Stringer Fabrication

[captjon]

Tribe:

I am contemplating the new stringers for my project on Tami T-Craft. She had what looks to have been mahogheny stringers the last time she was redone in 1972. Now, I have seen a lot of different stringer materials used from aluminum "hat" stock to screening frame, to various woods. What are people using out there? Some planes even have welded attachments on the tubing for the stringers. Mine were simply attached by what looked like thin lengths of soft aluminum run through crude holes drilled in the wood and wrapped around the tubing a couple times. I have seen some of the "hat" material attached with springs. Maybe I need to ask Harry what the TC says about stringers.

I know the factory used the aluminum "Hat" back in the nineties as Harry's F22 has them. In looking for them I find both Wicks and Aircraft Spruce has the stock, but only in eight foot lengths (UPS shipping restrictions). I really don't want to splice them. Anyone know where I can get 14 footers?

If I make them out of wood, has anyone done this recently? And if so, any good tips for the jigs or fixtures the keep my fingers out of the saw blades or router bits? Aesthetically, I like the idea of the wood better...........any good tips?

Cheers,

[Dick Huish]

Jon, what you have is the original t shaped wood stringer. They were mounted just as you found using 1/8 inch soft aluminum strips. Acording to the blue print they were made from white pine,with spruce as an alternate material. I have made them in the past and you end up with a LOT of sawdust. If you talk to some of your local lumber suppliers and cabinet shops You'll probably find one that can fabricate them to whatever length you want at a price that is comparable to what Wicks wants without the freight cost (over 8 feet is freight not UPS). One other thing the wood stringer is lighter than aluminum and will go back in the same as original. If you change to the aluminum you will have to modify the mounting system. Dick

[captjon]

Dick:

Thanks. I probably will search my local wood supplier this next week and see if he has some spruce.

I have envisioned the piles of sawdust, but also tried to figure out the best way to mill them up. I have a pretty good wood shop in the basement. 14 footers shouldn't be a problem, it's just figuring out the jigs needed to save my fingers that I'm concerned about. Kind of need them to fly.............. : - )

Thanks again, cheers

[Dick Huish]

I found a lumber supply here that can mill them in any length. They have the necessary dies to do it. I got prices for white pine,spruce and poplar. My engineering books show that all three have approximately the same strengths. The intention was to have them make enough for three ships. This fall has been bad for me and I am way behind. The owner of one of the ships backed out and that would have increased the cost. Some where around here I have a list of the amount needed for a BC-12D. Dick

[tunnel rat]

retaing fingers

Hey
Capt Jon;
Dont loose to much sleep about loosing a few digits in the milling process,it only hurts a little bit. Although it does cost more than your airplane does, to have them repaired,depending on how many you chop off, or mangle. But not to worry, I somehow managed to cut off my index finger and the two right beside that one and i can still fly as good as i did before the infamous incident.
Not only that god forbid it should happen,youll be able to help your grandkids,with there math problems when it comes to fractions like 1 1/2, 2-2 1/2, using the new math with your fingers, they will crack-up when you show them how much further up your nose you can get buggers,than they can.

P.S. Iwas just joking around with you.
But i really did chop the fingers on my right
hand off behind the first knucle, and yes i
did all the things i said, only with my neices
and nephews, they really did git a big kick out
of those little stunts. Oh yeah, my choice of
mass mutilation was the wonderfull joiner.
yes i got rid of it as soon as i could.
My t-craft has the alum stringers &springs.

[captjon]

Yup, reminds me of the first meeting I had with my milling man. I was going to make some wise guy comment about seeing how good he was by counting his fingers, until I noticed immediately the missing digits on his right hand.........ooops!

I know all too many who have done a number on their fingers with snow blowers, saws, and especially jointer planers! My machines have come close to getting me several times, but so far, knock on wood, I can still play my Scotish Small Pipes! (albeit, admittedly not very well)

[Billy Cave]

stringers

Capt Jon, I used douglas fir its Very flexible and not so expensive as spruce. I still sneeze up the occasional firball a year later!
Billy

[crispy critter]

Striggers

Jon,
I have used both spruce and aluminum stringers.Yes the aluminum is a little bit heavier but with the wood it took me and my father a hard week to cut,fit,varnish,and install them,with the aluminum it took us about an hour to get them out of the box,wipe them down,and spray them with Vari-prime(maybe an hour and a half by the time we put the primer,activator,primer gun,and air hose back up),then we let them dry for a couple hours and it might have taken us 3 hours to install all the aluminum stringers on the airframe.We did do them in 8' lenghts and we did have to splice them but if done properly you can't tell where there spliced at.Plus you never have to worry about them breaking in years to come as your fabric continues to tighten with age.
Moral of this story,there was no risk to our digits,the entire job was done in a day(not even a full day),and the aluminum cost about a third less than the wood not to mention all the mess and varnish we didn't have to fool with or the cost of the varnish,and the total wieght difference was about a pound....more or less.
Don't take me the wrong way,I like the wood too because it's original and it looks better,but the only people that will ever see the stringers is you and your IA.

[Acroeric]

Speaking of stringers and formers- I have a set of old wooden BC12-D door post/ Frames to be used for patterns if anyone is in need of a set. I am done with them and if you know of anyone in need they are welcome to them. I think I am the 5th person to use these as a guide-

[jgerard]

Hey Crispy, Where did you get the metal stringer material from? And Eric, I would sure like to get my hands on those wood door frame patterns.

Jason
N43643

[crispy critter]

Jason,
I ordered the metal stringers from Aircraft Spruce.The made the fuslage about half a pound heavier than with the wood.

[Hank Jarrett]

I have been designing a WW-1 replica for a friend and we are using the original 41/45 (they were the same) wood stringers from my plane for the cross section. (Multiple applications will allow a large quantity to be made at once) He is a wood worker and plans on making a large run to help offset the setup cost. We planned on shipping in a PVC pipe with caps by truck if we can.
He is setting up now to make the first set. What is a set of wood stringers worth? We hadn't gotten to that part yet.
Hank (to many irons in the fire, lucky this is HIS iron and HIS fire)