[David M]

Hi guys,I've got two lengths of solid fibreglass from a early "toy kite" that I bought before I saw the Revs.These rods can fit inside the 3 wrap rods of my SLE,my question is,would it be to any advantage do doing this i.e for strength

[stroke survivor]

I'm a bit surprised that no one answered this!! From what I remember from physics, a tube maintains it's strength from not being compromised! Any cracks or dents in the tube create a break point! You'll see that many use both LEs, 2 and 3 wrap together in the LE pocket, but to put something inside doesn't make sense to me!! Are you using the SLE tube or the 1/4 rod? Either is strong enough for most conditions! If you're flying in heavy winds, I would consider a vented or a 4 wrap LE! Adding a solid rod just adds weight! Any comments out there?

This post has been edited by stroke victim: 15 September 2010 - 11:15 AM

[awindofchange]

Stroke pretty much sums it up. Any additional rods that you would put inside of your current rods will add a lot of excess weight which will probably adversely effect the way the kite performs. I have flown Rev's in winds from practically zero wind all the way up into the mid 30's without rod breakage. Of course I was using rods designed for each condition and a vented in the stronger wind ranges but there wasn't any need to get a rod stronger than the 4 wraps, especially if you go with the SLE which is practically indestructible against pretty much anything.

If you are breaking rods then you are either flying in winds that are too strong for the rod you are using or you are contacting with the ground or other objects which are compromising the structure of the rod and causing it to fail.

If you are just testing to see if it is possible then by all means, test away and let us all know the results. I don't feel that it is necessary though and will probably give negative gains to your flying. Still, give it a try and see what happens. Experimenting is what fuels progress.

[RevWizard]

I always like to show off this photo of a vented with original REV I 4 wrap rods.
The wind was in the range of 45 to 60 MPH. Location: Fano, Denmark
This photo is from June 1995.

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[kitecowboy]

Putting something inside the sle would make it a much better flagpole or beating stick, which imo is the best two uses for the sle. but again, thats just me.

[David M]

awindofchange, on 16 September 2010 - 07:03 AM, said:

Stroke pretty much sums it up. Any additional rods that you would put inside of your current rods will add a lot of excess weight which will probably adversely effect the way the kite performs. I have flown Rev's in winds from practically zero wind all the way up into the mid 30's without rod breakage. Of course I was using rods designed for each condition and a vented in the stronger wind ranges but there wasn't any need to get a rod stronger than the 4 wraps, especially if you go with the SLE which is practically indestructible against pretty much anything.

If you are breaking rods then you are either flying in winds that are too strong for the rod you are using or you are contacting with the ground or other objects which are compromising the structure of the rod and causing it to fail.

If you are just testing to see if it is possible then by all means, test away and let us all know the results. I don't feel that it is necessary though and will probably give negative gains to your flying. Still, give it a try and see what happens. Experimenting is what fuels progress.

I was just curious about it and wanted others thoughts.I'm flying the 3 wrap in pretty strong winds with no problems at all.I might just experiment just to see what happens,could be just like adding weights to the wings?

[David M]

stroke victim, on 16 September 2010 - 06:12 AM, said:

I'm a bit surprised that no one answered this!! From what I remember from physics, a tube maintains it's strength from not being compromised! Any cracks or dents in the tube create a break point! You'll see that many use both LEs, 2 and 3 wrap together in the LE pocket, but to put something inside doesn't make sense to me!! Are you using the SLE tube or the 1/4 rod? Either is strong enough for most conditions! If you're flying in heavy winds, I would consider a vented or a 4 wrap LE! Adding a solid rod just adds weight! Any comments out there?

What is the reason for putting 2 and 3 wrap rods together

[jburka]

David M, on 15 September 2010 - 05:46 PM, said:

What is the reason for putting 2 and 3 wrap rods together

Just to provide a little extra stiffness; it would really only be done if you had exactly one full-sail rev and 2 and 3 wrap frames; most folks would rather just switch to a mid-vent or even a full-vent. But you can double up any sticks in the leading edge depending on your conditions and gear. I've had situations in which I've used a 3 wrap and a 4 wrap leading edge together on a full-vent kite (team flying in 40mph winds)

[stroke survivor]

John - Does that thing look like it wants to break or what!!?? I've got a 4 wrap for my 1 and I've never put it in those conditions!! Of course it's not vented, but HOLY S$#@!!!

[RevWizard]

stroke victim, on 15 September 2010 - 05:55 PM, said:

John - Does that thing look like it wants to break or what!!?? I've got a 4 wrap for my 1 and I've never put it in those conditions!! Of course it's not vented, but HOLY S$#@!!!

I was trying to break it too see how much the rods would take under constant strong wind driving it forwards and backwards. I did not succeed.
The big bends, some were more then the photo happened during reverse fights only.

[stroke survivor]

Does this tell us how well made and strong this product is!! It's nice to know that these kites are able to stand up to this kind of abuse, and still continue flying!! How impressive!!!

[RevWizard]

Do you know of any other kite, referring to those we fly in the air, that can take the abuse we all give it and still be in shape to fly very well without repair?
I can't think of a one, no matter what type it is or where it comes from.

[Taihapemike]

I have just inserted a piece of 6mm carbon tube into a 4 wrap I broke today ( I grabbed the LE in the wrong place in a high wind - my fault , not the spars...)
The wind is too good here at the moment to not make an effort to get in the air again tomorrow : )

Any one want to field bets on how long it will last? (1990 rev1 in 12 knots average)

[--Pete]

Adding a solid rod inside a tube does not add much strength. Think about it: the strength of a spar is based on stretching the outer arc and compressing the inner arc of a curve. The closer to the inner and outer extremes of the curve, the more effect the material will have on the strength. In construction, when you have to make a hole in a beam, you weaken it least if you make the hole in the middle of the beam.

The middle does nothing except keep the spacing between the inner and outer surfaces. That's why they leave it out of high strength-to-weight spars and beams - box beams, I-beams, tubes and the like.

A rod could be used as a repair for a broken tube, but it will never be as strong as the original tube. A stronger repair would be to glue a bigger tube around the outside of the break.

[David M]

If you put 3 wrap and a 4 wrap rods in the LE how do you secure them in there

[RevWizard]

David M, on 15 August 2011 - 09:00 PM, said:

If you put 3 wrap and a 4 wrap rods in the LE how do you secure them in there

End caps on one set of rods, the others set will be held by the capped set. Just make sure all rods are connected properly to other rods in their respective sets.

[REVflyer]

We have used the insertion method to increase the wind range of kites in our local environment.

As an example, KiteSquid made some mini-Ryvs (back in 2000 I think) using a 42 inch 2P Skyshark spine tube and the "no-sew" technique of sail assembly. A 6-pack of these will fly in zero wind on a 100 feet of line doing a slow 360 degree walk. But what happens if we take 'em to Jockey's Ridge or Buzzerkley? To test that theory fully, we tied two stacks together. The first 3 kites literally exploded, even shredding their sails.

His solution was to cut down a (point 125) carbon tube, a quarter inch longer (than the 42 inch Skyshark spars) and insert this stiffener inside the 2P tube. It's extra length makes it easier to withdraw when conditions return back to normal.

It works because the leading edge is a single tube with no ferrules, and the insert is also the same. . . . one fits into the other. You slap from one to 3 of these into the first few leading edge tubes to make a stronger frame. It can't bend as much so there's less chance of complete failure.

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[makatakam]

kitecowboy, on 15 September 2010 - 04:20 PM, said:

Putting something inside the sle would make it a much better flagpole or beating stick, which imo is the best two uses for the sle. but again, thats just me.

I like the sle leading edge (that's redundant, isn't it?), especially in wind above 45 miles per hour. I drive into the ground with a hammer and anchor myself to it with my belt so the kite doesn't drag me away.

[--Pete]

A solid rod is the least efficient use of material (weight) to attain stiffness. The farther from the center of the cylinder you can put your material, the more effective it will be in creating strength and stiffness. This means tubes, not rods. And bigger (but thinner walled) tubes are better, until they get too fragile (because of wall thinness).

[Khal]

--Pete, on 17 August 2011 - 10:28 AM, said:

A solid rod is the least efficient use of material (weight) to attain stiffness. The farther from the center of the cylinder you can put your material, the more effective it will be in creating strength and stiffness. This means tubes, not rods. And bigger (but thinner walled) tubes are better, until they get too fragile (because of wall thinness).

Using tubes is a trade-off between structural efficiency and simplicity of design and manufacture. The same amount of material could support more bending load with a non-circular cross section, but you would need to have a mechanism that prevented the spar from rotating in the sleeve. Circular tubes are also easier to fabricate. The two limiting factors in how far you can push the material from the center line to gain stiffness are 1) buckling and 2) not exceeding the maximum stress in the extreme fiber.

As for the question of whether it adds any strength to a tube to insert a solid rod into it, the answer is yes. As Pete points out, it's not an efficient use of extra material/weight, but it will add stiffness and strength. And sometimes, as with ferrules, it's geometrically more convenient than more efficient options.

P.S. I love a forum where nobody complains about "necroposting".