ferrite machining?

The one partedness can be lost through the heat rise at the machined point. They don't conduct heat well and neither does the grinder. I stand by my suggestion that temperature rise be watched.

On Jun 12, 1:33 am, Bill Sloman wrote: [...]

This has nothing to do with the reason to watch the temperature rise. It is just plain a mechanical issue. The material is brittle and a bad conductor of heat.

Are you trying to say that the particles "meld" together at the grinding site?

Well, they don't. It is mostly abrasive cutting, per se, not so much grinding like one does when trying to make a bar of steel shorter or the like, THAT heat soaks in and remains and builds and burns of the metal and annealing/hardening cycle occur. This ain't a steel bar. It grinds far easier, and it does not build much heat because it grinds easier.

I have modified more pot cores for production than you have likely ever seen in your life. I know exactly how easy it is to work and what tools are best to work it with.

You likely do not know what the word 'work' means since you are so paranoid about thinking that it would soak up so much heat or even have local heat issues when it will not.

It would not change anything even one ten thousandth of one percent if it did, which it doesn't, and that would only affect the are ground.

It does not happen, and your paranoia is nothing more than a fantasy... of yours.

And grinding it doesn't hurt it at all. It got heated when it got made. It is a sintered, stamped, baked manufacturing process.

Perhaps. But you snipped his " Learn to read, dumbfuck." which - to my mind - does justify a tolerably nasty clsong sentence.

And while one could assume that he was talking about the heat generated by the grinding operation, what he said could certainly be interpreted to mean that soft ferrites didn't have a Curie temperature. You are prone quoting stuff taken out of context - as you have here - and may not be sensitive to the risk.

-- Bill Sloman, Nijmegen

Maybe instead of all the grinding and since it is a rod with its incomplete magnetic path. Can you install your bobbin, wind your secondary and add the insulation amount of insulation needed and then put your primary on the outside? Or wind your primary on the ferrite and use a larger bobbin, ( know limited sizes) Do you have a high voltage problem you're working around? Mike

I just spent some time with a high speed hobby drill, various grinding attachments and a then piece of ferrite, a figure eight buckle type they wind those mains filters on, the type with sprocket teeth on the coil former so the ferrite is one piece.

Anyway, 150 grit diamond tool rips into the stuff, black dust everywhere, easy to fracture pieces off, very harsh if one applies too much pressure.

The sanders and other grinders a bit more gentle, most gentle (but slow) was the thin cutoff wheel when use with light pressure and kept moving to avoid localised heating. If I tried too hard to grind one spot, the ferrite would fracture from the hot spot, through several mm of ferrite.

Machining ferrite is easy, with a little practice to develop a feel for what is easy, and stuff that is dangerous in the sense of risking fracturing the job.

Diamond tools would need to be a lot finer than 150 grit to lessen the impact and give a smoother finish -- easy to control with light pressure and rips out the material quickly.

Interesting stuff to play with. And try different tool speeds, the abrasion rate doesn't necessarily go up with speed. Odd?

Grant.

--- His: "Learn to read, dumbfuck." had nothing technical to add to the discussion, so I snipped it for that reason.

More to the point, if what you're saying is true, then faulting him for _your_ misinterpretaion of his statement(s) is an error on your part.

That is, since the subject of the thread is "ferrite machining?", one with a modicum of sense would infer that the heat referred to was generated purely by mechanical means and that the Curie temperature of the material, at that point was immaterial.

I believe mention was also made of the fact that the material wasn't a magnet, so that should have been a further clue that the Curie temperature of the material was immaterial at that point.

---

--- Perhaps, but it would have to have been "interpreted" by someone ignorant of American English usage or ignorant of the differences between hard and soft ferrites.

---

--- Ah, I see...

It _is_ an English problem.

It should be, "You are prone to quoting"..., otherwise I'd be in repose while quoting.

In any case, your argument is nonsensical since you're the one who misinterpreted what was being said, thus it's _you_ who has been quoting out of context.

JF

With no dog in this fight, I have to agree with Sloman. In technical writing, you cannot fault the reader for not understanding what the writer intended. The burden placed on the writer in these situations is exactly what separates technical writing from poetry, for example.

Rather than annoying each other over syntax, it might be easier to just acknowledge that even more demands are placed on the technical writer in informal settings such as Usegroups. There will always be a trade-off between brevity and understanding, for all participants. I'm sure if the author had the time and inclination, he could have drafted something so succinct and clear, that nobody could misinterpret his intent. But is that really practical in a forum like this? Or it is just easier to call each other names?

Bullshit.

I already posed this question.

Ever seen a pot core pair with mirror polished mating faces? They are abrasively finished.

Jeez, I wish I could expound facts the way you do.

That's not what he did. He faulted him for the parts he failed to read.

Like the TOPIC HEADER.

Horseshit. Anyone with any NORMAL modicum of common sense, would have been able to discern that I referred to heat generated by the tooling. I did, after all, make that response to someone that made the statement that the grinding temp rise needed to be guarded against.

Fetish.

Yeah... you. A retarded behavior fetish. You cannot stop acting retarded.

And you can't keep from mentioning excrement.

John

Fetish.

Anyone with any NORMAL modicum of common sense, would have