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JackH
01/04/2019 10:55 AM
2 years today...Miss you Ginny!

JETROASTER
01/04/2019 4:24 AM
A little shout for the G'ster. 2 yrs. roar

allenb
12/27/2018 5:14 AM
Hi Brandon, please disregard the "please update". I think we're all up to speed now. The need for cache clearing get's me every time! limb

NetriX
12/26/2018 11:36 AM
Update? pouring Merry Christmas back atcha

allenb
12/26/2018 3:07 AM
Merry Christmas Brandon. Please update soon! christmas tree

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Another 1.5kg or 3lb drum roaster from scratch
allenb
Mornin Ralph,

When I posted the Jethro, barnyard method of truing the drum end I had forgotten you're working in a machinist environment. OTOH, maybe some folks reading it who don't have an equipped shop may find it useful.

Great looking drum and can't wait to see it spinning some beans.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
I've got two of these right angle gear motors. They are "torque motors" and turn about 120 rpm at the shaft so I'll have to do adjust the speed with appropriate sprockets.

The aluminum cone is an unused spinner from an airplane propeller and will be the green bean hopper.
oldgrumpus attached the following images:
img_0527.jpg img_0526.jpg

Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
Ringo
Thats what I used, worked great. Put a sprocket that double the size of the one on the drive on the drum shaft and you are at 60 rpm. I believe 60 is good. Lots of tork so when a bean gets between the drum and the face you will have all the power you need.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
oldgrumpus
Ringo, do you remember what pitch the chain links were? I looked at mcmaster.com and there are SO many choices. 1/2" pitch looks good, but I dunno if that's a good choice or not.
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
Ringo
I just measured the one I used it 1/2 inch pitch. It's just a little bigger than chain for a bike. I believe it is still overkill but works good. One warning on this layout. This gave me trouble when I built mine. The bearing on the front of the drum must be held tight. My original design was to have the plate flot. When a bean get between the drum and the face load on the chain increases. This pulls the drum side ways, when the drum pulls side ways it locks up because the drum hits the face plate. I had to Screew my face plate down to the frame to fix this. You could also put sprocket between two bearings on the back side to prevent the pull but then you would have three bearings on the roaster. Also do not tighten the set screews on the back side of the drum bearings, as the drum heats up it gets bigger it needs to be free in the back set solid in the front to adjust the gap between the drum and face.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
oldgrumpus
Excellent! I had totally misunderstood which bearing should "float". For some reason I thought it was the one furthest from the motor. Thanks for the clarification. I also appreciate you actually measuring your chain. I think it's a good choice. Maybe overkill, but better that way than too weak.
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
oldgrumpus
I've decided to try to make the vanes inside the drum resemble the way Diedrich did it. From the looks of it, I think there are 12 or 16 vanes set at about a 45 deg. angle. I started with a 1/8" x 1" cold-rolled flat bar and put it in our Hossfeld bender and attempted to bend it "the hard way". That actually a real metalworking term! The Hossfeld could do it but what you can't see in the picture is that it has a slight ripple.
oldgrumpus attached the following images:
img_0557.jpg diedrichdrumsmall.jpg

Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
oldgrumpus
So now it seems the easiest thing to do is cut out all the individual vanes. The first one I made with the Hossfeld was about the right length but needed more of a curve. Here are some progress photos. I first got the convex part right, then used layout fluid and a scribe to match the curve on the other side of the metal. Then it was cut by hand on a band saw.
oldgrumpus attached the following images:
img_0565.jpg img_0562.jpg img_0561.jpg

Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
oldgrumpus
This is a fun picture. It shows the Diedrich drum printed out to the left of my drum. Inside my drum (at the bottom) is the first vane. I tried to lay it out so the angle and lengh of mine look the same as the print out.
oldgrumpus attached the following image:
img_0566.jpg

Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
sversimo
Sounds like a fun project! I did some extensive testing the last 2 weeks on how to improve the beanflow in my roaster, and this is what I ended up with:
[img][/img]
sversimo attached the following image:
indretrommelnyliten.jpg
 
oldgrumpus
Well I'm back after shelving this project for over three years! It's been hectic, but now I'm ready to jump back in.

I'm working on the drum and have a bunch of questions and could use some expert advice.

Bean circulation pattern: I don't know anything about this. Do the beans stay evenly distributed along the length of the drum or are they forced to the front against the chute?

As they circulate, are they brought to the end of the drum then taken back to the other end, or is the process more random?

Is there a gap between the drum and the end piece that allows some particles to drop down? If so, then is there provision for cleaning below?

How much space should I leave between the drum and the outer cover?

Thanks Folks!!
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
allenb
Hi grump, good to have you back!
Here's a thread I participated in, dealing with drum vanes that may help with your questions. If it doesn't answer your specific questions, let us know and someone will lend a hand.

http://forum.home...rowstart=0

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
allenb
oldgrumpus wrote:

Well I'm back after shelving this project for over three years! It's been hectic, but now I'm ready to jump back in.

I'm working on the drum and have a bunch of questions and could use some expert advice.

Bean circulation pattern: I don't know anything about this. Do the beans stay evenly distributed along the length of the drum or are they forced to the front against the chute?

As they circulate, are they brought to the end of the drum then taken back to the other end, or is the process more random?

Forward vanes (attached to drum skin) are continually driving beans to the front face plate. The next set of vanes (closer to the shaft) drive the beans backward.

Is there a gap between the drum and the end piece that allows some particles to drop down? If so, then is there provision for cleaning below?

Yes, there's always a gap although very small, and some very small particles will drop down and you should allow a means to access this area to clean as often as necessary depending on how many lbs of coffee you're roasting per year.

How much space should I leave between the drum and the outer cover?

I typically leave around 1/32" to allow for drum expansion when heated. If you lock the front plate shaft bearing and leave the rear bearing floating, drum length growth from heating will primarily happen in the rearward direction.

Thanks Folks!!

1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks Allen!

So still need recommended space between drum and shroud/cover.

Also some new questions...

Sources for solenoid valves?

Should the shroud/cover be insulated? BBQ's aren't. Seems like it might be a nice touch but not a definite requirement.

Sources for ready made bean valve?

Source for viewing glass?

Drum-end with perforated metal... 1/4" perforated sheet metal is good?

Thanks All!!
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
oldgrumpus
In the past week I have ordered the titanium tube burner from sausagemaker.com, the pilot kit, thermocouple and LP orifice. On eBay, I purchased the same White Rodgers safety valve shown in the burner kit available on sausagemakers. Also on eBay I ordered the drum bearings. I am second guessing myself... Maybe a call to Maxitrol would be good even now. I suspect that they would help me figure out all the proper components needed between the propane tank and the burner which is something I don't fully understand. Maybe there are too many variables. I think I will call them next week. Still need the proportional gas valve and controls.
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
allenb
oldgrumpus wrote:

In the past week I have ordered the titanium tube burner from sausagemaker.com, the pilot kit, thermocouple and LP orifice. On eBay, I purchased the same White Rodgers safety valve shown in the burner kit available on sausagemakers. Also on eBay I ordered the drum bearings. I am second guessing myself... Maybe a call to Maxitrol would be good even now. I suspect that they would help me figure out all the proper components needed between the propane tank and the burner which is something I don't fully understand. Maybe there are too many variables. I think I will call them next week. Still need the proportional gas valve and controls.


You might be successful in getting guidance from Maxitrol on components between tank and burner but from my experience, they are less than forthcoming if the person asking the questions isn't fairly knowledgeable about combustion systems to start out with.

If you find them less than helpful, shoot your questions to us and we'll get you an answer. I've had to work with commercial burner systems including safety and igniter design recently so I can most likely steer you in the right direction.

Questions from previous post:
Space between drum and shroud cover? For a small roaster, go with at least 3/4" between drum and inner wall. Yes, use at least a small layer of high temp insulation (1/2" mineral wool) between inner wall and shroud cover.

Viewing glass:
http://www.mcmast...s/=1357cgh

Solenoid valves? Go with Kelly or Clippard
http://www.kpiweb...ducts.html
http://www.clippa...

Drum-end with perforated metal... 1/4" perforated sheet metal is good?
Too thick for no reason unless you'll be doing a single ended shaft design where the overhung load would create stress on the drum's back plate. For a standard drum design, 16 gauge should be fine.

Bean valve? The only ready-made options for this that I know of would be a blast gate type of valve which is a sheet metal sliding gate arrangement. But, would probably be too large to fit in with most small roaster designs (not elegant).

http://www.homede...lsrc=aw.ds

Keep us updated!
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks allenb! I REALLY need some expert advice on proper selection of the two components shown in the attached photo.
oldgrumpus attached the following image:
diag.jpg

Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
allenb
Hi Ralph,

This is timely as I'm in the process of trying to find an online store that can sell the Maxitrol M420H which works with LP at 11" H2O. I have a call into one of their distributors so give me a bit to receive a call back.

This valve is really the only modulating valve I've seen for controlling low pressure propane (11") that is affordable (less than $200) but it does require a maxitrol interface board unless you can send it a variable 0-20 VDC. I'm not sure what it will set you back but from memory it's less than $100. There are other companies selling valves for this application but are very expensive. Neither Clippard nor Kelly make a modulating valve that is able to pass a sufficient volume at that low of a pressure. They need at least a couple of psi.

In the meantime, you will need to find out what orifice size options there are for the titanium burner you ordered. This will tell us what LP pressure will be needed to produce the BTU output you'll want for your roaster.

What will you be using for control output to the modulating gas valve?

For a regulator, this would work for you:

https://www.amazo...06NKXJX6M3

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
Thanks Allen for the suggested tank regulator!

The Maxitol representative suggested using the EXA STAR Modulating E42 valve and the CV200 combination gas valve. The first thing I did was to see if these were available on eBay and elsewhere, eBay has some variants of the CV200 for reasonable prices but the EXA STAR can't be found there. In fact, I could not find it from any online source.

The CV200 is only available with electronic ignition, which would be great, but I'm a bit more comfortable with a pilot light. In order to make that a reality, I was told that the CV300, which is a bit larger, would be my choice.

As far as what I will use to control the modulating valve... I have not really thought that far ahead. I am open to suggestion, but my thinking was that I would vary the input voltage to the modulating valve with a knob and "upgrade" the roaster after using it manually for a while.
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
oldgrumpus
Here is a link to the Maxitrol modulating valve that was recommended by Maxitrol:
http://www.maxitr...7.2015.pdf
Espresso: Franke Ecolino
Grinder: Macap M4
Roaster: Old fire extinguisher with a crank, over a crab cooker, now building a drum roaster.
 
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