Tell us about yourself!
It certainly is AC on the secondary side of the transformer! When the magnetic field is building up it induces a voltage in the secondary in one direction, when the field collapses it induces a voltage in the opposite direction. Consider the sawtooth wave used for horizontal deflection on a CRT. It is produced by a DC pulse applied to a transformer, but the result is AC on the secondary. If it were not so, then the electron beam would only deflect in one direction and would never pass center in the other direction. Yes, anyone with a very basic understanding of electronics would know this!
With all due respect, it is indeed an AC output. Read my response to youcantoo for an explanation.
That certainly is a simple inverter, and could be useful for many applications. My concern, as someone else already pointed out, would be in the longevity of the relay contacts. If you could make it work with a solid state relay it might hold up a lot longer, only problem is I think most solid state relays require the zero crossing of the ac sine wave to turn off. By the way, I'll not mention any names, but someone here likes to blow a lot of smoke, and hasn't a clue what he's talking about! LOL Nice ible, thanks for posting it.
Mold Making & Casting Class
Nice instructable, I've used this circuit as a quick and easy test for tesla secondary coils. One suggestion; you should indicate connected wires on your schematic with a dot. Some may assume that the resistor and diode are just connected to each other, and that the base of the transistor only connects to the bottom of the coil.
There is one important exception to the above comment that I should point out before someone calls my hand on it; Tapered (pipe thread) taps do very much cut on the teeth, as the threads are progressively enlarged the deeper the tap is driven. It is critical that the teeth of tapered pipe thread taps be kept sharp. Again though, this sharpening is done by re-grinding the flutes, not the threads.
You're very welcome, and I thank you as well. I have some tools I'm going to try your technique on.
LOL, Yes, 3 1/2" is huge. I've used it twice that I remember in the 18 years I've owned it. Most of the taps I use are on the smaller end too, from 4-40 up to 3/4-NC & NF occasionally 7/8 & 1" and rarely smaller than 4-40. What I've found is that the realization I have the larger ones sometimes lends occasion to put them to use. They are not something I would have ever sought to purchase specifically, but came with a much broader acquisition. In answer to your question; No, the flutes are the grooves running the length of the threads on the tap. The threads in the work piece are, for the most part, fully cut before they ever see the full "teeth" of the tap. The teeth basically just scrape the threads to smooth them. Kind of like a twist drill where ...
LOL, Yes, 3 1/2" is huge. I've used it twice that I remember in the 18 years I've owned it. Most of the taps I use are on the smaller end too, from 4-40 up to 3/4-NC & NF occasionally 7/8 & 1" and rarely smaller than 4-40. What I've found is that the realization I have the larger ones sometimes lends occasion to put them to use. They are not something I would have ever sought to purchase specifically, but came with a much broader acquisition. In answer to your question; No, the flutes are the grooves running the length of the threads on the tap. The threads in the work piece are, for the most part, fully cut before they ever see the full "teeth" of the tap. The teeth basically just scrape the threads to smooth them. Kind of like a twist drill where the point does the cutting and the flutes clear the chips and smooth the sides of the hole.
Wrong, you don't regrind the threads, the vast majority of the cutting is done on the tapered portion, not on the "teeth" of the threads. If the thread teeth require sharpening, it is done inside the flute, not on the threads themselves. You are somewhat correct on the "pricy" statement, professional sharpening is not cheap. This is why I recommend replacement unless they are large (expensive). I have many large taps, (my largest is 3 1/2" diameter) many of them are 40-50 years old or older and have been resharpened many times. I have the equipment & do my own sharpening, but I seldom bother on taps smaller than 1/2". My time is worth more than the cost of replacement on most of the smaller taps.
I'm pleased you're not "being a know it", but it sounds that you've lived a rather sheltered life. Your implication that rusted tools are the result of careless neglect by the owner is quite often far from the truth. Many of my finest tools came into my possession with a healthy coat of rust. I'm reminded of a time a co-worker came begging to borrow a pair of snips and then had the arrogance to complain that they didn't look new enough. He knew nothing of their history or their functionality.
Well said meswanson, been there & done that.
I was so impressed by the cover photo I had to read this instructable. Awesome! While I'll not be trying this on my nails (my wife might look at me funny), I might adapt the technique to some other applications. Thanks for sharing.
Unless you have a surface grinder or a tool sharpener with the right fixtures to hold the correct angles & reliefs, and to index the flutes, then you are probably better off to replace the tap. The only way to properly restore the cutting edge is by grinding. While it is certainly possible to do this by hand, it is not at all easy and will rarely result in consistency from flute to flute. For large (expensive) taps, you might want to consider sending it off to a professional tool sharpener.
No. . . That does not make sense, and absolutely will not work! Unless your goal is to destroy the tap AND the die. Even if your suggestion were possible and feasible, the die would never even touch the critical cutting edges of the tap.
There are different kinds of taps, The vast majority of tapping operations in a machine shop or in industry are power tapping operations. With the proper tap and the proper technique, power tapping is far less likely to result in a broken or damaged tap than is hand tapping. I recommend a good quality spiral point tap, also known as a gun tap. Usually if a tap gets rusty, it's just surface rust and will have little effect on its performance.