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Gas grille coffee roaster
tiopaeng
I just converted my gas grille into a coffee roaster and installed a variable speed dc motor. Does speed matters when roasting?

Thanks,
Tiopaeng
 
Koffee Kosmo

Quote

tiopaeng wrote:

I just converted my gas grille into a coffee roaster and installed a variable speed dc motor. Does speed matters when roasting?

Thanks,
Tiopaeng


Yes it does
To slow and the beans burn from contact
To fast and the beans are flying in the air

You want a happy medium
Depending on the drum size and set up aim for 45 rpm to 55 rpm

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
tiopaeng
I tried roasting at 120 rpm and it gave me a very consistent roast. To be honest the result was better than the 50 rpm roast I had with a roast time of 13 [email protected] 500f .

Thanks for your reply
Tiopaeng
 
snwcmpr
How big of a diameter did you have?

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".
 
coffeeroastersclub

Quote

tiopaeng wrote:

I tried roasting at 120 rpm and it gave me a very consistent roast. To be honest the result was better than the 50 rpm roast I had with a roast time of 13 [email protected] 500f .

Thanks for your reply
Tiopaeng


While it may work fine with lighter roasts, you may find the excessively high RPM detrimental to darker roasts in that the high speed with actually "grind" a vienna, french roast, and italian roast. A better term yet is "smash apart" the more delicate darker roasted bean. thumbdown

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
rustic_roaster

Quote

coffeeroastersclub wrote:

Quote

tiopaeng wrote:

I tried roasting at 120 rpm and it gave me a very consistent roast. To be honest the result was better than the 50 rpm roast I had with a roast time of 13 [email protected] 500f .

Thanks for your reply
Tiopaeng


While it may work fine with lighter roasts, you may find the excessively high RPM detrimental to darker roasts in that the high speed with actually "grind" a vienna, french roast, and italian roast. A better term yet is "smash apart" the more delicate darker roasted bean. thumbdown

Len


For those delicate darker roasts I was thinking just go even faster and you dont have to worry about them banging around. (joke)

I know over a certain speed the bean will be pushed to the drum, Is there a rule of thumb for how far from the top of the drum arc the bean should fall?
 
coffeeroastersclub

Quote

rustic_roaster wrote:

Quote

coffeeroastersclub wrote:

Quote

tiopaeng wrote:

I tried roasting at 120 rpm and it gave me a very consistent roast. To be honest the result was better than the 50 rpm roast I had with a roast time of 13 [email protected] 500f .

Thanks for your reply
Tiopaeng


While it may work fine with lighter roasts, you may find the excessively high RPM detrimental to darker roasts in that the high speed with actually "grind" a vienna, french roast, and italian roast. A better term yet is "smash apart" the more delicate darker roasted bean. thumbdown

Len


For those delicate darker roasts I was thinking just go even faster and you dont have to worry about them banging around. (joke)

I know over a certain speed the bean will be pushed to the drum, Is there a rule of thumb for how far from the top of the drum arc the bean should fall?


60 RPM is optimum for drum roasting, I think that has been set in stone for quite some time. AFAIK the majority of commercial drum roasters rotate at that speed, and most smaller ones do too. rockon

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
tiopaeng
The diameter is 0.346 x 0.530 it's quite big compared to my other roast.
Also I would say this a Vienna light roast. I like to post a picture but I don't know how!

Thanks
Tiopaeng
 
Koffee Kosmo

Quote

tiopaeng wrote:

I tried roasting at 120 rpm and it gave me a very consistent roast. To be honest the result was better than the 50 rpm roast I had with a roast time of 13 [email protected] 500f .

Thanks for your reply
Tiopaeng


Is that the rated speed of your motor ? If so thats the free wheeling without load specs,
As one puts load on a motor it's speed reduces

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
tiopaeng
Yes it's 120 rpm w/out load. Is the bean diameter good?
Thanks
 
tiopaeng
Today's Roast Full City+ at 50RPM.
tiopaeng attached the following image:
img_2470a.jpg
 
coffeeroastersclub

Quote

tiopaeng wrote:

Today's Roast Full City+ at 50RPM.


From picture looks more like a City to City+ to me, but outside of that a very even roast. ThumbsUp

Good RPM, I'd stick with that to 60RPM.

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
tiopaeng
Pictures of my 2lb Roaster:
Fully automated w/PLC control and HMI
PID Control, SSR for heating w/2 thermocouples
Profile Recipe up to 5 Segments, Temperature and Time
Run in Manual when profiling, Automatic to run recipe
Variable speed DC Drum motor (very quiet)
--------
Things TO DO:
1. Be able to take samples between roast
2. Improve lighting inside
3. Install TC probe inside drum
4. Insulate top cover from inside (lot of heat loss here)
5. Install vent pipe (exhaust smoke)

I Appreciate everybody's comments and suggestions..

Thank You,
Tiopaeng
tiopaeng attached the following images:
img_2429copy.jpg img_2425copy.jpg img_2443copy.jpg img_2484copy.jpg img_2480copy.jpg img_2474copy.jpg img_2472copy.jpg
 
coffeeroastersclub

Quote

tiopaeng wrote:

Pictures of my 2lb Roaster:
Fully automated w/PLC control and HMI
PID Control, SSR for heating w/2 thermocouples
Profile Recipe up to 5 Segments, Temperature and Time
Run in Manual when profiling, Automatic to run recipe
Variable speed DC Drum motor (very quiet)
--------
Things TO DO:
1. Be able to take samples between roast
2. Improve lighting inside
3. Install TC probe inside drum
4. Insulate top cover from inside (lot of heat loss here)
5. Install vent pipe (exhaust smoke)

I Appreciate everybody's comments and suggestions..

Thank You,
Tiopaeng


Very impressive setup. That is the most I have ever seen anyone do with a grill setup.

The drum looks a bit familiar ... Grin

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
tiopaeng
That's rk drum.

Thanks
 
tamarian
Very impressive! WOuld love to hear more about the PLC and how you are using it. I can see PLC in a future upgrade for myself.

Does it control the gas/propane?
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
Dan
PLCs are great for controlling machines. Even a small one gives you 12 inputs and outputs. I have four machines at work that I designed and built that have PLCs. The problem is that, as far as I know, there's no PID code to insert in th PLC's ladder logit, so you have the added extra cost and complexity of a PID running off to the side. Most PLCs have the option of a touch screen for monitoring and minor input. I think a PLC is overkill for a home roaster since a likely scenario uses just 3 inputs and outputs.
1 pound electric sample roaster, 3 pound direct-flame roaster, both handmade; modified Mazzer Mini grinder, LaSpaziale Vivaldi II automatic espresso machine. When the electricity goes out I make vacpot coffee from beans ground on my Zassenhaus hand grinder, and heat the water with a teakettle on the gas range.
 
tiopaeng

Quote

Dan wrote:
I think a PLC is overkill for a home roaster.

Hello Tamarian, Dan is right, PLC's are overkill specially on a modified grille roaster. I just happen to have some old plc and parts lying around so it did not cost me anything for the automation.

Yes it controls everything in "Automatic Mode" including the heating gas valve, igniter, Drum and Cooling Fan. Heating is controlled by PID.

It's nice to just seat back and watch your roast repeat the profile and get the same results and consistency everytime.

Thanks for asking...
 
tamarian

Quote


Yes it controls everything in "Automatic Mode" including the heating gas valve, igniter, Drum and Cooling Fan. Heating is controlled by PID..


I'd like to know the valve used and how the PID controls it. Is it via voltage or current?

I'm working on converting my PID'ed electric fluid bed roaster into gas, using a Fuji PXG4 and a Clippard electronic modular valve. A couple of others here are working on similar setups, and what be great to see details of a working solution for automated gas control!
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
tiopaeng
If you want your control to be proportional ( voltage or current ) then your headed the right way. It's going to be a little bit expensive. Or you can do it the poor man's way - control by Solid State Relay ( ON/OFF ). You can achieved the same result. I'm using an ASCO gas valve, around $35.00.
 
butch burton
If the speed is too fast - beans don't move because centrifugal force makes them stick to the side of the drum and then u get burnt and green beans. A factor is the diameter of the drum - a small drum diameter beans slower rpm.

Another factor is the mass of the drum. Intelligentsia Coffee uses old German Hothow roasters cause they have cast iron drums. I used 12 gauge cold rolled steel in mine. Hot rolled rusts and flakes off almost immediately. My roaster is 10" in diameter and 23" long and has a theoretical capacity of 5 or 10# depending on whom u believe.

Mass is important because when you dump cold beans into the drum, it really lowers the temp. Many people use thin stainless steel trash cans and get good results. Drilling SS is a PITA. My gearmotor is a maxitorque and runs at 30 RPM. Got it from surplus center for $30. Once the word got out - they were out of them and if you pay full price, it is around $200.


Other Equipment
Large Bunn commercial grinder - got 2 of them for $100. Have a bunch of press pots, several vac pots - fun to watch the water go up and down. One is absolutely huge. Use a Bunn most of the time. Have a large dual wheel Enterprise coffee grinder - gift from a friend - pita to move - weighs over 150# It looks really cool with the hopper on top which will hold at least 10# beans. That and an ancient duck press will look great in my new kitchen.
 
tiopaeng
I have installed a variable speed DC gear motor and it's super quiet. I can now adjust the RPM.

That's good information about the Cold rolled and Hot rolled steel.

thanks for the info and welcome to HRO
Tiopaeng
 
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