Feedback sought: New corretto/KKTO build

[nikko.the.scorpio]

Thanks as always to everyone for the excellent replies!

Sounds like you made it too efficient Nick!

Ah I didn't do much myself - just a very good design by KK and the main thing is that my pots are smaller than those most folks seem to use. It's definitely a GOOD problem to have as a lot of folks seem to be asking about more powerful TO's, chopping up the heat screen etc and well this worked too well and did so without all kinds of insulation, lid being kept tightly down etc.

I haven't read anywhere about internal foil insulation, let alone foil + modding the heat diffuser - so doubt you'd need to touch it as you say.. You could experiment with only foiling half the glass - might back it off just a little to give you a little more room to move? Or do you think you're happy with it's efficiency and you'll just play with the green volumes?

IMHO foiling the glass is a good thing - if for no other reason it cuts down the VERY harsh glare of the halogen bulb - I accidently looked at it when it was on while I was roasting and my eyes hurt for 5mins! Hence I put the sunnies on.

I'm all about finding the 'smart point' of tweaking/modding stuff - so I know you could do all kinds of lil tweaks/mods etc and squeeze every drop of efficiency out of whats already an excellent design by KK but I want to do the easy, cheap and simple stuff first - assuming it works well (and it ALREADY does) thats enough for me!

So yes, I'm very happy with the efficiency already - I figure I'll prolly increase the green bean volume slightly and also know to decrease the heat used, atleast initially in the roast as I want to try and drag 1C out until later (I believe the recommended roast profiles for espresso coffees (I know this is being massively simplisitic to lump all in together but anyway) is 1C at around 17min - 2C 7min after or so.

With the corretto/HG you often had the opposite probelm - in that you'd have trouble getting enough heat in and would have to really turn the HG up, resulting in tipping and scorching on the beans.

Keeping it at 200 C is pretty impressive - would be interested to know once you have your thermocouple what your ramp is like at 200.

Are you just using regular home foil - or some of the more heavyweight stuff? Might be more durable if using stronger foil? - I'm thinking of getting some of the foil insulation from bunnings (not alfoil) and making a sleeve for outside the glass - hopefully it might manage a bit of reflection even through the glass - and I'll top it with a sheet of silicone - see how that goes. But I'll give it a run without insulating the glass at all first and see if it's satisfactory as it is.

Yes, from the number of other KKTO threads I've read, and thats quite a few I was pleasantly surprised that getting the required heat in wasn't a challenge.

Yes, just regular aluminium foil. FWIW if you wanted to be smarter I came up with a better solution (that I might switch over to myself!). The problem with the foil is it's very delicate and easy to rip etc. Also after a few roasts a layer of dark residue will build up on it and this will (I would expect) massively decrease it's efficiency as an insulation. Cleaning it might be hard due to it being so delicate.

So what you do is you buy one of the disposable foil cooking trays - you know the ones meant for BBQs etc? I was in Woolies this morning and they sell what appeared to be a near perfect one for ~$3.50. It was round and almost has a template on it for where to cut so you get this perfect piece of much thicker foil to place on the underside of the TO's lid. Being that it's round it should be a lot easier to fit to the curved lid than using multiple rectangular strips.

I've used this material in my previous corretto and it's strong enough that you can wipe it off and can't easily damage or rip it. One nice big piece, instead of my 7 or 8 - and put a lil window in it and you're done. You could always be a real smarty and have the window with a cover on the outside to maximise heat retention. Super simple - anyway if I was doing again I'd do THAT instead of the multiple layers of foil - is a much better solution and only $3-4. Just a few dabs of heat silicone and I suspect it's very close to the perfect size!!!

Dunno about the insulating foils at Bunnings - a lot of the ones I saw has a plastic or asphalt backing to them that made them unsuitable. Technically the foil on the inside of the lid would be the most effective (otherwise the glass absorbs a lot of the heat first) but I suspect we're splitting hairs here as any foil as all will be very effective - and on the outside you don't have to worry about it's performance diminishing over time (do have to clean inside of lid though!).

The silicone or another layer would definitely take it to another level - no argument there but for me I think the foil (specifically using the round disposable foil pan cut out) is the minimal effort/maximum benefit sweet spot. But thats just me. :-)

I've got a bunch of my stuff arriving in the next fortnight, so hopefully I'll have a build pretty soon to show off as well! Did you end up getting and ALDI TO?

Al

Cool, oh well I really look forward to your thread and updates. Yes, the TO is the current Aldi Lumina one.

@bcspark, thanks for that I'll have a look - though that thread link by @readeral does make me think perhaps I could use the existing motor (which does the perfect speed) with minimal hassle. But good suggestion!

@readeral, oh I didn't know he still sold stuff, he's so modest that while many others would shove/force buying from them down your throat it wasn't even mentioned. Thank you for highlighting this!

[nikko.the.scorpio]

Well after @readeral's advice I'm going to stick with using the breadmaker's motor for the KKTO and will mount/house it in a similar manner to the 'Burnsy's KKTO' thread. Thank you very much for this.

The speed of the breadmaker motor at full speed is very similar to the ~70rpm that KK advocates. It should be no more difficult mount/house this than a direct drive motor such as KK sells and it saves me the potential minor long term hassle of heat coming down the driveshaft and affecting the motor. That it's the perfect speed and onhand is the deal clinchers.

So it's just a matter of coming up with the drive shaft (which essentially allows a fair bit of flexibility - as long as it's stainless steel and around the right gauge). I'll then just have to figure out how to most effectively join/connect it to the breadmaker's connection/paddle mounting point. It'll likely either be through a couple of old sockets (possibly adapted in some manner) or some spare/scrap metal bits I locate around the house.

Thanks to @readeral for reminding me of that thread (as I had seen it before but completely forgot).

[Koffee_Kosmo]

I know of 2 other builds that use the smaller pots and they work just fine
RPM is important but more important is the agitation and mixing result

Have a look at the videos I have posted with the red bean mixing tests and try to replicate it on your roaster

KK

[260zman]

Enjoying watching your experimenting and problem solving with your kkto.

Sorry to jump in on this thread, feel free to shift this and tar/feather me if it bugs anyone.
Has anyone noticed any issue with roast times when using an extension cord with a multi box coming off it. My roaster is set up in a remote part of my workshop and the nearest power point is about 10m away, initial testing I was plugged directly into power socket but since then I've used the extension. Coming off the multi box I have the turbo oven, a 12v battery charger (runs my datsun wiper motor for stirring) plus the bread maker element (2nd heat source).
In my opinion it must rob a fair bit of power from the one socket?
Cheers

[readeral]

Yeah this might not be the thread so much for that question right now. In a month or two we might have answers, but you're more likely to be able to answer the question for us at the moment!!

[nikko.the.scorpio]

Enjoying watching your experimenting and problem solving with your kkto.

Sorry to jump in on this thread, feel free to shift this and tar/feather me if it bugs anyone.
Has anyone noticed any issue with roast times when using an extension cord with a multi box coming off it. My roaster is set up in a remote part of my workshop and the nearest power point is about 10m away, initial testing I was plugged directly into power socket but since then I've used the extension. Coming off the multi box I have the turbo oven, a 12v battery charger (runs my datsun wiper motor for stirring) plus the bread maker element (2nd heat source).
In my opinion it must rob a fair bit of power from the one socket?
Cheers

260zman, @readeral's points are valid - however, FWIW I'd expect there to be more than ample electricity from a conventional power point to easily supply all those devices you detailed. If you're hypothesising that changing roasting/heat results are due to the extension cord/power board being used I'd strongly suggest that it is far more likely to be other variables that have influenced your results and not there being less power to go around the devices. But thats very much a laypersons opinion and I would suggest either conducting further experiments yourself, popping a thread up to ask but I'd be amazed if that made any real and discernable difference at all - the TO, breadmaker (even with element on) and battery charger would use very little juice compared to a whole range of other devices that still run quite happily on domestic power supplies. :-)

[260zman]

Cheer guys, and yeah sorry about that, I just thought of it as I was reading through each post.

I'll do some testing and get back to you via a new thread. I have a feeling that the length of extension lead does make a difference (especially if it's a cheap, low amperage one).

[Koffee_Kosmo]

Enjoying watching your experimenting and problem solving with your kkto.

Sorry to jump in on this thread, feel free to shift this and tar/feather me if it bugs anyone.
Has anyone noticed any issue with roast times when using an extension cord with a multi box coming off it. My roaster is set up in a remote part of my workshop and the nearest power point is about 10m away, initial testing I was plugged directly into power socket but since then I've used the extension. Coming off the multi box I have the turbo oven, a 12v battery charger (runs my datsun wiper motor for stirring) plus the bread maker element (2nd heat source).
In my opinion it must rob a fair bit of power from the one socket?
Cheers

OK let's start the ABCs of electricity

A home can have one line from the board to an outlet but that is rare
Most homes have several outlets per line and is calculated that if all outlets are used they should not exceed 2400 watts total or the breaker will trip

To your question - If only your TO and motor is connected to an outlet without other electrical appliances draining the power you should get full power
However for long extension cords my understanding is that you should use 15amp internal cable as im sure the long length will have a small power draining affect when thinner cable is used
( Electrician required to verify )

KK

[Mono]

Hi guys, I don't visit here all that often anymore but have been following this thread with interest, great work.

Steve M.

[nikko.the.scorpio]

Anyway back on the discussion of a KKTO-esque roaster build - I had a good catch up with a nearby friend who has a real, ridgy didge KKTO. He was gracious enough to allow me to look it over thoroughly and take a whole load of close up pictures of it's bits and pieces - with a view to having them to compliment the already great info and plans that KK has been ridiculously generous and shared with the world.

Cut a long story short I thought I'd have a bit of a hunt around for a similar spec'd electric motor to the one KK uses in his builds. Evidently his was a special on made via a custom order - and as such I was very realistic in knowing that the gearbox & motor combo would almost certainly NOT be the same likely perfect pairing that KK sourced. Neither would it have the socketed connection point (though that shouldn't be a huge issue).

Anyway after much hunting around I came across two likely options - one was 12v 70rpm, claimed 7kg/cm of torque but relatively generic makers. The other was the same maker as KK's motor, Zheng - 60rpm - claimed 6.5kg/cm of torque. Chose the latter as seemed superior build quality, for the curious the item number is 131458749952 ( the other one I didn't buy is 311359199279).

Both motors were ~$AUD11 delivered. Like I said am certain they're NOT as good as KK's ones but are very similar physical size/weight and known specs (KK's combo does 69rpm/min).

I think the breadmaker motor might have had a bit much 'play'/wiggle in it's shaft by the time the multiple bits were cobbled together - this alternative option should be a tad more stable, guess we'll see. :-)

[readeral]

Great!

That'd be a bunch easier to wrangle - did you order a mounting bracket for it as well, or you'll wait till it arrives before hunting for one of those? I guess the benefit with the KK motor is it's fairly robust mounting points built into the unit's casing. But, great find!

I just reread your post on the TO test run, and realised how you 'stirred' the beans. That's commitment! I assumed you had meant you'd put in an agitator and shaft and just used your hand to twist it manually. So, re. the shaft, will you go with the socket extension bar as you mentioned above? I assume you can convert from D shaft to the square socket extension with a coupler of some sort... Otherwise would a D shaft suffice? The gauge of the shaft that KK has sent me today looks about 10mm, maybe 12mm. Very sturdy! Also has a piece in the middle to stop the shaft collecting beans in the middle that won't then agitate.

It's great to see you're pulling bits together!

Al

[readeral]

The genius part of using the socket extension bar as drive shaft would be rigging it somehow that you can build a second agitator to fit on the top of the original, with a hole drilled in an (even smaller) insert for small batches - the original pot set comes with a pasta insert, and a steamer insert that would be perfect. This wouldn't be at all worth doing in your instance though given you're using a smaller pot set anyway! Also I guess there's the risk that the TO would be too close to the beans... but interesting thought experiment.

[nikko.the.scorpio]

Great!

That'd be a bunch easier to wrangle - did you order a mounting bracket for it as well, or you'll wait till it arrives before hunting for one of those? I guess the benefit with the KK motor is it's fairly robust mounting points built into the unit's casing. But, great find!

I didn't buy a mounting bracket as it seems to have screw holes in the top of it that you could use to affix it directly to your enclosure/base section. Worst case it'd be easy enough to cut a piece of metal and then drill holes for mounting but I'll have to see when it arrives and I've a better idea of the drive shaft option thats been used.

I just reread your post on the TO test run, and realised how you 'stirred' the beans. That's commitment! I assumed you had meant you'd put in an agitator and shaft and just used your hand to twist it manually.

Thanks but I really didn't have a lot of other options and it really wasn't either that hard or overly effective! But the roast was vaguely as desired, though I think my experiement with going well past 2C will see me had back on the otherside of it so more bean characteristics come out and not so much roast characteristics. :-)

So, re. the shaft, will you go with the socket extension bar as you mentioned above? I assume you can convert from D shaft to the square socket extension with a coupler of some sort... Otherwise would a D shaft suffice? The gauge of the shaft that KK has sent me today looks about 10mm, maybe 12mm. Very sturdy! Also has a piece in the middle to stop the shaft collecting beans in the middle that won't then agitate.

I'm not really sure to be honest. The socket extension bars obviously have the handy benefit of having premade connectors at either end of them BUT the length is also critical and sure I can cut one off if needed but I'll have to weigh that up vs using some plain steel rod and then modding extenders/connections onto either end of it. Whichever way is easier & ultimately more effective I'll go with.

The trick is to have something that allows you to take the top section (roasting insert with beans, agitator etc) and easily lift it up to tip the beans out and into your cooler. Thats one of the many little genius features of the KK design. If you have something thats difficult or tricky to get out you run the risk of having a PITA when it comes to do that quick dump at the end of the roast.

The only alternative option that could be a good work-in with this is if your bean cooler has a workshop vacuum or similar partially driving it and you can run the tube direct from the top of the cooler and literally vacuum the beans into it - there's a design on here that was done in this manner.

Anyway a lot of options.....it's not something I'm rushing to get together so we'll see how it evolves as I meander along. Cheers and thanks again for your suggestions and feedback.

[readeral]

An update on my build -

Today I received from KK a motor with screws and washers, aluminium drive shaft (with washers to keep it attached to the roast chamber), agitator wires, some insulation, and an aluminium false floor.

Next week I'll have my pots and will try to drill them next weekend (I've found a workshop attached to a small community organisation that had a press drill that I could use! Huzzah!) and then will be able to put all the mechanical bits together.

I've got an old 12v 2.5A power supply from an old external hard drive - so I've just got to get a hold of the right female socket for that, and wire it all up to the motor, and then build a base for the pot-set out of MDF and mount the motor the right depth for the drive shaft to fit perfectly, and I'll basically be done!

I'm tempted to use a wooden IKEA stool as my roaster base, rather than MDF, but that would mean that the whole roaster would take up more space in storage - and the extra height would give it a higher centre of gravity... Choices choices.

Once I've got the pots drilled I'll upload some more details.

[readeral]

I'm not really sure to be honest. The socket extension bars obviously have the handy benefit of having premade connectors at either end of them BUT the length is also critical and sure I can cut one off if needed but I'll have to weigh that up vs using some plain steel rod and then modding extenders/connections onto either end of it. Whichever way is easier & ultimately more effective I'll go with.

The trick is to have something that allows you to take the top section (roasting insert with beans, agitator etc) and easily lift it up to tip the beans out and into your cooler. Thats one of the many little genius features of the KK design. If you have something thats difficult or tricky to get out you run the risk of having a PITA when it comes to do that quick dump at the end of the roast.

The only alternative option that could be a good work-in with this is if your bean cooler has a workshop vacuum or similar partially driving it and you can run the tube direct from the top of the cooler and literally vacuum the beans into it - there's a design on here that was done in this manner.

So the KK design is all once piece - and where it disconnects for dumping is actually pulling out of the motor - so for you, you could use the socket extender and just yank it from your coupler instead (which is firmly fixed to the motor). So when you go to dump it, your agitator stays in place - but so does the whole shaft (in that it is connected to the roasting chamber). Then - in a sense it wouldn't matter what length the socket extender was - as long as it's long enough - and you're able to fix it to your roast chamber somehow (drill two small holes in the socket extender, slide it into the base of the roasting chamber, fit some washers and then drop in a split pin to each hole either side of the roasting chamber base). A la this image. Then you'd have to further modify the socket extender to hold an agitator, but you'd have to do that with any sort of rod anyway.

I dunno... heaps of options as you say!

I'd been thinking about the whole bean cooler thing, and trying to work out if it's possible to suck the beans without using a vacuum. A bloke in a thread I started reckoned that maybe the extractor fan design would have enough air speed (with care given to restricting the airflow to increase it's speed) to manage drawing the beans out - so I'll be testing this next week - and if it doesn't work - working out another way that enough draw can be made without a vacuum cleaner (I don't want another appliance dragged outside - already will be a TO, the motor PS, and the cooling fan). My first step is to find a clean hose somewhere :-/