Cutting Icarex

[ozzymat]

I am about to start building a Christian Derefat designed sports kite called Le Quartz.

Since this is my first attempt at building a sports kite I made a practice sail out of some cheap ripstop, I used a 30 watt soldering iron to cut the ripstop but noticed I was left with a small ridge like a burr along the cut.

I am guessing the tip of the iron is the wrong shape, so before I start cutting the Icarex can anyone tell me the best tip shape?

Cheers

Mat

[Jason]

Something thinner as the tip will help but also a better and hotter Iron will give better results.

You can still cut polyester with a blade, just make sure it is ultra sharp and backed by a good piece of board

[SoutherlyBuster]

Also don't breath in the fumes, they are poisonous. From time to time I file my soldering iron sharp which helps to get a better cut. This also gets rid of the crud that may have built up on it.

Regards,

Norman.

[ozzymat]

Thanks for the advice.

I am trying an iron because the panel templates are only cardboard and there's quite a few curves.

I filed the tip of the iron so it looked like a flat bladed screwdriver then used 200 wet and dry get a sharp(ish) point.

Cut all the panels out today without to much drama, so now I am ready to stick the panels together and sew then up.

And thanks for the warning about the fumes, I left the shed doors open to get some air flow.

I am going to try a double side tape pen from the local scrap book shop that's acid free and non yellowing (that's the pen, not the shop) to glue the panels together before sewing.

On other projects I've used spinnaker tape and a silicon oil bath for the top thread to reduce the glue from the tape sticks to the sewing thread, so I am hoping this might eliminate the need to clean the needle.

Has anybody used this type of tape pen successfully.

Cheers

Mat

[SoutherlyBuster]

Haven't tried the pen you are talking about. I use double side tape to hold the panels together whist I do the sewing, it's called basting tape (available at sewing/fabric shop). A few drops of oil on the needle keeps it from gumming up, but occationaly I need to wipe the needle with some alchohol to remove the gummy bits.

[KaoS]

Hot cutting can be a bit of a black art at first. A lot depends on the surface you are resting the cloth on and the template material.

If you are cutting on or against burnable material ( cardboard, hardboard, formica, etc. ) the heat setting on your iron needs to be as low as possible while still being able to melt the cloth. You don't want the template or the bench surface to start scorching or burning.

Good quality soldering irons maintain a more consistent heat than cheaper ones, which tend to heat up and cool down in bursts. For curved work I use a 40 Watt iron with the tip shaped down to a fine point (conical), for straight lines I use a chisel tip filed to a sharp edge, then slightly rounded off with fine wet and dry.

I used to use Engel Hot Knives, but for light fabric these are definitely overkill.

Icarex doesn't need to be hot cut, the coating is good enough to maintain a non fraying edge.

When Prism were still making kites in their Seattle workshop, the sport kite panels were cut out with "Stanley" knives. They had hard templates (aluminium) that wouldn't get cut up by the razor edge. I don't remember what the bench surface was - I think it was MDF. The templates got held down with push pins and they cut panels 10 layers at a time.

I never heard of a Prism kite fraying.

[mojo]

I cut on a glass topped table (which still isn't big enough)

If you're only cutting out small pieces, one of those big smooth ceramic tiles works well too, just heavy to move around.

[ozzymat]

Thanks again for all the advice.

I am about ready to start sewing, the machine is a 20+ year old Elna Contessa 400 and the yarn is a bonded nylon 210D/2.

Just out of curiosity what does 210D/2 signify?

On a practical side is there any words of wisdom when sewing Icarex or using bonded nylon.

Apologise for the open question but this is my first kite build with Icarex and bonded nylon so I don't know what I don't know.

Cheers

Happy Easter

Mat.

[KaoS]

Thanks again for all the advice.

... the yarn is a bonded nylon 210D/2.

Just out of curiosity what does 210D/2 signify?

210D is the Denier of the fibre being used in the thread. The Denier system is based on the weight in grams of a 9 kilometre length of the thread. So the higher the number, the thicker the thread

/2 signifies it is a 2 ply thread.

210D/2 is about the same as 60 weight in Metric. This is quite a heavy thread. The metric system is based on the number of kilometres you get from 1 kilogram of thread. So in this system, the higher the number, the thinner the thread.

I use 80 weight for sewing kites (125D/2), I use 60 weight for sewing heavy duty bags, etc.

I'm sure that using the 210D/2 will be perfectly okay, it is just a bit of overkill. You may find the seams appear a bit bulky.

Be sure to use the correct size needle. The needle should be big enough to accommodate the thread inside the needle groove, so you don't get the thread catching on the fabric each time it passes through the fabric. However, it should not be so big that the thread doesn't properly fill each hole the needle punches into the Icarex. I'd guess a needle size of around 90/14 would suit your thread.

Mat, feel free to call me if you want more info

Kevin

Willunga, S.A.

[mojo]

Does your machine sew a stepped zig zag?

If not, you will need to get one. You can probably pick one up pretty cheap, I bought one second hand a few years ago ($130), and when I bought in the thread I wanted to use, and the fabric, there were quite a few interested eyes looking on.

The $3k bernina that I bought about 15 yrs earlier, throws an absloute hissy fit when it comes to using anything other than regular dress makers thread, but the earlier models, with metal cogs, "should" sew just about anything. Just gotta keep em oiled up.

The new (second hand machine) does not seem to mind what thread I put thru it 60, or 40, it just sews away. But do a test sew first.

If you're using reels, which you should be, you might need to come up with a different delivery system on the top side of things. Fill up 2-3 bobbins for the base, and you're off n away.

[ozzymat]

Thanks again for replying, all really helpful.

Had a good day sewing with all the panels and the two halves together also all the Mylar and the training edge ripstop have been sewn onto the sail.

Spent about an hour practising to build up the confidence and to get the top and bottom tension right, the machine has a stepped zigzag which I set to 1mm stitch spacing and a 5mm zigzag. For the straight stitch on the spine, stand off and upper spreader fortifications I used 3mm stitch spacing.

Used an 90 size needle as you suggested Kevin and a silicon oil bath for the top thread and had no problems with the thread binding.

Glued the panels together with a UHU glue roller which looks a bit like one of those correction tape dispensers, the roller puts small dots of glue instead of a constant layer. The glue has good adhesion but also allow you to redo the join without reapplying the glue, it had no problem holding the spine together or the Mylar.

As you said Mojo I had to devise a different delivery system for the thread, took some photos to share what I come up with, it's a bit agricultural but it works ok.

Cheers

Mat

[SoutherlyBuster]

Does your machine sew a stepped zig zag?

If not, you will need to get one.

What does a stepped zig zag look like? Any chance of a pic of what is look's like.

Here is a picture of the zig zags I have on my mechanical sewing machine:

I used 1) for tightly spaced runs like for loops on bridles or at end of regular runs for reinforcements, 3) for trailing edges and some times for repair patches.

Regards,

Norman.

[ozzymat]

3 stepped zigzag pictures.

This machine only has 1 step or 3 step ZigZag in the position shown (3 step) the machine will put 3 stitches between opposite peaks in a zig zag.

Increasing "Zig Zag width: will widen the zig zag, (distance between opposite peaks).

Increasing "Stitch Length" will lengthen the distance between repeats.

Mat

[KaoS]

...

Increasing "Zig Zag width: will widen the zig zag, (distance between opposite peaks)...

The ability to widen and narrow the zig zag on the triple step is a real bonus!

Looking good there Mat!

Kevin

Willunga, S.A.

[ozzymat]

Just finished the Le Quartz and thought I would share the end results, for my first kite I am really happy with the way it turned out I guess only time will tell if my sewing is up to scratch.

Thanks to everybody for replying to my questions.

I've learnt a lot with this project, now I am on the look out for another kite this time with a more challenging sail pattern. Maybe a Christian Derefat Vortex.

Oh and what does it fly like, a very responsive kite more so that the kites I already have so I am going to try a slightly different bridle set up to allow for more of a ham fisted flying style.

If anybody is toying with the idea of building a kite then I can recommend http://www.tweelijners.com/tom/tomskite ... /Home.html

as a good place to start.

Cheers

Mat

Port Augusta

[KaoS]

Looks great - welcome to "the club"

Kevin

Willunga, S.A.

[ozzymat]

Have to make a correction on the performance of the Le Quartz.

In my hast to fly I miss read the instructions on tying the turbo part of the bridle, instead of being 80mm it was 150mm so consequently the pig tail location and inner legs were too long.

So with the standard arrangement of

Upper = 480mm

Lower = 455mm

Inner = 620mm

Turbo = 80mm

and Activator leg

With a nice 5 to 10km/h wind and on 15 Metre lines the kite flew very respectable.

Axels and axel based tricks were smooth and it's stable on it's back so back spins, lazy susans are a pleasure. Fades and flic flacs not a problem nor are backspins.

I did have trouble with 540's, slot machines and Yoyos either from a fade or vertical the kite just seem to float on the turtle to long and the same thing with jacob ladders. I am going to make a heavier tail weight (20grams) and see if that helps.

And thanks Kevin, I've got a long way to go before I can design my own but it feels good to fly one you built yourself.

Mat

Port Augusta

[mojo]

Your finished kite looks really good ozzymat. I hope your new kite flies well.