My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Don Foreman wrote:
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

If you have time you can make bends the way I do on auto headers. Pick a
45, 90, or 180 bend, lay your straight sections out then just cut out
the appropriate section from the bend you have. Weld it in, grind smooth
and plate/paint as needed. With this trick you can make smooth bends
that will drive folks nuts.

--
Steve W.

I've use a street 45 elbow and a regular 45 elbow many times for all those
odd angles between 90 and 180 degrees. I'm certain you can get all these
angles with just these two parts if you don't mind the slight offset. From
a mathemtical point of view, you get the mirror image also, so 90 to 270
degrees is covered. Assuming you're not after acute angles, where is the
third 45 needed?

Karl

"Don Foreman" wrote in message
...
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Check with a muffler shop. They have machines that can bend it to the nth
degree, and it comes out nice and finished so the wire can pass through it.
Inexpensive, too.

Steve

"Don Foreman" wrote in message
...
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Just get somebody with a hydraulic tubing bender to do it for you. A buddy
of mine has the local dune buggy shop do his.

On Mon, 29 Mar 2010 05:51:15 -0500, "Karl Townsend"
wrote:

I've use a street 45 elbow and a regular 45 elbow many times for all those
odd angles between 90 and 180 degrees. I'm certain you can get all these
angles with just these two parts if you don't mind the slight offset. From
a mathemtical point of view, you get the mirror image also, so 90 to 270
degrees is covered. Assuming you're not after acute angles, where is the
third 45 needed?

Karl

No offset. Both pipes are in the same plane -- the outside of the
house.

On Mon, 29 Mar 2010 08:05:06 -0700, "Steve B"
wrote:


"Don Foreman" wrote in message
.. .
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Check with a muffler shop. They have machines that can bend it to the nth
degree, and it comes out nice and finished so the wire can pass through it.
Inexpensive, too.

Steve

I did think of that. The 2" conduit used for outside feeds is
considerably heavier than exhaust pipe, don't know if they could bend
that or not.

On Mon, 29 Mar 2010 11:23:21 -0700, "Bob La Londe"
wrote:

"Don Foreman" wrote in message
.. .
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Just get somebody with a hydraulic tubing bender to do it for you. A buddy
of mine has the local dune buggy shop do his.

There's a shop half a mile from here that does that. I priced one
bend about 15 years ago. Yikes!

On Mon, 29 Mar 2010 01:51:57 -0400, "Steve W."
wrote:

Don Foreman wrote:
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

If you have time you can make bends the way I do on auto headers. Pick a
45, 90, or 180 bend, lay your straight sections out then just cut out
the appropriate section from the bend you have. Weld it in, grind smooth
and plate/paint as needed. With this trick you can make smooth bends
that will drive folks nuts.

I like that idea! I was trying to avoid burning off zinc and needing
to re-plate, but it would make a slick job of it.

"Don Foreman" wrote in message
news
On Mon, 29 Mar 2010 08:05:06 -0700, "Steve B"
wrote:


"Don Foreman" wrote in message
. ..
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Check with a muffler shop. They have machines that can bend it to the nth
degree, and it comes out nice and finished so the wire can pass through
it.
Inexpensive, too.

Steve

I did think of that. The 2" conduit used for outside feeds is
considerably heavier than exhaust pipe, don't know if they could bend
that or not.

Two things: Don't cost to ask, and it don't have to be perfect.

Steve

Steve B wrote:

"Don Foreman" wrote in message
news
On Mon, 29 Mar 2010 08:05:06 -0700, "Steve B"
wrote:

"Don Foreman" wrote in message
...
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.
Check with a muffler shop. They have machines that can bend it to the nth
degree, and it comes out nice and finished so the wire can pass through
it.
Inexpensive, too.

Steve
I did think of that. The 2" conduit used for outside feeds is
considerably heavier than exhaust pipe, don't know if they could bend
that or not.

Two things: Don't cost to ask, and it don't have to be perfect.

Steve

3 words: Hydraulic Pipe Bender

Horrible Fright has them to bend up to 3" pipe or rigid conduit for
about $200.

This one is slightly more, but the 'air over hydraulic' is a big help:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=97468

The usual caveats about HF quality apply...

Carla

I love wearing low cut shirts cuz then when class gets boring, I can
look down and admire my breasts. textsfromlastnight.com

On Mon, 29 Mar 2010 17:22:56 -0500, Don Foreman
wrote:

On Mon, 29 Mar 2010 11:23:21 -0700, "Bob La Londe"
wrote:

"Don Foreman" wrote in message
. ..
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.

Just get somebody with a hydraulic tubing bender to do it for you. A buddy
of mine has the local dune buggy shop do his.

There's a shop half a mile from here that does that. I priced one
bend about 15 years ago. Yikes!
Forget about metal conduit - use PVC and heat bend it as required.
Gerry :-)}
London, Canada

"Carla Fong" wrote in message
...


Steve B wrote:

"Don Foreman" wrote in message
news
On Mon, 29 Mar 2010 08:05:06 -0700, "Steve B"
wrote:

"Don Foreman" wrote in message
...
My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.
Check with a muffler shop. They have machines that can bend it to the
nth
degree, and it comes out nice and finished so the wire can pass through
it.
Inexpensive, too.

Steve
I did think of that. The 2" conduit used for outside feeds is
considerably heavier than exhaust pipe, don't know if they could bend
that or not.

Two things: Don't cost to ask, and it don't have to be perfect.

Steve

3 words: Hydraulic Pipe Bender

Horrible Fright has them to bend up to 3" pipe or rigid conduit for about
$200.

This one is slightly more, but the 'air over hydraulic' is a big help:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=97468

The usual caveats about HF quality apply...

Carla

I love wearing low cut shirts cuz then when class gets boring, I can look
down and admire my breasts. textsfromlastnight.com

I have been considering a combination of tubing bender and notcher to make
some frames for canvas work, and some covered with corrugated profile
roofing. Really not rocket surgery, and if you get the triangulation and
cross bracing right, pretty sturdy.

Steve

On Sun, 28 Mar 2010 23:55:16 -0500, Don Foreman
wrote:

My neighbor is re-doing his electrical service feed because he wants
to increase capacity to 200 amps. As part of that, he wants to
re-route the outdoor conduit from meter to relocated mast. We found
that his roof pitch is 5 in 12 or 22.62 degrees. He wondered if I
could bend 2" pipe. The short answer is "not well".

I got to thinking about elbows. It's fairly obvious that any arbitrary
angle can be achieved in a given plane with four 90-deg elbows. We
wondered what could be done with 45 deg elbows. I played with Alibre
for a while. Turns out four 45's can't get it done ... but three 45's
can! They go a bit out of plane but not a lot and the two runs can be
coplanar as in up against the house. I was even able to get the
various rotation angles, as if such a thing might need to be
fabricated and welded a priori. I just did that to see if I could, and
how hard it might be to do with Alibre.

Three 30's, like the familiar 3-section flue elbows, might work even
better but I don't know that 30 deg elbows are available in 2". I
don't know that 45's are either, but it seems likely.


If I'm reading the first part of this post correctly this "pipe" is a
part of the 'service entry' system. The NEC and local codes have some
very hard and fast requirements for the material used and the
installation of same. PLEASE check with a local electrician, or your
electrical inspector, for his advice before material is 'cut', 'bent',
_'welded'_, etc. (most codes frown on PVC for service entry use)

Bending Rigid Metal Conduit is just like bending Galvanized Metal
Pipe. Any electrical shop or pipe shop should be able to do the
bending for you.

Bob (used-to-was electrician)
rgentry at oz dot net

Bob Gentry wrote:
.... (most codes frown on PVC for service entry use)

Around here (NW of Boston) it's used almost exclusively. For
residential anyhow. Bob

On Tue, 30 Mar 2010 13:43:07 -0400, Bob Engelhardt
wrote:

Bob Gentry wrote:
... (most codes frown on PVC for service entry use)

Around here (NW of Boston) it's used almost exclusively. For
residential anyhow. Bob


Cool Sure would be easier to form into place. The day hasn't been
a total loss. . . . . I learned something

Thanks!!
Bob
rgentry at oz dot net

On Tue, 30 Mar 2010 13:43:07 -0400, Bob Engelhardt
wrote:

Bob Gentry wrote:
... (most codes frown on PVC for service entry use)

Around here (NW of Boston) it's used almost exclusively. For
residential anyhow. Bob

My neighbor is a guy that would be sure he meets applicable codes. The
Fridley electrical inspector is a good guy, very willing to answer
questions and help homeowners do things right the first time.

The three-elbows problem was mostly an interesting puzzle for me. If
an electrical shop can bend the conduit, that's the clear way to go.

On Wed, 31 Mar 2010 00:02:53 -0500, Don Foreman
wrote:

On Tue, 30 Mar 2010 13:43:07 -0400, Bob Engelhardt
wrote:

Bob Gentry wrote:
... (most codes frown on PVC for service entry use)

Around here (NW of Boston) it's used almost exclusively. For
residential anyhow. Bob

My neighbor is a guy that would be sure he meets applicable codes. The
Fridley electrical inspector is a good guy, very willing to answer
questions and help homeowners do things right the first time.

The three-elbows problem was mostly an interesting puzzle for me. If
an electrical shop can bend the conduit, that's the clear way to go.


A small, residential only, might have a bit of a problem. (That was
the focus of my business back 'in the day'. I did make a few 'offset'
bends with a small hydraulic bender so it is doable)

But bends like this are done all the time in the commercial electrical
world. If you made up a sketch with the planes on which the conduit
will 'lay' and the various offset dimensions, a commercial shop should
be able to give you a bid.

Sounds like it might be a fun Alibre project using the NEC
requirements for bend radius grin.
rgentry at oz dot net

On Sat, 03 Apr 2010 18:32:28 -0500, Wes wrote:

Don Foreman wrote:

On Tue, 30 Mar 2010 13:43:07 -0400, Bob Engelhardt
wrote:

Bob Gentry wrote:
... (most codes frown on PVC for service entry use)

Around here (NW of Boston) it's used almost exclusively. For
residential anyhow. Bob

My neighbor is a guy that would be sure he meets applicable codes. The
Fridley electrical inspector is a good guy, very willing to answer
questions and help homeowners do things right the first time.

The three-elbows problem was mostly an interesting puzzle for me. If
an electrical shop can bend the conduit, that's the clear way to go.


IIRC, you are allowed 270 degrees of bend between pull boxes. I'm going from memory so I
could be wrong, don't have a copy of the NEC at the house.

Wes


....not more than the equivalent of four quarter bends (360) degrees
between any two "pull points"...

EMT, IMC or GRC

NEC 346-11
rgentry at oz dot net

Don Foreman wrote:

On Tue, 30 Mar 2010 13:43:07 -0400, Bob Engelhardt
wrote:

Bob Gentry wrote:
... (most codes frown on PVC for service entry use)

Around here (NW of Boston) it's used almost exclusively. For
residential anyhow. Bob

My neighbor is a guy that would be sure he meets applicable codes. The
Fridley electrical inspector is a good guy, very willing to answer
questions and help homeowners do things right the first time.

The three-elbows problem was mostly an interesting puzzle for me. If
an electrical shop can bend the conduit, that's the clear way to go.


IIRC, you are allowed 270 degrees of bend between pull boxes. I'm going from memory so I
could be wrong, don't have a copy of the NEC at the house.

Wes