Saturday 30 January 2016

First play with the BitScope Micro

I picked up a BitScope Micro to teach myself a bit about oscilloscopes. So far I've only used the first analog channel to monitor the wave generator, but it seems to do what it says on the box:

The test leads aren't the best quality, but otherwise this looks like a useful tool. You can't expect it to be in the same league as the professional gear, but for the money it's great for learning.

Saturday 23 January 2016

Modifying the (Aldi) Lumina coffee grinder to produce a finer grind

I purchased one of the Lumina coffee grinders from Aldi a few years ago, but only just tried to use it for the first time recently. Even on the finest setting it was producing grinds that were very coarse. The product really should be marketed as a herb grinder in standard form.

As this machine uses burrs to do the grinding I thought I'd try shimming one of the burrs to bring the two closer together, hopefully resulting in a finer grind. This actually ended up working really well, and I've been using it at least three times a week for a few months now for all my coffee grinding duties!

Here's what you will need to do the modification:

  • Useless Lumina coffee grinder.
  • Suitably sized Phillips head driver (you'll want to make sure it is clean).
  • Three 8x1mm washers (again, make sure they are clean).

First of all you'll want to remove the top burr assembly, which you can do by turning it clockwise:

You can see the tabs that lock it into place here:

Once you've removed it, flip it upside down and you should be able to see three Phillips head screws, you'll want to remove these:

Lift the metal burr away from the rest of the plastic assembly and you will then be able to fit the three 8x1mm washers as per the picture:

As you can see this has shimmed the burr by 1mm:

Fit the burr back onto the assembly and fasten the screws, don't go overboard with force though as they are just screwing into plastic.

Adjust the machine to the coarse setting and insert the top burr assembly, lock it into place by turning anti-clockwise.

Test out some grinding!

Fluke 17B+ multimeter review

This is just a quick and honest review of my Fluke 17B+ multimeter.


  • Excellent build quality and decent/safe input protection.
  • Nice large screen with good backlight.
  • Continuity tester seems fairly fast and the latching works well.
  • Has a diode tester, frequency, thermistor input and can measure in the microamp range.


  • Hold function is not Fluke's auto hold (as you would get on the 87V), it simply freezes the current display.
  • Only 4000 count with 0.5% +3 accuracy (DC volts).
  • Not a true RMS meter.

The included TL75 test leads seem sufficient and seem to be of a reasonable quality.

As a hobbyist, this multimeter should serve me well. If you need more precision or you do AC measurements you might want to consider something like the Brymen BM257S.

I had assumed the 17B+ would have featured auto hold, so I was a bit disappointed about that (in fact it probably would have swayed me toward the BM257S) but I'm certainly not disappointed in the overall product.