Maker Pro
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Need Earth Ground Without Drilling a Hole

D

D from BC

Jan 1, 1970
0
---
Why can't you drill and countersink a hole and use a flat head screw
to keep the sides smooth?

What are "shock levels?"

140VDC with 2A electronic current limiting.

I thought about countersinking but I think all the bolts in my
fastener collection have heads in excess of the material thickness.
I could try shopping for a 1.5mm heads..
But..I recall some years ago using washers on the inside to fix that.
D from BC
 
D

D from BC

Jan 1, 1970
0
Oh yeah....huhhh..I'm forgetting everything.. :(
But I do remember trying to get PEM fasteners about 2 years ago..
I think I still have the link to a distributor on my PC.
Thanks
D from BC
 
J

Jamie

Jan 1, 1970
0
D said:
I need to connect the green earth wire to an aluminum box but... the
tricky situation is that I can't drill a hole for a bolt, screw or pop
rivet.

What do I do?


D from BC
We use to have some putty that was high temperature flash burn
that contained metals to bond conductors much like soldering. The
flash putty we used contained Silver Solder and it would form an
ash on it after the flame went out which was quick. you brush it away
and you had a nice formation of silver solder bonding the conductors.

At the time, they made various different metal mixes for what ever.
I do remember seeing one for ALUMINUM but never used it.

We no longer use it and I don't know if you can still get it how ever,
it would be great thing to flash weld a stud on.

How about a beam clamp?
 
R

Robert Baer

Jan 1, 1970
0
D said:
I need to connect the green earth wire to an aluminum box but... the
tricky situation is that I can't drill a hole for a bolt, screw or pop
rivet.

What do I do?


D from BC
"Can't"?????
How did you *type* the query?
 
M

mpm

Jan 1, 1970
0
Oh yeah....huhhh..I'm forgetting everything.. :(
But I do remember trying to get PEM fasteners about 2 years ago..
I think I still have the link to a distributor on my PC.
Thanks
D from BC- Hide quoted text -

- Show quoted text -

How is a PEM fastener going to work if you can't drill a hole?
Either I'm missing something here, or....
 
D

D from BC

Jan 1, 1970
0
How is a PEM fastener going to work if you can't drill a hole?
Either I'm missing something here, or....

I didn't express the problem accurately...
Better expressed:
I need to bond a ground wire inside a box but I don't want to create
any external protrusions.
There are PEM's that can be countersunk and have thin heads.

Someday I'd like to weld an aluminum bolt to the inside of the box for
an earth ground connection.
Anybody here do little welds like that?

D from BC
 
R

Robert Baer

Jan 1, 1970
0
D said:
I didn't express the problem accurately...
Better expressed:
I need to bond a ground wire inside a box but I don't want to create
any external protrusions.
There are PEM's that can be countersunk and have thin heads.

Someday I'd like to weld an aluminum bolt to the inside of the box for
an earth ground connection.
Anybody here do little welds like that?

D from BC
How about a spot welder?
 
D

D from BC

Jan 1, 1970
0
No, i meant "do you have arms and hands?"

Yup.. No missing parts...
I just "can't" think of a clever way of bonding a ground wire to an
aluminum box.

It's done now.. PEM will be used next time and welding will be down if
I learn welding and find it worthy to get the equipment.
The welder might look good next to the scope :)
D from BC
 
A

Adrian Tuddenham

Jan 1, 1970
0
D from BC said:
I need to connect the green earth wire to an aluminum box but... the
tricky situation is that I can't drill a hole for a bolt, screw or pop
rivet.

What do I do?

If the hole itself isn't the problem, but you have to avoid anything
projecting on one side of the panel, drill a countersunk hole and use a
conventional countersunk rivet.

(Assuming there is anyone left who still remembers how to close a rivet
by hand.)
 
E

Eeyore

Jan 1, 1970
0
Rich said:
Use the kind of lockwasher with the teeth all around, to dig into the
metal.

Now, should one use an internal or external shakeproof washer here ?

Graham
 
D

D from BC

Jan 1, 1970
0
Now, should one use an internal or external shakeproof washer here ?

Graham

Wha?
The washer is inside the box..
The outside of the box has no protruding fasteners.
D from BC
 
D

D from BC

Jan 1, 1970
0
How about a spot welder?

I guess 4 spot welds might be enough to hold a 4mm wide threaded stud
on an aluminum box.
The stud is so small, welding all around adds very little time.

D from BC
 
D

D from BC

Jan 1, 1970
0
If the hole itself isn't the problem, but you have to avoid anything
projecting on one side of the panel, drill a countersunk hole and use a
conventional countersunk rivet.

(Assuming there is anyone left who still remembers how to close a rivet
by hand.)

Countersink rivets!... That exists!?
I'll check with my fastener suppliers.
D from BC
 

neon

Oct 21, 2006
1,325
Joined
Oct 21, 2006
Messages
1,325
you may ground the alunimumn box any way you want the question in my mind is how is the box grounded to begin with flex cable or what?
 
J

Jasen

Jan 1, 1970
0
One time I did mix epoxy with aluminum splinters..Worked good.

Commercial silver conductive adhesive sounds ok.. I'm clueless if this
can pass 15amps in the event of a ground fault. I'll check some
specs..

how do you intend to limit the fault current to 15A?

Bye.
Jasen
 
A

Adrian Tuddenham

Jan 1, 1970
0
D from BC said:
Countersink rivets!... That exists!?
I'll check with my fastener suppliers.

I've got a bag of them that I bought a couple of years ago from a local
metalwork supplier. You could always machine one up in the lathe if you
are just making a one-off job.

If the panel is too thin to drill a decent countersink without weakening
it, it should be possible to deform the metal to the required shape.
< http://www.poppyrecords.co.uk/other/CountersunkRivet.gif>
 
J

John Fields

Jan 1, 1970
0
140VDC with 2A electronic current limiting.

I thought about countersinking but I think all the bolts in my
fastener collection have heads in excess of the material thickness.
I could try shopping for a 1.5mm heads..
But..I recall some years ago using washers on the inside to fix that.
 
D

D from BC

Jan 1, 1970
0
how do you intend to limit the fault current to 15A?

Bye.
Jasen

A 15Amp draw trips the circuit breaker in the electrical room.
I'm using the breaker trip level as a guide to know how much current
the ground connection should handle in the event of a short circuit.

For example, during a fault, a soldered earth ground wire might melt
by the time the 15amp breaker trips in the building electrical utility
room.
D from BC
 
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