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Acrylic PipeBending 101

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This thread is a brief how to on bending acrylic pipe and the basic use of a former.

First up is the basic kit we need.....(Magoo optional)

z3bAHvY.jpg

We have a heatgun,tube,silicone fuel line that has an OD matches the ID of the tube you wish to bend and a former....the square is for checking the 90 bends on the former.

So,the former,in this case a 2" wide piece of sheet alu rolled over a deodarant can to get a radius,you can select anything with a diameter of 40mm or over,thick walled tube will need a larger radius to prevent kinks.

ZpnxeUn.jpg?1

The line is the bend start,this will become clear in a minute

The beauty of this is that you can form any specific angle you like and bend tube to it.
For instance: You have 2 ports you wish to join on the same plane,you can form the pathing from the inner measurement between the ports and bend a former to suit. Measure the closest points between the fittings from the actual tube insert point,bend the former so the 2 faces on the 90s match the gap and Bob is indeed your uncle

The silicone fuel line.

ei98ypK.jpg

This needs to be around .5mm smaller that the ID of the tube you are bending

UGfrUTS.jpg

Normally used for RC cars,chosen for its high melt point and great flexibility.

The small cut line round the tube is placed at the start of you bend and is the reference point for another way of doing point to point bending.
Remember the pencil line on the former? Well,put the cut line  of the silicone tube on that ref point when doing the bend and you will get consistent bend radius measurement.

Like this.

61hvnRf.jpg

For example: I want to tube 2 ports 150mm away,inlet to inlet on the inner points,I know that a bend will have a measurement of 20mm from that mark in the fuel line to the inner wall of the radius. Knowing that,we can make the first bend using the ref point on the former,insert the tube with the mark 130mm away from the inner wall of first 90,make the bend using the ref point on the former and both inner walls will be 150mm away from each other.

The bend.

ItCUUbQ.jpg

You cant see the fuel line mark but its ion line with the former ref point,this is  the distance you will need to heat up ,around 100mm with the bend start 2/3 its length .

This creates a very even bend.

CVzfKxa.jpg

Hold the tube around 70mm above the heat gun on high.
IMPORTANT: Keep the tube moving,rotate constantly,do not let the heat sit in any one place.

Soon the tube will not be able to hold its own weight,this is the critical moment,too long and it will create visual anomalies and start to burn.

f3lSYzF.jpg

Now i dont have pics for the next bit as i only have one pair of hands ...

When the tube starts sag,quickly transfer to the former,matching the 2 ref points up and slowly 'form' round the radiused section,dont force it,take your time. If it starts to stiffen then re heat as required.

When you are happy with your bend then let it cool naturally,when cool you can twist the fuel line straight out with no fuss.

You should be left with this

xsrAnck.jpg

I will be adding more on the former when Magoo finds a human lackey to do the pics.

As always,heatguns are awesome but burn stuff,be careful.

 

Fittings and Tube:

EK & E22 acrylic tubes come in 10mm ID and 12mm OD sizes. Both EK and Bitspower have non-compression fittings for the 10/12mm acrylic tubes.
EK and Bitspower C47 fittings are double O-Ring fittings.
Bitspower C48 fittings are skinnier and use a single O-Ring.
EK & Bitspower fittings grip really tight and you need to ensure you camber the edge of the tubes at an angle else (eg: 45deg), else you will tear your O-Rings when you put in your tubes. It helps to coat the tip of your tube in silicone grease,a thin smear will do,prior to inserting into the fittings.
You'll need to ensure your tube is seated all the way to the end and past the 2nd O-Ring.
The “seating depth” of the tube on C47 fittings is 8mm.
The “seating depth” of the tube on C48 is 4mm.
The “seating depth” of the tube on EK fittings is 9mm.

The PrimoChill acrylic tubes comes in
Inner Diameter: 3/8in.
Outer Diameter: 1/2in.
Wall Thickness: 1/16in.. This means that PrimoChill acrylic tubes and fittings are NOT compatible with EK, E22, & Bitspower tubes and fittings.

ITDiva has done some testing of other former materials and found that Buna N cord has nice properties for this method,it swells slightly when warm and shrinks when cold.
A nice alternative to the silicone currently used. As always,a former OD of 1mm less then the acrylic ID applies.


Monsoon have come to the game with a new mandrel set with everything you need with the basic technique shown above but with purpose built mandrels/formers and a new range of fittings with a novel locking technique.

The Monsoon hardline kit videos:

http://geno.boxgods.com/Hardline_Premium_Fittings.mp4

http://geno.boxgods.com/Hardline_Tools_Heatgun_Kit.mp4

http://geno.boxgods.com/Hardline_Tools_mandrels_and_Measure.mp4

http://geno.boxgods.com/Hardline_Tools_mandrels_and_Measure_2.mp4

http://geno.boxgods.com/Hardline_Cutting_Kit.mp4

This OP will be updated with a pictorial of it in use when my kit arrives.

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Fittings and Tube:

EK & E22 acrylic tubes come in 10mm ID and 12mm OD sizes. Both EK and Bitspower have non-compression fittings for the 10/12mm acrylic tubes.
EK and Bitspower C47 fittings are double O-Ring fittings.
Bitspower C48 fittings are skinnier and use a single O-Ring.
EK & Bitspower fittings grip really tight and you need to ensure you camber the edge of the tubes at an angle else (eg: 45deg), else you will tear your O-Rings when you put in your tubes. It helps to coat the tip of your tube in coolant prior to inserting into the fittings.
You'll need to ensure your tube is seated all the way to the end and past the 2nd O-Ring.
The “seating depth” of the tube on C47 fittings is 8mm.
The “seating depth” of the tube on C48 is 4mm.
The “seating depth” of the tube on EK fittings is 9mm.

The PrimoChill acrylic tubes comes in
Inner Diameter: 3/8in.
Outer Diameter: 1/2in.
Wall Thickness: 1/16in.. This means that PrimoChill acrylic tubes and fittings are NOT compatible with EK, E22, & Bitspower tubes and fittings.

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very cool idea, I had been thinking for awhile of how to get consistent and repetitive bends easily. I had an idea but i never tried it, If you can find metal conduit with an id the same as the tubing od you could bend the conduit to the desired angle and then slice it down the middle to have a jig or form. I guess its basically the same thing you are doing really.

 

great minds. haha

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very cool idea, I had been thinking for awhile of how to get consistent and repetitive bends easily. I had an idea but i never tried it, If you can find metal conduit with an id the same as the tubing od you could bend the conduit to the desired angle and then slice it down the middle to have a jig or form. I guess its basically the same thing you are doing really.

 

great minds. haha

 

 

Interesting but it wont work for a good reason,when you push the tube in,the walls of the tube will draw heat out of it quickly and,more importantly,you would need to heat the whole length inserted in to the tube to get round the 90 bend. When you push the tube in,it will try to collapse on itself.

 

It wont work as you intended.

 

 

However,the tube cut thru the middle and round the bend to make a cupped former,this would work very well. So much so that im going to have a go and make that former myself.

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Right then,I have something new to suggest as a former.
The way to fine angles as a carpenter is the use of our friend ,the Bevel.
$T2eC16ZHJGEFFmyVVOwiBSKyJ1ffjQ~~60_58.J
Most bevels have the 'blade' mounted along the centerline of the tool and also have a rounded end,set your angle and form the tube round the blade and 0 block.

Much easier and endlessly reuseable.

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im glad you posted that b negative, I forgot about this completely somehow. Can you actually measure stuff with that? If you get a combination square you can find angles, find center lines and find centers on pipe (you can do tubing with a smaller unit)

 

http://www.garrettwade.com/product.asp?pn=74N04.06&&SID=W4011000&EID=W4011001&utm_source=Google&utm_medium=ProductAds&utm_campaign=Google1&cvsfa=3928&cvsfe=2&cvsfhu=37344e30342e3133&gclid=CP7Cm_yV3LkCFdGd4Aod8EAAkg

 

did you ever make that former?

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im glad you posted that b negative, I forgot about this completely somehow. Can you actually measure stuff with that? If you get a combination square you can find angles, find center lines and find centers on pipe (you can do tubing with a smaller unit)

 

http://www.garrettwade.com/product.asp?pn=74N04.06&&SID=W4011000&EID=W4011001&utm_source=Google&utm_medium=ProductAds&utm_campaign=Google1&cvsfa=3928&cvsfe=2&cvsfhu=37344e30342e3133&gclid=CP7Cm_yV3LkCFdGd4Aod8EAAkg

 

did you ever make that former?

 

Nearly,got 12mm ID SS tube in the mail.

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Honestly, I've never had the need for bending jigs when doing this. I just do it free hand, and haven't had any issues yet. Though obviously if I were doing SS then I'd need something lol

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