Bending conduit…A bit different

[Knobhead]

Not a job of mine but was asked about making a frame out of 25mm conduit. Not a single wire involved in this project.

What ID radius can you bend 25mm 180° to using a standard Hilmore bender?

Nothing to do with sledges or anything along those lines.

 

[johnboy6083]

It will be 2.5 x the conduit diameter. So 50mm for M20 conduit, 67.5 for M25, and 80mm for M32

 

[benji]

surely size of former will dictate radius

 

[mogga]

thats what tony seems to be asking benji anyone with a Hilmore bender measure the ID

 

[Knobhead]

I don't have access to a Hilmore now otherwise the tape measure would have been the first port of call.

If needs be I'll just nip in to hire station or where ever and measure a former. As I say it's not for me, but I'll be doing the drawings for it.

 

[ian.settle1]

Use a block of wood you get a tighter bend.

 

[ackbarthestar]

A slight deviation....
Dropping switch lines in cavity walls often meant that the standard 90deg bend with a 20mm former would not allow a coupler on the end with a m/c flush fitting switch box, so we used a 16mm former on 20mm pipe. Worked every time.

 

[Knobhead]

My mate and I would like this to look professional, not a wrinkled mess.
This is going to be on display so has to look just right. We can work the dimensions of the finished piece around whatever the bend radius is.

We did look at using hydraulic pipe and use a hydraulic pipe bender but the end result would be to heavy.

 

[Silly Sausage]

Just a thought...
Would heating the pipe up to a slight glow, with a pipe spring inside stop it crinkling?
I can just imagine the spring being permanently trapped inside though.

 

[Knobhead]

I give up!

I’ll just go to the hire shop and measure one! It won’t be as accurate as I want because of the natural spring back in the conduit.

I don’t want to find the tightest bend. I want a nice regular bend that can be reproduced time and time again.

 

[Silly Sausage]

I give up!

I’ll just go to the hire shop and measure one! It won’t be as accurate as I want because of the natural spring back in the conduit.

I don’t want to find the tightest bend. I want a nice regular bend that can be reproduced time and time again.

Calm down dear!

Have you tried asking on the plumbers forum...

 

[Knobhead]

Plumbers forum? For conduit!

Please Archie it's a serious question. We'll only get one bend out of one length. I suggested conduit for lightness which my mate is well up for. It's got to look solid, but strong and be light at the same time.

 

[alarm man]

Plumbers forum? For conduit!

Please Archie it's a serious question. We'll only get one bend out of one length. I suggested conduit for lightness which my mate is well up for. It's got to look solid, but strong and be light at the same time.

what is this project tony,sounds interesting

 

[spark 68]

I have measured the former on mine, but mine has only the 25mm former, is this any use ?

Outside Dia = 220mm,

I will go and measure the I/S dia.

I/s Dia = 170mm, lol.

 

[Silly Sausage]

Plumbers forum? For conduit!

Please Archie it's a serious question. We'll only get one bend out of one length. I suggested conduit for lightness which my mate is well up for. It's got to look solid, but be strong and be light at the same time.

Just slinging some ideas into the mix. Obviously no use. Never mind.
Sounds like a serious/pro job. You'd be better off getting professional advice somewhere else.

 

[alarm man]

I have measured the former on mine, but mine has only the 25mm former, is this any use ?

Dia = 220mm

sounds about right i got 250mm using me fingers,

 

[Knobhead]

It was 25mm I wanted.

At long last a dimension I can work on.

This has got to look right, not for my sake but my friend's reputation. I can now do the rough drawings to provide the overall dimensions. A mil or two either way he can cope with in the fabrication work.

I’m not having anything to do with the project other than advise and pre production outline drawings. But I’ve a horrible feeling I’m going to get a MIG welder shoved in my hand if he gets the contract.

 

[Silly Sausage]

Plumbers forum? For conduit!

Aye, apen.

But I do known plumber Dave, the man is a true craftsman! He is!

 

[johnboy6083]

it seems i got the complete wrong end of the stick in my initial reply. i have however been able to confirm spark 68's measurements. 67.5mm is the measuremtn fro the inside of bend to the back of bend. so from the last point on the former horizontally, to the first point on the former that is vettical. So to find the measyremnt tony is after, it is the measurements i gave x 4. so 67.4 x 4= 270mm. to find the inside measurements, -4x the conduit diameter, in this case 100mm. so 270- 100 = 170mm.

i havent got an M20 former to hand in order to check this theory, but if anybody has, could they please give us the measurenments.