of sharing I would love to pass on the circuit diagram I used for anyone to use. I've attached it to this discussion. It's just a .jpg file and I kept it pretty simple and specific. The power supply needs to be 12V 15mA. You can wire one of these up yourself, but I just found the power supply for an old answering machine to use. Basically there are 2 buttons and one dial on the final product. There's a start button, a reset button, and a dial which controls the amount of time you set for it.
Hope someone finds this useful!
Yours,
-Eric Tissot
- Attachments:
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Circuit Diagram for Ryan.JPG, 69 KB
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Replies to This Discussion
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Permalink Reply by Brady on
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Fantastic. I've been contemplating modding a SJ and this looks darn useful. Thanks for sharing.
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Permalink Reply by Joe Marrocco on
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You're a good man.
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Permalink Reply by Nathanael Everhart on
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the problem with this is that the time you'll need to pull varies on the grind (courser comes out faster), which varies based on multiple things such as volume of the hopper, humidity, temperature, etc. So it's impossible to get exactly what you want based on time of grind, though it will reduce waste. When grinders can be set up to automatically shut off based on weight (21grams espresso, 14 grams, etc.), that's when I'll upgrade!
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Permalink Reply by Eric Tissot on
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That's why I keep a gram scale next to my grinder so i can re-check when grinds are changed. Also, the amount it varies depending on humidity, amount in hopper, etc is evident but minimal, and is easily fixed by adjusting the time knob. I admit it's not a perfect system, but it still works wonders.
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