[TASEsq]

Does anyone know of any good tutorials online for fabricating fuel lines? I’m building a -14 and doing a full fuel return line setup so the lines won’t be the same as the plans.

What is the best method for measuring and templating a custom line?

Any good tutorials on using the tube bender (never used it!) and doing the flares? (only ever did a couple for the vent line in the tank and have a bunch of practice flared tube ends on my windowsill! so obviously not that good at it).

 

[terrye]

I used a Ridgid No. 406 (cat. no. 36097) 3/8" (fuel lines) and Ridgid No. 404 (cat. no. 36122) 1/4" (brake lines) benders. I had no luck with multi benders, spring benders, etc so buy quality single tube size benders. The benders dies are marked with the centerline radius of the finished bend as well as the tube size and the degree of bend from 0 to 180. I used a Ridgid No. 377 (cat. no. 41162) flaring tool (3/16" up to 3/4") for 37 degree SAE flares. You should be able to find online tutorials for these tools, also check the EAA website for tutorials.

I was fortunate in having a Solidworks CAD system to work with, but the key to using this or manual methods is very careful measurement. I used a 6" and 12" flexible steel engineer's rule calibrated in fractional and tenths. I built all my fuel and brake lines in Solidworks and then plotted them full scale which worked out very well although laborious (but less laborious than cut and try). In plane bends are easy with CAD or manual methods, out of plane bends are easy with CAD, more difficult with manual methods. My CAD drawings showed the OD of the tube, centerline of the tube and the intersection lines of the straight and curved segments. Manual methods would still work here. Overall lengths of tubes is done by measuring the centerline of the drawing. Bends are PI x radius^2 x angle of bend/360 degrees of bend.

Yes I still have a few pieces that are sitting on my bench that didn't quite fit.

After doing research and trying the 3003 alloy tube that Vans supplies in a coil, I decided to use a better grade 5052-0 aluminium which comes in straight lengths, thus don't have to unroll a coil first. I marked the start of each bend with a fine black Sharpie marker and then while still on the bender, marked the end of each bend. Then offered these up to my drawing for the start of the next bend.

I used 0.10 inches for the flare length at the end of each tube. Do not forget to put the sleeves and nuts on the tube before it is too late.

 

[fl-mike]

I used aluminum ground wire, about 1/8" dia, to make the pattern. Bend hard 90's (don't worry about the radius you will use on the tubing).
Then, if at all possible, make the beginning and ending of the tubing, when bending it up, a bit long to allow for trimming to fit.
Buy extra tubing! Some times it takes a couple tries. You'll start to get a feel for how to mark the bends from the pattern.
And, don't forget to put the sleeve on before flaring!

 

[TS Flightlines]

I used aluminum ground wire, about 1/8" dia, to make the pattern. Bend hard 90's (don't worry about the radius you will use on the tubing).
Then, if at all possible, make the beginning and ending of the tubing, when bending it up, to allow for trimming to fit.
Buy extra tubing! Some times it takes a couple tries. You'll start to get a feel for how to mark the bends from the pattern.
And, don't forget to put the sleeve on before flaring!

Trent-, there are several on You Tube. it DOES take practice to get things correct. Different tube material and wall thicknesses, have different springback so thats something to be considered. In your case of wanting to do your own duplex tubes, take a stiff piece of wire and make a pattern of BOTH tubes---since they have to parallel each other and the spar in a fairly confined space. Then make several bends that you can use to configure the tubes. This way you'll get comfortable doing them. Then merge all of this together. Or---purchase pre-bent CNC tubes.
Tom

 

[JonJay]

Some excellent advice. You know a class act when a vendor who makes a product tells you how to do it yourself.

Here is my tutorial. Have Tom do them. End tutorial.

Seriously, it’s a huge challenge to do custom lines. It’s also satisfying and kind of fun. You will ruin some tubing. You will scratch your head. You will get frustrated, but it’s a great skill to learn, even if you don’t ever have to do it again.
The 6’s tank to fuel selector lines are very challenging. I bailed on my build and used flexible line and fittings. Later, I decided I needed to go through the “right of passage” and make them. I did. It took me a couple times and some wasted tube, but I did it. I wouldn’t do it again.
I’d call Tom!

 

[Richard Connell]

I used an Imperial 370FHC 180 bender for both planes. Also used 5052 tubing. Waste the 3003 practicing.
It’s tricky but also very satisfying.
The key as mentioned above is careful measurement and understanding the offsets involved for different handed bends. Left v Right.
The imperial has the offsets on the bender which helps.
Here are the instructions for it. I’m sure they’ll be relevant no matter what bender you use. In conjunction with some videos you should be right.
Lots of info on flares here. My 2c is just to make sure that you clean and debur the tube cut as well as you can prior to flaring and lube the flare tool.

 

[[email protected]]

Some excellent advice. You know a class act when a vendor who makes a product tells you how to do it yourself.

Here is my tutorial. Have Tom do them. End tutorial.

Seriously, it’s a huge challenge to do custom lines. It’s also satisfying and kind of fun. You will ruin some tubing. You will scratch your head. You will get frustrated, but it’s a great skill to learn, even if you don’t ever have to do it again.
The 6’s tank to fuel selector lines are very challenging. I bailed on my build and used flexible line and fittings. Later, I decided I needed to go through the “right of passage” and make them. I did. It took me a couple times and some wasted tube, but I did it. I wouldn’t do it again.
I’d call Tom!

AS I was going through this thread I was thinking this same thing. (call Tom) If you are not comfortable making your own line you want to call Tom. Had them build all my fwf lines and fit great.
But, if you want to get into building your own line you will want to go to Summit "Aviation" Racing and start buying the Teflon lined SS braided line stock and fittings.
You may have the same Dollars involved when done though. And a bit of extra parts left over you get to look at in the future.
My luck varies FIXIT

 

[Mikeyb]

A trick I use to mock-up complicated bends is to put a couple of lengths of soft Iron wire in plastic tubing of the appropriate size. You can bend and straighten it at will. You can even mark and bend the plastic tubing with a bender then straighten it out and use it to mark the metal tubing.

 

[PhatRV]

During the learning and building process, I wasted a few yards of the fuel tube and vent tube. First of, if you can, use the tube bending tool because it will give you the correct radius for the various tube diameters. I also used the spring tube benders to manually manipulate the odd angle bends when there are interferences with the big tool.

I learned to prototype the tubing using the steel wires from the cloth hangars you find from the dry-cleaning store. They are soft enough to bend by hand and they approximate the final shape very well.

 

[rockyfatcat]

Anyone who has ever bent a tube knows they can get squished into a funny oval shape or get flattened when bending.

I’m surprised that no-one has mentioned the trick of filling the tube with sand, or something similar before bending.

I like the really fine sand out of the sandblast cabinet.

 

[cajunwings]

To mock up lines I like to use a length of white 10 gauge house wire inserted into some 3/8” clear vinyl tubing. Mark lines on the tubing every inch with a sharpie.

The tubing benders will make an accurate radius and the O.D. is very close to the -6 tubing used for the fuel lines.

 

[TASEsq]

Thanks all. Appreciate the tips.

I am feeling the love for Tom and his products and would love to go that route - but bring in Australia with the dollar and the shipping makes it just ridiculous, unfortunately.

Plus - I’m in this to learn!

I’ll be off to get some 10mm OD pvc hose and some solid core wire this arvo.

Been watching heaps of videos on the imperial bender and I think I get the L / R marking etc. I.e. you measure where you want the centreline of the tube to be after it’s been bent, align that mark with the L or R on the tool, align the zeros and pull the zero on the tool to 90 (or a bit past).

What if the bend is not 90 degrees? I assume you align the mark you make with the 45 on the tool, but how do you mark the tube for that? Where would a 45 be measured to? The start of the bend?

 

[TS Flightlines]

Thanks all. Appreciate the tips.

I am feeling the love for Tom and his products and would love to go that route - but bring in Australia with the dollar and the shipping makes it just ridiculous, unfortunately.

Plus - I’m in this to learn!

I’ll be off to get some 10mm OD pvc hose and some solid core wire this arvo.

Been watching heaps of videos on the imperial bender and I think I get the L / R marking etc. I.e. you measure where you want the centreline of the tube to be after it’s been bent, align that mark with the L or R on the tool, align the zeros and pull the zero on the tool to 90 (or a bit past).

What if the bend is not 90 degrees? I assume you align the mark you make with the 45 on the tool, but how do you mark the tube for that? Where would a 45 be measured to? The start of the bend?

Yes, shipping to Australia is somewhat of a pain, especially for just the rigid tubes, that there are 4 of. The shipping would actually be quite a bit more expensive than the tubes. BUT--The tubes are CNC bent, and fit, and the kit package also has the spar clips for securing the tubes

 

[TASEsq]

The tubing bender i have is the 470FH - the instructions are actually very good and cover how to do 45 and 45 double offset bends.

I ordered double the amount of 3003 tube when i got my fuselage kit, so keen to get stuck in and do some practice.

Any tips on straightening 3003? I was planning on making a cheap tubing straightener out of some patio door roller wheels. They aren't quite the correct diameter across the curve, but close. https://www.bunnings.com.au/rolltra...MFCOG4Au6KBbfzxTzKwaAs2MEALw_wcB&gclsrc=aw.ds

 

[PaulvS]

The tubing bender i have is the 470FH - the instructions are actually very good and cover how to do 45 and 45 double offset bends.

I ordered double the amount of 3003 tube when i got my fuselage kit, so keen to get stuck in and do some practice.

Any tips on straightening 3003? I was planning on making a cheap tubing straightener out of some patio door roller wheels. They aren't quite the correct diameter across the curve, but close. https://www.bunnings.com.au/rolltra...MFCOG4Au6KBbfzxTzKwaAs2MEALw_wcB&gclsrc=aw.ds

For straightening I rolled the length of tube on a flat hard surface, using a board as the roller. Initial straightening was by hand and this all worked well enough but the soft tube tends to bend out of line easily when it is being installed so it won't ever look perfect like the harder 5xxx tubing!

Another tip for bending up a complex line is to practice with some scrap to make the end bends separately. These can then be used as templates to help bend the whole spool.

 

[rsultzbach]

Anyone who has ever bent a tube knows they can get squished into a funny oval shape or get flattened when bending.

I’m surprised that no-one has mentioned the trick of filling the tube with sand, or something similar before bending.

I like the really fine sand out of the sandblast cabinet.

Does anyone know of any good tutorials online for fabricating fuel lines? I’m building a -14 and doing a full fuel return line setup so the lines won’t be the same as the plans.

What is the best method for measuring and templating a custom line?

Any good tutorials on using the tube bender (never used it!) and doing the flares? (only ever did a couple for the vent line in the tank and have a bunch of practice flared tube ends on my windowsill! so obviously not that good at it).

One tip I learned off a Boeing Aircraft training film is to always mark your tubing a full 360 degrees around using a sleeve as a circular straight edge.

 

[Bookworm1707]

The tubing bender i have is the 470FH - the instructions are actually very good and cover how to do 45 and 45 double offset bends.

I ordered double the amount of 3003 tube when i got my fuselage kit, so keen to get stuck in and do some practice.

Any tips on straightening 3003? I was planning on making a cheap tubing straightener out of some patio door roller wheels. They aren't quite the correct diameter across the curve, but close. https://www.bunnings.com.au/rolltra...MFCOG4Au6KBbfzxTzKwaAs2MEALw_wcB&gclsrc=aw.ds

Not sure if you 3d printed the bits you send me files for but there are some 3d printable straighteners on thingiverse or similar, need some common size bearings from Bunnings. Should be able to find the files if you need, send me an email.

 

[TS Flightlines]

Not sure if you 3d printed the bits you send me files for but there are some 3d printable straighteners on thingiverse or similar, need some common size bearings from Bunnings. Should be able to find the files if you need, send me an email.

Here is a great idea from a client in Canada that was wanting to duplicate these into a 1 piece tube. He made these in sections connected by a small inserted tube and aligned them. Tape index lines. So all we had to do was put them together, make sure the lines matched and scan them. You can do a similar job in your shop. LOL---getting the prebent tubing in palce might be a fun project---you can alsoo put a AN union in the long sections.

 

[cajunwings]

To mock these up I insert a piece of white 10 gauge house wire into 3/8” clear vinyl tubing. The O.D. is about the same as -6 aluminum tubing and the regular tubing benders

 

[TASEsq]

To mock these up I insert a piece of white 10 gauge house wire into 3/8” clear vinyl tubing. The O.D. is about the same as -6 aluminum tubing and the regular tubing benders View attachment 61830

Great idea.

I went to our local hammerbarn and made up a quick straightener using some wheels designed for screen doors. It worked 95% and I got the last little waves out by clamping one end in the vice and the other in vice grips and giving it a calibrated whang.

It also worked for straightening some 2mm fencing wire and I’ve placed this into some 6mm OD pvc tube. Once I get the fuel clips and fuel valve installed I’ll template up a tube and see how I go.

Thanks for all the great advice!

 

[Toobuilder]

Anyone who has ever bent a tube knows they can get squished into a funny oval shape or get flattened when bending.

I’m surprised that no-one has mentioned the trick of filling the tube with sand, or something similar before bending.

I like the really fine sand out of the sandblast cabinet.

I use sugar. It dissolves with hot water.

 

[rockyfatcat]

The thing with sugar is that it will form crystals. I think everyone had heard the horror stories about cars being scrapped because someone put sugar in the gas tank, and it was too expensive to replace the entire fuel system.

With any material it will be necessary to completely remove ALL the material before final assembly.

If all the sugar is not removed, it could grow into crystals that potentially could plug the fuel system. You aren’t going to get that with sand.

Either will work with the right precautions.

 

[TASEsq]

First go and making the fuel line went pretty well - I templated them using wire / pvc hose to approximate the length and angles. Took me 3 goes to get the measurement spot on - but one was a brain fart where I put the nut on in the wrong order. Doh. The second line (mirror image) I made to the same dimensions and it came out great. Fuel return lines next.

Thanks for everyone’s advice. It’s fun to learn a new skill. The bender is a cool bit of kit. Kinda nuts you can put a bend in a tube +/- 1mm from where you intended!

 

[Dr_Dave_MT]

Some excellent advice. You know a class act when a vendor who makes a product tells you how to do it yourself.

Here is my tutorial. Have Tom do them. End tutorial.

Seriously, it’s a huge challenge to do custom lines. It’s also satisfying and kind of fun. You will ruin some tubing. You will scratch your head. You will get frustrated, but it’s a great skill to learn, even if you don’t ever have to do it again.
The 6’s tank to fuel selector lines are very challenging. I bailed on my build and used flexible line and fittings. Later, I decided I needed to go through the “right of passage” and make them. I did. It took me a couple times and some wasted tube, but I did it. I wouldn’t do it again.
I’d call Tom!

"....You know a class act when a vendor who makes a product tells you how to do it yourself." my personal shout out to Evoke Aviation ( Aircraft Painting) at OSH last summer when I mentioned "I love your quality, but do not have the $$ nor the wait list time for your beautiful results" - dl

 

[Jjackh10]

Tubing is easy and fun. I've run miles of it for instrumentation and steam trace in industrial plants. It's no different than running conduit (except lighter and more fun). Get yourself an "Ugly's" book. It will help you calculate takeup, offsets and such.

 

[TS Flightlines]

Tubing is easy and fun. I've run miles of it for instrumentation and steam trace in industrial plants. It's no different than running conduit (except lighter and more fun). Get yourself an "Ugly's" book. It will help you calculate takeup, offsets and such.

Trent----as you might be able to see in the pic, I have an Imperial 364 hand bender that I modified. First mod---and one strictly for my convienence, is I welded a piece os steel angle onto the forward edge, so I could lock this in a vise and use 2 hands. I did all my handbenders this way. Other mod was to cut a slot into the bend die so I could bend the tubing close to the flare. Works well for messing around and prototyping. Our production tubes are bent on a CNC bender.