Home made roaster

[Boris]

Re: Home made roaster

I ve been using a rechargeable Makita and one battery copes with two roasts back to back. Two roasts at 300grams each. Fairly primative setup but it works for me. I was thinking about using a power drill, but the power drill I have doesnt have clutch like the cordless. When the rotor jams on a bean occasionally, with a clutch, the rotor can slip without mincing the bean. But if the clutch is up to tight and it jams, the drill will try to rotate the whole container (happened twice and I lost the lot both times >). I still have to stand and watch but I dont have to stir anymore.

Boris

[nunu]

Re: Home made roaster

You can buy rotisserie motors at Bunnings. Either battery powered or 240V. Saw one today, and it got me thinking. I think it was around the $35 mark.

[TEPIN]

Re: Home made roaster

Ah Bunnings, Gods gift to the Average Joe // Been there done that..
Visit your local electrical Wholesaler , You can Buy better quality motors ..
No fense tended Nunu..

[Framey]

Re: Home made roaster

Im going to spend my next day off searching for a slightly used ceiling fan. Mal made the suggestion and Im going to follow up on it.
A quick trip to Bunnings (again) and I was inspecting prospective roaster motors in the ceiling fan section   They were pretty heavy and fairly large but nothing prohibitive. Will also need a mounting system...

[Boris]

Re: Home made roaster

Framey,
If youre looking to convert a fan, maybe an old mixmaster motor, would already have speed control. Im just thinking a ceiling fan might not have the nuts to turn your RPG proof roaster because its only designed to push air, whereas the mixer, designed to mix doe and stuff should. Justa thought.

Boris

[Framey]

Re: Home made roaster

It goes against my tightarse tendencies, but Ive gone ahead and ordered a new stack motor. I asked for 55rpm 1.5 inch stack ac motor. I dont think shaft diameter matters too much but I ordered half inch. $192 plus GST was the damage, after considering other options I decided variable rpm wasnt imperative and I wanted something that was built for the job rather than pulling a MacGyver.
Next thing is a couple of brackets to mount the motor. Then bearings, a bushing, shaft and coupling...
Off to Gameco in Sydney on Monday. It would seem when it comes to gas applications they are the people to see. I need to get some injectors along with a valve to control the flame.

[AndyCJ]

Re: Home made roaster

Whats the go wtih drilling holes in the roasting chamber? Do most sample roasters have solid bean chambers, or do they mostly have holes??

[robusto]

Re: Home made roaster

Holes allow direct heat into the beans, otherwise they are insulated and bake instead of roast.

As children we would make pop-corn poppers by punching nail holes through an old frying pan and then set it over a fire.

Commercial coffee roasters like the fluid bed ones, roast by blowing hot air through the chamber.

Robusto

[Javaphile]

Re: Home made roaster

AndyCJ,

From what Ive seen it appears most current production commercial roasters, including sample roasters, use the perforated drum style. This is the primary reason why the old Gothot and Royal roasters are so sought after, they use a solid drum.

Java "Loving his Gothot" phile

[Javaphile]

Re: Home made roaster

Holes allow direct heat into the beans, otherwise they are insulated and bake instead of roast.

Solid drum roasters draft air through the drum, as do commercial roasters with perforated drums. Amoung the other reasons they do so is to clear the chaff from the drum/bean mass. With-out that draft the chaff would have nowhere to go.

Java "All chaffed up and no place to go" phile

[Framey]

Re: Home made roaster

Its seems roasting beans relies on a combination of heat types:

Convection - Basically hot air. Like what happens when you cook something on a spit in a hooded bbq.

Conduction - Contact heat. Like cooking meat on a bbq plate.

Radiation - I think this is the heat produced by a hot surface. Put your hand in front of a bar radiator and I think you are feeling radiant heat?

Of course drum roasting is a combination of all three. Perforated drums allow lots of convection while solid drums rely more heavily on conduction. As Java mentioned, management of airflow alters the percentages.

The way you manage bean agitation via the vanes and drum rpm seems to have an influence on the outcome aswell. Beans in a drum that are agitated to a high degree by the vanes and higher rpm spend longer in the air and less time in contact with the hot surface of the drum. Variations on that could be achieved by tuning the drum, depending on the desired outcome.


NB: All the above information is just my understanding, it may be flawed. Dont hesitate to point out inaccuracies.

The photo below shows a solid drum perforated end sample roaster kind of like what Im trying to achieve... kind of.

[Framey]

Re: Home made roaster

Picture 2, a perforated sample roaster. That flame looks a bit yellow and dangerous though.

I dont think Ive ever seen a solid drum used in bbq rotisserie roasting. Ive seen both solid and perforated drums used in sample roasters, and Ive never seen anything but solid drums used on larger commercial roasters. I think the much higher degree of airflow management in commercial drums means solid is the way to go. Not sure though?

[Dimal]

Re: Home made roaster

It goes against my tightarse tendencies, but Ive gone ahead and ordered a new stack motor. I asked for 55rpm 1.5 inch stack ac motor.

By the way Framey,

When I proposed the use of ceiling fan motors as an option, I wasnt alluding to trawling through op-shops, tips, etc..... I thought you were after a new unit and mainly because of the short shaft length, etc to reduce fitment problems within the roaster cabinet, is why I suggested it.

As for having enough torque at the requisite 60 rpm range, Im sure there would be plenty in that speed range, and once the "ideal" rpm was determined, the variable speed option could be made permanent by employing any one of a number of very simple options.

No matter, you have a standard fixed speed unit on its way now and soon youll be cookin

Mal.

[AndyCJ]

Re: Home made roaster

Framey, have you got any more picks of sample roasters - Im definatly heading that way myself - or at the very least thinking about it all the time!!

If you do could you send them on via email or post them here?

Otherwise Im gonna head to the local steel fabricators to see what they think could be cooked up... so to speak!

How much did you pay for the fabrication work (do you mind me asking?) so Ive got an idea if Im getting ripped off!
Cheers.

[AndyCJ]

Re: Home made roaster

Java, Perhaps a post with a bunch of pictures of the Gothot? Thatd be great for inspiration!