Hello! I’ve been working through what it would take to create a dimmer mod that has the simplest wiring possible. DaveC already suggested the voltage controller, which was half the battle. I am now working through how this should all fit together, and would really appreciate if someone could look over the proposal below. I will edit this post at the end to become a bit of a user manual. Items I have bought: Crimping tool Male and female spades (B&Q) just make sure you get the correct size for the cable you purchase 3 way electrical cable - the power cable on the Gene cafe is 0.75mm (I bought 1.5mm so am using that) Voltage control unit - https://tinyurl.com/25twjjdr Electrical Tape Electricity usage monitor power plug The schematic I propose is below. I’ll do this in paint once confirmed it is correct! The steps: Remove the fuse from the entry point and tape elsewhere Cable routing goes through the fuse entry point: The blue cable goes from Power PCB (1) in Gene Cafe to the input L (1) in the voltage control unit The brown cable goes from output L (2) in the voltage control unit to the heater (2) in the Gene Cafe This is the inside of the Gene cafe with the labelled connections that are to be moved This is the voltage control unit with labelled connections related to the Gene cafe wires the one goes to the one, the two to the two as I describe above. The wall plug of the Gene cafe is then connected to a electricity usage monitor power plug Does this all look correct? The two questions I have: This will leave two spade halves in the machine empty, can I confirm that is correct? How significant a wattage loss will I likely get from not having an on off switch? Many thanks for any comments in advance! Dan

http://coffeetime.wikidot.com/genecafedimmermod2017 Answering your questions: Yes. not sure, depending on the quality / type of the voltage controller. You can always retrofit the switch if you think you need it later.

Gene Cafe Dimmer mod - A simple version

Danth

Hello!

I’ve been working through what it would take to create a dimmer mod that has the simplest wiring possible. DaveC already suggested the voltage controller, which was half the battle. I am now working through how this should all fit together, and would really appreciate if someone could look over the proposal below. I will edit this post at the end to become a bit of a user manual.

Items I have bought:

Crimping tool
Male and female spades (B&Q) just make sure you get the correct size for the cable you purchase
3 way electrical cable - the power cable on the Gene cafe is 0.75mm (I bought 1.5mm so am using that)
Voltage control unit - https://tinyurl.com/25twjjdr
Electrical Tape
Electricity usage monitor power plug

The schematic I propose is below. I’ll do this in paint once confirmed it is correct!

The steps:

Remove the fuse from the entry point and tape elsewhere
Cable routing goes through the fuse entry point:
The blue cable goes from Power PCB (1) in Gene Cafe to the input L (1) in the voltage control unit
The brown cable goes from output L (2) in the voltage control unit to the heater (2) in the Gene Cafe

This is the inside of the Gene cafe with the labelled connections that are to be moved

This is the voltage control unit with labelled connections related to the Gene cafe wires the one goes to the one, the two to the two as I describe above.

The wall plug of the Gene cafe is then connected to a electricity usage monitor power plug

Does this all look correct? The two questions I have:

This will leave two spade halves in the machine empty, can I confirm that is correct?
How significant a wattage loss will I likely get from not having an on off switch?

Many thanks for any comments in advance!

Dan

MediumRoastSteam

Danth The blue cable goes from Power PCB (1) in Gene Cafe to the input L (1) in the voltage control unit
The brown cable goes from output L (2) in the voltage control unit to the heater (2) in the Gene Cafe

Now that I read properly what you did… yeah… it’s wrong.

Leave the blue cable alone; you don’t have a display, so you don’t need a neutral line.
leave the brown cable connected where it is. You want normal A/C to feed the PCB!

You essentially only re-route the ter4 heater connector output - most likely whatever you flagged as “2” - through your voltage regulator.

I’d recommend you read and re read the guide Dave provided. Once you familiarise yourself with that, and understand all the basics, then read what I wrote.

If you don’t understand the basics… then I’d suggest you leave all of this well alone. After all, it’s electricity you are dealing with. It’s dangerous, it’s lethal, so please take all the necessary precautions.

MediumRoastSteam

http://coffeetime.wikidot.com/genecafedimmermod2017

Answering your questions:

Yes.
not sure, depending on the quality / type of the voltage controller. You can always retrofit the switch if you think you need it later.

Danth

Hello,

Thanks very much, I followed the process that you link to, the discussion you had on the coffee forum as you went through with your build and the original dimmer mod process.

I think my approach is correct as is laid out, but it’s reassuring to have some confirmation from someone who has gone through the process previously.

The key is just confirming that I am correctly connecting the input and output wires to the correct connections in the gene cafe.

Thanks!

Dan

Danth

OK, lots of this was wrong, so could an admin remove this thread? Thanks!

Dan

MediumRoastSteam

Danth - what was wrong?

Danth

Yes indeed thanks! I realised before I started yanking things out, so ended up only changing the wiring on the heater section. It works, which is thoroughly exciting.

The main problem I found was using 1.5mm cable has meant reassembly was more challenging, given its too large to sit under the heat protector section of the outer body, so had to be rerouted. Given there are far better guides out there, happy for this to be removed!

I also realise a project box is a must as the connectors to the voltage control unit are exposed on my current set up, so I haven’t really made a simpler version…

Dan

MediumRoastSteam

Danth - where are you based? I just realised I have a whole spare box ready, all setup, from my previous mod. I sold the Gene on. All you need to do is to wire it up - at your own risk of course.

Happy to donate to someone enthusiastic.

Danth

Wow that’s very kind! I’ve bought all the bits now to get it together, so perhaps it should go to another eager novice.

Will run a few batches through tonight so will see how it goes.

Danth

So I got it running with just the dimmer, I was surprised how a small change in the wattage can really change the temperature. I can stall the temp rise for example by reducing the wattage from 1230 to 1150. This meant the small wattage loss from the dimmer being on all the time meant roast times increased by a minute or two.

So I have gone back and added the switch. It all seems to work great and has made quite the difference in terms of reduced scorching.

This is a recent light roast I did in a 14 minute roast. Not sure if that’s too long, but the ability to adjust the RoR opens up lots of options.

DavecUK

Danth you will like the ability to reduce power in the summer when it goes too fast…in winter you may want to switch in the dimmer at or near 1st crack. I assume you still have the 240V element?

If your dimmer has a separate potentiometer, you can change it for one that gives less total power reduction, but more control…say in a range of 300 or 400W reduction max, rather than 0 to 1200W or whatever it is.

Danth

Thanks Dave, I did two roasts of an Indian which required quite a bit of energy, so I only dropped wattage after 1st. I also roasted a quicker Yirgacheffe where I dropped a few watts at the maillard phase, then slowed further at 1st crack. This ended up with a very long maillard phase (35% of the time) and the pretty light roast pictured above, so I may have further sweetened quite a sweet bean. Will see how it is in 2 weeks.

The ability to reduce the total power reduction would be nice, but I seem to have a good amount of control as is.

Will run it for a few months before making any further adjustments!

Doram

Danth This ended up with a very long maillard phase (35% of the time) and the pretty light roast pictured above, so I may have further sweetened quite a sweet bean. Will see how it is in 2 weeks.

Looking forward to hear how this roast turned out. 👍

MediumRoastSteam

Danth This ended up with a very long maillard phase (35% of the time) and the pretty light roast pictured above, so I may have further sweetened quite a sweet bean. Will see how it is in 2 weeks.

Or you baked them :-) https://perfectdailygrind.com/2020/04/roast-defects-in-coffee-how-to-identify-them-in-the-cup

Danth

Could well be possible! Given the speed of the initial rise (I’m sure the 15 watts from using the switch made all the difference) first crack was under 10 minutes, so I’m hopeful I just expertly adjusted the ror rather than it crashing at any point.