Goal: A Huky 500 with digital controls and display

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
Robert_S

#1: Post by Robert_S »

I have been lurking around here a while as I am curious about home roasting. The forums have been a great help with a lot of good info, thanks!!

I started looking at coffee roasting to save money and decided to get serious about it as a distraction during this pandemic lock down. :) I first looked at entry level consumer roasters though I wanted more control on the roast from the info I read in these forums. I also took a basic roasting class and learned a ton about roasters and what is helpful to get a great roast. I next looked at pro-sumer/commercial 1lb roasters and they cost a fortune, plus many still had basic mechanical buttons and not-so-pretty PID displays/controllers.

Since this pandemic is lasting months... I thought it would be fun to try to build a fully digital home roaster as a DIY project. I want full digital controls and display - all the temps, gas, fan, cooling, etc. My other goal is to get as commercial-level as possible in a DIY fashion at the lowest cost. I decided to start with a bare-bones Huky 500 - Shell, drum, bean fan, no probes, etc and will build up from there.

The roaster's 'brain' is a Raspberry Pi + 7" Touchscreen display with an assortment of Phidgets to run the gear. I finished the software portion and here is a current view of the UI:



I am moving on to the enclosure, gas system, chaff collector, mounting, etc. More to come and I will certainly have questions for the forum as I run into obstacles. :)

User avatar
Chert
Supporter ♡

#2: Post by Chert »

In making an idealized version of the Huky, why include the original fan setup? It is a slow down - quite significant - as one must remove the chaff frequently and the plastic blades of the fan are exposed to a level of heat that shortens their lifespan.
LMWDP #198

User avatar
Brewzologist
Supporter ♡

#3: Post by Brewzologist »

Having done much of what you are embarking on to my Huky, I recommend you use Artisan as your software platform. It already has the functionality you seek and will need to roast with. Unless of course part of the fun for you is in writing the software.

User avatar
hankua
Supporter ♡

#4: Post by hankua »

Sounds like a fun project, not sure the Huky platform is the best candidate; if you have one already great. The DIY platform would be an easier one or choice as the owner is a serious DIY roaster builder in Taiwan; take a look at his blog and you'll see. http://www.cafecreator.com/433304584

Jrodanapolis

#5: Post by Jrodanapolis »

Sounds like an awesome project! I'll be looking forward to the results. The Huky is a fun roaster for those who like to tinker. I've enjoyed working on mine to get it to the point it is today. Nowhere near digital controls and display, but Flint hit the nail on the head - I think finding a chaff collection solution should be high on your priority list. It used to kill my flow to have to take it down to dump the chaff, and cleaning the plastic fan blades is not fun.
Several of us have tried solutions - some take time, but exactly as you said, this was one of my quarantine projects to keep me distracted. I got a huge chaff collector for free from an HB member, but there are a lot of cyclones out there that you could mess around with to work with the Huky. I had to build my table around the chaff collector since it was so big, but it works like a charm now and roasting is much more enjoyable. Here's a great thread on some people's solution to a chaff collection system: Cyclone Chaff Collector and Fan Setup -Huky 500
Keep us posted on your progress!

Robert_S

#6: Post by Robert_S »

Chert wrote:In making an idealized version of the Huky, why include the original fan setup? It is a slow down - quite significant - as one must remove the chaff frequently and the plastic blades of the fan are exposed to a level of heat that shortens their lifespan.
I am only using the original Huky bean fan for the cooling tray. I learned from these forums that a separate chaff collector was certainly necessary and I also read through the chaff topic with all the different options people have. I had Mr. Li extend the T-pipe so it would reach the chaff collector. I will post on this thread my current idea on the chaff collector.
Brewzologist wrote:...I recommend you use Artisan as your software platform. It already has the functionality you seek and will need to roast with. Unless of course part of the fun for you is in writing the software.
Thanks for this. I am planning to use Artisan to graph the roast profiles in the short term. Indeed part of the fun was writing the UI, so all good. At some point in the future I will look at having Artisan control the entire roast start to finish.
hankua wrote:...The DIY platform would be an easier one or choice as the owner is a serious DIY roaster builder in Taiwan; take a look at his blog and you'll see. http://www.cafecreator.com/433304584
I saw those DIY Cafe Creator options as well, very cool. They were my second choice. I decided to go with the Huky as it looks fantastic, had the bare minimum I need, and at a good price point.

Some construction pics. This is the enclosure I am using. I already cut a rectangle hole in the top for the burner and also the mounting holes for the Huky.



This is the gas system. Most of it will be inside the case except the gauge and ball valve.



The cooling tray (ie. flour sifter) that comes with the Huky sat on the fan top and I wanted a more secure and sturdy setup. I could not find a perfect container for the stock cooling tray, but I finally found a container that fits the fan and another flour sifter that has a bottom lip that fits perfectly in the container. Cooling goes straight down (table overhang intended):




User avatar
Chert
Supporter ♡

#7: Post by Chert »

Is the solenoid looking some kind of valve or a gauge for the gas? and what is the next distal piece of sliver metal ?
LMWDP #198

Robert_S

#8: Post by Robert_S »

Chaff Collector Concept

Reading a lot of posts I know this was a must-have and I wanted to have a cyclone design with a removable chaff container. I saw some of the ones on the other DIY collectors on the above referenced thread and they were very helpful. I checked Ali Express and shops out of Taiwan but I could not find a metal one at a reasonable price w/shipping. I started trolling bath and kitchen supply sites and found a combo which seems like it may work:
  • 8" metal trash can
  • 8" cake pan (heavy gauge), fits perfectly over trash can
  • Stainless lunch container (collector!)
Here is the concept:



I plan to cut a hole in the top to drop the fan and extend a 4" duct halfway down the trash can. I am going for an 'inside' cyclone and used some HVAC duct material to create a cone inside the can that dumps to the smaller opening at the bottom. Rough idea below, not the final assembly:



The bottom container (lunch container) screws off. The contraption will be mounted high enough to leave room to unscrew the container.

I am trying to find the best technique to cut a 1.5" circular hole on the left side/edge of a cylinder. Any suggestions? This seems like a really tough cut without a hole saw sliding off the intended cut path.

Robert_S

#9: Post by Robert_S »

Chert wrote:Is the solenoid looking some kind of valve or a gauge for the gas? and what is the next distal piece of sliver metal ?
The solenoid is a 12V on/off control so I can turn the gas flow on via a phidget relay. The next item is a standard needle valve where I cut off the thumbscrew and have attached a coupler that will attach to a stepper motor to change the position of the valve via software. There is also a hot surface ignitor on the burner with flame off detector that I can turn on via a phidget relay as well. Thus the 'Gas On' switch will turn on the ignitor and open the solenoid. The % slider on the UI controls the stepper motor position.

I needed the low pressure gas analog gauge as the needle valve is not linear in terms of gas flow to turns. Thus, I have to create a calibration curve of gas percentage from 5% to 100% using the gauge as a reference while I set the stepper motor position and lock in the correct position for each %.

User avatar
Chert
Supporter ♡

#10: Post by Chert »

Excellent. I think the stepper motor is feasible. Gas control valves flummoxed me. My needle valve requires a fair bit of torque to position. I know this method has been done. Are you aware of stepper motor roasting controls functioning well. I have seen posts just not followed to the point of knowing if the roasters got that type control all the way through to reliable software level control.
LMWDP #198