RK Drum

[Hooblah2u2]

Has anyone tried building a roaster using the RK Drums that doesn't use a grill?

I'm wondering if there's a DIY method to replicating roasters like the Quest M3 and Huky 500 with an RK Drum.

[dickcoffee]

Actually I have one of each and I theorize that the perforated drum in the Huky is very similar to the RK. Biggest difference is air flow. If I had the skills, I'd put a chimney on the back of my Weber grill and put a fan in it to suck air through the roasting beans.

[Ed]

And now for something completely different.  I have the 5# drum in a surplus ammo box.  The drum has about an inch clearance all around, so the thing heats up instantly.  I cut the bottom off the ammo box and it sits on a Coleman compact 2 burner gasoline stove, a perfect fit.   The idea originated from the camping ovens that sit atop these stoves.  Everything sits on a small, rolling cart in my shop. 

 The stove puts out 14,500 btu - enough heat to get the job done.  A typical one pound roasts in about 12 minutes with no pre-heating at all.  At $3.00 gasoline prices, a roast costs 9 cents.  It has performed without problems every week for over 2 years now.  I have never liked dealing with propane in cold weather.  This gasoline powered roaster works as well in 20 degrees as in 100 degrees.

My cooler is a full size perforated baking sheet pan from a restaurant supply on a box with a suction fan down under.  It cools 2 pounds in less than a minute.  I leave the fan on as I gather up the roasted and cooled coffee and chaff sticks to the perforated pan.

[wideasleep1]

Sounds fascinating Ed! Would love to see pics if you get a chance! Cheers

[Ed]

Not sure how to get a photo up on this forum.  But here I think is the issue this compact roaster brings to the forefront.  With an enclosure only slightly larger than the RK Drum itself, it takes little heat to power it.  In the typical RK drum application, you have a big honking hummer of a BBQ grill with a lot of empty space to heat up.  Along with that, there is a lot of surface metal wicking away precious heat.  To overcome all of that it takes a gas-guzzler of a propane engine.

Since this thread is on the RK Drum, I will say I have praise and complaints.  It is nicely crafted and will certainly last a lifetime.  I appreciate the "heft" of this drum.  A few things on the minus side:  The door hinge-pin slid partway out during one roast and eventually locked everything up.  I pounded the pin back in and brazed it in place.  The unlock pin on the door (on mine a tiny spring pin on a keychain) was impossible to grasp with gloves.  I re-engineered it into a spring-loaded clip.  The 5/16" shaft that the drum spins on is a bit skimpy.  I bent one right off the bat.  I know that is the BBQ industry standard for rotisseries, but I would like to have seen an accommodation for 3/8 or even a 1/2" shaft with bushings for the smaller size.

A couple of additional notes on the gasoline powered compact roaster:  The only modification to the Coleman stove was metal plates on the grill just large enough to cover the burners so there is no direct heat from flames.  The drum shaft quick couples to a 40 rpm surplus gear motor.  On the other end of the shaft is a manual crank.  After the first crack I uncouple the motor and hand crank, stopping every so often when complete silence is needed to listen (stopwatch in hand) for the faint onset of the second crack.

[wideasleep1]

Not sure how to get a photo up on this forum.

I usually upload to imgur
http://imgur.com/
(no joining needed, just click 'upload images') and choose a pic file from my computer, hit upload, start upload, then select the 'BBcode(message boards and forums)' code, save to clipboard...now you can simply paste that code directly into a post. Cheers!

[Ascholten]

Adding pictures in here is easy.  At the bottom of where you are typing your post, you see 'Attach' and a "BROWSE" button, use that to go through your directories and click on the photo to attach.  I think it has like a 500k size limit so keep them fairly small.    Then click post and you should be done.

Aaron

[foreRB]

Hello BBQ roasters.
For the last 5-6 years I have been using a DIY electric drum roaster. I have relocated and now have plenty of room for a second dedicated grill and can convert the drum and rotisserie I have been using (60-80 RPM). The grill has a pretty substantial deflector covering the burners and the grill is 40,000 BTU’s. Any of you advise me getting fire bricks to line the bottom? I’m in San Diego so no weather considerations. Opinions?....RB 

[bbqbeans]

Hi RB, I just ran into this post.  After trying different things when I first set up my grill including fire bricks, plate steel etc in the bottom, I didn't like how the extra thermal mass slowed down my ability to change temperatures during a roast.  With my old Weber Genesis, the burners run horizontally with a grid of "flavorizer" bars covering the direct flame and that seems fine for heat distribution by itself.  I did however insulate the inside lid of the grill with fiberglass which I completely covered with a piece of sheet metal bowed and wedged in to fit like a reflector of sorts.  Also covered 2/3 of the rear vent when the lid is closed with a strip of metal bolted to the lid to retain more heat.  This saves A LOT of propane and allows me to get many more roasts per tank.  Every grill is different and you just have to find the combinations of mods that work best for your situation.  I'm in Los Angeles so weather is the same for me...that said, it's still worth tinkering with your setup to make it as efficient and responsive as possible. 

[dwight]

I like these type a great deal.   I've seen them in a local hardware store.
After a while they seem to get fragile and break.   

http://www.thenoflaresquare.com/

But if you google this ....   bbq squares no flame   ... you will find others ...

What I like about them is they cut the flames but provide a faster response to adjustments.

I've been using these for almost 5 years with the RK drum

Much Regards,
Dwight

[Abqbomb]

I saw a few mentions of methods for temperature monitoring in the thread including IR.  Can anyone comment on how the IR thermometers have performed or what is your preferred method of monitoring your roast temperature?  Have been considering switching to a thermocouple with a datalogger but always open to more cost effective methods!
Chris

[headchange4u]

So after checking in on this thread a couple weeks ago, I was intrigued dwight's mention of the ceramic bricks for a grill. In the past I have tried to find inexpensive radiant tiles for my RK system without much luck. I was really excited to find a plethora of options available on Amazon for the grill tiles.

This is a shot of the inside of my RK setup. I've got all the back vents sealed up, as well as and seams or holes that could be closed off. I also have a couple of fire bricks in the bottom of the grill to help add some thermal mass. In the first pic you can see the stock heat spreaders that go over the burners. The second pic shows the inside with the heat spreaders removed:



I searched through what Amazon had to offer and finally settled on these ceramic tiles. I chose that particular tile because it was thicker than most others (~5/8") and the dimensions of the tiles would cover the majority of the area over the burners, which was 17"x24" in my grill. I also purchased this adjustable grate so that the tiles would have a nice plat spot on which to rest.

The rest was pretty easy. I sized the grate to fit over the area where the heat spreaders normally rest and then laid the ceramic tiles directly on top of the grate:



Couple of shots with the drum installed. The tiles covered probably 90% of the area of the grill. Couldn't ask for a better fit:



Next I plan to add some handles to the grate to allow me to remove the setup for cleaning. I also plan on securing the tiles to the grate so they don't fall off and break when removing them.

So how did it work? Not sure just yet. It certainly takes a bit longer to heat up, but it also seems to heat hotter at the same heat setting. Heat retention after opening the hood is much better. Unfortunately, the battery on my IR thermometer died, and I was not able to get temp reading from the tile itself. The only roasts I have done so far have been test roasts with old, junk beans in the drum, so I can not compare "tiled" roasts with "untiled" roasts. I plan on roasting 2 batches of the same coffee for comparison. Stay tuned.

Here are some more pics of the setup:

[Abqbomb]

For those who use their RK setup (or other drum roaster) at higher altitudes, is anyone willing to share some roast profiles or other tips/tricks you’ve discovered?
I’m at 6,000 fmsl, and compared to the quick profiles posted on the RK site, my roasts take several minutes longer to get to first crack for the given temperatures.  From what I’ve been reading so far, most are saying first crack is reached more quickly and at lower temperature at altitude.  I am occasionally getting some bitterness up front on the finished product which tends to subside the longer the coffee rests.

I haven’t yet checked my thermometer calibration but will be doing that soon.  Thanks in advance!
Chris

[dwight]

Nice set up.

Some years ago I lived up in Colorado and roasted with the RK drum.

I can't say I knew enough then to know about a roast profile to suggest. 

If I remember correctly the grill manufacturer had a recommendation on high altitude. ie allow more or less air into the venturi valve.

I have less clearance then you on my bricks.   I also notice it takes longer to heat up.

Most recently I've been letting my beans go into 2nd crack a lot longer.   I used to stop at a few snaps into 2nd.  Now I wait till I get a very good rolling 2nd before I dump into a vacuum cooler.

What I have noticed and no one seems to talk about this very much, is cooling vs the effect on flavor.  Namely the faster I cool the beans the more pronounced the flavor.

It seems to me if I get my bean mass to cool down in under two minutes I get a pretty nice flavor.  However if I let the beans take over four minutes to cool the flavor is pretty flat.   

I tried to even use dry-ice as an experiment.  To cool the beans down super fast. 
Can't say I noticed a lot of difference. 

But thought it might be a pretty good marketing idea to sell my beans against a competitor.

Much Regards,
Dwight

[Abqbomb]

Appreciate your thoughts Dwight. As a follow up, my thermometer had some calibration issues which was throwing off my profiles. Can't believe that wasn't the first thing I checked! Doh!
Chris