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Bladder Buster tanks from Reed Mfg

No, I don't think so

I have a pair of the tanks on my RV-6A and they are excellent, providing 17 gallons of additional fuel. When I bought my kit in 1996 I rented a Budget truck in Portland and drove it home to Orange County, California. On the way I picked up my tanks at the airport in Grants Pass, Oregon. Others have tried to get these in recent years without success. Farn Reed sold them for several years but when I tried to help locate him with an inquiry of his wereabouts in this forum I was told that he was killed in an aircraft accident. If anyone had picked up production I'm sure it would have come out in the forum by now.

Bob Axsom
 
A photo

Here is a photo of the initial instalation. I take them off for short races.

Bob Axsom

TIPTANK.jpg
 
Those would be a a pretty nice addition to my RV-4. Is there a kit or something? Or are you guys fabrication from scratch?
DM
 
Would be interested in drawings/info myself if possible to: [email protected]

Any reports on performance, issues, gotchas to watch out for?

Also, my wingtips are held on with the hinge method. Would that work with these or am I asking too much strength-wise?

Clive Whittfield
Auckland
New Zealand
RV6 (very) slow build
 
Me too...

Me too please:
alainvanseveren(at)gmail.com
(at)=@ of course... always cautious about netbots when giving my email on forums.

Thank you.
 
Business opportunity?

Looking at the responses, looks like there is some $$ to be made if someone would start building these again. If so, I would likely buy some.
 
I am interested in the tank info too

My e-mail is:

first set: aaa

then of course: @

then the next: pacifier.com

Thanks
 
Huuuummmm! Given the continuing nature of these requests, give me a little while and I will put the files on one of my servers. Then I'll post a link to download the files.

I might mention that what I have for the Farn Reed "Bladder Buster" tanks is just a collection of photos, sketches, original instructions. There are no real drawings or plans.

GH
 
Huuuummmm! Given the continuing nature of these requests, give me a little while and I will put the files on one of my servers. Then I'll post a link to download the files.

I might mention that what I have for the Farn Reed "Bladder Buster" tanks is just a collection of photos, sketches, original instructions. There are no real drawings or plans.

GH

For those wanting my files on the Farn Reed "Bladder Buster" wing tip tanks, please go to

http://www.cherryfamily.net/bill/n63tx/rebuild/?page_id=870

where there is a link to download the archive.

Thank You,
GH
 
Farn Reed Documents

Thanks GrayHawk. I don't know if I'll ever build them but they look interesting and I'm glad to have the information.
 
Good idea..

Meanwhile, thanks for the email copy.


Huuuummmm! Given the continuing nature of these requests, give me a little while and I will put the files on one of my servers. Then I'll post a link to download the files.

I might mention that what I have for the Farn Reed "Bladder Buster" tanks is just a collection of photos, sketches, original instructions. There are no real drawings or plans.

GH
 
Experienced Builders, Aero Engineers . .Help needed

Here is a picture of Bob Axsom's tip tank. Amazingly the other picture is still posted at the beginning of this thread.

I have all the documents listed earlier here, and was thinking about building some from scratch. In looking at the picture the rib, it appears there are no flutes and there are definitely bosses welded to it. Also, unseen, there are some baffles internally. At least one at 20" back from the leading edge. A vertical row of rivets closer indicates there may be two baffles.

So - 1. what material might be appropriate for this rib, that can be welded, and 2. what construction method can yield a flat piece with no flutes on the bent flange?

Thanks

tank9os.jpg
 
Bill, probably both 5052 or 6061 alloys can be welded. I know the 6061 can be. They can be formed, if soft, with a hydropress (Univair can do it). They can be heat-treated after forming, might also need stress relieving, but the welding will knock the strength down by at least half and easily more.

In the photo it looks like the end rib is riveted to the skin.

You're aware of the effects of increasing the span on wing's ability to carry flight loads, right? There will also be an effect on the flutter speed.

Dave
 
Dave, thanks for a quick response. Hydroforming is probably out of scope. That flange would certainly have to be compressed, shrunk, yielded, to yield a 90 deg bend nicely from a sheet.

Regarding flutter, Bob A. mentioned he had pushed his speed to at least 190 its, but I could not find any actual flutter information posted. I had read all the Farn Reed posts before and just reviewed what I could find once again. Apparently, Farn is no longer with us.

There are other types of extended range , ER, tanks that would not affect the wing length. There remain a number of issues to be considered. This one was just the construction.
 
I bought Bob's plane from his estate. The vendor materials are a bit scant but they do not mention flutter or VNE issues. They do mention (1) that the full tanks increases take off roll by 100 feet and stall speed by 2mph, (2)empty tanks decreases stall speed by 2 mph, (3) ride in turbulence is more stable, (4) aerobatics with the tanks on are not recommended." Curiously the materials also say W&B are not affected. I would think and extra 18 inches of wing span would increase useful load somewhat.
 
I would think and extra 18 inches of wing span would increase useful load somewhat.

Be careful here. Extending the wings increases bending moment at the root, and increasing load will do the same (plus increasing shear load). The structure weighs something, which REDUCES useful load unless you raise max gross.

I'm not sure on what basis you're thinking useful load would increase. And yes, I am an engineer, although not an aircraft structural engineer.
 
I would think and extra 18 inches of wing span would increase useful load somewhat.
If you are assuming that the gross weight is based on meeting a minimum climb rate (like in FAR23) that would be true, but RV's have never had any problems meeting the common minimum performance requirements.

Be careful here. Extending the wings increases bending moment at the root, and increasing load will do the same (plus increasing shear load).

This would be the main reason to be careful.
If you increase the span you would automatically increase the bending moment slightly (longer lever arm), even if you used the same max. gross weight value.
If you increase the span and increase gross weight, the bending moment on the wing goes up even more.
 
The link is not working for me. Any suggestions?
Sorry for the link not working. We were forced to change upstream isp and naturally IPs, znd chose to do it today (Sunday).

Everything should be back to normal tomorrow after new DNS ripples out.

GH
 
Pardon me opening an old thread, I'd like to build similar tanks. But I don't believe that adding weight on the end of the wing increases the bending moment at the wing root. In fact I believe, if it doesn't by its shape generate enough lift to make no difference, it will create a negative moment (relative to the moment at the wing root) in the last few inches or foot of the wingtip.

When not flying, there will be more negative (relative to flying upright) moment at the wing root but this is minor compared to the negative G rating or load under inverted or turbulence load (both of which I think are minor due to the location of and the shape of the tip tank).

I do understand that the moment around the Z axis at the wing root will be increased due to the drag of the wingtip tank, but I don't believe this is what was being referred to. Although I also have no idea how to analyze this relative to the strength of the front spar/back spar attachments.

I have a civil engineering degree but 40 years in IT has corroded any real knowledge I may have had. How should I visualize the impact of the tip tank on wing loading?

Thanks,
Mark Cantrell
 
But I don't believe that adding weight on the end of the wing increases the bending moment at the wing root. In fact I believe, if it doesn't by its shape generate enough lift to make no difference, it will create a negative moment (relative to the moment at the wing root) in the last few inches or foot of the wingtip.

I think the discussion was about an extension of the wing that did match the airfoil shape of the wing so it would produced lift. That additional lift is further outboard so it would increase the bending moment on the wing.
During times when the tank contains fuel, its mass would reduce the bending moment, but it would be higher when the tank is empty.
 
Bladder Buster Tanks

Good afternoon,

I’m very interested in these tanks. If there not available and someone has one maybe I can reverse engineer it and share it with the group but I would like to buy them completed. Any ideas.

Thanks
Kevin R
 
It may have been for these tanks but Vans posted something years ago about how these could exceed the bending moment strength of the wings mid-span. This is different from bending moment at the center section.
 
Another option ..

It may have been for these tanks but Vans posted something years ago about how these could exceed the bending moment strength of the wings mid-span. This is different from bending moment at the center section.

I worked with Marvin of "Smoking Airplanes" fame to design a 7.5-gallon aluminum tank that fits behind the seats of RV6, 7, 9. Two of these yield 15 gallons.

Most of the weight ends up under the seat back (forward of the back brace).

I have used them (successfully) as 1 with 100LL and one with Smoke Oil, along with 2 with 100LL. There is a planned scenario that would have 2 with Smoke Oil.

I did a quick video about it if anyone is interest (long ago, LOW resolution.)

Just FYI.
 
I remember seeing that at Sun-N-Fun some time ago! That was a very slick installation.

I worked with Marvin of "Smoking Airplanes" fame to design a 7.5-gallon aluminum tank that fits behind the seats of RV6, 7, 9. Two of these yield 15 gallons.

Most of the weight ends up under the seat back (forward of the back brace).

I have used them (successfully) as 1 with 100LL and one with Smoke Oil, along with 2 with 100LL. There is a planned scenario that would have 2 with Smoke Oil.

I did a quick video about it if anyone is interest (long ago, LOW resolution.)

Just FYI.
 
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