ferrite machining?
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From: Archimedes' Lever on 13 Jun 2010 17:04 On Sun, 13 Jun 2010 13:24:33 -0700 (PDT), dagmargoodboat(a)yahoo.com wrote: >On Jun 13, 9:37�am, MooseFET <kensm...(a)rahul.net> wrote: >> On Jun 13, 1:21 am, BlindBaby >> >> >> >> <BlindMelonChit...(a)wellnevergetthatonethealbumcover.org> wrote: >> > On Sat, 12 Jun 2010 09:29:32 -0700 (PDT), MooseFET <kensm...(a)rahul.net> >> > wrote: >> >> > >On Jun 12, 8:30 pm, Grant <o...(a)grrr.id.au> wrote: >> > >> On Fri, 11 Jun 2010 20:20:54 -0700 (PDT), MooseFET <kensm...(a)rahul.net> wrote: >> > >[...] >> > >> 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 problem is mostly the local temperature rise. �If you are >> > >careful, you can cut an O-ring groove into a rod core to seal >> > >the place where it goes through a wall. �Fine work can be >> > >done but when making any sort of a groove a lot of care >> > >is needed. >> >> > � Your brain is on overkill, and you can't even get that right. >> >> I stand by my warning. �What you claim doesn't matter because >> I know I will be shown to be correct. > >Flooding with work with coolant would help. Keeps the dust down too. >But yeah, it's messy. There is no need to flow a coolant over a simple, low mass, ferrite grinding operation. G E T A C L U E.
From: Grant on 14 Jun 2010 03:15 On Sun, 13 Jun 2010 10:38:12 -0400, John Ferrell <jferrell13(a)triad.rr.com> wrote: >On Sun, 13 Jun 2010 11:05:06 +1000, Grant <omg(a)grrr.id.au> wrote: > >>On Sat, 12 Jun 2010 15:59:17 -0400, John Ferrell <jferrell13(a)triad.rr.com> wrote: >> >>>On Fri, 11 Jun 2010 05:42:19 -0700 (PDT), Yzordderrex >>><powersupplyguy(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. >>>> >>>>regards, >>>>Bob >>>I made a simple fixture to hold a Dremel tool on the toolpost of my >>>Jet 9X20 Metal lathe. Most of the 9X20's seem to have the same >>>castings so there are a lot of them around. The cutting tool for this >>>job would be the same as what I use for e-clips on rod stock: the tiny >>>abrasive disk that shatters every time you use one hand held. >> >>The 22mm red and black ones? I break them not in use, but in careless >>handling of the tool! Only had high speed thingy for a few weeks, it's >>been great. >> >>> It will >>>last a while in this application. As for the tool post mount, think >>>about a piece of angle, wood block & wood screws and hose clamps. >>>light cuts don't need to be super rigid. A well positioned vacuum >>>cleaner (use duct tape!) will save a lot on clean up. >> >>Yes, I need to arrange some dust vacuum here, but it's more difficult >>for handheld -- I'm dreaming up some sort of blower + vacuum arrangement >>that could help direct the dust to a vacuum. Or maybe a high volume, >>low vacuum fan and duct arrangement so some sort of filter; like I've >>seen in some photos of handheld machining. >> >>The 150 grit diamond tool tips in the cheapy abrasive sets seem too >>harsh for ferrite, they jar and shatter, but diamond does cut the >>stuff quite well. So I imagine finer grit diamond tools would be >>good to try. >> >>The miniature thin cutting off wheels are much slower cutting ferrite, >>but very little vibration if you properly mount and dress them before >>use. >> >>Grant. >I prefer abrasives whenever possible for cutting. They simply costy a >lot less. I just tried grinding some ferrite with what was on hand, I'm not likely to use this technique very often. > >I sometimes need a special dust collector for a project. It does not >have to be fancy. Think shoe box with perf board duct taped to to the >top, vacuum cleaner hose in the side with a rag for a seal. All vacuum >cleaners need to move a lot of air for cooling. Actually the morning after I played with grinding ferrite, I noticed black edge highlights on the small rare earth magnets on the fridge, collected the fine dust, they did. So next time I try grinding ferrite I'll try a decent magnet near the work. Grant. -- http://bugs.id.au/
From: Grant on 14 Jun 2010 03:19 On Sun, 13 Jun 2010 07:41:34 -0700 (PDT), MooseFET <kensmith(a)rahul.net> wrote: >On Jun 13, 8:51 am, Grant <o...(a)grrr.id.au> wrote: >> On Sat, 12 Jun 2010 09:29:32 -0700 (PDT), MooseFET <kensm...(a)rahul.net> wrote: >> >On Jun 12, 8:30 pm, Grant <o...(a)grrr.id.au> wrote: >> >> On Fri, 11 Jun 2010 20:20:54 -0700 (PDT), MooseFET <kensm...(a)rahul.net> wrote: >> >[...] >> >> 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 problem is mostly the local temperature rise. If you are careful, >> >you >> >can cut an O-ring groove into a rod core to seal the place where it >> >goes >> >through a wall. Fine work can be done but when making any sort of a >> >groove a lot of care is needed. >> >> Yes, I discovered that last night, localised heating trying to get a >> narrow cut will easily start a fracture, there's no great pressure or >> vibration evident to cause the fracture, it's the localised heat. >> Obvious, when one works with the material. Need to keep the tool >> moving to distribute the heat loading. > >If you want accurate machining of a groove, you need a small grinder >mounted to a lathe. Doing it by hand is ok if you just need to make a >small notch or the like. > > >> And the generated heat is very localised, I was holding the ferrite >> in my hand, and the stuff did not warm up after being ground. >> >> Ferrite not a good heat conductor. I've also fractured ferrites by >> heating with a hot air gun trying to soften the varnish and/or glue >> to separate and recover transformer parts. same story, localised >> heat will fracture ferrite material. > >I have used a heat gun to get glue off cores. I think the trick is to >have a big heat gun so that the whole core is warmed up. I was trying to separate a large transformer, couple inches across, fracture lines showed the cooler core inside bobbin. I'm thinking I'd have better luck with slow temp rise rate oven. Another day... Grant. -- http://bugs.id.au/
From: nuny on 14 Jun 2010 06:10 On Jun 14, 12:15 am, Grant <o...(a)grrr.id.au> wrote: > On Sun, 13 Jun 2010 10:38:12 -0400, John Ferrell <jferrel...(a)triad.rr.com> wrote: > >On Sun, 13 Jun 2010 11:05:06 +1000, Grant <o...(a)grrr.id.au> wrote: > > >>On Sat, 12 Jun 2010 15:59:17 -0400, John Ferrell <jferrel...(a)triad.rr.com> wrote: > > >>>On Fri, 11 Jun 2010 05:42:19 -0700 (PDT), 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.. > > >>>>regards, > >>>>Bob > >>>I made a simple fixture to hold a Dremel tool on the toolpost of my > >>>Jet 9X20 Metal lathe. Most of the 9X20's seem to have the same > >>>castings so there are a lot of them around. The cutting tool for this > >>>job would be the same as what I use for e-clips on rod stock: the tiny > >>>abrasive disk that shatters every time you use one hand held. > > >>The 22mm red and black ones? I break them not in use, but in careless > >>handling of the tool! Only had high speed thingy for a few weeks, it's > >>been great. > > >>> It will > >>>last a while in this application. As for the tool post mount, think > >>>about a piece of angle, wood block & wood screws and hose clamps. > >>>light cuts don't need to be super rigid. A well positioned vacuum > >>>cleaner (use duct tape!) will save a lot on clean up. > > >>Yes, I need to arrange some dust vacuum here, but it's more difficult > >>for handheld -- I'm dreaming up some sort of blower + vacuum arrangement > >>that could help direct the dust to a vacuum. Or maybe a high volume, > >>low vacuum fan and duct arrangement so some sort of filter; like I've > >>seen in some photos of handheld machining. > > >>The 150 grit diamond tool tips in the cheapy abrasive sets seem too > >>harsh for ferrite, they jar and shatter, but diamond does cut the > >>stuff quite well. So I imagine finer grit diamond tools would be > >>good to try. > > >>The miniature thin cutting off wheels are much slower cutting ferrite, > >>but very little vibration if you properly mount and dress them before > >>use. > > >>Grant. > >I prefer abrasives whenever possible for cutting. They simply costy a > >lot less. > > I just tried grinding some ferrite with what was on hand, I'm not likely > to use this technique very often. > > > > >I sometimes need a special dust collector for a project. It does not > >have to be fancy. Think shoe box with perf board duct taped to to the > >top, vacuum cleaner hose in the side with a rag for a seal. All vacuum > >cleaners need to move a lot of air for cooling. > > Actually the morning after I played with grinding ferrite, I noticed > black edge highlights on the small rare earth magnets on the fridge, > collected the fine dust, they did. So next time I try grinding ferrite > I'll try a decent magnet near the work. Brilliant, sir. I'm putting a speaker magnet in my Dremel case right now. We all know what high voltage, HF radiation, and similar electronic hazard warning signage looks like. What's the standard warning sign for "strong magnetic field"? Mark L. Fergerson
From: John Fields on 14 Jun 2010 07:19
On Mon, 14 Jun 2010 03:10:29 -0700 (PDT), "nuny(a)bid.nes" <alien8752(a)gmail.com> wrote: >On Jun 14, 12:15�am, Grant <o...(a)grrr.id.au> wrote: >> On Sun, 13 Jun 2010 10:38:12 -0400, John Ferrell <jferrel...(a)triad.rr.com> wrote: >> >On Sun, 13 Jun 2010 11:05:06 +1000, Grant <o...(a)grrr.id.au> wrote: >> >> >>On Sat, 12 Jun 2010 15:59:17 -0400, John Ferrell <jferrel...(a)triad.rr.com> wrote: >> >> >>>On Fri, 11 Jun 2010 05:42:19 -0700 (PDT), 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. >> >> >>>>regards, >> >>>>Bob >> >>>I made a simple fixture to hold a Dremel tool on the toolpost of my >> >>>Jet 9X20 Metal lathe. Most of the 9X20's seem to have the same >> >>>castings so there are a lot of them around. The cutting tool for this >> >>>job would be the same as what I use for e-clips on rod stock: the tiny >> >>>abrasive disk that shatters every time you use one hand held. >> >> >>The 22mm red and black ones? �I break them not in use, but in careless >> >>handling of the tool! �Only had high speed thingy for a few weeks, it's >> >>been great. >> >> >>> It will >> >>>last a while in this application. As for the tool post mount, think >> >>>about a piece of angle, wood block & wood screws and hose clamps. >> >>>light cuts don't need to be super rigid. A well positioned vacuum >> >>>cleaner (use duct tape!) will save a lot on clean up. >> >> >>Yes, I need to arrange some dust vacuum here, but it's more difficult >> >>for handheld -- I'm dreaming up some sort of blower + vacuum arrangement >> >>that could help direct the dust to a vacuum. �Or maybe a high volume, >> >>low vacuum fan and duct arrangement so some sort of filter; like I've >> >>seen in some photos of handheld machining. � >> >> >>The 150 grit diamond tool tips in the cheapy abrasive sets seem too >> >>harsh for ferrite, they jar and shatter, but diamond does cut the >> >>stuff quite well. �So I imagine finer grit diamond tools would be >> >>good to try. >> >> >>The miniature thin cutting off wheels are much slower cutting ferrite, >> >>but very little vibration if you properly mount and dress them before >> >>use. >> >> >>Grant. >> >I prefer abrasives whenever possible for cutting. They simply costy a >> >lot less. >> >> I just tried grinding some ferrite with what was on hand, I'm not likely >> to use this technique very often. >> >> >> >> >I sometimes need a special dust collector for a project. It does not >> >have to be fancy. Think shoe box with perf board duct taped to to the >> >top, vacuum cleaner hose in the side with a rag for a seal. All vacuum >> >cleaners need to move a lot of air for cooling. >> >> Actually the morning after I played with grinding ferrite, I noticed >> black edge highlights on the small rare earth magnets on the fridge, >> collected the fine dust, they did. �So next time I try grinding ferrite >> I'll try a decent magnet near the work. > > Brilliant, sir. I'm putting a speaker magnet in my Dremel case right >now. > > We all know what high voltage, HF radiation, and similar electronic >hazard warning signage looks like. > > What's the standard warning sign for "strong magnetic field"? --- A triangle with a horseshoe magnet in it and lightning bolts coming out of the ends of the magnet? http://www.magmedix.com/products/safety/magnet_danger_sign.html |