chopamps

Seem like it should be avoided, if possible. On the other hand, if there is just one horse in the stable, you go with it.

Thanks Phil

Mu metal is great stuff, if you can do the hydrogen anneal. Otherwise mild steel is usually the best bet.

Cheers

Phil Hobbs

On Sun, 26 Jul 2015 14:05:27 -0400, Phil Hobbs Gave us:

Ahhh... a chopamp can chopper. I knew someone made those.

I have an 'Ironton' brand electric model from Harbor Freight. Clunky but functional.

Cheers

Phil Hobbs

boards in the hundreds per year? Companies that take care of PCB fab, stuffing, maybe some testing or even box assembly.

Hmm, Creation Tech in San Jose might be of use? I forget if they're more production or proto, actually. They have lots of cells, though.

Disclaimer: I do layout work for them. :)

Tim

Thanks, Tim. They do seem to fit the bill plus this client is in Texas and they've got a site there:

Do circular saw cuts degrade mu metal?

TIA.

I've never measured it. Probably so, in the deformed zone near the cut, especially if it gets hot. The repeated shock from the teeth impacting may also hurt the mu.

It's delicate stuff, but works wonders when used intelligently.

Cheers

Phil Hobbs

The saw blade shouldn't be "impacting" the edge. It should be cutting the metal. If it's getting very hot it's probably abrading the metal, which won't go on very long before the blade fails.

If you have some nonzero feed rate, an N-tooth blade impacts the surface N times per revolution. Not rocket science.

Cheers

Phil Hobbs

A saw blade can be said to be "cutting smoothly" if it's got more than one tooth in the cut at a time (the usual metalworker's rule of thumb is to have 2 or 3 -- more and it's too slow, fewer and it's too rough). You'd have to have a magnificently fine sawblade to cut the thickness most mu metal comes in. Most common blades (say in the

On Wed, 29 Jul 2015 19:00:08 -0700 (PDT), Phil Hobbs Gave us:

I prefer a Dremel with the little 'concrete' cutting disc in it.

And no, it does not take the metal anywhere near the curie point.

All one needs do is progress slowly.

You know, like krw's brain has all his life. He has like four firing neurons now. That's up from two after his mom dropped him on his head getting his flailing arm retarded ass out of the high chair one day when he was 5.

Metal cutting proceeds (usually) by forming a chip, deforming the metal and doing work (heating) on it, so the chip curls up and goes away... and that chip, while still attached to the bulk material, will stretch it a bit.

Abrasion (as in water-jet cutting) might be much less stressful on the metal left behind.

Do you consider peeling an orange "impacting" the orange? The point is that there isn't (or shouldn't be) any significant shock to the remaining metal.

No, it should be cutting the metal, not punching it. I haven't cut mu-metal but aluminum cuts very nicely on a table saw. I have a few miter gauges with some real pretty cuts that show just how well. :-(

Water jet, sure , because it's being cooled. A grinding (cut-off) wheel, probably not.

Mu metal gets damaged by dropping it on the floor from waist level, even with no visible dings whatsoever. It's very delicate stuff.

Cheers

Phil Hobbs

On Fri, 31 Jul 2015 08:09:02 -0400, Phil Hobbs Gave us:

What do they call that? Domain tossing?

Oh wait... that's what the cops (PIGs) do when they raid a citizen's house!

You tosser!

It's actually called flux pinning, due to dislocations. If you hit a piece of metal and it rings, probably you haven't made any dislocations. If you hit a piece of metal and it clunks (or thuds), probably you have made dislocations. Mu metal is a thud producer.

On Fri, 31 Jul 2015 10:26:24 -0700 (PDT), whit3rd Gave us:

The Egyptians could carve a monolithic column from mere sandstone and it would make a resonant ring whenever one struck it with a wooden mallet. Tons of 'tuned' sandstone. Amazing.