Somebody usually comes up with better ways of doing things, but here's
what I did - for the cost of four rivets!

I needed to make a couple of copper electrical fingers that were
missing from a motor controller, and found some suitable copper in the
scrap bin. There's a piece of phosphor bronze for a spring. Since
there's maybe 100 amps to conduct, that's too much current for the
spring or it will get hot and lose its springiness, so I made a few
layers from the pure copper shim shown at the top. The finger itself I
cut from the piece of bar and bent it and rivetted it with copper
rivets (new ones!)

The new finger is on the left, and an original one on the right:
http://i53.tinypic.com/1z04.jpg

The two new fingers in place on the controller, at the far left:
http://i56.tinypic.com/o5dp1l.jpg

Those fingers simply change the direction of the current and are not
switched while the power on.

Here's the whole controller. The fingers at the bottom change the
voltage going to the motor while it's operating, so they have to be
bigger:
http://i55.tinypic.com/118qb0l.jpg

Parts for these controllers are not available any more so need to be
fabricated. Copper and brass are quite nice to work with, but are
easily dented with steel tools. I made a brass hammer to use instead
of a steel hammer.

Matty F wrote:

Here's the whole controller. The fingers at the bottom change the
voltage going to the motor while it's operating, so they have to be
bigger:
http://i55.tinypic.com/118qb0l.jpg

And look like they have blowout coils too :-)

Another fine piece of work.

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

"Matty F" wrote in message
...
Somebody usually comes up with better ways of doing things, but here's
what I did - for the cost of four rivets!

Parts for these controllers are not available any more so need to be
fabricated. Copper and brass are quite nice to work with, but are
easily dented with steel tools. I made a brass hammer to use instead
of a steel hammer.

Nice bit of DIY, thanks for sharing.

Mike

Matty F wrote:
Somebody usually comes up with better ways of doing things, but here's
what I did - for the cost of four rivets!

I needed to make a couple of copper electrical fingers that were
missing from a motor controller, and found some suitable copper in the
scrap bin. There's a piece of phosphor bronze for a spring. Since
there's maybe 100 amps to conduct, that's too much current for the
spring or it will get hot and lose its springiness, so I made a few
layers from the pure copper shim shown at the top. The finger itself I
cut from the piece of bar and bent it and rivetted it with copper
rivets (new ones!)

The new finger is on the left, and an original one on the right:
http://i53.tinypic.com/1z04.jpg

The two new fingers in place on the controller, at the far left:
http://i56.tinypic.com/o5dp1l.jpg

Those fingers simply change the direction of the current and are not
switched while the power on.

Here's the whole controller. The fingers at the bottom change the
voltage going to the motor while it's operating, so they have to be
bigger:
http://i55.tinypic.com/118qb0l.jpg

Parts for these controllers are not available any more so need to be
fabricated. Copper and brass are quite nice to work with, but are
easily dented with steel tools. I made a brass hammer to use instead
of a steel hammer.

Your ingenuity and workmanship never cease to amaze me! I certainly hope
someone realizes what a genius they have :-)

On Jun 17, 1:34*pm, Matty F wrote:
Somebody usually comes up with better ways of doing things, but here's
what I did - for the cost of four rivets!

I needed to make a couple of copper electrical fingers that were
missing from a motor controller, and found some suitable copper in the
scrap bin. There's a piece of phosphor bronze for a spring. Since
there's maybe 100 amps to conduct, that's too much current for the
spring or it will get hot and lose its springiness, so I made a few
layers from the pure copper shim shown at the top. The finger itself I
cut from the piece of bar and bent it and rivetted it with copper
rivets (new ones!)

The new finger is on the left, and an original one on the right:http://i53.tinypic.com/1z04.jpg

The two new fingers in place on the controller, at the far left:http://i56.tinypic.com/o5dp1l.jpg

Those fingers simply change the direction of the current and are not
switched while the power on.

Here's the whole controller. The fingers at the bottom change the
voltage going to the motor while it's operating, so they have to be
bigger:http://i55.tinypic.com/118qb0l.jpg

Parts for these controllers are not available any more so need to be
fabricated. Copper and brass are quite nice to work with, but are
easily dented with steel tools. I made a brass hammer to use instead
of a steel hammer.

nice one


NT