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11/26/2020 6:37 AM
Everyone have a super Thanksgiving and may all your roasts turn out stellar woohoo

11/25/2020 4:20 PM
Howdy 1st CH and welcome to HR forum! Be sure to read in the forums to see if anything covers the topic and please post away in drum roaster forums Welcome

11/25/2020 3:35 PM
Hey everyone! I am new to the home roasters forum. Mainly here to read and learn! I’d also love to get advice about modifying my roaster (a Huky 500)

11/10/2020 5:29 PM
Welcome MJ, post away! Cheers

11/08/2020 6:05 PM
Hello All, New here, started with an air popper, now using fresh roast 800. I'm here to learn and connect with others Thank you

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Fluidbed Roaster project
cdrake39
Turns out my TC issues were caused by loose connections at the screw terminal block. They would read fine until I plugged in the AC power.
Calibrated all the thermocouples with water just off the boil. Thermometer read around 90C as did all the thermocouples.

Now that it's all sorted, I tried another roast yesterday evening. Results were better and FC was definitely audible this time around. Maybe even SC.

It seems as though the BT thermocouple is showing an artificially low reading, so I'll swap out that for a bare wire TC (thanks jkoll for the recommendation) and see how it responds.
cdrake39 attached the following images:
20201014_081329.jpg 20201014_081400.jpg
a1970gto
Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?
cdrake39

Quote

a1970gto wrote:

Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?


Correct - there is a mesh sleeve inserted into the wye so the beans don't drop onto the element. It work's okay, but there is room for improvement. You have to wiggle the handle for the valve quite a bit to get the beans moving out the chute. I'll post a video next time I roast (waiting on new thermocouple so early next week)
jbrux4

Quote

cdrake39 wrote:

Quote

a1970gto wrote:

Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?


Correct - there is a mesh sleeve inserted into the wye so the beans don't drop onto the element. It work's okay, but there is room for improvement. You have to wiggle the handle for the valve quite a bit to get the beans moving out the chute. I'll post a video next time I roast (waiting on new thermocouple so early next week)


Ummmm, any way you could walk me through your bean dump? Parts and set-up?

SWEET BUILD!!!! Nice use of what looks like a PC case.
R/
Jared
cdrake39

Quote

jbrux4 wrote:

Quote

cdrake39 wrote:

Quote

a1970gto wrote:

Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?


Correct - there is a mesh sleeve inserted into the wye so the beans don't drop onto the element. It work's okay, but there is room for improvement. You have to wiggle the handle for the valve quite a bit to get the beans moving out the chute. I'll post a video next time I roast (waiting on new thermocouple so early next week)


Ummmm, any way you could walk me through your bean dump? Parts and set-up?

SWEET BUILD!!!! Nice use of what looks like a PC case.


Thanks!! It is indeed a PC tower - all the electronics tuck away nicely underneath.

The bean dump is comprised of a tri-clamp butterfly valve which has been bored out and a mesh screen secured over the top. Depending on blower power, you may be able to just drill a bunch of small holes - but that didn't work for my application. When the valve is closed, air can pass through the screen. When the valve is opened, the beans are able to drop out the chute (which is lined with another mesh screen salvaged from a kitchen strainer). It works ok, but the beans sometimes get hung up and you have to wiggle the valve handle a bit. I think a gate valve would work much better and is something I plan to add at some point down the road. Hope that helps!
jbrux4

Quote

cdrake39 wrote:

Quote

jbrux4 wrote:

Quote

cdrake39 wrote:

Quote

a1970gto wrote:

Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?


Correct - there is a mesh sleeve inserted into the wye so the beans don't drop onto the element. It work's okay, but there is room for improvement. You have to wiggle the handle for the valve quite a bit to get the beans moving out the chute. I'll post a video next time I roast (waiting on new thermocouple so early next week)


Ummmm, any way you could walk me through your bean dump? Parts and set-up?

SWEET BUILD!!!! Nice use of what looks like a PC case.


Thanks!! It is indeed a PC tower - all the electronics tuck away nicely underneath.

The bean dump is comprised of a tri-clamp butterfly valve which has been bored out and a mesh screen secured over the top. Depending on blower power, you may be able to just drill a bunch of small holes - but that didn't work for my application. When the valve is closed, air can pass through the screen. When the valve is opened, the beans are able to drop out the chute (which is lined with another mesh screen salvaged from a kitchen strainer). It works ok, but the beans sometimes get hung up and you have to wiggle the valve handle a bit. I think a gate valve would work much better and is something I plan to add at some point down the road. Hope that helps!


It helps, but I am in need of the visual to put it all together. Could you provide detailed pics or something?
R/
Jared
cdrake39

Quote

jbrux4 wrote:

Quote

cdrake39 wrote:

Quote

jbrux4 wrote:

Quote

cdrake39 wrote:

Quote

a1970gto wrote:

Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?


Correct - there is a mesh sleeve inserted into the wye so the beans don't drop onto the element. It work's okay, but there is room for improvement. You have to wiggle the handle for the valve quite a bit to get the beans moving out the chute. I'll post a video next time I roast (waiting on new thermocouple so early next week)


Ummmm, any way you could walk me through your bean dump? Parts and set-up?

SWEET BUILD!!!! Nice use of what looks like a PC case.


Thanks!! It is indeed a PC tower - all the electronics tuck away nicely underneath.

The bean dump is comprised of a tri-clamp butterfly valve which has been bored out and a mesh screen secured over the top. Depending on blower power, you may be able to just drill a bunch of small holes - but that didn't work for my application. When the valve is closed, air can pass through the screen. When the valve is opened, the beans are able to drop out the chute (which is lined with another mesh screen salvaged from a kitchen strainer). It works ok, but the beans sometimes get hung up and you have to wiggle the valve handle a bit. I think a gate valve would work much better and is something I plan to add at some point down the road. Hope that helps!


It helps, but I am in need of the visual to put it all together. Could you provide detailed pics or something?


For sure! Bit of a busy weekend but I'll get some pics uploaded soon
floptronica
I think your roaster is a thing of beauty, but I can't help thinking that with a bigger blower and that 4" roast chamber, you could do way more than 200g at a time. Is a capacity increase in the plans for this baby?
cdrake39

Quote

floptronica wrote:

I think your roaster is a thing of beauty, but I can't help thinking that with a bigger blower and that 4" roast chamber, you could do way more than 200g at a time. Is a capacity increase in the plans for this baby?


Thanks!! Definitely planning on increasing capacity down the road.
cdrake39
I was playing around with PID tuning today (empty roast chamber) and I've seemed to create an issue. I used a flat line profile as my basis, but when doing this it seemed as though the heater power would cap out around 30% and never reach the set value. So I switched back to my normal roast profile, and now my heater won't go above ~30%. Has anyone had a similar issue? The heater seems to respond fine with the manual slider, but not with the PID control.

Edit: Brain fart on my end. Integral was set to zero so it couldn't overcome the offset. Oops
Edited by cdrake39 on 10/19/2020 2:22 PM
renatoa
Even with a zero I term, the behavior should be different when back to normal profile.
P only does not mean fixed power output.
cdrake39

Quote

renatoa wrote:

Even with a zero I term, the behavior should be different when back to normal profile.
P only does not mean fixed power output.


Interesting. It seems to have fixed the issue for now. The power output wasn't necessarily constant, it just wouldn't go above a certain threshold. The BT was following the flat line path well, but by about 25 degrees too low.

Edit - it may have also been because I was in P control only and the P value was too low. Increasing the P value and keeping I at 0 also fixes the problem.
Edited by cdrake39 on 10/19/2020 2:37 PM
renatoa
Correct, I mean this part: "25 degrees too low"

The output of a PID controller, when the I and D terms are zero, is given by the formula: output = error * kP

Let's suppose for 150 C degrees setpoint you need 60% power, and kP is 5
In this case, the temperature will stabilise at 138 C, 12 degrees lower that 150 setpoint, because you need that 12 degrees error as an input for the PID, to deliver the 60% output. 60 = 12 degrees error * 5 (kP)
If temperature would increase, then error will decrease, output will decrease too, and temperature will step back to reestablish equilibrium.

If increasing kP, error will decrease, and you can go closer to setpoint, but never reach it. Also, increasing kP make your system sensible to oscillations if you have a sudden outer influence.
cdrake39

Quote

renatoa wrote:

Correct, I mean this part: "25 degrees too low"

The output of a PID controller, when the I and D terms are zero, is given by the formula: output = error * kP

Let's suppose for 150 C degrees setpoint you need 60% power, and kP is 5
In this case, the temperature will stabilise at 138 C, 12 degrees lower that 150 setpoint, because you need that 12 degrees error as an input for the PID, to deliver the 60% output. 60 = 12 degrees error * 5 (kP)
If temperature would increase, then error will decrease, output will decrease too, and temperature will step back to reestablish equilibrium.

If increasing kP, error will decrease, and you can go closer to setpoint, but never reach it. Also, increasing kP make your system sensible to oscillations if you have a sudden outer influence.


Makes sense! Thanks for the explanation

So would you think that decreasing Kp slightly would help smoothen out this curve below? Right now my PID values are set to 2, 0.23, 0.05
cdrake39 attached the following image:
pidtunecurve.jpg
cdrake39

Quote

jbrux4 wrote:

Quote

cdrake39 wrote:

Quote

jbrux4 wrote:

Quote

cdrake39 wrote:

Quote

a1970gto wrote:

Are you using the y type tri-clamp as your bean extraction? How is that working and could you post a video?


Correct - there is a mesh sleeve inserted into the wye so the beans don't drop onto the element. It work's okay, but there is room for improvement. You have to wiggle the handle for the valve quite a bit to get the beans moving out the chute. I'll post a video next time I roast (waiting on new thermocouple so early next week)


Ummmm, any way you could walk me through your bean dump? Parts and set-up?

SWEET BUILD!!!! Nice use of what looks like a PC case.


Thanks!! It is indeed a PC tower - all the electronics tuck away nicely underneath.

The bean dump is comprised of a tri-clamp butterfly valve which has been bored out and a mesh screen secured over the top. Depending on blower power, you may be able to just drill a bunch of small holes - but that didn't work for my application. When the valve is closed, air can pass through the screen. When the valve is opened, the beans are able to drop out the chute (which is lined with another mesh screen salvaged from a kitchen strainer). It works ok, but the beans sometimes get hung up and you have to wiggle the valve handle a bit. I think a gate valve would work much better and is something I plan to add at some point down the road. Hope that helps!


It helps, but I am in need of the visual to put it all together. Could you provide detailed pics or something?


Sorry for the delay in getting back to you on this. To give a good understanding of how it is assembled I figured this schematic would explain better than photos. Let me know if you have any questions, or suggestions on ways to improve!
cdrake39 attached the following image:
beandumpmechanism.jpg
renatoa

Quote

cdrake39 wrote:

So would you think that decreasing Kp slightly would help smoothen out this curve below? Right now my PID values are set to 2, 0.23, 0.05


I think the P coefficient is low enough as is now, and oscillations are rather from too high I term.
It's easy to find: set I and D to zero, and apply a sharp power step impulse, about 10% of range, let's say from 40 to 50%.
You have to be stable at 40% power when doing this.
Observe the evolution, if having oscillations decrease P, if not increase.
Don't use small steps, be generous with value changes, double or halve, else will waste too much time to find the right values.
So, try P values by succesive doubling, like 1, 2, 4, 8...
If 4 has no oscillations, but 8 start looking as above, then lower to 6 and try again, then finally either 5 or 7 should be the winner. The goal is to reach the highest P with no oscillations.
For the last value you have oscillations, measure the time between two peaks, this will give you KI, as Tu/2, where Tu is expressed in minutes. For example if oscillation period is 5 seconds, then KI = (5/60) / 2 = 0.04
cdrake39

Quote

renatoa wrote:

Quote

cdrake39 wrote:

So would you think that decreasing Kp slightly would help smoothen out this curve below? Right now my PID values are set to 2, 0.23, 0.05


I think the P coefficient is low enough as is now, and oscillations are rather from too high I term.
It's easy to find: set I and D to zero, and apply a sharp power step impulse, about 10% of range, let's say from 40 to 50%.
You have to be stable at 40% power when doing this.
Observe the evolution, if having oscillations decrease P, if not increase.
Don't use small steps, be generous with value changes, double or halve, else will waste too much time to find the right values.
So, try P values by succesive doubling, like 1, 2, 4, 8...
If 4 has no oscillations, but 8 start looking as above, then lower to 6 and try again, then finally either 5 or 7 should be the winner. The goal is to reach the highest P with no oscillations.
For the last value you have oscillations, measure the time between two peaks, this will give you KI, as Tu/2, where Tu is expressed in minutes. For example if oscillation period is 5 seconds, then KI = (5/60) / 2 = 0.04


Thanks for explaining that process - very helpful

I just finished another roast. Things are definitely improving. This was 200g of Ethiopian Sidama. Result was quite uniform, but difficult to hear FC with the cyclone attached. I may have to implement something to amplify those sounds in the future. I also need to stop fiddling with the fan during the roast as it messes up the RoR a lot haha learning as I go
cdrake39 attached the following image:
20201021_193757.jpg
Anot

Quote

cdrake39 wrote:
The bean dump is comprised of a tri-clamp butterfly valve which has been bored out and a mesh screen secured over the top. Depending on blower power, you may be able to just drill a bunch of small holes - but that didn't work for my application. When the valve is closed, air can pass through the screen. When the valve is opened, the beans are able to drop out the chute (which is lined with another mesh screen salvaged from a kitchen strainer). It works ok, but the beans sometimes get hung up and you have to wiggle the valve handle a bit. I think a gate valve would work much better and is something I plan to add at some point down the road. Hope that helps!


Quote

cdrake39 wrote:
Sorry for the delay in getting back to you on this. To give a good understanding of how it is assembled I figured this schematic would explain better than photos. Let me know if you have any questions, or suggestions on ways to improve!
homeroasters.org/forum/attachments/beandumpmechanism.jpg


Thanks for explaining and illustrating your concept! I think this is a great idea and I'm looking into implementing it for my roaster. As I understand, beans only get stuck by the valve, not when falling into the "drain part"? Also how is the mesh screen attached above the heating element?

What I'm not a fan of, however, is the tri-clamp ball valves. Not only because they might get stuck like you mention but also because they require quite a lot of effort to turn thereby putting lateral strain which my roaster wasn't build to handle. So a gate valve, like you mentioned would be prefered. Have you seen the below post? I'm thinking about combining this idea with yours.

https://homeroasters.org/forum/viewth...ad_id=4961
cdrake39
Thanks! It's attached using high temperature flue tape. Will be spot welded eventually but it works fine as is for now.

I agree that there is a lot of strain when opening/closing the valve. I made a custom bracket to support this strain. It's mounted underneath the valve. A gate valve would definitely work better, and that design looks well suited for this application.
jbrux4
Thanks - nice diagram and explanation. I will look at it for a while and see what happens!
R/
Jared
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