Is there a market for a 1kg DIY drum roaster?

[cuppacoffee]

Re: Is there a market for a 1kg DIY drum roaster?

Looks can be deceiving HV...

Dudley actually has 4 fans - some push and the others pull. The stove pipe in the pic leads into a fairly large, baffled, chamber (for chaff collection) with the exhaust fan at the other end of the chamber.

[HV_MAN]

Re: Is there a market for a 1kg DIY drum roaster?

LOL,
Super-charger.....Id better change the fuel source to Methanol and add NOS to boot roasting speed!

OK on the serious side most commerial roasters pull/suck air though the roaster
Just look at the following examples

Poundys roaster for instance REAR & SIDE

And Denniss roaster although it has longer pipe work between the drum and the fan pic of its REAR

Temperatures are on a concern however shouldnt be a problem.

Which of the two do you think would work the best? ver 1 would be cheaper due to less components.

[marcstolk]

Re: Is there a market for a 1kg DIY drum roaster?

A super-charged roaster.... what would my friends say about that....

And you dont need an intercooler ;-)

[yeeza]

Re: Is there a market for a 1kg DIY drum roaster?

A super-charged roaster.... what would my friends say about that....

[Koffee_Kosmo]

Re: Is there a market for a 1kg DIY drum roaster?

Something to keep in mind is seperating the 200+C  heat from motors and fans.

Chain drive helps limit the heat transfer from shafts and if you can blow the air (not suck it) then you have more chance of the fan and bearings keeping cool too.

I think a centrifugal or roots supercharger might have an application on a coffee roaster.  One of the problems with a supercharger on a petrol motor is that it heats the air which reduces the efficiency.  In a coffee roaster this becomes an advantage!

The Eaton superchargers (and others) have lifetime sealed lubrication for the gears so you dont have to worry about feeding oil to it.    



I have seen secondhand ones very cheap although finding small ones for a 1kg roaster might be tougher.

I agree with Andy
However that may cause a cost blowout over the magic $1K mark taking into account all other parts needed

I beleave Eaton makes blowers for the Toyota TRD range

A creaper alternative may be a motor / blower combo
Some electric and gas heat clothers dryers have a combination motor and blower fan

KK

[andy]

Re: Is there a market for a 1kg DIY drum roaster?

Something to keep in mind is separating the 200+C  heat from motors and fans.

Chain drive helps limit the heat transfer from shafts and if you can blow the air (not suck it) then you have more chance of the fan and bearings keeping cool too.

I think a centrifugal or roots supercharger might have an application on a coffee roaster.  One of the problems with a supercharger on a petrol motor is that it heats the air which reduces the efficiency.  In a coffee roaster this becomes an advantage!

The Eaton superchargers (and others) have lifetime sealed lubrication for the gears so you dont have to worry about feeding oil to it.    



I have seen secondhand ones very cheap although finding small ones for a 1kg roaster might be tougher.

[HV_MAN]

Re: Is there a market for a 1kg DIY drum roaster?

Second air flow idea

[HV_MAN]

Re: Is there a market for a 1kg DIY drum roaster?

Ok, Ive scrapped allot of my initial ideas and started again today.

A very basic layout is hopefully attached of ver1..(.this is not to scale only concept scribble at this stage. detail later)

For the drum and nearly all the roaster good old steel will be the material of choice.

Im tossing up with the air flow route.

The pic Ive posted shows the air being drawn into the rear of the burner chamber up into the front of the drum through holes/mesh through the drum and out the back wall into a fan that pull air through the system.

My other idea was to again taken in air via the front sides of the burner chamber up into the rear of the drum (rear of drum meshed/screened & additional space between drum and back panel inserted to allow air in) through the drum up and out via the top of the drum via the been filling arrangement and then to fan.....(see next post for this pic)

[grendel]

Re: Is there a market for a 1kg DIY drum roaster?

Im avoiding stainless steel as a drum material as its heat retention profile is inferior to carbon steel.

The weight of steel to use will be a crucial factor - enough to retain the heat and not too much for the mechanism to handle a good rate of rotation on the bearings.

The issue of airflow is also important and there will have to be some degree of perforation within the drum skin or at the ends to allow airflow and chaff removal.

Part of my experimentation will be with that.

Dennis - love the capital raising idea - I wonder if it is OK to use old drawings of a patent submission for that.

[Koffee_Kosmo]

Re: Is there a market for a 1kg DIY drum roaster?

Depends how big a drum

Old front loading washing machines and dryers have great S/Steel drums

1) Could be used upright if you use an agitator
2) Or as a traditional drum with little mod needed

However they could also make a great outer casing

KK

[HV_MAN]

Re: Is there a market for a 1kg DIY drum roaster?

Ive done some research on IR burners etc and I believe for the size and cost reasons Ill be sticking with a traditional type burner arrangement and maybe revisit IR later. IR is cleaner and more efficient however is great for direct heat conduction but it doesnt heat air very well thus requiring a heat exchanger or an additional heater for the hot air both of with would add considerable cost.

[HV_MAN]

Re: Is there a market for a 1kg DIY drum roaster?

I should read the threads more often - and would do if life wasnt so busy right now.

Over here in the west a number of us have been actively discussing and designing a next stage roaster for home roasters - if people are keen to collaborate on design discussions, including some cheaper ways of doing certain refinements then Id probably be happy to share my ideas so far.

Ive gone as far as looking at the drum material and fabrication and the designs of a worm drive for drum rotation.

I have also commenced work on a missing link roaster that should roast up to 1.5kg and that will be a test bed for some of the materials to be used in the drum roaster (to test heat retention, warping etc).

But yes - there is a market for a 1-2kg drum roaster that is under $1000.


I could sell 5 in WA tomorrow.

Hi Grendel

Your most welcome to added any input, Im open to any ideas and suggestions.

Im interest in the drum material you have investigated.

For drum rotation Im planing on using a package direct drive unit, basically a small motor with gearbox on the end, makes it very simple.

[Dennis]

Re: Is there a market for a 1kg DIY drum roaster?

Hey Grendel, maybe you could raise some capital by creating some posters from the 1881 patent you have...Id be up for one!

[andy]

Re: Is there a market for a 1kg DIY drum roaster?

if people are keen to collaborate on design discussions, including some cheaper ways of doing certain refinements then Id probably be happy to share my ideas so far.

Surely that is exactly what is happening in this thread already Grendel, share away!

A top idea Craig.

From all the devices that I have tinkered with I would strongly suggest that you forget about electric heating. Once the bean mass is larger than 400g the electric just doesnt offer enough heat to get creative with the profiles.
Well at the domestic 10amp anyway.

GAS - cheap, easy and most have access to a BBQ bottle so fittings etc are familiar.

Hi Andy

This has been a major concern to me...getting enough heat into the roaster in a sensible time..coming form an electrical background electric heating would be the easiest however I agree gas would be the way to go. The larger electric roasters Ive seen >1kg have all been 15A single phase to 3 phase units which the average home would not have, so with this in mind now Im going to focus on a gas solution. gas may = more expense due to the cost of the burner control etc...need to do some more investigating.

Craig A

I have fiddled with an auto-LPG solinoid as a simple gas burner control.

12v operation, gas rated, handles the pressure, fittings are common sized and they are pretty cheap. With a small bypass tube you can keep the burner running at minimum flame and with some pulsing you can control the flow / flame height.

I think a lot of auto LPG fittings and controls could become the basis of home roasting devices. (after a qualified gas fitter inspected it of course!)

[grendel]

Re: Is there a market for a 1kg DIY drum roaster?

I should read the threads more often - and would do if life wasnt so busy right now.

Over here in the west a number of us have been actively discussing and designing a next stage roaster for home roasters - if people are keen to collaborate on design discussions, including some cheaper ways of doing certain refinements then Id probably be happy to share my ideas so far.

Ive gone as far as looking at the drum material and fabrication and the designs of a worm drive for drum rotation.

I have also commenced work on a missing link roaster that should roast up to 1.5kg and that will be a test bed for some of the materials to be used in the drum roaster (to test heat retention, warping etc).

But yes - there is a market for a 1-2kg drum roaster that is under $1000.


I could sell 5 in WA tomorrow.