Help with Conduit/Pipe/Tubing Bending and Fabrication

Metal Shop
#1

Hey all! First time poster and soon to be new Makerspace member here. I’m trying (in my mind) to make a fairly straightforward semi-circle bend in a pipe/conduit/tube (I understand those are three different things, but let’s go with “tube” for now).

What I’m trying to do is take a 1’’ diameter tube, bend it in a circle-ish shape and then flatten the ends / drill holes in them so I can then bolt them under the handlebars of my Vespa so I can mount a little phone holder.

Not the most ambitious structural project ever attempted, I’m sure, but eager to learn and try to do it at the DMS!

And here is a rough attempt I tried to create with hand tools - which didn’t come out so great. The cardboard template is a cut out of the clearance I need under the bolts to turn the handlebars once the pipe is mounted. I need a U-shaped or wider circular shape bend such that the center of the flattened pieces are about 6 3/4’’ apart

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I originally thought it wold be easier / lighter to do this in aluminum, but this 3/4 steel electrical conduit works fine (if I can get it to the right shape and all without kinking it).

Any help / ideas / guidance MUCH appreciated!

#2

And here’s an image with bolt view under the vespa and my very rough design idea.

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#3

Most common way is to tightly pack it with sand and cap the ends, this helps prevent it from kinking.

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#4

Solid tip! I haven’t been up to DMS yet, but I’m hoping there’s a pipe bender / radius bender with the right dies that will help me get this done?

#5

There is an electrician’s conduit bender in the Electrical Room behind the Machine Shop

Another method is to insert the pipe in a long spring, bend the spring and it will keep the pipe from kinking.

#6

Adding on to Ray’s advice: Here’s an example using a spring, the video shows it being bent manually. If you are doing with conduit, then you’ll get really good results using both of these - the spring will allow for a tighter bend radius. The bender mandrel will help keep everything straight and reduce likelihood of a kink.Spring bender

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#7

What is the max diameter on the slip roller? It has groves for round stock.

#8

Per the manual. off thewiki, 1/2"

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I presume that’s outside diameter…

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#9

The springs in the machine shop only go to 5/8”

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#11

So on 1 diameter”, you are looking about a 3” CLR. That would give you a outside diameter of about 7”. Any tighter & you might start to kink.
Here is what is Pro-Tools has to say.
https://pro-tools.com/pages/90-degree-round-tube-dies-for-105-standard-duty-and-heavy-duty-tube-and-pipe-benders

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#12

Have NO idea what any of that means. ;-(

Here’s my ultimate question:

“Does DMS have the tools to give me the bend in the pipe I want? (ideally 3/4’’) or if not, what are my limitations? Smaller diameter pips on the roller? Less bend on the larger machines? What are my constraints?”

Thanks in advance!

#13

So what happens is the tighter the bend, the more likely you will kink on the inside of your bend. You may be able to achieve your diameter since it’s close to the minimum bend. If you were to go with 3/4 outside diameter, it could be achieved easily.

As to if we have the tool, I’d have to check dimensions of the tooling we have. The tubing bender that is on loan does not have that die size currently.

A standard 1/2 conduit bender (1/2 in conduit is about .706 OD)will get you in area of about 8 1/2 outside diameter.

That said, we do have a large radius roller that might could be used to give you that diameter, I’m not certain on the diameter of it at this time. When I say this I mean using the upper roller as a die similarly as you would use on a conduit bender.

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#14

Or if you wanna do it the hard way… theoretically this could be done with round pipe as well.

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#15

Maybe conduit/tubing is not the right choice of material for the job. Square tube of even flat bar cur on the band saw.

#16

With flat stock could just heat with induction forge and bend accordingly. I assume they need round for their phone mount.

#17

Interesting way to make a round corner.

#18

I’m thinking the radius roller might work perfectly… a half circle or larger scribed parabola / circle would work, then we just cut the circle at the space I need for the holes.

#19

Tim / Jim - When’s a good time to come up there and try to figure this out?

#20

that is supposed to say Cut on the band saw, I was not clear on this. bending is a PITA but anybody can cut aluminum on a vertical band saw.

#21

bump - would love to come up to DMS and see if we can make this pipe bend work. How do i go about scheduling a time / trainer / orientation for the metal shop?