topbanner.gif
Login
Username

Password




Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Shoutbox
You must login to post a message.

CharcoalRoaster
11/04/2019 1:58 AM
+1 snwcmpr

snwcmpr
11/03/2019 2:16 AM
Can we make the shoutbox UNAVAILABLE until a member has a certain number of posts?

allenb
11/01/2019 2:20 AM
Funopt, please post in the gas and electric heat sources forum

Funopt
10/30/2019 5:17 AM
Can someone help me for using forced propane burner as my heating element. I rather want to use lpg than electric. Do you think it would work

snwcmpr
10/22/2019 5:31 AM
Thanks to you all....... I was not sleeping ... I stayed awake worried about it all. :)

Users Online
Guests Online: 2

Members Online: 0

Total Members: 6,247
Newest Member: Natesforu9
In Memory Of Ginny
Donations

Latest Donations
renatoa - 2.00
JitterzZ - 2.01
renatoa - 2.00
allenb - 25.00
snwcmpr - 10.00

View Thread

Who is here? 1 guest(s)
 Print Thread
My Third Roaster
BenGeldreich
KK,

Thanks I had a quick email chat with the supplier of the thermocouples. Below are his thoughts.

1) It is very unlikely the grounding will cause the reading lower. Normally, if there is a grounding issue, the reading will be very unstable. The thermocouple signal is in micro volt level. The grounding noise is in the mv level or higher.

2) The problem is related the sensor used. The sensor you have is originally designed for measuring plastic injection mold temperature (solid metal). It will be slow to respond the air temp change. It will be significantly affected by the mounting base temperature. To measure air, you need a thin and long temperature probe. The thin probe makes the response faster because air has much lower thermal mass than solid metal. The long probe make the interference from the mounting site to be minimal. TC-K5 or TC-K3MM will do better job. If the TC-K3MM is too long, you can bend it to save the space.

3) The location of the sensor will affect its reading. Without knowing the heater location and how the heat flow, I can't comment on your system. Are you sure that the location of the sensor should have the same temperature as the coffee beans?

Seems fair and truly what I suspected. So I am going to purchase a K type long probe like my current ET and mount it inside the wooden box below my pot. THis will be an easy change as the holes are already in place I just need to mount the probe at the exact height so it just pokes up into the bean mass. I don't think the placement is a 50°F variance issue. THe current placement is right in the mix and can't imagine a bean not hitting the probe on every pass.

Not having an accurate BT reading is most likely the cause of my tipping issue so hopefully this "will kill two birds with one stone". Though I would never actually kill a bird.

Ben
Edited by BenGeldreich on 12/02/2011 4:35 PM
--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
Koffee Kosmo
That is an excellent response and communication from that supplier

We will see what transpires when you get a more suitable probe

KK
I home roast and I like it
Blog - http://koffeekosm...gspot.com/
Bezzera Strega: Mazzer Robur Grinder: 5 Box hand grinders: Pullman Tamper Convex: (KKTO) Turbo Oven Home Roaster: CONA Glass Rod Syphon: Pyrex Brewer:
 
http://koffeekosmo.com.au
BenGeldreich
I finally finished my TC4C project box and thought I'd post some pictures.

Big shout out to Jim and Jack for all there support!

I found the wooden box as a set of two in Michaels, which is a hobby store, for $2.99. I got the switches, and LED's from a local Radio Shack style shop. Most or the square wholes were drilled then filed to shape.
BenGeldreich attached the following image:
img_0541.jpg

--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
BenGeldreich
Here's a shot of the back.

I was shaking a bit in these shots so you will have to excuse the camera shake.
BenGeldreich attached the following image:
img_0543.jpg

Edited by BenGeldreich on 12/22/2011 9:52 AM
--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
BenGeldreich
The inside of the project box.
BenGeldreich attached the following image:
img_0545.jpg

--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
BenGeldreich
With all LED"s lit up and the lights down low. ;)
BenGeldreich attached the following image:
img_0544.jpg

--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
JackH
Nice job with the enclosure Ben. It looks great! Clean wiring job too.

Have fun with the roaster.

--Jack
 
BenGeldreich
I have also recently mounted a new K-type thermocouple. I wasn't happy with the original BT thermocouple that I purchased. I mounted the probe to my motor mount assembly. I am hoping to get a faster response from this and a closer reading when hitting first crack.
BenGeldreich attached the following image:
img_0552.jpg

--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
BenGeldreich
Lastly I added a part of a thin silicon matt that I had lying around to the top of my wooden box. I did this to prevent the wood from getting the full force of the heat from the bottom of my pot and to keep the smoke grease off the wood and on to something I could clean if need be.
BenGeldreich attached the following image:
img_0548.jpg

--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
allenb
I vote Ben's TC4 case best and sexiest to date! This is stunning and I'm now ashamed of my little gray plastic box.

I'll bet this would fit in perfect with Jon's "D*&%nation" steampunk roaster design.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Want to Help?
By donating you can ensure that HR will continue to be open for years to come. Expenses are 100% transparent and can be viewed publicly at all times. You can find more information on donations and why we request them by reading up on the forum topic here. Thank you.

Koffee Kosmo
Beautiful work on the TC4 & K type probe
Now that you have had the roaster up and running for a while!

How are the roasts ?

KK
I home roast and I like it
Blog - http://koffeekosm...gspot.com/
Bezzera Strega: Mazzer Robur Grinder: 5 Box hand grinders: Pullman Tamper Convex: (KKTO) Turbo Oven Home Roaster: CONA Glass Rod Syphon: Pyrex Brewer:
 
http://koffeekosmo.com.au
seedlings
Wow, these are some of the sexiest roaster gut shots I've seen! Well done!

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
BenGeldreich
Thanks for the kind words on the TC4C project box!

KK,

You will be the first to know!

Ben
--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
BenGeldreich
With the holidays behind I had a chance to roast yesterday!!! Woot Woot!

I am still having BT thermocouple issues!! With the new TC4C I was able to focus on RoR but soon discovered that I was getting a 60 F variance throughout the roast. I quickly changed to just watching the beans to try and save the roast.

After the roaster had cooled I ran the following test. I took the metal colander where the beans sit out and ran the TO with both the ET and BT exposed. When ET hit 300 F, BT was at 222 F! I think that the temps are too far apart for both thermocouples being exposed. It is to my understanding that a TO is convectional and in a convectional oven the airflows from the heater down the sides and back up the middle. If that is true my only thoughts are that a vertical BT thermocouple would not read the same as a horizontal thermocouple due to the airflow of the convectional TO.

My thoughts are to mount the BT probe right underneath my ET on the side so the tip slides into the side of the Bean mass as others have done.l I could use a wire bead type thermocouple and move it around the bottom holes till I find the sweet spot but mounting it and the possible long term damage to the tip is preventing me from trying that.

Ideas? Thoughts? Am I way off on this?

Ben
Edited by BenGeldreich on 12/30/2011 9:42 AM
--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
lmclaren
Hi Ben, It is unclear from the photos, but where the thermocouples attach to the board, are you extending the cables to a socket on the back? If so, you will loose the cold end reference, the thermocouple wire / thermocouple socket should be directly attached the the board. Note sure if it would make that much difference though.

Have you tried putting both thermocouples together and immersing in boiling water and ice water to see if they agree with each other?

I had real problem with one of my thermocouples when I let the metal probe touch the metal of my roaster, the readings where all over the place. I ended up replacing the probe with a bead so it remained isolated from the metal work, it is now totally stable.

best regards

Lee
 
BenGeldreich
Lee,

Thanks for your reply!

lmclaren wrote:
Hi Ben, It is unclear from the photos, but where the thermocouples attach to the board, are you extending the cables to a socket on the back? If so, you will loose the cold end reference, the thermocouple wire / thermocouple socket should be directly attached the the board. Note sure if it would make that much difference though.


The thermocouples are attached to female sockets which use an extension of the same thermocouple wire to attach to the TC4C. From what I've read there may be a slight variance because the thermocouple aren't directly hooked up.


Have you tried putting both thermocouples together and immersing in boiling water and ice water to see if they agree with each other?


I tried the boiling water test last night! I added two thermometers one digital and one analogue. I discovered that the BT probe was always 2 degrees higher than the ET probe and both thermocouples were a couple degrees higher than my thermometers. There was never more than 8 F difference between all of them. I let everything sit for 10 minutes and upon my return everything had reach the same reading of 96 F.


I had real problem with one of my thermocouples when I let the metal probe touch the metal of my roaster, the readings where all over the place. I ended up replacing the probe with a bead so it remained isolated from the metal work, it is now totally stable.

best regards

Lee


I too feel like this had been the issue with my BT thermocouple attempts. Both BT thermocouples that I mounted have always been touching some type of metal which is part of the roaster. I'm still not sure if I'm getting an air reading or the metal hole where the probe sticks up into the bean mass.

My thoughts are to ask omega build me a 4" K-Type probe with an exposed tip like this. http://www.omega....E&Nav=

If my logic is correct an exposed tip would not touch any metal and would only take a reading from the air or items that are in direct contact with the tip. Right now I am using a grounded thermocouple. It is correct to say that a grounded thermocouple takes its reading from the outer casing of the probe and not just the tip?

I have also thought of a way to mount the probe on the side but would prefer to keep the BT mounted underneath.

Thanks for the help!!

Ben
Edited by BenGeldreich on 01/01/2012 8:58 AM
--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
lmclaren
The fact that the sensors are not too far from each others readings is encoraging, I expect if you terminated onto the board the TC's should read the same, I find all my TC's are within .5C of each other.

I use just a bead on the end of the insulated cable to measure air, to measure beans, you could mount the thermocouple using an insulated holder, I have used porcelain insulators before and they work well.

http://www.jaycar.com.au/productView.asp?ID=HM3182&keywords=porcelain&form=KEYWORD


To measure bean temp, I now use:

http://www.instrumart.com/products/32275/micro-epsilon-cs-series-infrared-thermometer

I am using a fluid bed roaster and as the beans are in flight most of the time, I did not like the chances of reading the bean temp with a thermocouple, I can recommend the IR enough.
 
lmclaren
It is correct to say that a grounded thermocouple takes its reading from the outer casing of the probe and not just the tip?


No, the temp is measured at the TC junction, probably at the tip of the probe, the problem is that the TC wires are not insulated from the metal enclosure which means that any earth potential will also flow into the TC signal. TC signals are very very small.

I expect in commercial equipment the TC interfaces are floating and do not have the same problem, commercial interfaces are expensive to buy.

I think it will work well if you keep the probe away from metal.

Lee
 
lmclaren
But I expect you are also correct for another reason, the body of the probe will conduct heat, so while it is measured at the tip, the heat further down the probe will be conducted to the tip and affect the readings.

Lee
 
BenGeldreich
lmclaren wrote:

No, the temp is measured at the TC junction, probably at the tip of the probe, the problem is that the TC wires are not insulated from the metal enclosure which means that any earth potential will also flow into the TC signal. TC signals are very very small.



Lee,

Thanks! Excuse the ignorance but when you say any "earth potential" are you referring to loose voltage trying to ground itself? If all the electrical equipment used in my roaster are grounded then why would there be any loose voltage? Or is there always fly aways! :)


I expect in commercial equipment the TC interfaces are floating and do not have the same problem, commercial interfaces are expensive to buy.

I think it will work well if you keep the probe away from metal.

Lee


Yeah the price is my only concern when looking at commercial TC's.

Ben
Edited by BenGeldreich on 01/01/2012 11:21 AM
--------

Ben

Turbo Oven Roaster w/ Variac, TC4Cw/ Bourbon | Bezzera Strega | Baratza Vario Grinder | Yama 5 Cup Syphon | Aeropress
 
www.bengeldreich.com
Jump to Forum:

Similar Threads

Thread Forum Replies Last Post
Aria Coffee Roaster? Fluidbed Roaster (Store-Bought and Commercial) 5 11/19/2019 8:29 AM
Fluid Bed Roaster Build - bye bye Heat Gun and Flour Sifter Fluidbed Roaster 56 11/18/2019 1:34 PM
5 Lb Roaster Perf Plate Design Help! Fluidbed Roaster 46 11/18/2019 4:43 AM
San Franciscan Roaster Co New Members say hello or you may update your profile. 4 11/11/2019 3:21 PM
Fluidbed Roaster project Fluidbed Roaster 12 11/07/2019 5:51 AM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion Copyright © 2019 PHP-Fusion Inc
Released as free software without warranties under GNU Affero GPL v3
Designed with by NetriX