Winston wrote:

Bob Engelhardt wrote:
Bob Engelhardt wrote:
Bob Engelhardt wrote:
... I've asked on the Practical Machinist forum. If I don't get an
answer, I'll try Bottomly. ...

I just got the reply on P-M:
"I have spoken to Alan about the hinges and he has brought a box of
the prototype hinges into work today. I think he will write a bit of a
story about the Magnabend development over the next week or so. Geoff
is away on holiday at the moment (far southwest of Tasmania) where
there is no technology, but when he gets back I will see if he want to
add something."

Bob

Alan Bottomly (the MagnaBend's inventor) has joined the discussion on
the Practical Machinist forum. As to the original hinges ("cup hinges"
he calls them), he said they tended to jam when being returned from
large-angle bends. Too little engagement after 90 degrees. He also had
comments about wire size used for the magnets, but I'm not going to keep
repeating what's said & recommend that interested RCM'ers join P-M.

Thanks for the P-M cite, Bob. I enjoyed hearing from Alan.

At the risk of turning the 'elegant and beautiful' into the
'byzantine and ugly', what would prevent one from designing
a current-mode PWM controller so that electromagnets with
'too thick' wire could be driven optimally, with just the
proper amount of current for maximum attraction yet not so
high as to cause excessive power dissipation?

I don't understand the conflict with using multiple MOTs as
electromagnets. Every second electromagnet could be driven
with opposite polarity so that no repulsion occurs between
them, yes?


You could connect the primaries in series.


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.