How to bend conduit

Jimmy5

Hi guys,

Well i'm in my 3rd year as an apprentice and i'm still crap at conduit and bending it. I don't know what measurements to use and i usually just make a piece longer than i need then cut to suit,can be a problem when i'm doing an offset, i then chop it to fit only to find i can't thread it,and other silly things like that

Why do people put a mark on the top of the former,what is this measurement for? Also whats the ,to the back of the bend measurement?

I've been looking on the net but can only find American guides

http://www.porcupinepress.com/_bending/TheoryAndDrawings.htm

Any help or tips appreciated

steifanc

Jimmy5 wrote: »

Hi guys,

Well I'm in my 3rd year as an apprentice and i'm still crap at conduit and bending it. I don't know what measurements to use and i usually just make a piece longer than i need then cut to suit,can be a problem when i'm doing an offset, i then chop it to fit only to find i can't thread it,and other silly things like that

Why do people put a mark on the top of the former,what is this measurement for? Also whats the ,to the back of the bend measurement?

I've been looking on the net but can only find American guides

http://www.porcupinepress.com/_bending/TheoryAndDrawings.htm

Any help or tips appreciated

hi jimmy 5

there are a lot of sparks out there that have trouble with the bending machine , this is normally due to lack of use and forgetting rather than not being able .

first off forget that Yankee nonsense, it will confuse you more . i was working in the states a couple of years ago , sparking , i couldn't believe when i saw the sparks drawing out sketches using sine cos and tan to work out sets in tubing and tray , i taught they were taking the piss.

as for the mark on the top of the former, i honestly cant remember what that is for , i never done it that way .

the back of the bend is the bottom of the tubing hard to explain it in words,
if you were bending tubing around the inside of a room .bending from wall to wall at 90degrees the back of the bend measurement is where the tubing will hit the wall after the bend ,if that makes any scene.

when i was measuring and bending. say from a rose box along the roof down the wall to a switch .
the measurement from the thread in the box at the ceiling rose to the drop where you are coming down the wall for the switch . thats where you need the back of the bend , accounting for your saddle . hence the back of the bend measurement.

I'm sure there are loads of ways of measuring it and going about it. but this is how i use to do it.

measure from the rose to the back of the bend , <the wall , less the saddle >
mark the tubing with this measurement .
put the tubing in the bending machine pulling your mark up to the former,
i use to place a off cut of tubing against the former in the grove horizontal to my piece I'm going to bend.
line the off cut up with your mark , use a level or a square to get your angle right , making sure your off cut and marked piece are at 90 to each other.
and bend .

the off cut held square to your finish piece should line the outside of the former ,witch will be the outside of your bend , up with your measured outside of the bend.


now best of look if you can understand any of that , its really simple when your show /
maybe some of the other guys can explain it better

Jimmy5

Hi there,

steifanc wrote: »

i use to place a off cut of tubing against the former in the grove horizontal to my piece I'm going to bend.

Do you mean vertical as wouldn't the piece i'm bending be the horizontal piece?


Also if i measure 900mm to the back of the bend,i mark the conduit at 900mm but where abouts in the former do i place the mark?

Is it where you said to use an offcut piece and hold it vertical to my mark?

eire-kp

Fairly well explained there! But its really just practice. If you spend a bit of time at it you will be flying.

2011

Well explained steifanc!

Why do people put a mark on the top of the former,what is this measurement for? Also whats the ,to the back of the bend measurement?

This is if you want (for example) a piece of conduit that is 80cm from the conduit end to the back of a 90 degree bend.

1) Put a mark on the conduit 80cm from the end.
2) Place the mark at the far edge of the formour.
3) Bend the conduit 90 degrees.
4) Look at what has happened; when you measure from the end of the conduit to the back of bend you will see that it is about 76cm, ie shorter than you want. The length has been lost due to the rafius of the bend.
5) Now put a mark the formour 4cm from the edge.
6) The next time put the 80cm mark on the conduit at the mark and you should find that the completed piece of conduit has the correct measurement from the end to the back of bend.

I hope this makes sense!

steifanc

Jimmy5 wrote: »

Hi there,



Do you mean vertical as wouldn't the piece i'm bending be the horizontal piece?


Also if i measure 900mm to the back of the bend,i mark the conduit at 900mm but where abouts in the former do i place the mark?

Is it where you said to use an offcut piece and hold it vertical to my mark?

yeah on the vertical to the piece your bending.
measuring 900mm . place your offcut in the former at 90 deg to the piece ur bending . line the outside of the off cut , the side closest to you , up with your mark ,
when you have the mark on your bending piece square with the outside of your off cut , your ready to bend.
when your squareing up the two bits of tubing , make sure the piece your going to bend is tight against the stock, or you will loose a few mill on your bend.

.G.

If your making a 90 bend you line your mark up with the outside edge of the former as steifan has explained.

If however your doing a saddle jump, a 30 degree or a 45 degree offset then thats when you would use the mark on the top of the former which lines up directly with the centre of the former spindle.

I have my fas books as I'm not long out of phase 2,I could scan and email you the pages relating to this if you like.

PM your email if you want me to.

Jimmy5

Hi superq, pm sent

.G.

Email on the way:)