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Skywalker, the ALM chinese one pound roaster
renatoa
The winter holidays are close, so a rising star should appear on the sky, even in the roasters realm Grin

This is a new machine, that started to be sold about one month ago on the Aliexpress market, very nice looking, at a surprising low price, about $450.
A copy landed this morning at my door, and it is now under dissection for examination.

Funny that I should wait until unboxing to find that this machine has a name, see the thread title, name that you will not find anywhere on Aliexpress, so attempts to find the machine searching by Skywalker roaster will return nothing.
I bought mine from a seller named ITOP, that seems to be very active in the world of coffee, lot of other gear you can browse on their pages. This is the page of the product: https://vi.aliexp...89609.html
There are other sellers selling same stuff with names more or less close to ITOP, but same price range.

Searching further by the name Skywalker and roaster related terms I found also a set of three video clips, 2 month old.
You can find them here: https://www.youtu...1vr/videos , the unboxing, and two roasts, the full Auto and the Manual modes.
Yep, this machine has a rare feature in the roasters world, a full auto, one button touch, completed unattended roast mode, using one of the 9 factory embedded profiles...wow ! You can choose such profile from a 3x3 matrix of light/medium/dark roasting, for natural/wet/honey processed beans.
Beware, your definition about light/medium/dark levels could be different than the machine manufacturers... Grin
For this reason, to fine tune the roasting, there is an intermediate Assisted mode, where the logic is like in Auto, but you can decide the evolution of the roast during development phase.

Another rare feature of this machine, even if skeptical about how effective will be in real operation, is the presence of a smoke filter.
For those with over sensitive noses, an exhaust pipe is provided, for a classic smoke exhaust via the house ventilation or oven hood.

Because my machine is already opened for deeper examination, the videos above are for now the only resource you can enjoy until I come back with first impressions.
And also the attached pdf, same as the printed manual that comes with the roaster.

Some details that revealed so far:
- there is no computer connectivity; this is my main interest now, to decipher the machine electronics, and find a way to stream outside the beans temperature.
- there is no ET temp probe, which has less relevance for this machine, due to the specific roasting mode, see below.
- the roasting is done by direct to beans infrared radiation, produced by a carbon fiber filaments lamp, inside the drum
This is a rare thermal model used in the roasters world, I can't count many machines using such approach, the closest to Skywalker capacity/size being Sandbox R2, with some notable differences:
- For R2 the lamp is placed in the center of the drum, not farthest opposite diagonal related to beans bed surface, as is Skywakler
- R2 is controlled by an app, not a wired panel. Both are closed systems, without connectivity to other roasting apps
- R2 has no trier, is designed for smartphone generation, with less inclinations towards sensory appreciation of roast progress
- R2 has no internal cooling, yep another nice Skywalker feature !
- R2 is 5 times more expensive Shock

It can't be compared to Behmor, because the radiant different placement, inside vs outside, that change a lot the thermal model and management approach. Also, no full manual control for Behmor, no trier, no cooling...

In a word, Skywalker is the most complete machine you can get atm at this money and capacity.

Relating to the machine build... it is the same degree of technology and materials/toughness as a PC case.
The roaster weight is about 9-10kg, more of less, the total package weight was 12.4 kg, that includes the smoke filter, exhaust pipe, and a lot of cartoon.
There is no special insulating stuff on the internal side of the walls, because there is very little heat that escapes outside the drum, everything happens inside, the lamp and the beans.
A proof of this small heat leaks is the fact that the trier mount on the frontal panel has... plastic parts !!!

Back to surgery now... see you later Grin
renatoa attached the following file:
skywalker_coffee_roaster_p1-9.zip [2.95MB / 286 Downloads]

Edited by renatoa on 02/29/2024 3:46 AM
 
renatoa
Some raw pictures, until better light conditions are prepared.

The drum
renatoa attached the following image:
image_2023-11-24_161041544.png
 
renatoa
The front panel, with beans probe (left), trier hole (center), and the heater lamp, enclosed in a protective sheath
renatoa attached the following image:
whatsapp_image_2023-11-24_at_124801.jpeg
 
renatoa
The heater lamp, sheath removed
renatoa attached the following image:
whatsapp_image_2023-11-24_at_124802.jpeg
 
allenb
Wow, this is quite the development! I am so thrilled to see someone offer a radiant type roaster without the shortcomings of most of the other offerings to date. Namely, the lack of control during the crucial development stage which seems to plague most radiant-only heat source roasters.

Looking very much forward to hearing your critique of this roaster when you've had the chance to run it through its paces.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
renatoa
If you check the Auto mode video, will see that around 172C degrees power is reduced by 20% (70->50%), and air increased by 20% (65->85%).
No idea yet how is this decision triggered... typical for closed source machines... will try several roasts, without beans inside, to find if the trigger is BT or time, or...
Also, curious to find if this amount is the same for all the embedded profiles.

Will see if this amount is effective or needs further adjustments.
 
rustwood

Quote

allenb wrote:

Wow, this is quite the development! I am so thrilled to see someone offer a radiant type roaster without the shortcomings of most of the other offerings to date. Namely, the lack of control during the crucial development stage which seems to plague most radiant-only heat source roasters.

Looking very much forward to hearing your critique of this roaster when you've had the chance to run it through its paces.

+1 It certainly looks like it offers a lot for the money. I'd be interested to know how the results of the automatic profile compare to what one gets from a Behmor. If they are comparable, the additional capacity and control options would make this a very tempting upgrade for me.

Also, I found it on Ebay for ~$40 more "Electric Coffee Bean Roaster Drum Roaster W/ Smoke Filter 3 Baking Modes New"
Edited by rustwood on 11/25/2023 7:03 AM
 
Piotrkurak
Having a behmore.....AND getting used to the obscure Reverse Polish notation logic they use for their programmed roasts, anything else should be simpler. Hopefully you have a big supply of inexpensive test beans.

Annd, I am leary of smoke arrester claims. Neighborhood knows when I roast
 
HarryDog
I can't wait for the renatoa review!

I wanted a small drum roaster, might make me a great Christmas gift!
 
renatoa
I can't compare results with a Behmor, because there isn't any in my local community.

What additional capacity? :confused:
Both are in a class we can define as "close to one pound"

The Automatic... (for the people Grin ) mode is ... well... not so smart.
Spent today a lot of time trying to decipher its logic and it seems there aren't algorithms involved, simply some lookup tables with parameters (presets), and that's all... Nothing variable according to roast progress, trying to compensate for an unexpected derailing from an hypothetical profile following, etc.
For example, preheat temp is 200C for naturals, 220C for washed, and 215 for honey. Fan is zero during preheat.
The process is on-off, no PID, with some serious overshot at first preheat, about 10C over target, then small 1-2 degrees oscillations.

Next, when pressing Roast, the heater is set to 65% for naturals and honey, and 70% for washed. Fan is 65% for all.
When temperature reach 170C parameters are changed to 40% heater and 90% fan for naturals, or 50% htr 80% fan for washed.
Finally, there is a preset drop temp for each processing... for naturals at 196C for example.

For two roasts today, different origins, one having FC at 191C and the other at 184, you can guess the result: very different development times, 40 seconds vs 2 minutes... but both were ok, withing the boundaries of the medium roast range.
So everything boils down to how well your particular beans match one of the nine Auto presets...

The above are important if your main interest is into fully automatic unattended roast mode usefulness.
For the rest there is the Assist mode, where you can decide the development outcome, or the full manual mode, where you have the freedom to drive any way you like, even off-road smile
Edited by renatoa on 11/25/2023 11:58 AM
 
renatoa

Quote

Piotrkurak wrote:

Having a behmore.....AND getting used to the obscure Reverse Polish notation logic they use for their programmed roasts, anything else should be simpler. Hopefully you have a big supply of inexpensive test beans.

Annd, I am leary of smoke arrester claims. Neighborhood knows when I roast


Reverse Polish, lol... you remember of my youthness Grin

Smoke filter looks like using an oven hood technology/cloth, and atm I can't tell you how effective it is because I roast light, without smoke, as natural as breathing smile
But I should confess that smell is still there... even if smoke is less visible, smell can't be stopped by a cloth.
Also, when drop... you can't keep the genius inside, while the beans are going out...
Edited by renatoa on 11/25/2023 12:06 PM
 
renatoa
What about a look inside the rabbit hole ? Grin



LE: the concrete mixer noise you hear in the video is due to automatic gain control of the microphone, pushing recording gain to the maximum, because recording done in absolute silence.
The real noise during preheat is absolutely reasonable, comparable with a copier/printer for example. 64 dB +/-
Edited by renatoa on 11/25/2023 2:20 PM
 
HarryDog
Is the control panel responsive enough for good/easy enough manual control?
 
Piotrkurak
On the behmor, running dry process Ethiopian beans, the chaff resting on the heat tubes typically catches fire the moment the cooling process starts and there is more oxygen inside the roast chamber. Lots of starbucks coffee smell smoke that sets off the fire detector in the attached garage.

Renatoa's description so far sounds like a vertical modified behmor.
 
renatoa

Quote

HarryDog wrote:

Is the control panel responsive enough for good/easy enough manual control?


Yes, flat touch capacitive membrane, no clicks, no wear.
 
renatoa

Quote

Piotrkurak wrote:

On the behmor, running dry process Ethiopian beans, the chaff resting on the heat tubes typically catches fire the moment the cooling process starts and there is more oxygen inside the roast chamber. Lots of starbucks coffee smell smoke that sets off the fire detector in the attached garage.

Renatoa's description so far sounds like a vertical modified behmor.


Vertical what ? Drum is horizontal, heater tube too... :confused:

Nothing common to these machines, other than using IR. And roasting coffee smile
- the heater is inside drum not outside, big difference.
- the heater is wrapped in a tin sheath, probably to protect it from chaff, or stuck beans
- the drum is perforated tin, not expanded tin mesh like Behmor.
The drum perforations have long razor sharp edges, probably to ease the chaff peeling.
- when chaff pass through such perforation, the only way is drop in the chaff tray, because there is no airflow path or reason that could push it back into drum, or the heat tube area.

The chaff has a honey... or lager beer blonde Grin color, no excessive browning, to signal any burning.
Edited by renatoa on 11/26/2023 9:10 AM
 
renatoa
As stated in the introductory post, atm the closest machine on the market, as build and thermal model, is Sandbox R2.
Edited by renatoa on 11/26/2023 2:49 AM
 
HarryDog
I'm sure you are roasting and testing but if you have any shots of the motor and drive train I would love to see those.
 
rustwood
Thanks for the info. I only use my Behmor in manual mode and I'd use this the same. I just thought that might be a good starting place for comparing them given that there are so many potential variables. Based on the profile info in the manual, I suspect the Behmor automatic modes aren't smart either.

While the Behmor is rated at 1 lb, the consensus seems to be that the practical roasting capacity is closer to 250 grams (I go with 200). The specs for this unit say "350-400g (best)". I'd be interested to know if that seems accurate given that the heating elements in both units are around 1000 watts. Of course this design could be more efficient.

Unlike the Behmor, this has independent power and fan control, plus much easier bean loading and unloading. It would also be nice to be able to pull out a sample of the beans during a roast. I use my Behmor half-out of my garage because it is far from smoke free, but I'd be tempted to try venting this unit into my range hood.

I didn't see anything in the instructions about waiting between roasts. Behmor says I should wait an hour between roasts, but I usually cool it down for 10-15 minutes and then run another batch. That may not be good for the longevity of my roaster though.
 
renatoa
All my tests were and will be done using 250 grams.

Skywalker looks overpowered imo, because the power and beans are packed so close together.
But not overpowered in the wrong sense, as over-burning the beans/chaff, and not capable of light roasts...conversely.
If understanding her well, and driven accordingly, I think it's a machine capable to perform the whole range of roasts.

An example of overpowered meaning... when empty, preheated at 220C, then started a simulated roast (empty) with power reduced at 50%, the 250 C limit is reached in less than a minute, entering into error E2 = over temp protection.
For my custom built machine 50% barely reach 220C degrees after 10 minutes, and I need to push it into 70% ballpark, to reach 250C.

Back to Skywalker... non-empty figures: loaded with 250g of greens, using natural, the least powerful profile, that starts preheated at 200C, with 65% power, then reduced to 40% at 170C FC, FC happens in the 6:40 ballpark.

I can't imagine what kind of roasts could result when using the washed program, with 70% starting power, reduced to 50% at 170C... making Starbucks envious probably smile

For further tests I plan to try full manual mode, starting with a more reasonable 180C charge temperature, and lower power levels, in the 50-60% ballpark.

You are right about wait times, nothing mentioned. Probably they rely on the 3 minutes beans cooling time, to cool enough the machine too.
However, the way how cooling tray is built, as a tin perforated tray into another plastic tray, allows extraction of the beans immediately after drop, moving them to a separate cooling unit, and performing back to back roasts.
For how long... try on each own risk... as already stated, there are parts of front panel made entirely of plastic!
Probably a heat resistant plastic, I guess... because it's only a millimetre steel plate between that plastic and the hot air inside oven !
Edited by renatoa on 11/26/2023 9:46 AM
 
Mike_Mathis
I'm thinking this roaster may use NIR (Near InfraRed). Here is something I found on this technology. The entire video is interesting but skip to about 8:30 for how it may apply to this roaster.


Edited by renatoa on 11/27/2023 10:56 AM
*Fresh Roast SR800 w/ext tube Phidgets & Artisan
*Kaffelogic Nano 7
*Skywalker V1 (heavily modded)
*2023 BC-2
 
renatoa
Yep, NIR is when we see red incandescent, so it's a visible source of heat.
Near meaning as "the closest to visible spectrum of light".
NIR produces superficial heat, not penetrating too deep the tissues.
By contrast, F(ar)IR is not visible, but produce heat, as those radiant panels used to heat homes.
The FIR sources aren't incandescent or glowing, but we feel their heat effect deeper under the skin than NIR.

Another roasters using this kind of heating: Ceroffee CRF-800, Sanbox R2, or the discontinued model, the veteran DigiRosto 1500

NIR is used for cooking for millenniums, the most known principle being the rotisserie oven, the great classic here being the Shawarma/kebab vertical model.

Do not mismatch IR burners, as those used in Diedrich rosters to heat the drum, with direct to bean IR radiation.
 
HarryDog
I was thinking of trying a vertical BBQ Grill like the rotisserie oven just to see what it could do. I never got around to buying one to try. Cheap ones are around 1100 watts and I didn't think that was enough heat but placing it in the inside of the drum might work.
 
Mike_Mathis
I just bought one of these. I couldn't resist the ridiculously low price. As I stated in a thread on Reddit, I have plans to get a Kaldi New Wide with the chaff collector/cooler. The price of this roaster is almost exactly what just the bean cooler/chaff collector costs. This is at the least a temporary detour. At best, it will satisfy me for a while. cross fingers
*Fresh Roast SR800 w/ext tube Phidgets & Artisan
*Kaffelogic Nano 7
*Skywalker V1 (heavily modded)
*2023 BC-2
 
HarryDog
I was told 11 day lead time before shipment? Backlog or made to order?
The other store must have stock... delivery is 12 days earlier last I checked.
Edited by HarryDog on 11/29/2023 9:24 AM
 
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