Home made roaster

[Javaphile]

Re: Home made roaster

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

Sure, Ill take a bunch here later today and postem. Its nearing sunrise here and almost time for me to grab a few hours of shut-eye. Theres quite a few pics of it in the Epic Journey ( http://coffeesnobs.com.au/YaBB.pl?num=1121040424 ) post of course. But Ill post a series in this link of the barrels specifically.

Java "Running on two barrels" phile

[wrstikoff]

Re: Home made roaster

Just a couple of photos of the roaster Im working on. Just the drum and roaster shell. The burners are yet to be hooked up and the motor is on the way from the USA... hey that rhymes

Any bushing experts out there? I need something that will take the heat.

I used to work for a company that made carbon reactivation kilns - esentially the same as what you have there but a bit bigger and operating at around 800 C. We used basic brass bushes with high temperature grease. I dont think there will be any non-metalic materials that will take the heat [smiley=undecided.gif]

For your roaster the choice of brass is not going to be very important since the loads will be very small. I would maybe use a leaded brass as this will give you some protection if the bearings should run dry.

Good luck with the roaster - I look forward to seeing the final product

[Javaphile]

Re: Home made roaster

OK, as promised heres some pics of the barrels on my Gothot.

This one shows the lid of the barrel assembly closed as it would be for roasting.

[Javaphile]

Re: Home made roaster

Here the lid is in the locked open position as it would be for dumping the beans.

[Javaphile]

Re: Home made roaster

Heres one looking straight into the barrel showing the vanes and the opening out the back of the barrel. The barrel rotates in the clockwise direction.

[Javaphile]

Re: Home made roaster

This one shows the rear of the barrel assembly where the shaft of the barrel goes through a housing.

This is the only point of contact for the barrels. The rest of the barrel does not touch anything.

The hole in the top of the housing is the oil point. This is the hole that, on all 3 barrels, had a solid bolt in it. Kind of made it a bit hard to put oil in.

This is the barrel with the stripped gear. Notice how the gear teeth come to a point instead of a nice wide flat edge as they should.

[Javaphile]

Re: Home made roaster

Here is a view of the burner with the worm gear that drives the barrel visible at the top.

[Javaphile]

Re: Home made roaster

Here is a view of the inside of the barrel assemblies looking up from the bottom of them.

On the left one you can see on the left of the barrel where it was covered with the high temp coating. The darker right side of the barrel is what it looked like when I got it.

The right barrel assembly has had the barrel cleaned of the coating over-spray and the years of carbon build-up leaving the barrel with an almost mirror finish. A fiber wheel made for paint removal was used to do this and worked like a charm.

On the inside of each barrel assembly on either side of the barrel you can see a flap of metal. This holds an insulating pad which I assume is made from asbestos given the age of the roaster.

The old socks are on the gears to prevent the grease on them from getting on everything.

[Javaphile]

Re: Home made roaster

Any other views yall would like to see?

Java "Having fun with his toys" phile

[wattgn]

Re: Home made roaster

Java:

Impressive looking machine...

How does it roast? How many roasts so far?

Grant

[Javaphile]

Re: Home made roaster

Java:

Impressive looking machine...

How does it roast? How many roasts so far?

Grant

Thanks Grant. I thought it turned out pretty nice myself.

So far Ive put hhmmmm......lemme think here now....there was the 10kg or so for Christmas presents, 3 batches of CP at 3kg each, another 5kg for the bowling crowd, and a month of my own usage so lets see....that would total up to about 27kgs. So that would be 108 roasts as Ive been using a 250g batch size.

So far the roasts have been very even with the exception of the Yirggy I have due to its widely varying bean size. Im still very much getting used to it and trying to devolop the appropriate roasting profile for each bean in it.

Heat control has been problematic as there are no thermometers in it and the only one I have thats made for those temps is a glass/mercury one which for obvious reasons Im reluctant to use. :-/ As a result roasting has been by best guesstimate for flame height. This is not helped by the touchiness of the flame adjustment on 2 of the burners as they appear to have been made for natural gas instead of propane as well as figuring out how much air should be getting pulled through the barrels.

For now Ive been setting the air flow so that its strong enough to pull all the smoke and chaff out of the barrel but low enough so that not to many beans are sucked out. This was really tricky with some Tanzinian Peaberry beans I had as they were very small yet produced lots of chaff.

I have been trying to hit 1st crack at about the 7 minute mark with the roast completing at 10 minutes which is where a solid barrel sample roaster such as this should be from what Ive been able to find out.

Figuring out the flame height for getting to first crack Ive now got pretty well established. Initially I was using too high of a flame and was getting burnt tips.

From the onset of first crack on though has been where its gotten really tricky. If the roast enters first crack with too much momentum it will go almost immediately into 2nd crack. What seens to be working pretty well ahs been to start dropping the heat as first crack nears and then drop it dramatically as soon as the first crack is heard and as soon as the cracks start tolling to drop the flame to the absolute minimum height that the burner will stay lit at. At this point flame height/control becomes really tricky. I have to play with the flame height so that the roast doesnt loose too much momentum and completes first crack in an appropriate time. Usually I end up having to bump the flame height up just a touch partway through first crack.

Determining when to pull the roast has also been tricky for those beans that are best when pulled before 2nd crack. I can no longer simply roast a set time past 1st crack as I could with my Z&D roaster. I think I need a better light by the roaster to better help me determine their color. There is plenty of light there currently but it appears its spectrum isnt very good for judging the color of the roast as there isnt much apparent change in the last 1-2 minutes of the roast.

The trickiest bean to roast so far has been the Columbia Mesa de los Santos as it doesnt like to done anywhere near 2nd crack, yet it has to have fully passed through 1st crack and be about halfway to 2nd. This is the lightest roast bean I do and because of that Ive been staying away from it until I got more familiar with the roaster. I did some up yesterday and from todays taste test it appears I pulled them a bit too early. Theyre still drinkable but are not yet at their full flavor. I think Ill put them back on the shelf for awhile longer yet and stick to the beans that go just too or into 2nd crack.

So in short Id say the Gothot is doing its job just fine, but the roasterer needs more practice.

Java "Still practicing" phile

[AndyCJ]

Re: Home made roaster

awesome Java - thanks for those pictures and the info. What a roaster! Man-o-man I could do with one of those badboys!

Cheers.

[refreshinglygood]

Re: Home made roaster

wow, finely got onto the site, and I must say the roaster is indeed impresive

D.Mc (The Tamworth Link)

[Framey]

Re: Home made roaster

Hey Danny
Welcome aboard.

I picked up the motor, and a new regulator for the gas bottle yesterday. Only 29 small but tricky steps to go...

If anybody in Sydney needs anything gas related I can thoroughly recommend Gameco in Auburn (161 Parramatta Rd). Excellent service and advice.


Looks really nice Java. Sounds tricky but rewarding.

[Javaphile]

Re: Home made roaster

Looks really nice Java. Sounds tricky but rewarding.

It has indeed been a bit tricky but its slowly teaching me its tricks. It has also been very rewarding to finally get to use what Ive been working on soooooo long!

One of these days when I run into an affordably priced one I plan on picking up an infra-red thermometer. That will help take a lot of the guesswork out.

Java "da Roastin Fool" phile