Need lighter materials

LAST EDITED ON Dec-01-03 AT 10:50 AM (CST)
 
I need sources for a few specific materials to build lighter mufflers, tanks and control systems.

Specifically, I am currently using .007 tin stock from Brodak to build tanks. Where can I find thinner tin stock? Tin stock, I suppose, is sheet steel which is treated to solder well.

I need a source for light weight carbon tubes of approximately 8mm or 5/16" outside diameter. The carbon tubes from my hobby shop of about that size are 7.9mm, 1 meter long (39") and weigh 32 grams. I think similar carbon tubes of similar size are available in thinner wall thickness.

I need a source for thinner aluminum for mufflers. At present, I am using .005 gutter flashing from Home Depot but the stuff is very hard. I used to work as an apprentice aircraft mechanic. We used specific identification such as "6061" and "T-3", but, for now, I simply want to find some soft or half hard sheet aluminum of .005 or less.

I know what is commonly available in very good hobby shops, I need very specific materials not generally found at that level of availability.

Thanks,

Al [email protected] (972) 257-0193

LAST EDITED ON Dec-01-03 AT 02:21 PM (CST)
 
Al,

There may be possibilities in brass and aluminum shim stock available at most large tool supply houses. Here in Michigan we have Production Tool Supply and J&L Tool. I know Production Tool has branches in other states, don't know about J&L. Also there is McMaster/Carr at: http://www.mcmaster.com/ , they do have shim stock in many metals, in aluminum they carry it from .001-.010 in .001 increments and on up in larger increments from there. They deliver very quickly too. Take a little time and peruse the site, they have all kinds of great hard to find stuff we can use.

Al,

Later on this week I'm going to send you tapered rods which have been fabricated from aluminum foil/carbon and epoxy/aluminum foil. Taper is approximately 5/8" to 3/8" over 43". At 18 grams they do not Thud! when dropped.

You probably won't be able to use them as pushrods, but you'll love the technology.

These tubes sound like what some of the F1C (FAI FF power) guys were using for tail booms, I think they're even made quit small for Coupe De'hivre aproximately .100 at the small end and .250 at the large end. They've been used in F1B too.

Flog club kits??

These tubes sound like what some of the F1C (FAI FF power) guys were using for tail booms, I think they're even made quit small for Coupe De'hivre aproximately .100 at the small end and .250 at the large end. They've been used in F1B too.
Randy Ryan
AMA 8500
SAM 36
I fly 'em all and love it!

Pretty good. These particular tubes were made by one of those Ruskies with a name which defies spelling in English. And they are for FAI towline gliers, although my FF friends have used them for everything from 1/2A Power to HLG fuselages.

My first Smoothie has one as pushrod from flaps to elevator.

I once sent a couple to Don McClave, along with a big wad (not literally) of Kevlar tow, again sourced in Russia. He didn't see the same opportunity I did, used the beautifully-made tube as a doubler to a 3/32" piano wire pushrod, attaching it with thin CA and the Kevlar. I found this to be quite humorous, although it did of course work just fine.

Dan,

Thanks, but the material you describe won't work for the application I am interested in trying. I need just a constant diameter tube as I intend to try Howard's idea of using a carbon torque tube as the leading edge of my flaps and want to use a commercially available material.

Thanks, much, anyhow,

>Dan,
>
>Thanks, but the material you describe won't work for the
>application I am interested in trying. I need just a
>constant diameter tube as I intend to try Howard's idea of
>using a carbon torque tube as the leading edge of my flaps
>and want to use a commercially available material.

Might want to try Aerospace Composites. It's run by a former stunt flier.

http://www.acp-composites.com/

I haven't looked for what you asked for, but either check the website or call them and talk directly, and they might be able to put you on to a source. Or tell you how to fabricate your own.

>I intend to try Howard's idea of
>using a carbon torque tube as the leading edge of my flaps
>and want to use a commercially available material.

Remember that Howard's approach relied on a relatively flexible
tube that resisted twisting. He wanted it to bend so it wouldn't
bind the hinges. To get there, he made his own by wrapping two
layers of uni-directional prepreg around an aluminum tube,
one at +45 degrees bias and the other at -45 degrees.

I'm not sure anyone makes such a thing commercially.
Commercial stuff seems to be rigid to avoid bending.
Maybe Howard will elaborate.

Al's wing is completely sheeted, so it shouldn't bend. I think a stiff-in-bending tube should work OK.

I don't know of any commercially available, light torque tubes. I could make some commercially available, but because of the labor that goes into them, they would be pricey.

>I need sources for a few specific materials to build lighter
>mufflers, tanks and control systems.
>
>Specifically, I am currently using .007 tin stock from
>Brodak to build tanks. Where can I find thinner tin stock?
>Tin stock, I suppose, is sheet steel which is treated to
>solder well.
>
>I need a source for light weight carbon tubes of
>approximately 8mm or 5/16" outside diameter. The carbon
>tubes from my hobby shop of about that size are 7.9mm, 1
>meter long (39") and weigh 32 grams. I think similar carbon
>tubes of similar size are available in thinner wall
>thickness.
>
>I need a source for thinner aluminum for mufflers. At
>present, I am using .005 gutter flashing from Home Depot but
>the stuff is very hard. I used to work as an apprentice
>aircraft mechanic. We used specific identification such as
>"6061" and "T-3", but, for now, I simply want to find some
>soft or half hard sheet aluminum of .005 or less.
>
>I know what is commonly available in very good hobby shops,
>I need very specific materials not generally found at that
>level of availability.
>
>Thanks,
>
>Al [email protected] (972) 257-0193

Ron B.
F4Fguy

Al:
The steel you're looking for is refered to as either "tinplate"(pure tin coated)or "terneplate"(lead/tin coated)it should be available from almost any sheet metal working shop and in thicknesses from about .005" and up.For what it's worth, my experience with tanks less than .007/.010 has been negative.With the thinner steel I found myself constantly chasing fatigue cracks.It doesn't take long for the patches to outweigh the tank!
For the carbon tubes,George Spaarr(sp?)at Aerospace Composites is the first I'd check,also there's Composite Technology,both have a fair selection of thin wall tubes.Model Research Labs(free flight outfit)has some good stuff too.You might find it useful to check your local kite supply and archery supply stores.
Aluminum(at last somthing I really know)as you point out is usually specified by alloy;6061,2024,7075,etc and temper;T-6,O,H14 etc.If your'e TIG welding Alloy doesn't make a whole lot of difference(some are a little more trouble than others),but if your'e brazing, or soldering(not recommended),stay with the low alloy contents such as the 1000-3000-5000 series.I don't understand your comment re the "flashing"material being too hard.This is usually 1200alloy dead soft,as it's prime requirement (next to keeping the rain out)is formability.You may be over working it,as it work hardens easily.In any case you can readily anneal it.Put it in your(cold) kitchen oven,and set it at 475-500F for at least four hours.Turn the oven off and allow to cool all the way down before opening the oven.Incidentally,this works for soda and beer can material too.this is useful since it is 5252(brazeable) and averages about .005"thick in the wall of the can.
The same caveat here as with the steel, if you get much below .010" fatigue cracks are a real problem,especially in a muffler where the temp is high and exhaust pulses are strong.

Hope this helps,

LAST EDITED ON Dec-02-03 AT 11:19 AM (CST)
 
Ron,

Do you happen to have web addresses for Composite technology and Model Research Labs. The Aerospace Composite outfit has Carbon tubes but the same stuff as the LHS with .035 wall and about 34 grams/meter. I saw very thin wall tubes at a recent modeling show but didn't appreciate my upcoming needs. The locally available tubes are about .25 ID plus two walls at about .035 for an outside dimension of about .310-.320" or about 5/16". It is the 8mm to 5/16" OD I'm looking for.

As for fatigue cracking of thinner tin stock, I hadn't considered it as the .007 works fine. If I find it, I will probably stop at .005 to be safe.

As for the aluminum, my flashing is very hard. It is in a coil which I keep wrapped very tightly with multiple rubber bands. If they were to all fail at the same time there would be a loud "sporng" and a silver metallic strip running from my workshop to the kitchen. After reading your post, I wondered if by chance the flashing could be steel. I tried magnets and they are not attracted to it and it sure looks like aluminum.

There have been some very helpful suggestions so far here, and I appreciate them. so far, I have leads to try out and will. One of the problems I find when trying to deal with commercial suppliers is the large minimum order. Still, if I can solve any one of my three requirements it will help now and in the future as I always seem to be fighting weight. Maybe if I would only use more than 550 sq ins for a .65 airplanes expected to corner like an Impact, I wouldn't have such problems.

Thanks to all, and keep those suggestions coming.

Now that you memtiom it, I did build a muffler can from a Diet Coke can for my Classis Bearcat and it did fatigue and fail with a piece of it blocking the muffler exit and killing the engine. Frank McMillan was flying it at the time at VSC and was really supprised to find himself in the middle of the square eight flying a glider. But it was really light. Will I never learn?

>Do you happen to have web addresses for Composite technology
>and Model Research Labs?

You can find them both on http://www.clcombat.info/suppliers.html

Good grief. There's a source of real pen bladders listed on clcombat.info. Does anyone still use these?

http://www.pendemonium.com/penrepair.htm#sacs

>Good grief. There's a source of real pen bladders listed on
>clcombat.info. Does anyone still use these?

I don't know. I think they were preferred due to their low pressure,
but then they got hard to find. I added them to the suppliers
list 'cause I was amused to find them.

LAST EDITED ON Dec-02-03 AT 11:57 AM (CST)
 
Al,

McMaster Carr has no minimum order. My last order was $15.00, some brass hex and round stock and a little bag of 4-40 philister head screws. I ordered online with VISA on Thursday evening and had the stuff Friday, thats an unbelievable turnaround, I had to check the calendar thinking I'd lost a week somehow.

Are you sure your flashing isn't stainless steel? It sure sounds like it and I've only seen flashing in sheets, not coils. Then again, I certainly haven't seen everything either!

Ron B.
F4Fguy

Al,

Composite Systems Technology(CST)is at:www.cstsales.com

Model Research Labs is at:www.modelreasearchlabs.com

LAST EDITED ON Dec-02-03 AT 02:10 PM (CST)
 
One place the local FF guys like is Small Parts inc. They are a bit pricey but have a lot of small and hard to find parts. Such idems are their selection of different bearing balls and tubing types. They also sell in small lots (10) as apose to box (100) qtys. Their catalog is hard to get but most stuff is on there website at http://www.smallparts.com . Another place to find links for all kinds of control line stuff is http://www.plasma.kth.se/~olsson/cllinks.html . At the bottom is a listing of suppy houses. There are some other places that the FF guys know and if you check with your local FF club they might have more places and may be local ones too. [email protected]