Jacken's Computer and Electronics Blog
I’ve recently got interested in RF radio. But I live in an apartment, so I can’t do any installing of large antennas. So after doing the obligatory Google search, I narrowed it down to two antennas. The Wellbrook Loop Antenna and the (much cheaper) PA0RDT Mini-Whip. Being short of cash, I decided to buy a cheap Mini-Whip from eBay.
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I’ve been busy the last couple of weeks, learning all the ins and outs of my new Cetus3D 3D-printer. It’s a cheap printer for around $300, but it has linear rails and can give excellent results. Unfortunately, the calibration quality from the factory was terrible, which is unfortunate on such a superb printer.
My Y-axis was way out. If I zeroed out the nozzle on the left side, the right side was 2.0 lower. There is a calibration feature inside the program, but you need to always print with a raft to get your prints level, with the accompanied wastage of PLA plastic. But I finally found an easy way of fixing the Y-axis adjustment. Here’s how I did it.
After finally getting my Cetus3D MkII 3D-printer I was eager to start to print. When I started through the steps to calibrate the printer by adjusting the build plate height, but the print head/nozzle refused to get close enough to the build plate to finish the calibration! The cables on the motor came in contact with the chassis of the printer! So the injector was 5mm from the build plate and couldn’t get any closer by increasing the step values. But there is an easy fix for the problem.
ITEAD contacted me about testing some new equipment and write an unbiased blog post about it. I usually reject all such offers, but this one worked for me. Why? Well, all the stuff they offered was on my shopping list anyway! And my home is quite literally chock full of Sonoff relays, lamps, etc.
So the first thing I started to play with was the SONOFF RF BRIDGE 433. The bridge makes it possible to control switches, doorbells, curtain openers, etc. that uses 433MHz communication frequency. I’m not interested in using the original firmware because I prefer to do my home automation setup in Node-RED. Here’s how it works.
Over the years I’ve been reading about a way of restoring old computers and other equipment where the plastic has turned yellow and how some bright guys developed a method called Retr0bright to reverse the process.
The reason for the yellowing of the plastic is the flame retardant bromide that is infused in the plastic to prevent fires. When exposed to UV-light, the bromide comes to the surface of the ABS plastic, and the yellowing begins.
Unfortunately, even after treating the item with Retr0bright, the yellowing returns after 3-4 years, looking worse than your grandfather’s underwear.
Here’s my attempt at a fix to that problem.