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Titanium Bolts ?

Wolf Cub

Registered User
Alaska
I am Looking at replacing some steel AN bolts with titanium bolts on a cub, thinking of bolts for the, engine mount, tailwheel, landing gear, propeller etc.*Any particular applications to avoid?*What grade ? ti6ai4v ? Thanks.
 
F'n with fate comes to mind.... do your homework. AN hardware is strong enough to hold it... yet soft enough to bend vs shear off when needed the most. For the sake of 4 x AN8 bolts and 4 x AN5 bolts I wouldn't be messing with it.
 
Weight....


Wolf Cub, have you exhausted all the other means of weight savings on your airplane? Are all the aerodynamic tricks accomplished to make it best?

...or is there some other reason? (I don't know you or your airplane, so the context of your quest is unknown to me. )

....with all due respect I ask these questions. I had never heard of someone wanting Ti hardware on a Cub. Thanks. D
 
Thanks Crash,
I have had good luck ordering from Met-Tec, *the bolts are well made and have rolled treads-Unlike some of the junk ti bolts available. I haven't run them on The landing gear, engine mount, or prop, but my research hasn't come up with any reasons not to yet? Maybe galling with non ti nuts or flange bushings ?
 
F'n with fate comes to mind.... do your homework. AN hardware is strong enough to hold it... yet soft enough to bend vs shear off when needed the most. For the sake of 4 x AN8 bolts and 4 x AN5 bolts I wouldn't be messing with it.
Thanks, This is just part of the homework. The metal comes in many different types, ti has some shear issues.. Will be careful on the F'n with fate. ;-)
 
Dave,

No, but Most Means within my means and for it's intended use. No electric, minimal interior, carbon fiber, etc. I am always looking for new ounces. Ti hose clamps can save up-to 40% vs stock . I believe the only thing you can add to a cub is weight. Thanks.
 
I run titanium bolts in my snowmachine there about half the weight of a steel bolt. There expensive but have held up great. Google "titanium bolt strength chart" grade 5 titanium is quite strong.
 
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All my pulley bolts are ti. and my tail wheel to spring is ti. In fact I even used the basket or ashtray type lock nuts on most everything because they are a lot lighter. I know this saved some pounds on my SQ-2.
 
I have found that the easiest way for me to save on weight is to back away from the trough every once in a while.....
 
I think one might be going a little overboard if one starts trimming the fat with simple hardware, especially on an aircraft that already has so little hardware. This makes me feel guilty for daring to leave 4 and sometimes 6 threads showing after tightening the fastener as opposed to the textbook 2 threads (ie, excessive fastener length).

Seriously though, if you intend to use Ti, please bear in mind that electrical potential difference is quite high when compared to steel and aluminium (it's considered a strong cathode) as opposed to aluminium which (is rather anodic).

Galvanic corrosion plays a large factor in assembly, often that is why the industry standard is what it is.

Like some other conventions; Aluminium is a better conductor than copper and weighs less, but copper is the standard for conductors, because Aluminium would strain harden and it's very susceptible to corrosion (which is critical).

This means Ti is an outstanding material with no doubt oodles of great applications, but not worth the headache when it comes to collateral implications.

My 2c
Pete
 
I have said this to many people, to hell with the weight,how many airstrips will 20lb be the difference between life and death.Stay with the tried and proven methods.The ultimate question is will this aircraft hold together in a serious turbulence problem.I have flown all types of aircraft world wide in all types of weather strip lengths etc.Never have I run short of takeoff distance,but many a time have I thought,"I hope this girl holds together in this turbulence."Might I suggest if we are worried about weight work on your diet.It may also save you from an inflight incapacitation.
 
Hear hear

I have said this to many people, to hell with the weight,how many airstrips will 20lb be the difference between life and death.The ultimate question is will this aircraft hold together in a serious turbulence problem.I have flown all types of aircraft world wide in all types of weather strip lengths etc.Never have I run short of takeoff distance,but many a time have I thought,"I hope this girl holds together in this turbulence."Might I suggest if we are worried about weight work on your diet.It may also save you from an inflight incapacitation.
 
I would still love to hear about WolfCub's Cub.

Ti hardware on a Cub ain't for me, but I have the stuff on my bicycle, and........he wasn't asking me if I wanted Ti hardware on MY Cub.
 
Just because you're experimental (is he?) doesn't mean you want to experiment with putting Ti bolts in structural applications. Wing/strut attach, engine/prop, and landing gear steel AN bolts are a proven and known entity, Ti bolts are not. Do you really want to be the idiot that finds out why this is a bad idea? These types of applications should be tested in a controlled environment. You find out if it is going to fail without sacrificing yourself (or the aircraft)in the process. All of your known torque values for AN steel, would have to be recalculated for Ti in the testing process. The galvanic properties mentioned above would also have to be addressed. + many, many other issues come to mind....good luck if you go that route...

Palhal, you state you are using ashtray or basket lock nuts? These are the pressed missile nuts? Hopefully not the pawl nuts
 
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Pete
you sure Aluminium is a better conductor than copper?:smile:
I have a heavy cub, but If I had the weight religion going strong I think bolts (LENGTH, THIN WASHERS, JET NUTS) would be a place you could save several LBS. Heck I carry extra gear,and tailwheel bolts, so i am a sinner when it comes to weight. The real question to ask is do we really need the strength we have if the plane is light? Tailwheel bolt is one I would replace (heck I saw some kid with just a pice of plastic back there one day) I need all I can get on my gear cause I have been known to bounce.
:p
DENNY
 
I have said this to many people, to hell with the weight,how many airstrips will 20lb be the difference between life and death.Stay with the tried and proven methods.The ultimate question is will this aircraft hold together in a serious turbulence problem.I have flown all types of aircraft world wide in all types of weather strip lengths etc.Never have I run short of takeoff distance,but many a time have I thought,"I hope this girl holds together in this turbulence."Might I suggest if we are worried about weight work on your diet.It may also save you from an inflight incapacitation.

Always seemed the other way around to me. I've never worried about the aeroplane even while getting a pounding, but pedalled a few times on take off and given a few places to land away wishing I had five or even three mph less stall speed.

What size engine you putting in your plane Ron?

Cheers,
Andrew, flying an underpowered 150 hp Cub in the North Island.
 
:p

To answer your question, copper has slightly better conductivity than Aluminium.

Losses due to resistivity on Aluminium were considered acceptable for these purposes when aluminium was used, given the weight savings (which of course would be astronomical in a large Direct Current installation), regrettably the repercussions were less than desirable; oxidation on terminals caused poor grounds = constant problems and conductors would work harden (in a high vibration environment) over time and fail.

Copper is the next best thing to silver or gold (affordable, relatively common and lighter than those two), in using Alternating Current on more sophisticated aircraft they were able to do away with the ridiculously thick gauges of copper they would have had to use.

Hence copper is the standard.

I'm pretty sure a similar development exists for steel hardware.

Pete
you sure Aluminium is a better conductor than copper?:smile:[COLOR=#333333 [/QUOTE]
 

Look at post #13 also.
[/QUOTE] I see no problem substituting non structural hardware with titanium or gold if you must but unless you fully understand the requirements to use titanium bolts in a load bearing capacity, I would stay away from those.
It has been pointed out by a previous poster but substituting load carrying
AN bolts with titanium is a very bad idea in the hands of most experimental kit builders.
Titanium bolts require Precision machined holes with very tight tolerances and will not tolerate any king of abuse. AN hardware is very forgiving and a bolt may bend and twist before breaking.[/QUOTE]
 
Always seemed the other way around to me. I've never worried about the aeroplane even while getting a pounding, but pedalled a few times on take off and given a few places to land away wishing I had five or even three mph less stall speed.

What size engine you putting in your plane Ron?

Cheers,
Andrew, flying an underpowered 150 hp Cub in the North Island.
Andrew,without applying mathematics you need a lot of weight reduction to achieve your objective of a 3-5 mph approach speed reduction.I would suggest carry less fuel,loose body weight or most importantly do not land if in doubt.My last 3 cubs were 150/160 hp.The one I am building is a 195.I wish I had stuck to 150hp with this one,now I am building the cowls!
 
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Cautions from NASA -

"Titanium fasteners should be selected only where their advantages relative to steel are
essential for an application and should never be employed as single point failure tensile
fasteners. When using titanium fasteners, engineers must measure all torsional friction
loads, torsional preloads, and torsional breaking loads. If one decides to use these alloys,
he/she should expect to be especially scrupulous in the design and testing of its
application. MSFC-STD-557 should be consulted for usage criteria."

http://code541.gsfc.nasa.gov/Uploads_materials_tips_PDFs/TIP 133R.pdf
 
As an orthodontist, I deal with Titanium daily, wires-braces. Titanium is very brittle, it give no warning of failure,it just snaps - under very little force once a critical area - a nick - is created. Kind of like glass, you scratch glass and it fails on the etched line. There is no bending titanium, just breaking.

I think all of these threads on making your plane lighter should start: "My BMI is... and I'd like to cover my plane with feathers to save weight". We know that if the BMI is 18.5 or below the poster has done everything to reduce His/Her personal body weight and then can seriously reduce airplane wight. Put yourself on a diet before you put your plane on a diet.

P.S Don't know you Wolf Cub - you could be a skinny bean pole - just an observation of previous threads.
 
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