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HotTop OEM probe
snwcmpr
Has anyone moved the OEM probe?
Too low for ET, and too high for BT, I am capable of moving the probe, but would like to know if anyone has tried that before I find out it doesn't make enough difference. I would add a ring of silicone to insulate it from the oven wall, too. I would use the upper hole as the new lower hole, and plug the old probe holes.

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
ciel-007
Ken, that's an interesting question. As far as I can tell, the large temperature sensor inside our older HotTops is designed to be 1) partly submerged in the roasting bean mass, and 2) partly exposed to the hot air above the beans. The software running the Main Circuit Board and the Control Panel has been designed with those sensor characteristics in mind. If the sensor was to be moved from its present location, and thus deprived of either one of these two distinct environments, I expect that the software controlling the roasting process might have to be rewritten. An easier, and probably more reliable solution to date, has been to add 2 separate K probes to monitor each of these unique envirionments.
Ciel... seeking Heaven in my cup with ................................................................................................................. EXPOBAR Brewtus II - MAZZER Mini E - MAHLK?NIG Vario - GeneCafe - RAF-1 Extreme (Modified B-2 HOTTOP) - BellaTaiwan XJ-101
 
snwcmpr
Ok, but there must be something in the way I roast, I find that temp reading useless and inconsistent. If I roast anything beyond SC I have to worry about the 428 alarm going off, because it is reading the temp of the beans, not the oven (sort of because it depends on how far the roast is in the process).
My idea with this is the probe I have for BT is correct for BT. I may make that permanent, but that is only for convenience.
If I move the OEM probe, I won't need an ET probe, and then the OEM probe will be more accurate measurement of the ET.

Not sure how the "process might have to be rewritten", except that the 428 temp alarm will be different. That may be a serious issue, but that is the only possible issue I see.

Without any beans in the roaster ... my BT probe reads in the 400 range when this OEM probe is still in the low 300 range. That tells me the OEM probe is not accurate. The OEM probe is probably reading the temp of the wall, too.

Ken

P.S. And yes, Ginny, I do agree it is easy to get "way too far" with this. I am just thinking a simple solution of moving this probe will do what I want it to do. I just don't have any other forum to discuss this.

Also, I am not going to install the new circuit board alterations available. I would better spend that money making a bigger roaster.

I am also not going to add a bunch of other probes to measure motor temp or circuit board temp, because I don't do back to back roasts, I let it cool down by doing something else and come back later. I do appreciate the work done by Miroslav though.
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
ciel-007
Since I seldom roast beyond SC, I have never encountered the 428F alarm issue. However, earlier in this thread, I had hypothesized that a modification called ?Cracking the 165F Barrier? might possibly assist in this regard.
http://homeroaste...post_40018
I would be interested in finding out if someone who roasts to very dark levels might have tried using the above modification to address Ken's issue.
Ciel... seeking Heaven in my cup with ................................................................................................................. EXPOBAR Brewtus II - MAZZER Mini E - MAHLK?NIG Vario - GeneCafe - RAF-1 Extreme (Modified B-2 HOTTOP) - BellaTaiwan XJ-101
 
smico
I used to hit 428 at the end of roast at times when I was running back to back without any cooling. Alarm would turn off the heat at 428, but as soon as I pressed any button roasting would continue until the end of roast.
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
ciel-007
Thanks Miroslav. Did the HotTop's display indicate what was the maximum temperature it actually reached while terminating the roast?
Ciel... seeking Heaven in my cup with ................................................................................................................. EXPOBAR Brewtus II - MAZZER Mini E - MAHLK?NIG Vario - GeneCafe - RAF-1 Extreme (Modified B-2 HOTTOP) - BellaTaiwan XJ-101
 
smico
Yes, 428, and the display went off.
I just pressed any button and roast continued. I always had a minute or two until the end, so I never had to anything else.
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
snwcmpr
So, the roast continues if the 428? threshold is reached AND a button is pushed? Just like the 356? and 410? alarms?

Doh!!! I assumed it just dumped. I got there, and every time it dumped.

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
smico
It happened twice, and it was the same behaviour: I continued the roasts till the end. It might be related to HT controller.
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
Randy G
Some HT's had an auto eject at 428. it was changed in later models of the "B" board. Contact Michael at Hottop to see if that is what you have. I will add that in my case it wasn't a matter of the roaster hitting 428, but that it thought it was at 428 even though it had not reached 2nd.

Life's too short to drink bad coffee.
 
smico
Thanks for the clarification Randy. I am glad to have version without auto-drop.

At time, I was running 170g batches and going back to Ken's observation from the top of this thread about OEM thermocouple being mixture of ET/BT, small amount of coffee probably turned my OEM thermocouple into mostly ET measurement.

Thank you Ken, very fruitful discussion... I will probably be running only 225g batches in back to back roasts.

Miroslav
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
snwcmpr
Next time I take it apart to clean, I will (possibly) drill out a location higher to insert the OEM probe. Also make a plug to seal the old hole using the threaded holes to hold it in place. A silicone ring around the OEM probe should shield it from the wall temperature. I suspect I can get a more accurate ET and take the roast to Light French Roast without an early eject. All this would be still safe because I would not be fooling the alarm, just making the ET alarm more accurate.

Ken
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
smico

Quote

snwcmpr wrote:
Next time I take it apart to clean, I will (possibly) drill out a location higher to insert the OEM probe.

Ken,
I thought that you want OEM probe to measure BT.
ET is leading indicator and it will reach 428 much earlier than BT.
If I was you I would drill the hole lower to measue BT only.
I don't know if I am missing something?
Thanks,
Miroslav
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
snwcmpr
Thanks,
I have a probe for BT.
If I lower the OEM probe, it will hit 428 before SC.
I think mine might be one Randy mentioned just ejects, no choice of alarm reset to finish roast. I need to raise it or leave it alone.

Ken
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
smico
For me this is theoretical exercise, but I probably got confused because of the way I roast, or the fact that I never go close to the SC.
All my temperature curves are always upward sloping (at least a bit), and my ET is always above the BT. In my case ET will always hit 428 before BT.
In your case, it must be that BT goes above ET at some point when you decided to use ET.
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
snwcmpr
Yes, right now it is all theoretical.
And yes just about 400-415 the temps match. Then BT rises until I eject.
I suspect the OEM probe is inaccurate at all times, except when it first starts the 1st roast. At that time the wall is the same as the environment.
I put the BT probe in at the start, and the temp it reads rises a lot faster than the OEM probe reads. So that tells me the oven air is much higher than the OEM probe is reading. Possibly corrected by simply insulating this probe from the wall with a bit of silicone.

Ken in NC
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
ciel-007

Quote

snwcmpr wrote:

Next time I take it apart to clean, I will (possibly) drill out a location higher to insert the OEM probe. Also make a plug to seal the old hole using the threaded holes to hold it in place. A silicone ring around the OEM probe should shield it from the wall temperature...


If you suspect that the sensor may be faulty, you might consider ordering a replacement sensor from HT for $20.

Another option to consider might be to add a temporary manual switch on one of the wires leading from the thermal sensor to the Control Panel. That modication is a simple one, and I expect it should allow you to overide the alarm in order to delay premature ejection. Adding a switch to a sensor wire is easier than the meticulous work involved in modiflying the sheetmetal inside the chamber to displace the actual sensor; further, the temporary switch may be easily removed at any time without visible signs of damage to your roaster. It might be worth considering...
Ciel... seeking Heaven in my cup with ................................................................................................................. EXPOBAR Brewtus II - MAZZER Mini E - MAHLK?NIG Vario - GeneCafe - RAF-1 Extreme (Modified B-2 HOTTOP) - BellaTaiwan XJ-101
 
snwcmpr
Thanks, yes that is an option, But, I am not too comfortable overriding a high temp alarm.

I don't think the probe is faulty. I think it reads wrong. As others have said elsewhere .. "It's too low for ET and too high for BT." and I think the wall interferes with the reading. Te mfg did fix this with a new K probe, so I think it is a known issue.
So, all I would do is make it an ET probe.

I was a machinist. The way I would do it, it could be put back easily. I am past my warranty period, so I wouldn't void that. Maybe I can buy parts from Ginny.

Ken
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
ciel-007

Quote

snwcmpr wrote:

... So, all I would do is make it an ET probe...


Before reaching FC, the BMT in my HT is typically lower than the ET (air above beans). I expect that would also be the case if I were to continue roasting beyond SC (which I have not done in a long while). It is only when I begin to cool down the chamber to prolong roasting time after FC has occurred that the BMT is typically higher than the ET in my roaster. Should the above also be the case in your HT, then might you not expect that moving the sensor into the hotter environment above the bean mass would likely aggravate the 428F alarm problem?
Ciel... seeking Heaven in my cup with ................................................................................................................. EXPOBAR Brewtus II - MAZZER Mini E - MAHLK?NIG Vario - GeneCafe - RAF-1 Extreme (Modified B-2 HOTTOP) - BellaTaiwan XJ-101
 
snwcmpr
My HT matches temps at about 415?. My BMT and the OEM temps match then. The beans continue then to create their own heat. An oven does not need to be above that for the beans to continue raising temp.
I believe the oven temp to be below the BMT after 415?.

Well, when I ever get done doing the stuff I am doing, I will get around to proving or disproving this theory of mine.

If nothing else, I am learning first hand about what I want in a roaster, if I ever make one.

Thanks for you great input,
Ken
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
smico
It looks like Ciel and I are afraid that your Hottop will loose too much blood if you drill another hole in the backwall :)

If you would like to test your theory before installation, and if you have some idle thermo probes, I would suggest installation of thermically insulated ET probe through the bean chute.
It?s basically Randy?s installation technique, but I used Teflon to insulate the the probe from the rest of the roaster.
Hottop B2 + HTC, Cremina 83, OE Pharos, Brewtus IIIR, Baratza Vario
 
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