Im building a bbq roaster! a few questions:

[MachoSilvia]

Hey guys, Im in the process of building a bbq roaster. I have the barrel pretty well sorted, and I want to find something to rotate the drum, and a shaft. I am wondering if a stock rotisserie would suffice? I saw one in kmart for $90, and it had a 5 kg limit. My drum at the moment, weighs less than 2kg, and I intend to roast 1-2kg of beans at a go. How fast will the rotisserie rotate? fast enough? what are other options? Any advice?

Barrel measures 25cm diameter, and 36cm long.

Cheers, Mark

[TC]

Re: Im building a bbq roaster! a few questions:

Hey guys, Im in the process of building a bbq roaster. I have the barrel pretty well sorted, and I want to find something to rotate the drum, and a shaft. I am wondering if a stock rotisserie would suffice? I saw one in kmart for $90, and it had a 5 kg limit. My drum at the moment, weighs less than 2kg, and I intend to roast 1-2kg of beans at a go. How fast will the rotisserie rotate? fast enough? what are other options? Any advice?

Barrel measures 25cm diameter, and 36cm long.

Cheers, Mark

Hi Mark- Great idea, but alas too slow. Aim for about 20 RPM...Brett (AKA fatboy) is a resident CS BBQ roaster. I think he uses a windscreen wiper motor and suitable power source...

Good luck!

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

cheers, thats what I suspected, I think I will look for a windscreen wiper motor, shouldnt be too hard to find...

Cheers, Mark

[fatboy_1999]

Re: Im building a bbq roaster! a few questions:

Mark,

As Chris said, I use the windscreen wiper motor.
The one I was given had a nut that was originally attached to the wiper assembly. This nut spins continuously (in one direction) when 12V power is connected. I attached a socket from a cheap set over the nut and the reverse fits nicely over the rotisserie rod (BBQ galore, mutli-part rod).

Once I was happy with the method, I superglued the socket onto the nut.

My motor has been going since 2004 doing an average of at least 1 roast a week. Ill be devastated when it dies. I suppose I should organise a backup one day ;-)

[mylesau]

Re: Im building a bbq roaster! a few questions:

Hi MachoSilvia,

My BBQ roaster is considerably smaller than what youre putting together (see http://coffeesnobs.com.au/YaBB.pl?num=1180848792/0#0), it runs at 12 RPM using a BBQ rotisserie with very consistant roasts.  However, as others have suggest, I doubt a standard BBQ rotisserie would provide a high enough RPM for a consistant roast with your larger drum.

Jaycar sell some nice little, high torque motors that Ive been considering as I find the BBQ rotisserie a little on the loud side (its what I had so didnt cost me anything...):

YG-2734 - 12.0kg/cm - 4.5-18Volt - 36 RPM - $19.95 (From current catalogue - other higher RPM models available).

They also sell some nice little shaft couplers that would match the motor.

Might be worth looking at for yours?

[Dennis]

Re: Im building a bbq roaster! a few questions:

Mark,

As Chris said, I use the windscreen wiper motor.
The one I was given had a nut that was originally attached to the wiper assembly. This nut spins continuously (in one direction) when 12V power is connected. I attached a socket from a cheap set over the nut and the reverse fits nicely over the rotisserie rod (BBQ galore, mutli-part rod).

Once I was happy with the method, I superglued the socket onto the nut.

My motor has been going since 2004 doing an average of at least 1 roast a week. Ill be devastated when it dies. I suppose I should organise a backup one day ;-)

Nah Brett, just call the RACV

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

Cheers guys, btw what rpm does the wind screen wiper motor spin at? and what 12 volt power supply do you use? does it need a transformer? I checked out that motor on jaycar, and it looks perfect! Thanks mylesau, looks like itll either be that motor, or a wiper motor from a car wrecker... Fatboy, where did you get your motor from?

Thanks once again, im going over to a friends place now to get the shaft (12mm threaded steel rod) mounted throug the centre of the barrel...

Cheers, Mark

[robusto]

Re: Im building a bbq roaster! a few questions:

Have fun assemblying MachoSilvia.

Yes, the windscreen wiper motor is 12v dc so does require a transformer to step down 230v AC.

Transformers capable of handling at least one amp are costly, but you can probably pick one up for nothing from a discarded computers power supply. The leads are 5v dc and 12v dc. A little on the bulky side though.

Alternatives are: a 12v car battery. A charger for a 12v car battery.
Power supply for a 12v television (they are usually over 1 amp).

I have one concern about your drum: It doesnt appear perforated. That could increase the roasting time and tend to bake the beans rather than roast them. Especially depending on what barbecue you use and how close to the burner the drum sits.

It takes my set up about 15 minutes to roast about 400 grams. That is with the lid closed and all burners on maximum.

-Robusto

[fatboy_1999]

Re: Im building a bbq roaster! a few questions:

Mark,

My motor was given to me by a friend who does up cars. I was boring him silly with my plans for a BBQ roaster back in 2004 and asked him the best place to get a wiper motor. He said the wreckers and then said, "Hang on". Went out to his shed and came back with one.

I think mine spins at around 50rpm.

I use a 12V battery charger to power mine. Just plugs into mains, has a red and black clamp which goes to the 2 wires on the motor. On mine, if I get them the wrong way around, the motor spins the other way. Probably not good for it and has the added problem of unscrewing my multi-part rod, so I make sure I get them the correct way around.

I do ~700g green down to ~500g roasted per roast.

Brett

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

I have seen different designs of drum roasters, some are perforated, some are not... im not sure what the implications are, better or worse, but I am sure the design is workable. I went to jaycar, and saw exactly the motor mylesau recomended, and It is on my shopping list this week, with a little brass addapter, to attatch onto a 6mm threaded steel shaft, which will have the barrel mounted on. more pics to come, along with progress!

cheers, Mark

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

The roaster is now working! sorry I havent been posting on this thread, Ive documented the process on my blog, here...
http://in.lits.gen.nz/modules/journal/journalview.php?space_key=1&module_key=8&journal_u ser_key=5

So here it is:

I havent yet tested the capacity,; my test roast was 1.2kg of yergacheffe, which took 30 min... I know this is too long, I will find a way to speed up the heating of it, to bring the second crack to between 17 and 22 minutes... I might make this longer for the sumatran I have, as this tends to like longer roasts.

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

and...

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

and...

[Dimal]

Re: Im building a bbq roaster! a few questions:

Great Job MS 8-),

Whered you get that neat little gearbox from, its a little beauty ....

Mal.

[MachoSilvia]

Re: Im building a bbq roaster! a few questions:

Thanks Mal, my friend who helped build (most of) it had friends in many industries, and when he asked around, was given the gearbox by a carpet manufacturer, which fitted perfectly for my purposes, and it holds the whole barrel itself, with no need for another bearing.

Cheers, Mark