The hurdles of fixing a puncture in a Xiaomi M365 scooter

I can say that I am pretty seasoned at fixing bicycle tires. It dates back to my childhood, where numerous times I had to fix the punctures by patching the inner tubes. I still remember the patching kits featuring an assortment of patches of different sizes and shapes, sanding paper, and the rubber cement.

Never had much trouble in separating the tire from the rim, and putting it back together, after having fixed the puncture. The same applies for fixing the tires of more recent MTBs, where upon following the usual technique no major obstacle arises in accomplishing these tasks.

But now, just after a bit over 100 Km into using my Xiaomi M365 scooter, I found a rattling noise in the front tire while riding it. Went on to take a look, and found a thumb tack, fully buried in the tire. As I started removing it, I could hear the air escaping. Decided to leave it there just so that I could ride the scooter back home.

Dealing with dishwasher failures

Albeit 10 years of flawless operation can be considered quite good for a home appliance, still when it finally fails, there is the brief criticizing thought of "why didn't it last longer? Bloody programmed obsolescence in modern industry!" ..and so on and so forth.

Well, the truth be said, 10 years of operation without a single glitch is either a product of sheer luck (i.e. one golden batch in the production line), or the brand really went serious with quality and the strategy at the time didn't include the need for recovering the same consumer soon in the product life cycle.

I can say this from the Whirlpool dishwasher model ADP 6837/1 that I have been using since 2009. During 10 years it never complained, while we threw dirty dishes at it on a daily basis.

Once again bumping into questionable product safety standards

About 6 months ago, I replaced the manual plastic pump I used to have for dispensing water from 5+ litre jugs, with what would in principle be a more sophisticated and convenient approach: looked for an electric water dispenser, and without much searching, found several options. Most, if not all were unfortunately designed to fit into the 19 litre office water bottles. Without any alternative, ordered one of these, considering that I would have to come up with some custom adaptation if I wanted to use it with the 5 litre bottles. Ended up ordering the one below, for its minimally elegant design and compact dimensions:

Adding metalurgical capability to a biological microscope - part 2

Like I had previously explained, I was able to obtain from eBay (for a minimally decent cost), just the bare vertical illuminator, which didn't include any accessories. The light house was not an exception. The vertical illuminator consists the main body:

and the light house, which in the original device would be based on a halogen bulb of at least 15-20 Watts:

Adding metalurgical capability to a biological microscope - part 1

Biological microscopes among a few other things, are characterized by the fact that rely on transmitted light rather than reflected light, to produce an image of the specimen.This is adequate for most biological needs because the specimen can either be made thin enough for light to go through, or the medium and/or the specimen itself is relatively transparent to light.

However there are other applications in microscopy where it cannot be assumed that the specimen is transparent or able to be ground to a thickness small enough for light to traverse it. Some materials are opaque even at thicknesses of few microns.

The only solution in these cases is to rely on reflected light. For this to be possible, a different illumination system is required on a microscope. This type of illumination is commonly designated of epi-illumination (as opposed to trans-illumination used for biological observations). This is where a device known as vertical illuminator comes into play (picture obtained from a Olympus BHM manual):

Reconditioning a 50+ year old microscope - part 3 - LED conversion

The microscope came with what I believe it must have been the original illumination system:

• a 30 Watt / 110 Volts tungsten bulb (in this case a GE branded one):

Reconditioning a 50+ year old microscope - part 2 - XY specimen stage mechanism lubrication

Like pretty much every moving part in this microscope, the XY specimen stage mechanism also suffered from dried/sticky grease, preventing the X axis from moving at all. As such like in the previous case, the only solution was to tear it down, clean it and apply new grease and oil.

The separation of the mechanism from the stage is simple: in the bottom of the geared side (where the knobs are) this forelock is moved as shown in the picture, and by moving the Y axis to the end of its travel range, the mechanism is removed:

Reconditioning a 50+ year old microscope - part 1 - Fine Focus recovery

I thought of giving my daughter a toy microscope, to let her know of some of the things that exist but go beyond what the eyes can see. But from searching in toy stores, I could not find any product that seemed to inspire proper optical quality. Some products seemed both expensive and very basic at the same time. Some products averaged 50 Euros retail, VAT included.

So I tried to take a look at what eBay had to offer. I quickly turned my attention to real lab grade microscopes. Some were obviously very expensive, but a very wide range of offer in price/age/condition could be found. After some extensive browsing, I managed to calibrate my price expectations and define a budget. My reasoning was that given I had a initial intention of buying a 50 Euro toy microscope, now that I was looking at real lab grade microscopes, I should at least relax my budget to be double that value. I even considered going beyond that, if I found an item that I could see, decide and obtain locally (decreased risk).

Reflashing a quad ESC to BLHELI firmware in an attempt to solve pancake motor cogging issues

Ever since I've switched motors and ESC's on my "primary" quadcopter, I have been running on problems keeping it reliable. Every now and then it would crash, once because of a motor connection that got broken, and other times in a unpredictable manner without  a cause that I could identify.

Improved quadcopter - more "avionics" and increased run time

In the several weeks that followed a crash caused by an ESC failure, plenty of work have taken place (some of which documented here). Several things have been done since:

• Replacement of the ESCs with a 30 Amp quad ESC;
• Upgrade of the flight controller firmware;
• Building and programming the PPM Sum encoder;
• Building a BEC/filter with 12 V and 5 V outputs;
• Adding landing gear;
• Adding voltage and current sensor;
• OSD firmware upgrade;
• Change of LiPO battery from 11.1 V (3S) to 14.8 V (4S);

Induction Stove

Some days ago my father asked me to check if I could repair this single element induction stove. I disassembled the device to inspect its inner workings. I was a bit curious because I have never taken apart this kind of apparatus.

Modded for long range and glitch free communication

After assembling my quadcopter, one major issue I stumbled upon was the (lack of) quality of my radio system.