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Any tips for SR540?
hotfishtacos
Top  #1 Print Post
Posted on 05/22/2020 1:31 AM
Hello! I am Steve from Southern California and am trying to develop a basic roasting profile for my SR540 modeling around the guidelines in the post, https://forum.hom...ad_id=2189. I understand the workings of the SR540 machine and have roasted a few batches for familiarity. My learning profiles ramped up temperature too quickly with insufficient drying time and overall, the profiles were too short. Cupping my results showed either grassy tasting results or insufficient finishing roast flavors. My goal is to slow the drying time to around 4.5 -5 minutes hitting 300 F around the 4.5 minute park and then ramping up to 400 F over the next appx. 4 minutes with about a 2 minute finishing between 400 and 450. Does this sound about right? If you have any recommended settings and/or profiles then it is much appreciated. Thanks in advance for your feedback.

Steve
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
hotfishtacos
Top  #2 Print Post
Posted on 05/22/2020 10:44 PM
Just an update on my efforts to develop an effective profile for my SR540; I roasted two batches today with the SR540 of very different coffees with a target profile and in both cases the machine was very responsive and easily adjustable and the actual bean temperatures measured every 30 seconds during the roast were very close to my target profile. What an easy, responsive system! Tomorrow I will cup these batches and am anxious to see how good they are.
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
Boki
Top  #3 Print Post
Posted on 05/30/2020 3:46 PM
I am new to this forum and was glad to see someone discussing the SR540 which I also use. I am curious as to approximately how long do you take to reach 1C and are you adjusting power level or fan or both? I seem to always reach 1C at 4 min which seems too early.
 
renatoa
Top  #4 Print Post
Posted on 05/31/2020 1:15 AM
If owning such machine, my first step would be to find the maximum stabilised temperature for each power/fan combination, and the time required to reach that temperature.
For example: lowest fan, lowest power: 175C in 2 minutes
Then I could elaborate some profiles...
 
hotfishtacos
Top  #5 Print Post
Posted on 05/31/2020 7:02 PM

Quote

Boki wrote:

I am new to this forum and was glad to see someone discussing the SR540 which I also use. I am curious as to approximately how long do you take to reach 1C and are you adjusting power level or fan or both? I seem to always reach 1C at 4 min which seems too early.


I originally had trouble with my SR540 with too much heat too early in the profile which lead to grassy flavor with the finished roast. I think the bean interiors were under-roasted. My goal was to achieve a classical profile with 300 F at 4.5 minutes followed by 400 F at 9.0 minutes (first crack around this time) then 2 more minutes of development. What I achieved was 300 F in less than 2 minutes followed by 400 at around 4 minutes for a short roast finished in less than 6 minutes....not what I wanted. This is with the settings on the roaster at their minimums; Fan 9 and Power 1 for almost the entire time. I then developed 2 successful ways of lowering temperature and the one I am now using is achieved with a 20 amp variable voltage transformer I purchased on Amazon to lower voltage supplied to the roaster. It is very successful. I measure temperature with a thermocouple I ran down into the area with the beans to measure bean temperature tied to a display device. (Digi-Sense Traceable Remote-Monitoring Thermocouple Thermometer with Calibration; Fahrenheit). I now start the roast with the voltage to the roaster at 100 volts AC, fan speed 9, power 1. I raise the voltage at 3 minutes to 105 with the temp at 260. At 4.5 minutes the temp is 300 with voltage is 120 and the fan is still at 9 and the power at 1. I hit 400 at 9.0 minutes (first crack around this time) with the fan at 5 and the power at 1. Power remains at 1 for the entire roast. I quit at around 12 minutes at 440 with the fan at 2. I've done a few 4 oz batches with this profile and the coffee is very good.
Edited by hotfishtacos on 05/31/2020 7:25 PM
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
Boki
Top  #6 Print Post
Posted on 05/31/2020 10:11 PM
OK, I have to admit that the thought of adding a variable voltage meter would never have occurred to me. But I am not sure what is the purpose of thermocouple thermometer here? Are you thinking the SR540 thermometer is faulty? It seems to me that you achieved your goal just by regulating the voltage and playing with fan speed.
 
hotfishtacos
Top  #7 Print Post
Posted on 06/01/2020 10:39 AM

Quote

Boki wrote:

OK, I have to admit that the thought of adding a variable voltage meter would never have occurred to me. But I am not sure what is the purpose of thermocouple thermometer here? Are you thinking the SR540 thermometer is faulty? It seems to me that you achieved your goal just by regulating the voltage and playing with fan speed.


I wanted to see the bean temperature, not the temp of the hot air supplied below so I added the other temp indicator. It also allows me to not have to constantly turn the control knob to display temperature, a PITA when also adjusting the other settings. Yes I did achieve my goal by lowering supply voltage. It lowered temperature more than the fan speed which was great.
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
renatoa
Top  #8 Print Post
Posted on 06/01/2020 11:22 AM

Quote

hotfishtacos wrote:

...My goal was to achieve a classical profile with 300 F at 4.5 minutes followed by 400 F at 9.0 minutes (first crack around this time) then 2 more minutes of development. What I achieved was 300 F in less than 2 minutes followed by 400 at around 4 minutes for a short roast finished in less than 6 minutes....not what I wanted. ...


Measuring true beans temperature in such turbulence is the most challenging part of such machines telemetry.
What you measured is very much influenced on the beans temperature probe placement.

You can judge the measurement was been right if the first crack occurred around 400F, ending about 430F.

If you can't reliably measure true beans temperature, is advisable to roast based on hot air temperature instead.
 
hotfishtacos
Top  #9 Print Post
Posted on 06/01/2020 2:06 PM

Quote

renatoa wrote:

Quote

hotfishtacos wrote:

...My goal was to achieve a classical profile with 300 F at 4.5 minutes followed by 400 F at 9.0 minutes (first crack around this time) then 2 more minutes of development. What I achieved was 300 F in less than 2 minutes followed by 400 at around 4 minutes for a short roast finished in less than 6 minutes....not what I wanted. ...


Measuring true beans temperature in such turbulence is the most challenging part of such machines telemetry.
What you measured is very much influenced on the beans temperature probe placement.

You can judge the measurement was been right if the first crack occurred around 400F, ending about 430F.

If you can't reliably measure true beans temperature, is advisable to roast based on hot air temperature instead.


Read..."I hit 400 at 9.0 minutes (first crack around this time) "
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
Boki
Top  #10 Print Post
Posted on 06/01/2020 4:06 PM
I then developed 2 successful ways of lowering temperature and the one I am now using is achieved with a 20 amp variable voltage transformer I purchased on Amazon to lower voltage supplied to the roaster.

Mind if I ask what was the other way of lowering temperature? And do you really need a 20 amp variable voltage transformer? I don't know which kind you bought on Amazon but prices I see are almost as high as the SR540 itself. I will be honest that electric power is not my forte but would a 5 amp variable voltage transformer work?
 
hotfishtacos
Top  #11 Print Post
Posted on 06/01/2020 6:19 PM

Quote

Boki wrote:

I then developed 2 successful ways of lowering temperature and the one I am now using is achieved with a 20 amp variable voltage transformer I purchased on Amazon to lower voltage supplied to the roaster.

Mind if I ask what was the other way of lowering temperature? And do you really need a 20 amp variable voltage transformer? I don't know which kind you bought on Amazon but prices I see are almost as high as the SR540 itself. I will be honest that electric power is not my forte but would a 5 amp variable voltage transformer work?


No. The SR540 draws over 14 amps during the roast so it will burn out or blow the fuse on a 5 amp transformer. The other way I lowered roasting temperature was injecting cold air in the air-stream under the roasting chamber. I made a 4" tall round aluminum spacer under the chamber and injected compressed air into the air-steam. It worked fine but I like reducing the supply voltage better. It is very responsive and controllable.

I'm sure there are other ways to make it work but I can control temp withing 5 or 10 degrees throughout the entire roasting profile. Considering all the time spent, cost of the green coffee, and the resulting great tasting results, a $105 transformer is cheap.
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
Boki
Top  #12 Print Post
Posted on 06/01/2020 8:29 PM
I agree with much of what you said here. I was also lucky this morning in trying a fan speed 9 and power level 1 and I did not get FC until 9 minutes into the roast. This was more time that I aiming for but this means I can play more with power levels at to get the roast I want. I just need to keep the fan speed at 9.

I also saw a YouTube video where the roaster said that he was hearing wild variations on heating levels among SR540 owners so each machine is probably a little different. If I am not happy with this new high fan speed approach, I will get transformer. Thanks for your information. Happy cupping.
 
hotfishtacos
Top  #13 Print Post
Posted on 06/01/2020 9:18 PM

Quote

Boki wrote:

I agree with much of what you said here. I was also lucky this morning in trying a fan speed 9 and power level 1 and I did not get FC until 9 minutes into the roast. This was more time that I aiming for but this means I can play more with power levels at to get the roast I want. I just need to keep the fan speed at 9.

I also saw a YouTube video where the roaster said that he was hearing wild variations on heating levels among SR540 owners so each machine is probably a little different. If I am not happy with this new high fan speed approach, I will get transformer. Thanks for your information. Happy cupping.


I know from experience from running my roaster from different places in my house that the end result is very different, which I attribute to differences in line voltages because of different length wire runs to the outlets. In the backyard I could not get sufficient voltage to get a complete roast. In the kitchen it was OK but there was too much smoke generated in the house. Where I do it now, outside the garage, there are short wire runs from the meter and roasting is done outside. I do not think there are differences in the machines. I do know where they are plugged in makes a huge difference. Control the voltage to your machine and you will be delighted!

Steve
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
hotfishtacos
Top  #14 Print Post
Posted on 06/01/2020 9:20 PM
Please let me know how it works out for you!!
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
renatoa
Top  #15 Print Post
Posted on 06/02/2020 2:44 AM
What about a $12 "4000W AC110V to 220V SCR Voltage Regulator" ?
Some of us are using such device for long time to regulate heaters in our roasters, and no issue.
 
Boki
Top  #16 Print Post
Posted on 06/17/2020 3:34 PM
I wanted to follow up on this thread about the SR 540. My initial use of the machine was playing with the temperature settings. I flipped my approach and now mess with the fan speed initially set at 9 and lowering it to achieve the roast level I want. It seems to me working for me as now I can achieve the FC at 8-9 minutes into the roast depending on going for medium or dark roast. Before I was getting FC at 4 minutes which IMHO was way too early.

But I still may consider a voltage regulator if I think I want more precise control on timing of FC. I just don't know how important that is for me.
 
hotfishtacos
Top  #17 Print Post
Posted on 06/18/2020 1:09 AM
Good luck with your efforts to get the profile you like. I haven't found this forum helpful for my needs so I'm going to bail. Good luck!

Steve

Quote

Boki wrote:

I wanted to follow up on this thread about the SR 540. My initial use of the machine was playing with the temperature settings. I flipped my approach and now mess with the fan speed initially set at 9 and lowering it to achieve the roast level I want. It seems to me working for me as now I can achieve the FC at 8-9 minutes into the roast depending on going for medium or dark roast. Before I was getting FC at 4 minutes which IMHO was way too early.

But I still may consider a voltage regulator if I think I want more precise control on timing of FC. I just don't know how important that is for me.
"Don't ever ask a question you don't want the answer to!"
"Don't ever be good at anything you don't want to do!"
 
JackH
Top  #18 Print Post
Posted on 06/18/2020 3:01 PM

Quote

hotfishtacos wrote:

I haven't found this forum helpful for my needs so I'm going to bail. Good luck!

Steve


Sorry to hear that Steve. I think you got a lot of responses to your question. There are so many machines out there and sometimes it takes a while for people to respond.
---Jack

KKTO Roaster.
 
renatoa
Top  #19 Print Post
Posted on 06/18/2020 3:17 PM
Everything should start with understanding what are the machine thermal regimes and match them with the basic roasting recipe.
 
Cranker
Top  #20 Print Post
Posted on 01/10/2021 10:49 AM
Has anyone been successful placing a thermocouple in the bean chamber? If so, can you possibly post pictures or a diagram describing it. I want to do this and save a heat profile for the roasts.
 
renatoa
Top  #21 Print Post
Posted on 01/10/2021 11:28 AM
Check this SR800 setup:

https://www.home-...67510.html
 
Mike_Mathis
Top  #22 Print Post
Posted on 09/15/2022 10:23 AM
Interesting thread for sure. I realize it has been idle for a while, so I am hoping to resurrect this conversation.
I have a SR540 with FR extension tube and I have been having decent results with the general profile of starting at Fan9/Heat1 and trying to hold off the temp rise to target 300°F in appx 3.5-4 min for drying and then increase temps for a 1stC at appx 7 min and drop time at 8.5 for a development of appx 20%. This is with the Amazon favorite Nicaraguan beans. The thought of regulating voltage is intriguing for certain. I wish I had seen this thread before hotfishtacos left because there are several on Amazon and some with not so good reviews. I would also like to know more about the 4000W AC110V to 220V SCR Voltage Regulator such as how do the connections work. I can see stripping wires to connect a male plug on the input and a female plug on the outlet. Is it that simple? Thanks for any replies.
 
renatoa
Top  #23 Print Post
Posted on 09/15/2022 3:55 PM
Yes, connection is the simplest part, as simple as cutting a wire and tighten 4 screws.
Understanding some quirks is the hard part.
First, these devices do not regulate voltage in the sense of maintaining it stable at output.
They just reduce the voltage to some percent you set display... percents, not voltage level... if the mains is very dirty and vary wildly, identical will be the output too.

Regarding the power rating, there are also some salt grains too, you can read more here: https://homeroasters.org/forum/viewthread.php?thread_id=6778&highlight=10000w&pid=75502#post_75503
 
Mike_Mathis
Top  #24 Print Post
Posted on 09/16/2022 12:56 PM
Thanks for the link. After reading with my less than stellar understanding of the nuts and bolts of electricity, I don't believe I will be utilizing a SCR voltage regulator. Kind of disappointed because they are so cheap. Maybe I will just take a chance on one of the voltage regulators hotfishtacos referred to.
 
renatoa
Top  #25 Print Post
Posted on 09/16/2022 2:08 PM
Which are... ? Maybe in other thread... :? <lack of confused emoticon>
 
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