New beta firmware 507 released

This firmware is compatible with all new V2 Bullets with the new more powerful induction module.

It also adds experimental support for calibrated exhaust fan speeds because we have seen that the RPM can vary a bit from bullet to bullet. We want this to be more consistent so this update is the first step towards this.

In general the new calibrations will lower the RPM and makes the steps smaller between each setting so it is easier to control the airflow. You will still be able to run full fan speed. It is possible to disable this feature in the menu option and use the old type of RPM control.

To give it a go do the following:

  1. Take off your chaff collector
  2. Turn on the Bullet and go to the menu section 6 by clicking F1 until the clock LED shows 6.
  3. Press the “A” button (top left button) If no calibration has been done this should start the process.
  4. Start the calibration process by clicking both fan Up and Down buttons at the same time.
    Now the calibrations starts and this can take about 5 minutes to complete. When it is finished the bullet will beep for two seconds.
  5. You can now toggle between un-calibrated or calibrated fan speeds by clicking the “A” button in menu 6. 3 dashes - - - is un-calibrated and P-b means calibrated.
  6. Put the chaff collector back and try to roast some hopefully great coffee.

So, if I have a profile that uses F4, for instance, it would need to use a higher “calibrated” setting to get the same air movement?

If that’s true, can you give us the conversion factor or function? Even a table would work. Without that, its simply more guesswork.

Is this just for V2 ?

We will try add the RPM to RT2 for the next release.

No this is for all bullets.

The only downside to this is not being able to blow off the chaff at the end of a roast. I assume toggling back and forth is only possible in between roasts.

I may try this as I’ve seen the step size for the fan is pretty large for 1# batches.

You will still be able to run full speed of the fans, no problem, the steppings will just start at lower speeds, be more linear and be more comparable between bullets.

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Can you give us a rough idea of the RPM we have been getting for each fan setting in the old system? That would give us a starting point for setting the fan in a reasonable way, using the new flexibility you’re providing.

I’ll start you off:
F0 = 0 RPM
F1 = ?
F2 = ?
F3 = ?
F4 = ?
F5 = ?
F6 = ?
F7 = ?
F8 = ?
F9 = ?

I’ve filled in what I can. Your turn.

I can give you mine, but as I said it will vary a lot from bullet to bullet.
The idea now is to calibrate without chaff collector but in the future I will make a PI controller to keep a constant RPM.

Thanks! I realize that it’s not perfectly accurate for MY Bullet, but it’s a place to start. Without this sort of info, all our old roast plots are useless and guaranteed to replay incorrectly. Now, we know about how to tweak them.

Next, we need a way to tweak them with an editor, rather than recording a new profile. :wink:

That is all about to be reality in a weeks time!

What the importance of having the Chaff Collector removed in the setup (original post) and why would we be looking at (or recording) fan measurement data with the CC off? I can see that it has an affect upon the fan RPMs, but since the CC has to be installed, I didn’t understand why it would be off/removed for this new Firmware release.

You only need to remove the chaff collector to run the calibration routine. After it’s calibrated, you reinstall and roast as usual, but your fan RPM will be different.

Thanks. I didn’t understand why we were calibrating the fan with the Chaff Collector removed. I was thinking it made more sense to calibrate with an in-use configuration to represent the real-world air restriction via the CC on the fan.

Since updating the firmware to 507 my drum speed always resets to D9 each roast even if doing back to back and changing to D8. Expected or undocumented feature ?

Jacob, perhaps stupid question: how do I determine weather I have a V1 or V2 bullet?

It will use the default drum speed that you set in the menu at the beginning of every roast.

Not a bad question. V2 only launched a week ago. V1.5 and V1 maybe it is written on your invoice?
Otherwise send an email with your serial number.

I have some questions since the Exhaust Fan (that is being affected by this change) serves (2) purposes. It provides air-flow/exhaust to the Drum (for roasting) and pulls Chaff from the Drum to the Collector via the same fan. The RPM differences between Old and New (with the Chaff Collector “on”) have been decreased significantly, especially for the F1-F5 ranges.

My question is will that have an impact upon removing chaff from the drum? Would we be now balancing air flow to effectively remove chaff versus drum air flow that affects the roast? is there a minimum Fan RPM to effectively move chaff from the Drum to the Collector?