ferrite machining?
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From: Bill Sloman on 12 Jun 2010 05:05 On Jun 12, 1:33 am, John Fields <jfie...(a)austininstruments.com> wrote: > On Fri, 11 Jun 2010 14:54:12 -0700 (PDT),Bill Sloman > > <bill.slo...(a)ieee.org> wrote: > >Learn to write in a way that doesn't make claims that you didn't > >intend. > > --- > Unnecessarily nasty when, in all fairness, the thread _is_ about > machining ferrite, and the heat he was referring to (which I think > most of the rest of us picked up on) could only have been caused by > the grinding operation. 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
From: amdx on 12 Jun 2010 07:46 "Yzordderrex" <powersupplyguy(a)netzero.net> wrote in message news:a9090b31-6b08-4114-ae8a-37c5eed33788(a)u7g2000yqm.googlegroups.com... > Does anyone know of ferrrite can be turned on a lathe? > > I have a short 1" long by 1" dia. rod ( i know, i know, a personal > problem) and I would like to have a grove machined into it to accept a > few turns of wire. there will then be a bobbin slipped over that with > the secondary on it. > > I suppose this might be done with some type of grinder as well. > > Just curious to know what machining options are available for ferrite. > > regards, > Bob > 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
From: Grant on 12 Jun 2010 08:30 On Fri, 11 Jun 2010 20:20:54 -0700 (PDT), MooseFET <kensmith(a)rahul.net> wrote: >On Jun 12, 12:07 am, BlindBaby ><BlindMelonChit...(a)wellnevergetthatonethealbumcover.org> wrote: >> On Fri, 11 Jun 2010 08:11:04 -0700, John Larkin >> >> >> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >On Fri, 11 Jun 2010 06:41:57 -0700 (PDT), MooseFET >> ><kensm...(a)rahul.net> wrote: >> >> >>On Jun 11, 8:42 pm, Yzordderrex <powersupply...(a)netzero.net> wrote: >> >>> Does anyone know of ferrrite can be turned on a lathe? >> >> >>> I have a short 1" long by 1" dia. rod ( i know, i know, a personal >> >>> problem) and I would like to have a grove machined into it to accept a >> >>> few turns of wire. there will then be a bobbin slipped over that with >> >>> the secondary on it. >> >> >>> I suppose this might be done with some type of grinder as well. >> >> >>> Just curious to know what machining options are available for ferrite. >> >> >>Grinding is the way to go. If you want to cut something that >> >>you would normally do with a lathe in metal, consider a tool >> >>post mounted grinder. Watch the temperature rise. >> >> >Maybe a dremel with a diamond wheel? >> >> >John >> >> After the grooves get ground (any cutting attempt will result in >> fracture), you need to cover the rod with transformer tape to insulate it >> from your primary wire. >> >> If you make an open ended core transformer, it will be pretty leaky >> unless you use a closed loop core arrangement. >> >> You would probably be better off with a pot core. >> >> I would use a dremel tool and grinding or cutting (abrasive cutting) >> disc attached. >> >> If you are making a large groove for a single layer of larger wire the >> grooves will allow the wire profile to sit a bit lower., >> >> If you are using fairly small primary wire, you do not need the grooves >> at all. >> >> Temperature rise? They are not magnets. There are no properties to >> lose via introduction of heat. > >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. 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. -- http://bugs.id.au/
From: John Fields on 12 Jun 2010 10:35 On Sat, 12 Jun 2010 02:05:35 -0700 (PDT), Bill Sloman <bill.sloman(a)ieee.org> wrote: >On Jun 12, 1:33�am, John Fields <jfie...(a)austininstruments.com> wrote: >> On Fri, 11 Jun 2010 14:54:12 -0700 (PDT),Bill Sloman >> >> <bill.slo...(a)ieee.org> wrote: >> >Learn to write in a way that doesn't make claims that you didn't >> >intend. >> >> --- >> Unnecessarily nasty when, in all fairness, the thread _is_ about >> machining ferrite, and the heat he was referring to (which I think >> most of the rest of us picked up on) could only have been caused by >> the grinding operation. > >Perhaps. But you snipped his " Learn to read, dumbfuck." which - to my >mind - does justify a tolerably nasty clsong sentence. --- 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. --- >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. --- 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. --- >You are prone quoting stuff taken out of context - as you >have here - and may not be sensitive to the risk. --- 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
From: mpm on 12 Jun 2010 10:49
On Jun 12, 9:35 am, John Fields <jfie...(a)austininstruments.com> wrote: > On Sat, 12 Jun 2010 02:05:35 -0700 (PDT), Bill Sloman > > > > > > <bill.slo...(a)ieee.org> wrote: > >On Jun 12, 1:33 am, John Fields <jfie...(a)austininstruments.com> wrote: > >> On Fri, 11 Jun 2010 14:54:12 -0700 (PDT),Bill Sloman > > >> <bill.slo...(a)ieee.org> wrote: > >> >Learn to write in a way that doesn't make claims that you didn't > >> >intend. > > >> --- > >> Unnecessarily nasty when, in all fairness, the thread _is_ about > >> machining ferrite, and the heat he was referring to (which I think > >> most of the rest of us picked up on) could only have been caused by > >> the grinding operation. > > >Perhaps. But you snipped his " Learn to read, dumbfuck." which - to my > >mind - does justify a tolerably nasty clsong sentence. > > --- > 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. > --- > > >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. > > --- > 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. > --- > > >You are prone quoting stuff taken out of context - as you > >have here - and may not be sensitive to the risk. > > --- > 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- Hide quoted text - > > - Show quoted text - 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? |