ferrite machining?

Actually, due to terrorist strains, it may make a comeback, and I know far more about it than you do as I never received a vaccination, and I was born in 1960.

Had I gotten one, I would have contracted the disease (a deadly version of cowpox). My brother did not get one either as he would have given it to me. I had a condition at the time known as spots.

So I knew more about the disease at age five than you do now.

If it is small enough to do the job it is a better choice. I don't throw the away until they are dime size! John Ferrell W8CCW

The cores I have experience with are metal oxides not metals. They are brittle.

I stand by my warning. What you claim doesn't matter because I know I will be shown to be correct.

I prefer abrasives whenever possible for cutting. They simply costy a lot less.

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. John Ferrell W8CCW

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.

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.

on

Or so you seem to think. I'm old enough to have been innoculated against small-pox, and I know enough to have heard about Jenner and where the term vaccination came from - it is a reference to the cow- pox which you claim includes a "deadly strain".

If you had got all that on board at the age of five, you'd have been a bright kid. The fact that you don't seem to have retained much of it as an adult does suggest that you were dropped on your head sometime in the intervening period.

-- Bill Sloman, Nijmegen

They are great for trimming way material of just about any strata, and they can be used for all types (methods) of said removal.

I buy 'em buy the five pack, I think.

Great for trace cutting. Great for PCB 'slotting' for HV isolation/creepage, etc.

There are so many places where it does the job, and leaves little abrasive debris behind in doing it.

I have used those little cut-off discs for soooo many things.

There are two types of ferrites. Hard ferrites will retain magnetization effects. Soft ferrites will not. Soft ferrite ARE 'machinable', typically though only by way of grinding.

Manufacturing processes for each type are similar, but do differ from maker to maker. There are many 'styles' however, that are manufactured in a common way so that designers can choose form more than one producer for their raw goods, and get like performance expectations. Common sense again... duh.

Lots of cutting edge hybrid stuff out there though. That's also how we got advanced magnetics science over the last 60 years too. The colleges toyed with materials, and the factories made the goods to be tested to prove the science.

The temp rise is not what you have to watch for. It is the RATE of temp rise, and that rate is not going to be exceeded by dremeling, unless you are a total idiot when you get the dremel in your hand, in which case, you should be on a different career path, such as street sweeping.

Actually, a bobbin winder is the right tool. A lathe, even on its slowest speed, is far to fast.

More proof that you do not know what is up.

The heat gun will cause the cracks you were so worried about in your dis-informing earlier horseshit post.

Yo have to raise the temp SLOWLY. That means a slow rise, like that of an oven.

The heat gun will ALWAYS exceed the temp rise rate maximum specified by the maker, which is typically 10C per minute.

The way to attack epoxy links on ferrite bobbins is with a soldering iron, and an old, no longer used for solder tip. You use the tip to 'melt' it way through the 'glue links' between segments. Most epoxies 'soften' at elevated temperatures, but that temp is pretty high.

Using a heat gun to bring the thing up is dumb because you bring it up too fast. Better to bring it up to 350F in an oven and THEN do the last thermal transition with added heat. Trying to do the entire transition with a hot air flow is just stupid.

The really sad thing is that YOU KNOW THAT I AM RIGHT, asshole. Looks like 'Kenny' ain't all he thinks he is.

There are some fairly soft sintered things, like sintered brass gas diffuser things. And sintered plastics.

John

here,

sure.

Flooding with work with coolant would help. Keeps the dust down too. But yeah, it's messy.

-- Cheers, James Arthur

He wants to blow flame (hot air) over them now too.

The filter elements are sintered with things like 'fine silt clay', and then the clay gets washed out after the sintering. leaving the porous medium behind. They can be brittle or be such that further press forming, etc. operations can be performed on them.

There is 'nearly dry' concrete mix that gets applied and formed on the ground, and after drying are very very porous, because they did no vibrational settling of the dry mix. One ends up with a driveway that never gets a rain puddle on it. It absorbs hundreds of gallons of water, and transfers it beneath the slab for storage or transport to drainage.

There is no need to flow a coolant over a simple, low mass, ferrite grinding operation. G E T A C L U E.

I just tried grinding some ferrite with what was on hand, I'm not likely to use this technique very often.

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.