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Post By Andy
Dalian Amazon coffee roaster modifications
Hi all, just wanted to reach out to fellow home roasters that have an electrical engineering background. I recently purchased a Dalian Amazon DL-A721-S coffee roaster, and while it works well, there is very little temperature control or recording offered. What I am hoping to do is modify this roaster with some type of control box. Does anyone have the required skill set to assist? Thank you
To give us a starting position, what are your qualifications and experience mate?
Hi Mal, sorry if I caused any confusion but I actually dont have any experience as a electrical engineer. I was hopeful that someone out there might be able to support with some advise. My assumption is that this type of person would have an electrical engineering background - or something similar.
I wouldn't recommend doing any kind of electrical modifications with advice via remote comm's for a complex piece of equipment.
Try to find a friendly Industrial/Commercial electrician in your neighbourhood along with a promise of wonderful, freshly roasted coffee to follow. Has worked for me in the past for small one-off machining jobs, etc...
Mal, I get the feeling FC was looking for a local snob appropriately qualified who might have an understanding of the appropriate mods without FC having to explain what they are - because as he freely admits he doesn't know what they are! FC google arduino and someone appropriately qualified with some coffee mods for that may be able to help, gives you a starting point.
I totally agree, not something for the inexperienced to do by remote instruction.
You already have a HeatSnob so you can see what you are doing (if you install it on this roaster).
On a lot of drum roasters you can remove one of the screws in the sight-glass and screw the thermocouple in there.
That sorts the "what's going on" part of roasting.
As for control... it's tough controlling an electric roaster of that volume as you make a change and it takes a long time to react. You might find it easier to control manually via the flue butterfly... venting hot air out of the roasters at different times through the profile should give you most of the control you need.
You can even save the "open 100%" "open 50%" type tags into a template profile to load-up into roast monitor and then manually change the air at those points.
PS: Get a sparkie to check the wiring before you use it. A lot of the Chinese roasters are well under spec and have dangerously light wiring inside the control boxes.
I added power control to my roaster, not the same model as yours. I used a United Automation PSR-25 like this one https://au.rs-online.com/web/p/thyri...blies/0841924/
You will need a matching filter from the same manufacturer, a fuse holder, fuse, variable resistor and heatsink. Some wire and crimps to join all the bits together. The data sheet contains all the information you need, including a wiring diagram. Check your available space because the filter is larger than the controller.
Last edited by upl8; 4th January 2018 at 08:03 PM.
I looked up the Amazon and found some videos of it on youtube. Very nice machine :-)
I would suggest just to get a Coffee Snobs thermocouple and multimeter and paired with the CS software that will set you up with temperature monitoring and recording. Some of the youtube videos even show a thermocouple inserted just above the sample extractor. This way you won't need to do any modifications. Just adjust the power manually to follow a roast profile.
Mike, if you have a look at the end of this video, you can see the control panel for this roaster https://www.youtube.com/watch?v=oAlU8PN6-vk
It looks like the element(s) can only be turned on and off with one switch. The controller I mentioned above is not for automated control of the roaster. It lets you control the power sent to the elements. It transformed my roaster into a much better machine. I only had three power levels before (on and off for each element) and it was difficult to control the roast. Now I leave all the elements on and control the heat with a knob on the panel.