DIY mini bbq roaster

[fg1972]

Did a roast last night & a couple more tonight and I'm either cooking the beans too much or not enough because I cant easily see the beans & don't have a way of measuring the temperature.
I guess I'm just used to looking straight at the beans & monitoring the temperature on my popper which is fitted with a thermocouple probe.
I'm quite handy at building stuff but roasting without any visual or temperature aid is not my style.
I'm most probably going to sell this setup & get something that can be temperature monitored like a corretto or Behmor.

[leograyson]

Geez Fiorello, I thought that I was DIY addict (some say tragic), but you leave me behind.

As that guy on the TV fishing show says, "I love your work"

Keep it up, Leo.

[fg1972]

Bit of an update,
The geared motor from eBay (less than $10) arrived the other day, it was tiny & looked like something out of a toy. I fitted it anyway just for a laugh and found it had enough torque to turn the drum easily but the gears did strip as soon as the drum caught on something by accident. In the bin it went and back to the drawing board I went.
I had a couple of low voltage motors lying around that I wired up but found them too fast without a gearbox, even reducing the voltage was not enough for an ideal speed.
One of the motors was from an old cordless drill so thinking outside the circle a bit, I thought to take the drill gearbox and trigger which is variable speed to make this thing work.
After removing the drill chuck, clutch and other things I didn't need, I fixed the rotisserie coupling to the centre shaft but had to drill & tap a thread though. Preliminary tests with a cable tie holding the trigger to achieve approx 40 rpm seemed to work quite well.
Was running it off a 2200 mAh 12 volt battery which was pulling around 500 mAh which would be good for approx 3-4 hours runtime.
Still to go, a bit more testing then tidy up the wiring and install on/off switch.

[brettryan]

DIY mini bbq roaster

I love these ideas, completely wonderful. I'm looking to find something I can make a basket with now too for a roaster based on a keg. Btw, keg isn't the vessel for beans it's actually the outer oven

[fg1972]

Nice work Glen.
I'm waiting for my motor to arrive, so still using the popper at the moment.

[themurphs]

Tried my new setup today, See photos

May have stuffed up the batch, but happy with the result

Nice even color, but may need to lower temp. <250degrees
Had 2C @ 16min

Can hear cracks, and running at 45rpm.

Trial and error will eventually sort things out

Glen

[themurphs]

I purchased off eBay recently for $7, a coupling for direct shaft mounting, Mine was 6mm to 8mm, i ended up filing one side square to sit on the shaft of the rotisserie, plan to test it out tomorrow.


They have another one on offer that is 5mm to 6mm ( see Link)

(eBay link removed - please see posting Site Rules for further information)

You can drill the 5mm side out to fit onto the shaft?

Might be just what you need but just a warning, it took over 20 days for it to appear in my letterbox.

Glen

[fg1972]

A few more pics
drum internals, inside the rotisserie unit, drum mounted on bbq.

I've just timed the rotisserie motor & was shocked to find out it barely does 2 revolutions per minute.
I'm going to get a cheap 30 RPM 12vdc motor & gearbox like in the 4th picture.

Specs
Voltage: 12V DC
RPM: 30RPM
Diameter: 37mm
Shaft length: 21mm
Length (excl. shaft): 88mm
Shaft diameter: 6mm
Weight: 322g

In the 2nd picture, you can see the rotisserie motor shaft which is 7mm and also the socket adapter above.
I reckon I could easily adapt the new motor to fit it to the existing socket adapter.

[fg1972]

Thanks Glen,

fatboy_1999's setup seems quite good.
I'm probably going to try one of these motors below as they are fairly cheap.
Link removed in accordance with http://coffeesnobs.com.au/coffee-har...icy-rules.html

This one is very much like the motor that is inside the rotisserie unit, mounting tabs & shaft seem very similar. I will measure it against the one I have.
Link removed in accorance with http://coffeesnobs.com.au/coffee-har...icy-rules.html

The paddles are made from 12x12mm angle strips of aluminium. I have 3 strips protruding 12mm into the center mounted at 180 degrees from each other that run the whole length of the drum.
The two halves of the drum are secured together by pop rivets into these aluminium strips.

Fiorello

[themurphs]

I have had a similar issue with the rotisserie motor, it is to slow, you need around 30-40rpm.
I am about to try a new motor (24vdc Automatic Curtain motor) , i have just finished my coupling connection and should achieve around 45 rpm, ( will Post Shortly!).

There is a post showing a wiper motor in a bucket connected to the rotisserie rod with a socket from "fatboy_1999".
Check out this post;
http://coffeesnobs.com.au/home-roast...out-there.html

Every Batch i Started with was 250g and usually took 20-21 minutes to achieve 2C and reach CS10.
I did a couple of stuff up batches and one of them was multi-color Beans (CS7 -CS9), another batch ended up as charcoal.


Though i am still currently using the rotisserie motor i have found a few tweaks that help;
Preheat for 8-10 minutes, approx 250 degrees.
I turn down the burner underneath the drum and turn the outer burners up, Try to average 250-270 degrees."this help a lot with the Multi-coloring"
At 250-270 degrees do not go any longer than 23minutes.
I do control the temperature by opening the lid if it is getting to hot.
Use Oven mitts.

I am curious, how big your paddles inside the drum are and how many do you have? i have 3 paddles to mix the beans and each of the are protruding 30mm into the center, you might need longer or more paddles.

Keep up the good work!
Glen

[fg1972]

Bit of an update,
I've decided to just use the square rotisserie shaft right through and done away with the tube at one end idea.
Because I don't yet have any idea of ideal mounting height/position in relation to burners, as a starting point I thought I'd just mount the drum in the standard rotisserie orientation as this requires no modifications to the bbq and take it from there.
The bbq was preheated without the drum for approx 5-10 minutes with the lid down was approx 200 degrees going by the bbq temp gauge & my thermocouple probe inside the bbq.
I placed 100g green beans in the drum, then inserted the drum inside the hot bbq & closed the lid.
There were signs of 1st crack at ~9 mins and the cracks kept going till 19 minutes which I decided something is not quite right so stopped the roast & removed the beans.
The beans were roasted very uneven, some where very black & oily & others were light brown. Probably more black ones though.
I'd say the cracks were a mixture of 1st & 2nd cracks happening at different times.
The slow speed of the rotisserie motor is most likely the problem. I'm now looking at a different motor configuration, does any one have any ideas?
I'm quite happy with the standard rotisserie mounting, it seems to be a good distance from the flames to produce enough heat without being too hot. Can always turn the burners down and or open the lid to stay at the ideal temperature,

[mtee]

The toilet brush idea has been canned.
I've found something with much thicker stainless steel which is more rigid & is 110mm diameter instead of 90mm.
Welcome to the cutlery holder roaster.

I tried using one of these over a BBQ burner. I also used a rotisserie motor and shaft and I just ran it an an angle with the end still open, using the (reshaped) meat prongs as agitators. I found the rotisserie motor to be way too slow, the beans poked their little noses out through the holes and got scorched.

I then went to a battery drill for rotation and found the increased speed to be much better. Emptying with the end open was easy.

I had plans of using a wiper motor, but in the end, I didn't develop it any further. I got hold of a new breadmaker for free and concentrated on refining my Coretto set up.

I think the real merit in the idea is the durability of the components compared to poppers and breadmakers. You rarely wear out a BBQ, electric drill or wiper motor.

Good luck!

[DesigningByCoffee]

Nice work! Those cutlery holders look ideal…
Matt

[fg1972]

One end has the square rotisserie shaft, the other end I've used an aluminium tube that is hollow inside.
I'm hoping to be able to insert a thermocouple probe into the tube to get some sort of temperature reading.
Ideally the probe should be amongst the beans but this is not possible with a spinning drum.

[fg1972]

The toilet brush idea has been canned.
I've found something with much thicker stainless steel which is more rigid & is 110mm diameter instead of 90mm.
Welcome to the cutlery holder roaster.