Quest M3 Mods - Page 26

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
User avatar
FotonDrv
Supporter ♡
Posts: 3748
Joined: 11 years ago

#251: Post by FotonDrv »

Root-Mean-Squared=RMS

So whats the worry? We all work in amps and watts and the biggest variable is the voltage coming out of your wall socket.
That Light at the End of the Tunnel is actually a train

User avatar
AssafL
Posts: 2588
Joined: 14 years ago

#252: Post by AssafL replying to FotonDrv »

The suggestion was to use Watts as a simpler way to communicate settings across different mains voltages. The rest of the discussion was how to get decent wattage readings.
Scraping away (slowly) at the tyranny of biases and dogma.

User avatar
FotonDrv
Supporter ♡
Posts: 3748
Joined: 11 years ago

#253: Post by FotonDrv »

The easy way to get proper readings is to measure them with the appropriate electrical instrument, like a good ohmmeter that measures voltage AC and DC and Amp meter. I use a clamp-on amp meter because it is easier but I have always suspected that running the current THROUGH the meter would be the most accurate. The engineering firms for whom I used to work were happy with clamp-on meters so I have owned one for years.

The way we used to spot circuits to test for potential overload was to first scan the equipment and look for something hot that should not have been hot with an infrared laser aimed heat detector gun. The we went to that circuit to try and figure it out. I used the same principal looking for overloaded or short circuit problems in the Apollo Project guidance systems. Same works with espresso machines so if you find a component that is hotter than it should be then find out why.

If you have something wired for 220-240V then the wiring does not have to be as heavy gauge but when you drop the voltage with the same load (especially resistive) then the current goes up. I recently owned an espresso machine that was designed for 230-240V and had different heating elements for the "110V" market. There was a switch and perhaps connectors that could not take the extra current, especially since the voltage coming from our kitchens outlets was 121V. In stead of the 1400W machine as was advertised the wattage was 1935W; big difference. Had to be run on a 20A circuit with those voltages because a 15A circuit was not enough. Drop the voltage and the machine fit the saleman's mantra-proaganda as I am sure it works just fine at 110V or maybe even 115V.

So one must pay attention to the wire/conductor sizes and what the primary design of the machine was for (voltage wise).
That Light at the End of the Tunnel is actually a train

User avatar
SlowRain
Posts: 812
Joined: 15 years ago

#254: Post by SlowRain »

AssafL wrote:Thanks for disputing.
This is one of the reasons why I love Home Barista. Now, carry on, gentlemen.

User avatar
AssafL
Posts: 2588
Joined: 14 years ago

#255: Post by AssafL replying to SlowRain »

For closure of this topic I did quite a bit of reading on how these single chip energy meters work. They all calculate RMS since they all have to integrate a series of multiplications (I^2 and V^2 for RMS and IxV for Active Power). So your assumption that having a PF reading is sufficient to guarantee RMS seems to hold true.

A bit more detail and OT for a coffee forum (but for closure...) to summarize quite a few datasheets:

So a standard Kill-a-watt or the ultra expensive Gossen Metrawatt Metrahit Energy DMM will all use simple "wideband" integration (which assume a non-sinusoidal waveform) to tell you that your PF is 0.89. These measurement IC all generally perform the following calculations:
1. They sample Voltage and Current.
2. They calculate the instantaneous I(t) x V(t) and integrate it over a period to get Active Power and Energy.
3. They also calculate I(rms) and V(rms). Multiplying I(rms) x V(rms) gets them the Apparent Power in VA.
4. Reactive power is SQRT((Apparent Power)^2 - (Active Power)^2).
An example chip is the Cirrus Logic CS5463 (http://www.cirrus.com/en/pubs/proDatash ... 463_F3.pdf).

Whereas a Fluke power quality analyzer will show you that a harmonic from a VFD is where most of the reactive losses are. These type of power analyzers (as well as industrial analyzers) use different chipsets ("Narrowband") which filter the sampled data into a series of harmonics to be used and actually calculate reactive power per narrowband frequency by shifting the phase angle between V and I (angle: phi) by 90 degrees. At that point the calculation (per harmonic) is a multiplication by Cos(phi) for Active and Sin(phi) for reactive. A nice example of this is the ADE7880 from Analog Devices that will calculate up to 62 Harmonics. http://www.analog.com/media/en/technica ... DE7880.pdf
Scraping away (slowly) at the tyranny of biases and dogma.

Goldensncoffee
Posts: 166
Joined: 10 years ago

#256: Post by Goldensncoffee »

Hopefully some of you still come back and check this thread. I've read it about 3 times now and wow. I just contacted Molly about buying the updated drum. I have a newer model with the thinner drum. I believe the new drums being offered are the thinner ones as well. Someone mentioned that she still sells clockwise/counterclockwise older style thicker drums. Would I be better off getting a thicker one and modifying it myself? Does the thicker drum make that much of a difference? Was planning on painting the new drum also.

Thank You

User avatar
wrz0170
Posts: 187
Joined: 10 years ago

#257: Post by wrz0170 »

Like Goldencoffee above, I'm interested in knowing if any who got the new, perforated drum painted them as well? Thanks!


William

User avatar
TomC (original poster)
Team HB
Posts: 10535
Joined: 13 years ago

#258: Post by TomC (original poster) »

After all these years with the Quest, I'd still advocate for not painting the drum unless you're routinely making efforts to roast as large of a batch as possible. The Quest doesn't need any more help as it comes stock, for a conductive roaster and having the drum painted black and roasting small batches only pushes it more towards unbalanced, primarily conductive roasting IMO. It's responsive enough with small batches that painting the drum isn't a necessity.

Drum thickness is likely not going to be the end-all either. I have both, they both work very similar. I do, however like having the rear perforated wall. I need to make a brief write-up here about the copper tube in the air inlet. I mentioned that in another thread and got a few PM's asking me to explain it more thoroughly here. It plus the modified drum pretty much make it work similar to a commercial roaster in terms of proper convective airflow, just smaller.
Join us and support Artisan Roasting Software=https://artisan-scope.org/donate/

User avatar
wrz0170
Posts: 187
Joined: 10 years ago

#259: Post by wrz0170 replying to TomC »

Thank you Tom. let's say pushing it to about 227g? Where would that batch size fall in the scheme of things? I'm getting back into it and revamping things. From software (Artisan) to workflow.

Thanks!

William

Nunas
Supporter ♡
Posts: 3661
Joined: 9 years ago

#260: Post by Nunas »

I routinely do 227 g on my unmodified Quest M3 Mk2. But, that's about the limit for it, as the heat is nearly maxed out much of the time, especially in the winter. Actually, I prefer doing these 'larger' batches, as the machine is less twitchy. The next time I take it apart for cleaning I intend to add Tom's air pipe...seems like a no brainer...wonder why it was not part of the original design.