Exploring the Huky 500 Coffee Roaster, Part III - Page 2

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
icke
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Joined: 14 years ago

#11: Post by icke »

it seems that mr. li is getting busier and busier :)

taking Joel's idea of using a 2nd set of bean tray/funnel combo, i ordered a set of those plus the faster motor (70 rmp) and a new motor housing from Kuanho. He convinced me that the spare motor housing makes swapping the motor out very easy.
i also found a rather high powered open fl
ame gas burner:
http://www.amazon.de/Gas-Hockerkocher-P ... 967&sr=8-1
9.5 kw seems to convert into ~ 32000 btu - that should be more than ample i guess.
a cable dimmer is on it's way too.

can't wait for it all to arrive and see what difference it makes :)

i'm also wondering if falling and burning chaff may affect taste? the perforated drum allows plenty of it through at the moment and parts of it burn up straight away when landing on the burner itself. when doing back2back roasts, i don't get a chance to clear out fallen chaff either causing the pile of chaff in the chaff collecting tray to be quite charred and most certainly causing some smoke to be passed through the drum/beans. i guess no chaff is passing through the solid drum onto the burner and the constant ventilation will ensure that it's all being passed through the chimney instead?

Kuanho also advised me that placing a 1mm (inner diam 8.5 mm) washer onto the drums axis just behind the front plate will make these tiny connection sleeve screws obsolete. i haven't tried it yet but as Joel said, they tend to come loose, making the drum rub against the front plate (causing some really worrying noises).

o
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docjoe
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#12: Post by docjoe »

Thanks for all the posts. The Huky is very interesting and is such a pretty roaster!

I was wondering if I might be able to make a couple of suggestions (just thinking) that may help.

1. You could try using blue Loctite for the set screws to help prevent them from getting loose. If needed, you could always take a torch/flame to it to break up the Loctite if you want to remove the screws. Just a thought. I've used Loctite on several different applications in the past with good success.

2. After dropping the beans, do you think a quick spray of compressed air (from a can) might free some of those trapped beans in the 90 degree bend to the roaster. I've been using the compressed air to help clean out chaff from my Hottop after roasting and it seems to work great for the stray bean as well.

Great work Joel! Your posts have definitely intrigued me and if I upgrade, Huky may be the way to go without breaking the bank!
Cheers!

Joe

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slickrock (original poster)
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#13: Post by slickrock (original poster) »

icke wrote: i too had the drum rubbing at the faceplate. it came down to, as you described it too, the loosening of the motor-drum connecting sleeve screws. i have tightened them quite strongly too but they're indeed a bit fragile looking and i may look into replacing them with more solid screws. but i frequently check before roasting if they're tight, which has since avoided more of the drum scrubbing noises.

...

Kuanho also advised me that placing a 1mm (inner diam 8.5 mm) washer onto the drums axis just behind the front plate will make these tiny connection sleeve screws obsolete. i haven't tried it yet but as Joel said, they tend to come loose, making the drum rub against the front plate (causing some really worrying noises).

Adding a washer per Mr. Li's recommendation may work. I thought about doing that myself, but thought this may add friction to the setup. Perhaps if the washer were perfectly sized OD/ID-wise it should work. I also like the idea of this allowing the coupling sleeve to float freely, which would accommodate thermal expansion and put less axial load on the motor, so it might be worth trying. Replacing the set screws with hardened steel (instead of stainless) and getting them longer length (1cm) so nuts can be used to fasten the coupling down has worked well so far.
icke wrote: i usually stick with 400g as i find even with 400g that there always quite a number of beans ending up in the elbow of the exhaust if i don't keep pushing them back into the drum during roasting. i use a thin long wooden skewer to push them back once in a while, which involves dismantling the exhaust construction - hence it's a bit annoying. if i don't do that, i end up with about 7 - 8 g of beans in the exhaust elbow that are only partially roasted after dumping the beans. with 500g batches, the amount of beans that end up in the exhaust is quite a bit higher.
During my early roasting experience with the Huky, I had the very same problem with a partially roasted beans left in the chimney. For some reason, however, this is no longer a pestering problem for me as I now have far few beans stuck after the roast and the ones left appear fully roasted. I'm not exact sure why this is the case and what I've changed in the process to mitigate this problem. Perhaps it was moving up to the 73 RPM motor, with increased agitation knocking out the beans in the chimney? Or perhaps because I've been using dimmer with full open damper and stronger fan setting (i.e. beans in the chimney get stronger convective heat transfer)?

Still, Mr. Li should work on reducing the elbow on the chimney as a design improvement.

icke wrote: i will however try to find a dimmer for the fan too as i suspect that the super strong fan might indeed suck the beans up into the exhaust pipe?
One thing I've leaned with the Huky is to not be afraid of using the fan at full range to control your roast to your preference. I really have not found a notable downside. The Huky, with high-BTU/Hr burner has heat production to spare, and chaff removal has been a revelation compared to Hottop, due to thorough forced-air ventilation.
icke wrote: i have stopped using the damper too as i ended up quite often with a totally chaff blocked exhaust pipe, making any further ventilation impossible. if i'd ordered another huky, i think i'd ask kuanho to leave the damper out so that ventilation can be controlled only via a dimmer? but i have to buy an dimmer and experiment with it for a while anyway...
The damper remains clear of any chaff when fully open so it probably wouldn't be cost effective to get another exhaust pipe without the damper.

icke wrote: even with the ir burner i can achieve 8 - 8.5 minutes to fc with full heat and full fan power. i have never seen any visible hear related roast defects like tipping or scorching. i saw a fair bit of scorching on my hottop when incresing drop temp but again, i've never seen that with the huky. i do have very often quite a bitter (perhaps ashy?) taste in my roasts. only the very first 5 or so batches were completely free of that and even though i try to repeat what i did back then, i have a hard time to get that bitterness all the way out. i might try to look into swapping the ir with some source of open flame heat source.
It's interesting that you are able to 8.5 minute FC with 400g. Others have had a harder time. Perhaps you should extend roast times a little to get the bitterness out, but not so much as to get flatness. That said, perhaps an open flame burner may fix things. When I started using the Huky, I recall having problems with ashyness in my initial roasts, probably since it is too easy to apply too much heat and my shy use of the fan. With the MET probe and improved technique, this is hasn't occurred in a quite a while.
icke wrote: i will also try to get a faster motor (i guess the spare motor that kuanho supplied me with is the same 50rpm motor as the builtin motor), a spare bean tray and funnel. the end of roast hectic is real and only aggravated by also having to think about clicking the drop button on artisan too.
Using two bean trays has worked like a charm.
icke wrote: i also found a rather high powered open flame gas burner:
9.5 kw seems to convert into ~ 32000 btu - that should be more than ample i guess.
a cable dimmer is on it's way too.
Looks like a good find. Open flame, high-capacity, minimal design.
icke wrote: i'm also wondering if falling and burning chaff may affect taste? the perforated drum allows plenty of it through at the moment and parts of it burn up straight away when landing on the burner itself. when doing back2back roasts, i don't get a chance to clear out fallen chaff either causing the pile of chaff in the chaff collecting tray to be quite charred and most certainly causing some smoke to be passed through the drum/beans. i guess no chaff is passing through the solid drum onto the burner and the constant ventilation will ensure that it's all being passed through the chimney instead?
You brought up an interesting point and possible advantage of the solid drum configuration. I've felt that the solid drum provides a better-channeled ventilation path through the beans and out the funnel (though I have no way of determining if this has a material affect on roast quality, unless I do A/B tests with a perforated drum). I've had no issue with falling chaff, even at lower fan speeds. Perhaps other users of the perforated drum can comment here.
07/11/1991, 08/21/2017, 04/08/2024, 08/12/2045

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slickrock (original poster)
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#14: Post by slickrock (original poster) »

JWilliams wrote: Well I finally freed up some time to roast today and took a few pictures( not very good quality as I used my phone). Since it was a beautiful day I set up on my patio with a folding table a some spare ceramic tiles to deflect the wind and the heat from the table...
Thanks a bunch for sharing the details your keen setup. This burner certainly looks robust enough and it looks like it integrates easily with the roaster. Kinda jealous about the gas gauge and fine-grain control to dial in flame settings. On my kitchen range, I can only go by the marks on the burner knob (and the knob has a lot of play) to control the flame. Heck, with a couple more components, you could PID your setup and have Artisan auto pilot your profiles!
JWilliams wrote: Today was the first day I roasted with the dimmer and what a huge difference in temperature control. I did not even try and use the damper as I am just getting used to my Huky ( had it about a month now), but the control with the gas needle valve and the fan dimmer was great....

Overall today was a successful day of roasting ( roasted 8- 1lb batches in 3 hours with set up and clean up) .
Agreed, the dimmer has a big difference... Eight pounds in 3 hours is respectable clip for the little beast. Bravo!
JWilliams wrote: ... I am going to build a wind block around the stove corresponding to its height because wind and the fan seriously affect the stoves performance. The side with the valves/gauge will remain open to feed the stove oxygen. For now I am using ceramic tiles. When next winter hits I'll be roasting in my garage, with a ventilation hood...
Admittedly, I haven't given much thought to outdoor roasting. Perhaps an IR burner could be somewhat of an advantage, since it is less susceptible to wind interference than a classical open flame burner. BBQ roasters have the open burners fully enclosed, to contain head and block out wind. I could imagine the community could develop over time list of suitable burners based on locality and setting: garage, outdoor, kitchen, high-altitude, etc.
JWilliams wrote: Here is another roast profile where I hit 1c pretty early. I was running the stove at 7" WC with the fan on about 5 (on a scale of 1 to 10). This was during the ramp to 1C (with a 465g charge weight). This stove has plenty of power to spare...

Looks like you no problem hitting your profile marks ☺
07/11/1991, 08/21/2017, 04/08/2024, 08/12/2045

icke
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#15: Post by icke »

I have tried to upload the pictures that kuanho emailed me, showing how to place a washer on the drum axle to make the shaft connection sleeve screws obsolete.
i haven't tried it myself yet but will do so as soon as my 70 rpm motor arrives.

those pics are rather small but seem to be too large to be uploaded here. i'm not going to resize them all to satisfy the boards policy, so if anybody is interested, pm me, i'll just forward kuanho's original email.
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icke
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#16: Post by icke »

the dimmer has arrived and the below profile shows the 3rd roast i've done using it. the fan was constantly on as it keeps spinning even on the lowest setting.
the background profile is showing one of the very first roasts i did on the huky around sept last year.



======================

i haven't tried the above roast yet but the below is surprisingly drinkable. it was the very 1st constant ventilation roast with dimmer i did. just after the drying phase my daughter woke up from her afternoon nap. her being sick, she needed a some close attention for a moment (i spare you the details), so i sprinted back down into the 'coffee-kitchen', turned the gas off and back up to her. when we together came down a few minutes later, things had cooled down a bit. instead of chucking the beans i thought to just continue the roast, they still can go to the bin if totally undrinkable. surprisingly however it indeed was quite drinkable :) not outstanding but certainly drinkable and even better than the usual roast without constant ventilation :o

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icke
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#17: Post by icke »

I received a parcel from Taiwan today. New 72 rpm motor is installed already - much higher pitched sound, a bit unnerving really. but the drum does spin much faster now :)

it was the first time for me to take the huky apart. quite simple design all in all really. what's indeed impressive is the drum. as heavy as it is it really deserves to be called a drum, while all of a sudden the one from my old and trusty hottop reminds more of a perforated tin can...

here's the the recording of my first roast with the new setup. bit of a run-away roast. didn't want it to be that short... the next one was a bit better but still quite a short finishing phase with under 4 minutes.
i'm still using the 'standard' ir gas burner, which doesn't seem to lack power for me.
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RI_ART
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Joined: 12 years ago

#18: Post by RI_ART »

Hello icke,

First I would like to say that the Huky 500 looks like a great roaster. Maybe someday! I am currently using the HotTop-B and haven't been roasting very long, my learning curve looks like a BT RoR chart. I noticed that you are using a pretty high charge temperature. What does that do for you? How does it affect the flavor?

Thanks
Art

JWilliams
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#19: Post by JWilliams »

Well I finally nailed a few this week...



I've been playing with profiles and cupping a lot of coffee this month trying to reduce the learning curve with this roaster. I've ended up with many good roasts, several mediocre, a few nasty ones (high residual isoprene), but up until this week, no exceptional ones. I really think that a fast drying phase (under 4:15) with a 450g-500g load does not work with many coffees in this roaster. Granted I've been roasting mostly wet processed centrals. Dry processed coffees are a different story.This may be due to drum size with a load that big, but I really don't know. My roasts have been very even. So I've lengthened my drying time and I've lengthen my ramp time and I've noticed a definite increased sweetness and richness to my coffee. I did eight roasts a few days ago, all centrals and all with similar profiles. I cupped 3 today and was astounded by the sweetness, clarity, and overall vibrant flavors. I am very happy. :D




Fan control is so important and the dimmer I was using required me to turn it all the way up just to get the fan blades moving. Once going I could reduce the RPM's with the dimmer, but I found my control frustrating. It annoyed me to the point I started using a small variable transformer (3 amp variac) with a kill-a-watt for much greater control and a wider speed range. I run the fan for the whole roast time, varying the speed. For drying I run it at a low setting(45v). For the ramp I run it at 60v. Near first crack~ it depends.
JW

icke
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#20: Post by icke »

JWilliams wrote:with a kill-a-watt for much greater control
good idea! i was thinking of getting my fluke out, opening up the dimmer and measuring a variety of voltages to mark power levels on the dimmer, but your solution is quite obviously a tad simpler. will do the marking so that i only have to play with my energy logger once.
JWilliams wrote:Well I finally nailed a few this week...
do you mind sharing one or two of you best profiles? would love to use it as background profile to see if i can replicate.
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