I've been tinkering for as long as I remember, in fact I think I may have learned to read a simple circuit diagram before I learned to read English! Reading and writing seemed daunting at infants school when I was first encouraged to learn, but then I discovered there were books about electricity in the local library! By the end of a weekend I was making strides, and in only a few weeks I'd read all the electricity books the children's section of the library.
That was back in the 1950's. At the time, my father used to take family portraits using photoflood lamps. These were ordinary tungsten bulbs but over-run in order to give a more intense light at the cost of a much shorter life. He had a piece of wood with two switches and two sockets on it (I can still picture it) with which he could switch two photofloods in series for modelling at his leisure without burning them out, or in parallel for full brightness to take a photo. The circuit diagram was one of the first I ever understood.
Having shown an interest in electricity I was given a few batteries, bulbs, switches and bits of wire to play with, and although in the course of time I graduated to valves and transistors, and later to integrated circuits and computers, I've never really stopped tinkering. Taking things apart has always been a fascination for me.
After (naturally) opting for sciences at school I went to university and studied electronic engineering. But in one Summer vac job I was given a piece of stripboard with 20 tracks per inch (rather than the more usual 10) and a bunch of early (DTL) integrated circuits to try and build a hybrid analogue/digital computer display. But after spending many frustrating hours trying to locate shorts and broken tracks, I decided software was much better behaved and was what I wanted to do, at least for a living. I'd already had some experience programming an early computer (the Elliott 803) at a local technical college, which I'd greatly enjoyed. So after completing my electronics degree I took the Computer Science Diploma at the famous Mathematical Laboratory (formerly, home of EDSAC) at Cambridge.
The first half (or more) of my career I spent in software development. I've always enjoyed programming though I have to admit that I'm very far from being a superstar coder. I particularly enjoyed my time as lead developer for a minicomputer kernel, especially a project where I enhanced it for a dual processor operation. This involved some fascinating hardware development for a conflict resolution module.
I spent the latter part of my career working in cybersecurity, which again I found interesting, and although I'm now retired, I still try to keep abreast of developments. I like to help people stay safe online, and where the opportunity arises, to consider cybersecurity as a fascinating, challenging and very well worthwhile career choice. (There's no shortage of jobs if you're any good, and the money's good, too!)
Since retiring at the end of 2013 I've been able to spend much more time tinkering, and this has included mentoring kids at a local school computer club, and volunteering with The Restart Project. In the latter we help people with their dead electrical and electronic goods, repairing them where we can and advising them where we can't. This has allowed me to tinker with and take apart all manner of gadgets, to write a number of iFixit repair guides, to answer questions on the Forum, and to record much of what I know and have learned in the Restart Wiki.
If you’re certain the solenoid is open circuit it should be relatively easy (if a little tedious) to rewind it. Ease out two or three of the iron laminations from the core. Then it should be possible to take the bobbin off the remaining laminations (or vice versa). Take off the yellow tape and unwind the windings. You’ll need to count the number of turns. (Yes, that’ll be a bit tedious.)
Measure the gauge of the wire - you’ll probably need a micrometer - and order some more. (Plenty of places online stock enamelled copper wire.) You can then rewind it by hand with the same number of turns, by hand unless you can rig up some sort of jig. The important thing is to add at east the same number of turns. 5% too many wouldn’t matter but try not to underestimate. Make sure you remove the enamel from the ends of the wire in order to remake the connections.
If you tell us what region you’re in someone might be able to help, though spares of this sort are going to be hard, possible impossible to find.
Have you tested the solenoid with a test meter as described? Unless there are obvious signs of overheating it’s most unlikely the solenoid will have burnt out. There could be a bad solder or crimp connection where the enamelled wire of the solenoid winding meets the solenoid terminals. My guess is that it’s much more likely the fault lies elsewhere.
Please can we have an oyster disassembly guide? I’ve got an iSlack but the shell is too rough for it (or any other suction cups) to grip. Plastic opening tools don’t seem strong enough, and whilst the jimmy might do the job, is this really the correct tool to use?
I notice that your banana curves upwards, but mine in fact curves downwards. I presume I have to hold it in my right hand and grip the stem between my left thumb and forefinger. This will be awkwards for a right handed person like myself. Is it possible to purchase right-handed-only bananas anywhere?
So what did the fault turn out to be in the end?
Please tell us what region you’re in and someone might be able to help with a relevant suggestion.
Constructive comments (once you’ve cooled off from your frustration) are always welcome. If you’ve ever tried writing a guide yourself you’ll know how hard it is to cover every problem anyone will encounter, including people with different skill levels to your own, and meanwhile, manufacturers change things. Some 15 people have contributed to this guide or added useful comments and it’s still not perfect as no guide will ever be, but 23 people have successfully completed it, which isn’t bad! In fixing you WILL make mistakes and sometimes you WILL break things - it’s all part of the learning process.
Por favor, publique una foto de la pieza y tal vez podamos ayudarlo.
Yes, just pull. See Step 2 in Riconoscimento e scollegamento dei connettori dei cavi
I’m looking for a replacement coreless motor for a Surreal A8 quadcopter. It’s 8mm dia by 16mm long with a 1mm spindle. Bangood have plenty of different ones but none 8mm diameter. Aliexpress on the other hand has some the right size but doesn’t give the CW/CCW option.
The direction of any normal DC motor can be reversed by swapping the polarity so why can’t I just reverse it if it goes the wrong way? Are the brushes designed for one direction only?
Also, is the speed likely to be standard? Obviously it’s not going to fly very well if one motor is faster than the others! Perhaps I could get two, and replace both the two front motors. Then if they are different to the rear ones it might be possible to compensate just by pushing the joystick either forwards or back.
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