J

J.Coles

Well Known Member
While I am waiting for my wing kit I thought I would make the tie down equipment. There are some excellent threads on the subject. My concern is by the time I load my wife and luggage into the plane I will be having to calculate how much fuel to leave out.

With this in mind I thought I would like to reduce the weight of the tiedowns. If I use titanium instead of steel I can halve the weight for five times the cost. Now I think I am also going to lose some strenght. Has anyone out there had any experience with using titanium pegs.

For my next idea I thought I could use a titanium axe which could also double as part of the emergency equipment. My thoughts are as these axes weigh in at 9-10 Oz., will they have enough weight to drive the pegs into the ground.

I guess there will be a number of trade offs with the different options, but it would be interesting to see what has been tried.

Julian
RV 120316
 
I have titanium stakes in my tie down kit. They work really, really well. It should be the standard material for tie down stakes. They are considerably stronger than normalized 4130 steel, so no worries about strength.

They replaced some 6061-T6 aluminum stakes which would bend and be hard to pull out of the fittings.

For rope, you can save a bit of weight there, too. Get some marine double-braid high-tech line. It'll have a core of Vectran, Technora or Dyneema, and the cover will be polyester. Be certain of these materials and avoid the polypropylene blends. Dyneema is preferred, since it's lighter and as I mention below, can be melted. For tie downs, the goal is no slack in the ropes, and we don't want stretchy ropes either - no nylon, guys! These marine ropes are far stronger than we need, and 1/4" or even 3/16" diameter is plenty strong.

The ropes with polyester cover and Dyneema core can be heat-sealed to prevent unraveling. One that I like a lot is called "Warpspeed." Another is "Endura Braid" and there are several more that I haven't tried on my boat.

You can get that rope from several sources. I like www.defender.com, also www.apsltd.com, and www.westmarine.com is also popular. In marine usage, ropes are called "line" or "cordage" and these ropes are often considered competition ropes.

These ropes will typically weigh about 1/3 of the old ropes that they replace, perhaps less.

3/16" Endura Braid has a strength of 2,250 pounds, and 1/4" has a strength of 4,000 pounds. The smaller diameters lose less strength when bent around the tiedowns, but in any case that's not an issue here.
 
Interesting video

Since the video shows that none of the systems provide stellar performance, should I just rent tie-downs while at Osh?

I was going to order some tie-downs from Spruce this week. Maybe I should save the weight and the money.
 
I always have a good angle between
the tie-down ring and the ring on the wing
and wish the tie-down 'testers' would have
also tested the tiedowns at an angle.
I'm not sure their results would apply in a
real world situation.

Just my opinion,
Tom
 
Flawed Test

tomwebster said:
I always have a good angle between
the tie-down ring and the ring on the wing
and wish the tie-down 'testers' would have
also tested the tiedowns at an angle.
I'm not sure their results would apply in a
real world situation.

Just my opinion,
Tom
Click to expand...

You got it Tom, very flawed test. If you tie your plane with the ropes straight up and down your plane will go flying without you!

Hans
 
re: rent

You can rent them at OSH, but they call it a donation to the EAA chapter that's parking the planes.:rolleyes: At least you have been able to in the past.

Marshall Alexander
 
Someone asked about where to buy titanium rod. You can get it from www.mcmaster.com. Look for the Ti-6Al-4V titanium rod and better sit down before you check the price.

Have to say again that this is exactly the right stuff for tie-down stakes: light and strong.

Dave
 
And the ropes -

A couple folks asked about tie-down ropes.

Avoid climbing ropes. They are designed to be stretchy. They absorb the energy of a fall by elastic strain energy, and this is exactly what you'd like to avoid with tie-down ropes.

Using Regatta Braid, I'd recommend 5/16" but 1/4" would probably suffice. I use 5/16" on my Cessna 180. http://tinyurl.com/c2xpwqg

Using a fancier line like Endura Braid, http://www.apsltd.com/p-22155-endura-braid-5mm-316.aspx, I'd be happy with 3/16".

I'm fond of Samson's Warpspeed, http://tinyurl.com/ckxswmv, and if you can find 3/16" that would do. The link is for 1/4" which is overkill. It's a nicer line to your hands than Endura Braid.

Dave
 
Climbing ropes

Actually there are two types of climbing ropes, static & dynamic. Static lines don't stretch.
 
"I always have a good angle between
the tie-down ring and the ring on the wing
and wish the tie-down 'testers' would have
also tested the tiedowns at an angle.
I'm not sure their results would apply in a
real world situation."

********************************

It's called Scope and Rode:

http://www.dulhunty.com/dmp3.htm

Bob Bogash
N737G
 
NASA515 said:
"I always have a good angle between
the tie-down ring and the ring on the wing
and wish the tie-down 'testers' would have
also tested the tiedowns at an angle.
I'm not sure their results would apply in a
real world situation."
Click to expand...

The leg brackets on the "Claw" tend to break off if you have the ropes at an angle. Saw many broken ones after the Sun 'n Fun storm. When using the "Claw", I tie straight down.
 
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