From what I understand the output box would have to have 2 (removable) separators to separate the good beans, the bad beans and the doubtful beans?
If that is so the disadvantage is that one cannot just pour the beans from the output bin into something else because there are 3 different kinds of beans in the box. Hence, one needs to scoop them out which is not very practical. Easier is to actually have 3 outlets and be able to put 3 buckets underneath. Then there is also no requirement on the size of bucket, any bucket will do. Using a Eurobox is nice, but if a farmer somewhere in the mountains breaks it he won’t be able to easily get a replacement unless he drives to the nearest city (wherever that may be).
Also, the principle of stacking sounds nice but it requires every time to lift the machine to put it from the output box onto the empty input box. Lifting and moving is a recipe for dropping it…better have the sorter on a fixed table (some roasters or farmers may even want to to bolt it to the table so that it can’t move nor be stolen) and “never” move it again…
I adapted the design accordingly now. Re-using the input boxes (with its pour valves at the bottom to empty it) also as output boxes is indeed cumbersome. Additionally it adds costs and considerable shipment costs without a good reason, as all coffee farmers and roasters will have some kind of suitable containers available.
Now the sorter will only use Euroboxes for the case and input box (with a funnel-style bottom). I found sizes that allow to place the sorter inside the input box for shipment, which reduces the shipment volume and costs. I think I like the design now …
Also good points! I had planned for a shelf / trolley format as an add-on, which would also avoid the stacking. But bolting to a table is easier and re-uses what farmers already have. So I added clamps to the design to support bolting it to a table.
As for the batch duration, with the new input box sizing one batch would need 1.8 - 3.7 hours for processing, depending on how fast we can make the machine (8.5 - 17 kg/h). Does that sound acceptable or would you want even larger batch sizes to tend to the machine less often?
Hi Matthias,
I completely forgot about your question on batch duration… I would say it’s long enough. Compared to a commercial color sorter it’s in fact considerably longer as the commercial laboratory size sorters have input hoppers for max 5 kg, hence less than 1 hr sorting.
Also I think that a bigger input batch would become increasingly harder on the sorter itself because of the weight and would maybe require an extra support frame. I would say this is something for the creativity of the farmer or roaster to add and goes a bit beyond the purpose of the sorter?
One more part of progress on the mechanical design
This is the part that kicks coffee beans off the conveyor. It is mounted to a stepper motor with a downwards-pointing axle, but slightly inclined so that the beans that should stay on the conveyor will not bump into the shovels passing again over the conveyor some way further along the belt.
I also got the case parts, so after drawing the last essential custom part (another motor mount) I can start to assemble a prototype.
Out of curiosity I dropped them an email to ask what’s the capacity and the price. I honestly don’t even expect an answer …
But if they do answer…anybody wants to make a guess about the price? I’d say around 4000 euro…
The price of this micro sorter is 10000 USD, you can contact our sales manager to get unexpected discount.WhatsApp:+86 13635690916.Or Email:info@grotechcolorsorter.com
That price point makes sense to me; it’s quite similar to the somewhat larger sorter made by the company of @smallcolorsorter and presented above in this topic. Theirs is 40×100×100 cm, weighs 80 kg, can do 250 kg/h, sells for 12,000 USD if I remember well. Both seem to use the same tech: industrial cameras to record beans in free fall, then eject them with compressed air. (There is an orange compressed air hose going into the GroTech sorter.) With that tech, scaling down more and making it cheaper probably hits a limit around 12,000 USD / 10,000 EUR as the fixed costs of the industrial components is high.
I actually got a price quote and some references in Europe that supposingly bought it. The price is US$5180, not including transport from China to Europe, import duties (I think around 4% as that is the import duty for most machinery from China) and an 8 bar air pump (which should be around 150 Euro). So I think all together it would cost about 6000 Euro to have it up and running…
But I do have some more data now: It has a maximum capacity of 50 kgs/hour for which it uses 18 solenoid ejectors. And they claim it uses a Toshiba CCD sensor of 5400 x 3 lines.
[10 minutes later]
I thought, I can just ask them in China if they know about sending costs and import duties…
And they answered within 5 minutes: the sending cost is approximately 350 Euro and the import duties are 1.7%. But I just realized there will also be some costs for the customs broker here. For a pallet of coffee that’s in the order of 300 Euro, so I guess for 1 single coffee sorter it must be less, but not much less - 200-250 Euro or so.
So that would make the total cost approximately, using 1 Euro = US$1.18 (5180/1.18 + 350)*1.017 + 250 + 150 (for the air pump) = 5200 Euro.
I’m afraid my wife, who is my business partner as well, may be interested now
It’s a good find! For artisanal roasters in Europe, it seems to be of a suitable size, cost and throughput. For small-scale coffee farmers, it will still be too costly I think … trying to design a machine that’s 10% of the cost.
For customs duties, you might want to also consult TARIC (the official source, with a moderately good online interface). (I remember checking the import rules for psychedelic honey and got around there …) VAT will be levied on import but I guess you discounted it as you’ll get it back as a business via pre-tax deduction.
Let us know your experience if you decide to get one Good luck as well! I had once tried to purchase a 10 kg roaster from a manufacturer in India and was advised to really, really check that I’m speaking to an official representative of the company. There had apparently even been cases where fraudsters even gave potential clients a tour of the company premises to “prove” that they are a real sales agent
Sorry, no real news right now. I had 3D printed most of the parts (shown above) except the slide and conveyor belts, and assembled one frame for a sorter unit and (partially) a case. I also got some of the electronics parts, such as the stepper motors and the AC adapter.
But then I started to doubt the commercial viability of the project. In comparison with the 5000 EUR Chinese machine that Dennis found, this machine would always look very DIY given the way it is built (3D printed parts, industrial plastic box as case). So inside Europe, it would possibly not have many customers … but these customers would be important for most of the commercial success, while customers in South America, Asia and Africa would get the machines at much lower prices.
So I took a kind of hiatus from building the machine, esp. because a major part of the work would be writing the machine control software and that is not even started. I’ll get back to the project eventually and plan to finish it, but don’t really know when that will be. All work results are open source and already online though, and the Dynalist document contains detailed documentation. So if anyone else is inclined to drive the project, at least for a time, now would be a good time to take it on.
Nooooooo! Don’t give up now. You’ve worked so hard on this and it’s still an awesome, much needed idea. Sure, 5,000 euro is better than previous prices, but it’s still too much for many small businesses / farmers to invest. Also, their website is no longer even running…
I would love to still see this project finished. Can I at least see some photos of your build? It’s exciting to me that the physical components got so far.
My only reservation with the 3D printed one is if it would need to be printed with food-safe filaments etc? Otherwise, it’s an excellent way to build it!
Well, as Neil says, 5000 euro is still quite some money and it comes with some extra issues:
it’s shipped from China so one has to do the import paperwork oneself. Not everybody’s cup of tea.
what about repairs if necessary? GroTech seems to have only 1 dealer in Europe (in Austria) and they seem to be only a sales point.
Hence, if you can develop a 500 euro sorter I’d rather make 2 or 3 of those. Two for green coffee and 1 for roasted coffee so I can completely separate green and roasted coffee processes.
And if I assemble it myself I can repair it myself.
Having said that, I do desperately need a coffee sorter for some of our coffees. Typing this I see another 14 kg order coming in…14 kg, that costs us 5 hours to clean the green coffee, 45 minutes to roast and then 2 hours to clean the roasted coffee. Can you imagine how much time we could save with even a DYI sorter?
So I hope you can continue and if you need some help you know where to find me…
@matthias. How are you? Can we tempt you to get back to this prototype? You’ve done sooooo much work already… just a little more to get something running!
Huh … 70 kg per hour is quite a lot for a small footprint machine. With that throughput, probably not much need to plan ahead, just let it run through before roasting. Way different from a machine like the one here that was intended to run 24 hours.
For any coffee processing in high and middle income countries, certainly that Chinese sorter is the way to go. Even for some coops in low-income countries. For small-scale farmers, also beyond coffee, a color sorter like the one we tried to develop here could still have its place.
I have certainly run out of entrepreneurial energy for some time, due to too many mishaps unrelated to the coffee sorter, so I don’t know when I will come back to this project. It’s still a lot left to do … the whole software side and testing … not very realistic to do alone and self-funded. I like it as a fun and meaningful project still …
Good luck as well! I had once tried to purchase a 10 kg roaster from a manufacturer in India and was advised to really, really check that I’m speaking to an official representative of the company. There had apparently even been cases where fraudsters even gave potential clients a tour of the company premises to “prove” that they are a real sales agent 
