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Bending, flaring tight bends

J

Jim Edwards

I'm New Here
I'm struggling with the flared tubing between the Andair fuel selector and the Andair fuel filter/boost pump. Here's the problem: My Parker Rolo Flare tool requires 3/4" of tubing to clamp the tube prior to making the flare and the AN819 sleeve adds another 1/2". Any tricks here to make the start of the bend closer to the flare? Thanks.
 
What @aerhed said. Also, google for another flairing tool that doesn't require as much length as the standard Rolo Parker. I've heard they're out there.
 
Vince Frazier has a nice tip for this on his website worth taking a look at. Check out vincesrocket.com and look under the engine section.
Ryan
 
After spending many, many, many hours on this problem, I finally ended up just moving the Andair pump forward an inch or two. Then there was enough room to have a longer tubing piece, which made it possible to make the bends properly. I ended up ordering a new center cabin cover, but that was minor compared to all the hours spent trying to make the tube bends work beforehand.
 
Jim---
I modified my bender to move the nut and sleeve back--towards the bend arm. If I need to make a real tight bend, I bend the tube and install the nut after bending. I also made a mandrel to put inside the tube to support it against the bend brace on the bender. Works great.
Tom
 
Many thanks to those who have responded. I greatly appreciate the suggestions. Aaron, I may end up using your method. (We share a common bond with the many, many, many hours invested in what looks so simple on paper.) Tom, I can't visualize exactly how you modified your bender (I have a Harbor Freight cheapie as well as an Imperial 370 FH) but I, too, have thought about inserting a mandrel to give the bender "hook" something to hold on to. With the 3/8" tubing that I am using, the smooth shaft from a 19/64" drill bit seems the right size. I'd appreciate a photo, also, when you have the time. Thanks again.
 
Hey Buggsy--Yep--I'll take a pic of it tomorrow and 'try' to post it. May need some help doing that. If not---I can email it to you.
Just so you'll know, Its a Imperial 470-FH. Nothing fancy, but I added a piece of angle to it so I can lock it in a vise. Much easier to use 2 hands and not fight it. I bend aluminum 5050-O and 304 stainless .035 wall with no issues.
(the stainless takes some muscle; thats the reason for the piece of angle and vise mounting).
Tom
 
Well anyway---using the IMPERIAL 470 bender the closest flare to bend centerline you can get is 1.5 inches. Any closer, and you need a mandrel bender. Pretty expensive, and way beyond what a normal RV builder would need. (If you happen to have one--call me!). I take the 819 sleeve and shorten the leg to where it just protrudes out of the nut about .050. This still gives great support to the flare, and centers the nut. It also allows the flare to tube bend centerline to be shortened from 2.25 inches to 1.5 inches.

I'll try to get pics posted tonite--
Tom
 
my modified bender

I hope these come out.
4 pics showing the 470 FH Imperial bender, modified to move the bend closer to the flare. One pic shows a short piece of stainless, nut & sleeve, and a support mandrel. It does NOT change the bend radius, on supports the tube against the tab while bending.



bend%20tools.JPG
https://lh6.googleusercontent.com/-cipCBOnLimc/T4yfNMHdjAI/AAAAAAAAAJU/Wa4VtFXs5BE/s128/bend%20tools.JPG?gl=UShttps://lh5.googleusercontent.com/-jvICrYiO-L0/T4yfJvD2zPI/AAAAAAAAAJM/QHlVTDa8Pow/s128/bend%20radius%20difference.JPG?gl=UShttps://lh6.googleusercontent.com/-cipCBOnLimc/T4yfNMHdjAI/AAAAAAAAAJU/Wa4VtFXs5BE/s128/bend%20tools.JPG?gl=US
 
Last edited:
I took the long URL https://lh6.googleusercontent.com/-...AAAAAJU/Wa4VtFXs5BE/s128/bend tools.JPG?gl=US

and shortened it to http://is.gd/k0ND43

using a URL shortening extension in Firefox. There are several different URL shrinkers, for instance, bitly.com is another one, or tinyurl.com.

However the photo that appears is quite small...looks like a thumbnail photo.

Google photo albums used to be easier to use before they forced the Picasa stuff into Google+. Here's how I share a Picasa album online.

First, using Picasa, select your photos and upload them. Seems you've already done that.

Now go to a web browser and enter this URL: https://plus.google.com/u/0/photos/

Click on the square button labeled Albums. At least that's what it is for me, but I have a Google+ page, and if you don't it might well be different.

Anyway when I click Albums I am sent to a page with all my photo albums. Click on the album you want (your 4 photos). You'll see all the photos.

Click on the square button labeled More and a popup menu opens. Click Share Album via Link. Ctrl-C to copy the highlited link. Paste into your message here on VAF.

I created a test album of some build photos I just took (canopy cabin frame for my tipup RV-9A). Here's the link:

https://plus.google.com/photos/106346622652388191518/albums/5732170168193902369?authkey=COflyJv_yvii8wE

Try this last link and you'll see it goes to my test album.

It seems you got almost this far but maybe produced links to each photo?

BTW, I almost don't use Picasa to share photos anymore because of the Google+ nonsense. I prefer Dropbox. But I only mention it as another option, not a suggestion you switch to that.
 
ok Buggsy---
Jim sent me an email, and I email the pics to him. Geee---this uploading pics stresses me out. Send me an email and I'll email you the pics too.
Tom
 
Aaron C said:
After spending many, many, many hours on this problem, I finally ended up just moving the Andair pump forward an inch or two. Then there was enough room to have a longer tubing piece, which made it possible to make the bends properly. I ended up ordering a new center cabin cover, but that was minor compared to all the hours spent trying to make the tube bends work beforehand.
Click to expand...

This was a good move. And you will be rewarded every time you service the filter.
 
Gasman,
You raise a good point. If I install my Andair fuel filter/boost pump assembly per instructions, it appears that I would have to remove the mounting screws from the boost pump, then shift it forward slightly before I could detach the filter from the aluminum lines. In addition, I'm trying to find a mounting location for a second fuel filter to satisfy the requirements of my Precision Airmotive Silver Hawk EX fuel injection. Lots of head scratching going on.

RV-9A
Aerosport IO-320
 
Another idea

Jim Edwards said:
Gasman,
You raise a good point. If I install my Andair fuel filter/boost pump assembly per instructions, it appears that I would have to remove the mounting screws from the boost pump, then shift it forward slightly before I could detach the filter from the aluminum lines. In addition, I'm trying to find a mounting location for a second fuel filter to satisfy the requirements of my Precision Airmotive Silver Hawk EX fuel injection. Lots of head scratching going on.

RV-9A
Aerosport IO-320
Click to expand...

Jim,
You might also consider moving your two fuel filters into the wing root area. This will make future filter inspection & cleaning easier and no worries about spilling fuel inside the cockpit. You also protect your fuel selection valve, as it will receive filtered fuel. Just an idea [not mine originally] and worth what you paid for it.
Charlie
PS The fuel filter sold by AFP and Vans is a Flow Ezy model 6 ILA. For wing root mounting, the slightly smaller model 4 ILA work well. They are available from numerous vendors including Pegasus Auto Racing Parts [owned by RV builder Chris Heitman] See

https://www.pegasusautoracing.com/productdetails.asp?RecID=3469

AFP probably could supply 4 ILA filters as well.
 
I've seen one person use an right angle fitting to avoid having to make the bend in the tube (specifically by the fuselage wall where the tube turns away from the spar).

Critics will say that's one more place to leak, but if you stressed the tube during bending trying to get it to fit, then which option has the better chance of leaking? If the fitting is leaking, you can just tighten it. If the tube is leaking, your replacing the whole tube...

Vince
RV-7
N567VB
 
TS Flightlines said:
ok Buggsy---
Jim sent me an email, and I email the pics to him. Geee---this uploading pics stresses me out. Send me an email and I'll email you the pics too.
Tom
Click to expand...
Tom gave me permission to post his photos, which I'm doing here, along with his email text:

IMG_1240.JPG

IMG_1241.JPG

IMG_1242.JPG

IMG_1243.JPG


Since posting with you and Jim Edwards the other day, I made a another little change, and can now get the flare to 1.5 inches from the aft part of the bend.
Bending aluminum with this bender is pretty easy, but 304 stainless is hard on the moving parts, especially the wiper die. I've ordered a little different (heavier duty) version from Spruce that I should have in a day or 2. I plan on making the same modifications, only 'prettier'.
Click to expand...
 
Thanks Buggsy!
Tom---
PS----I recieved my new 364FHA06 bender in the mail today. I'll let everyone know how I like it.
Tom
 
Imperial 364FHA bender

I recieved my new 364FHA06 bender in the mail yesterday. MUCH heavier duty than the previous 470 bender that I modified. It is for bending 3/8 tubing only, but thats ok.
I modified it the same way as my 470, with an angle bracket to vise mount it, and shortened the step on the bend die, to move the flare AFT, towards the bend. The bender can now bend closer to the flare than usual, which is now 1.0 from the INSIDE of the bend, or 1.625 from the outside of the bend. For you guys installing an Andair valve and filter set up, this will help ALOT.

For 180* bends, the inside dimension is 1.625, and the outside is 2.312. It can bend pretty tight bends that are 180* apart at 2.125.
So far, the only real drawback is cost---about $85 from Spruce. But since I bend alot of 3/8 tubing anyway, its ok. A mandrel bender would be really nice---- but the cost is probably not worth the investment , along with a the laser coordinate scanner.
If Santa Claus is listening---------oh and a RV7A slider kit!
Tom
 
Guys, I don't want to resurrect a thread from the dead... but I will anyway. :)

Today I started learning how to do the flares and bends to set up my FI pump & filter, but quickly found that the tools I had would not get the bend close enough to the end of the tube. I was scratching my head for a while, and figured I couldn't possibly be the first one to run into this. VAF to the rescue... in fifteen minutes I knew what needed to be done. An hour later and some serious heat from Mr. Dremel and I have a tubing bender that will do what I need it to do.

I told my wife, this kind of thing is why I send Doug a check every year. :)
 
DaleB said:
Guys, I don't want to resurrect a thread from the dead... but I will anyway. :)

Today I started learning how to do the flares and bends to set up my FI pump & filter, but quickly found that the tools I had would not get the bend close enough to the end of the tube. I was scratching my head for a while, and figured I couldn't possibly be the first one to run into this. VAF to the rescue... in fifteen minutes I knew what needed to be done. An hour later and some serious heat from Mr. Dremel and I have a tubing bender that will do what I need it to do.

I told my wife, this kind of thing is why I send Doug a check every year. :)
Click to expand...

I'm resurrecting this again. I'm doing the exact bend and can't flare the end connecting to the filter because it's too short.

All the pics and link in this thread don't work. Anyone have suggestions on how to do that tight bend and flare?
 
I just bent the 4 tubes for my 14A last week. I bought a $19 tube bender from Home Depot, Did some major cutting and grinding on it until it could make the correct bends close to the flair and then threw it away.
 
Reviving this old thread once again, but I come bearing gifts. The photos of the modified tubing bender courtesy of Tom Swearengen.
 

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