Cleaning the sensor on the bullet R1

OK - I am at the point where I need to clean sensor. I have seen a video or two about how to take the face plate off, but am a little nervous because my face plate looks a bit different. Also, how do I put the drum back into place properly.

Any and all tips, suggestions and guidance are much appreciated.

It’s not a big deal but you won’t believe that till you’ve done it once or twice.

Provide a support for the face plate while it is removed from the roaster body. The wires between the roaster and the face plate have no connector. Conveniently the measuring cups I use to hold the greens I’m about to roast are just the right height to rest the face plate and take the strain off the wiring. It’s a bit of a balancing act. Even a small card board box might do the trick.

The drum requires a little attention to keep track of the spacers set on the front of the drum shaft. There are likely one or more spacers on the end of the drum shaft. That shaft seats into the ball bearing mounted in the rear of the face plate. The spacers keep the drum from moving forward too far. The spacers look like washers but they have been carefully measured for thickness. These spacers set the clearance between the drum and the face plate:

  • too little clearance and the drum will rub the face plate;
  • too much clearance and beans will drop between the drum and the face plate where they will lodge in the insulated shell that surrounds the drum.

The point is to pay attention to the spacers and to keep together so that they all end up back on the end of the drum shaft when you reassemble the Bullet.

Clean the IBTS with alcohol and cotton swabs (I use Q-Tips). Wipe the inside of the rubber view port first to clean the smut that has accumulated there. Don’t make the mistake of re-wetting the swab tip after any contact with the roaster- pitch it and use a lean one.

After cleaning the inside of the view port then go after the IR sensor. The front surface of the sensor looks like clear glass (I’m not sure what the material is). I go thru at least a couple swabs (dipped in alcohol) to be sure it’s clean.

Cleaning the sensor is not very satisfying: I have yet to see anything on the swab after cleaning. But I can assure you there will be a difference in the spacing between the IBTS curve of a roast profile and the BT curve… they will move apart a small amount. It’s most noticeable at the end of a dark roast.

Btw, alcohol does not dissolve the coffee smut… at best it softens it. So I repeat the sensor cleaning steps several times. F/w version 606 uses a setting of F1 during Preheat to help minimize the accumulation of ‘stuff’ on the IR sensor and I think it has made a positive difference. Ymmv.

That leaves the thing I actually do first and that’s to clean the inside surface of the face plate. Lots of personal preferences pop up for that step but I think Simple Green does an OK job. They make 2 versions, one stronger than the other. The stronger version may be necessary for stubborn smut- the coffee oils pretty much weld themselves to the face plate and require some persistence. Suppress the temptation to use abrasive cleaning pads! Wear gloves- I keep a box of ‘surgical gloves’ handy for the purpose. Simple Green isn’t too bad. The amount of time exposed to the citric acid determines the damage to your skin. Some folks are more sensitive than others. The gloves are a cheap precaution.

Think about taking photos as you progress and to reassure yourself you are reassembling correctly.

And to repeat myself- be careful to support the face plate as you clean- letting it dangle by the wires is inviting a failure.


Edit- I don’t think I’ve ever found anything that needs cleaning on the drum. The face plate and the IBTS (the IR sensor) is what needs attention. Messing with the drum risks damaging the ‘seasoning’ you did initially.

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And from hard won recent experience, just plug it in turn it on and make sure everything’s aligned and running correctly before you put it away after the cleaning. It will make your next roast much easier!

Thank you for the responses! I appreciate the assistance and look “forward” to my first attempt at cleaning the sensors. Taking pictures along the way is a great idea. However, I am a little spooked about the spacers and will be doubly sure to be cautious.