This article will explain how to teardown a FreshRoast SR500 roaster and probably an SR300 as well. If you are looking to modify an SR500 the following content will be useful as well. It will include technical information about the components that make the SR500 work and suggestions of where modifications will need to take place if you wish to split fan and heater control to external dimmers, VARIAC devices, or otherwise control your SR500 with a Microchip PIC, Arduino, or other microcontroller or PID controller device.
Now that I’ve finally obtained a spare SR500 base I’m a little more comfortable with tearing down the roaster to see what is inside. This process has confirmed my initial memory of the roaster being simple to open up.
On SweetMarias’ forum there was a question by a user that I replied to about how to open the SR500 to clean it. I made reference to the FreshRoast SR500 being pretty easy to open up to clean it out inside if you felt it had clogged in any way but did not have the ability to just pop one open nor did I have enough notes about it. The user managed to clean his through the holes in the roaster using compressed air through the various openings due to having difficulty removing the screws and getting the bottom off. I suspect he missed taking out the screws in the middle labeled as 7 and 8 below.
This article will be the first part explaining how to teardown a SR500 roaster and probably a SR300 as well. If you are looking to modify an SR500 the later parts will be much more useful though everyone will need to know how to open it up to do most things.
Opening a FreshRoast SR500 Coffee Roaster
You will need:
- A phillips screwdriver.
- A SR500 Base (SR300 may be similar except for changes to the microcontroller board)
- A baggie or small tray to hold screws
- A clean area to work
- Optional: Vacuum and/or compressed air to clean chaff from interior of the roaster base
Step 1: Unplug your SR500 from the wall.
There is serious electrical voltage at levels that can kill you inside the SR500. DO NOT OPEN THE ROASTER BECAUSE YOU WILL VOID YOUR WARRANTY AND YOU WILL GET ELECTROCUTED AND BURN DOWN YOUR HOUSE. (No really…)
Step 2: Place your SR500 base in a clean work area.
Remove the roast chamber, chaff collector, and lid so that all that is left is a base.
FreshRoast SR500 Base
SR500 Control Panel
Step 3: Since you apparently do not mind getting electrocuted, burning your house down, or voiding your warranty it’s not my fault if you continue further.
When you electrocute yourself and end up dead don’t come crying to me about it…. or haunting me either. I also don’t want to hear from your spouse, parents, kids, lawyer, or the fire department either. I will smudge stick , holy water, and exorcise this house at the drop of a hat should your “ghost” come to haunt me… don’t tempt me. By continuing further you have indicated your agreement that you are willing to get electrocuted at your own risk and void your warranty and risk burning your house down. You also agree that you will not haunt me afterwards because this is what you wanted to do at your own risk. Now that we have the formalities covered you may (if desired) continue to Step 4.
Step 4: Turn the roaster over.
FreshRoast SR500 Bottom
Step 5: Remove the 8 screws from the bottom.
FreshRoast SR500 Screws (8)
Numbered Screw positions for SR500 Roaster
Step 6: Loosen and remove the bottom plate.
The bottom plate should be VERY loose at this point and could simply fall off. In addition be aware the top ring of the roaster will be very loose now too.
FreshRoast SR500 Bottom Plate and Screws
Step 7: Bag up your loose screws so that you do not lose them.
Better to be safe than sorry. Store the loose screws in a tray or sandwich bag. There will be additional screws later if you remove the micro control board later. Also be aware
Step 8: Inspect the interior.
From top to bottom in the picture below you have AC Power cord entering the roaster base, power control board, blower fan in the middle as well as the heater assembly around the fan, and the main logic micro control board at the bottom.
To the right you have the fan potentiometer wiring leading from the round potentiometer leading to the right side of the power control board. On the left you have the main logic board wiring leading to the middle of the power control board. In the middle the blower fan and the heater have black and white wiring that lead to the power control board. Out of the side of the heater assembly are two small wires that are not visible in this photo. Those are the NTC sensor wiring.
FreshRoast SR500 Interior
Step 9: If you are interested in cleaning the roaster you certainly can do so now.
Compressed air and/or vacuuming can be done at this time. With a narrow crevice tool you can probably get access next to the motor in the middle. There are many small blades as part of the blower inside the black housing shown above. If you are more adventurous you will need to disassemble further and this will get you closer to the intake around the motor assembly.
Step 10: Further Disassembly.
If you are disassembling the roaster further you will need to remove the power board, the lower housing from the upper housing, and disconnect the “microcontroller board” from the power board. These will be explained in Part 2.