projectnz 
Theres 50 grams of Copper in each magnatron (I just love using that word. Mag-nah-tron)
>(actually, you are right, its 80gms, I got it mixed up with something else.)
I'd machine the weld off if I had a lathe to do it in.
>(theres a fine weld where the copper body & the stainless steel flange meet. Under the steel flange theres a second steel disc with a hole in it.
This disc is set into the end of the copper bobbin & the flange sits on the disc, they then weld the flange on, with a TIG welder, around the OUTSIDE of the metal disc.
Because they don't use filler metal for the weld, the weld is very small & easy to cut off using a lathe.
I will describe it again.
The end of the bobbin has a relief machined into it. That lets the metal disc sit INSIDE the end of the bobbin, the flange sits on that.
They then run a weld around the end of the bobbin, welding ONLY the copper metal thats around the outside of the steel disc - to the outer edge of the stainless steel flange.
Because of that, theres a thin ring of copper around the outside of the metal disc.
IF you use a lathe & a very small parting off blade, like 1mm wide, you can machine thru this thin copper end part of the bobbin & the metal disc & end part/flange/beryllium etc will fall off.
Your cut will be 1mm wide & 2mm deep, thats not a lot of metal to machine away. You will not loose much of your copper machining this way.
A few times I have ground the weld off but the soft copper picks up some of the stainless steel dross & puts it into the copper bobbin.
That makes it magnetic & its a pain to clean up.
Its also **** hard to hold the bobbin in a vise, coppers soft & it crushes easy like & I have to remove the bent bobbin & regrip it to finish off the grinding. (I'm using a bench vise & a 9 inch grinder.)
Holding it in a lathe & doing a small cut will not squash the copper bobbin out of shape.)
I just puttem in a box & one day when I do get a lathe, I'll machine them up & get the 8+Kg copper & sell it for NZ$56.
>( OK, I have been saving them up for ages, I have over 100. At 80gms each, thats 8Kg & 8Kg x $7.00/Kg = $56. Oh, Thats NZ$, not US$.)
Bookmarks