Another KKTO on the cheap

[dsgfh]

Re: Another KKTO on the cheap

Thanks russell. Found my PSU seems to work fine first start, but if I stop it for any reason I need to wait a few minutes before it will fire up again. Only an issue if my aggitator drive shaft comes loose mid-roast. Ill give the diode a try

[russellb]

Re: Another KKTO on the cheap

Sorry, havent been watching this thread so closely, struggling with dying hard disc drives, inter alia.

Yes, my PSU was shutting down completely, and I had the 3.3v line connected. Seemed to be that it didnt like "back EMF" from the motor.

I actually played with connecting an original 12v battery which held only a little bit of charge, seeing if I could start it on the battery, then switch over to the PSU once things were rotating. I put a diode in each line to isolate them, and found the PSU worked OK.

[dsgfh]

Re: Another KKTO on the cheap

Nice work Russel. I salvaged an old PSU today, although its pre-ATX Im hoping it will still do the job. Failing that, I have another machine that I should have retired to a skip a long time ago that I can pull another power supply from.

With regard to the diode, was the PSU shutting down completely, or just stalling? Did you have the 3.3v line attached as in the instruction?

Just trying to save myself any headaches by learning from yours

[russellb]

Re: Another KKTO on the cheap

Thanks folk

@Thundergod - yes they did resurface, but obviously not as quickly as with the smaller quantity. I didnt roast red & green beans.

I think that having the temperature probe coming in from underneath and right in the stream of beans helps avoid the situation Mono refers to. Ive been lucky that hearing first crack has never been difficult. Hearing second crack is somewhat harder, and on occasion Ive been unsure it was in rolling SC until Ive lifted the lid and turned off the motor, then beans were snapping away brilliantly.

My impression was that mixing may have been better with a larger quantity, as the mass of beans tends to push adjacent ones around. I can see that next roast will have to be larger. Hopefully I will build up some profiles to guide me that Im on the right track with the temperature also.

All good fun learning.

[Koffee_Kosmo]

Re: Another KKTO on the cheap

For very small roast amounts one needs to alter the roast chamber set up

Beans piled on top of each other is better than beans in a single flat layer

For small roasts
1) Place a high sided steel ring that is of smaller diameter on the bottom of the perforated chamber
2) Alter the agitator to suit

Beans will roast in this smaller area
The roaster will operate as normal but will require a little more user vigilance

KK

[Mono]

Re: Another KKTO on the cheap

Russ, I tried 300g after I fitted the bearing etc. They ended up being cremated not roasted :-[ that was me not the roaster as I was relying on the temp probe and not using my senses of smell and sight. But this time round I could hear the beans cracking quite clearly, but what I thought to be first crack must have been second crack :-[ I reckon they were about CS 36 :.......anyway I digress. I called KK and what he told me (and I assume it relates to your TO roaster as well) was that the "sweet spot" for these roasters is 450-500g when it will almost look after itself. Smaller quantities can be done but require closer vigilance.

Steve

[Thundergod]

Re: Another KKTO on the cheap

My coloured beans disappeared into the mass very quickly.

The question is: "Did they resurface?"

[russellb]

Re: Another KKTO on the cheap

@WSully post 34

Ive put 600g in and, if anything, it seems to mix better. My coloured beans disappeared into the mass very quickly. I havent tried roasting that much as yet. Our consumption is about 250g brown per week, so at present I feel its better for learning to do smaller batches.

[Koffee_Kosmo]

Re: Another KKTO on the cheap

Is there any truth in the rumour that KK is working on a 4000kg/h roaster like the one in the pic that handles batch sizes between 350 to 550kg with standard roast times between 4.5 to 7.5 minutes?

If someone gives me a blank check I can build anything

How about it lads is there a millionaire amongst us

I would not need that much & I promise you will have change plus a brilliant roaster

KK

[Dennis]

Re: Another KKTO on the cheap

looks like a space simulator!

Great guess! Its Probats Saturn 4000 (centrifugal roaster) and they launched it last year.

[WSullivan]

Re: Another KKTO on the cheap

Is there any truth in the rumour that KK is working on a 4000kg/h roaster like the one in the pic that handles batch sizes between 350 to 550kg with standard roast times between 4.5 to 7.5 minutes?

;D hes using a UFO that was collected and stored at Area 51 for the turbo oven replacement!! that fair dinkum looks like a space simulator! who uses these? are they big time commercial roasters of average coffee? or huge distribution specialty coffee dudes?


PS the hopper doubles as a drinking deck, so you can sit there, have a beer and enjoy the view of the ocean........10 miles away!

[WSullivan]

Re: Another KKTO on the cheap

Well, having looked at Warrens system and doing a bit of thinking, I realised that one of the defects of device was that the agitator was too rigid, hence the jamming when beans caught between between the agitator and the pot wall or bottom.  I have therefore rebuilt it, with the member which runs close to the wall hinged and arranged so the "ploughshare" effect pushes it out, but it can swing inward if obstructed on the outside. The opposite vertical strut is attached with fairly light aluminium sheet, and the centre component is of the same sheet.

The effect is that the motor may now load down, but doesnt stall. I even have some video showing beans being catapulted around the pot before I tweaked the settings to reduce the risk of jamming. In the video linked, you can see that the motor slows at times, but keeps running. This is with a 300 gram load.

http://www.youtube.com/watch?v=gWti9utM5-s

I have done one roast, and I think the results look more uniform than earlier. I found I could easily tell the differences in my earlier roasts between beans roasted to the beginning of second crack and those done into rolling second crack. So Ill be interested to try these in a few days time.

Hows it go with more mass russell? brown and green? Looks good mate

[Dennis]

Re: Another KKTO on the cheap

I have no idea mate but bloody BIG seems to do it justice.... ;D

Mal.

;D

Is there any truth in the rumour that KK is working on a 4000kg/h roaster like the one in the pic that handles batch sizes between 350 to 550kg with standard roast times between 4.5 to 7.5 minutes?

[Dimal]

Re: Another KKTO on the cheap

I have no idea mate but bloody BIG seems to do it justice.... ;D

Mal.

[WSullivan]

Re: Another KKTO on the cheap

Gday Russell....

Heres a brief video clip of a commercial roaster just before and during the bean cooling process....

[media]http://www.youtube.com/watch?v=D7pm_qovD_Y[/media]

Gives you a good idea of how the design thoroughly works the beans to ensure efficient and even cooling. The same would hold true in a KKTO for heating the beans as its just about heat transfer in as efficient a manner as possible.... 8-)

Cheers,
Mal.

Mal that is the biggest roaster ive ever seen!, 120kg was the biggest ive seen, whats this?