Quagmirian

Not much to report on at the moment. The Bluetrac is built like a tank with heavy spanwise reinforcement, rolled seams and type 4 line attachments. The fabric also seems quite heavy as well. I also found this interesting explanation in big air sportz's manual. [inline germain.png]

Landing crosswind is much less likely to kill you. Don't do low turns. If you can't or are scared to land crosswind, downsize. Did you mean something else there?

You're shittin me. Dead or alive?

I have an exit weight of 160 lbs and I have a really hard job stalling a Spectre 210. I have jumped a Spectre and a PD 9 cell of the same size and would take the Spectre any day. The different handling characteristics you are noticing are completely normal. The Spectre can sometimes do with a bit of a stab at the bottom end of the flare, it won't flare like a nine cell. Use this experience to learn more about you gear, especially while you're still renting. Make sure you're familiar with handle locations etc when jumping a new rig.

How do these replacement line sets work then? Do you have to knot, trap and tack all ~44 line tops and then tack to the stabilisers?

I don't have anything exciting to report on at the moment. I bought a 'military elliptical parachute', probably a Bluetrac, from a surplus store and that should help with my studies. I've been in contact with my local mill and they're quoting £6.55/meter ($10/yard) for first quality Zero P fabric, is that about right? On the subject of fabric quality, what are the problems and dangers associated with using seconds quality goods for canopies like I am? Assuming the strength is good and it's not too bowed, porosity seems good etc, what can go wrong?

How have your exits been so far? Are you exiting and falling stable for the first few seconds? If that is the case, the you have nothing to worry about as you're just doing the same thing at a lower altitude. If you are having problems, talk to your coaches and see about doing some more full altitude jumps focusing on being nice and stable with maybe a practice pull or two.

I don't think this is such an unreasonable request. Flying jumpers can be a very good way to build hours, and you never know who you might meet at the DZ.

Interesting video I found http://www.youtube.com/watch?v=UD2h95V8YmU

Except that wing warping is actually aerodynamically superior to traditional control surfaces.[citation needed]

Yeah, that second one wasn't a misfire. The vigil did exactly what it was supposed to do.

It's very common to see people jumping Sabres and such. You should avoid equipment that is truly outdated though. Cirrus, Wonderhog etc.

Yes RiggerLee, at this stage of the game I am thinking about simplicity. I tried to make my shitty slider collapsible but it didn't go very well. Oh well, at least they're nice and cheap to replace. [inline HPIM4350_small.jpg] [inline HPIM4351_small.jpg] [inline HPIM4352_small.jpg]

Is it not commercially available then? Can you provide me with the name of the mill perhaps?

Hmm, how about this kind of Dacron from FWF industries? Apparently it's no longer in production. [inline AK0000181.jpg]

Not much to update on but I did go to my local DZ yesterday and got the chance to look at the details on a few PD canopies. I might go back with a tape measure and a camera. And can anybody tell me whether smooth clean concrete is a suitable cutting surface for canopy fabric? Since I have nothing better to do, I got a sample of zero p fabric from the local mill and it's interesting stuff. Definitely coated fabric (nice and crackly sounding) but it's not slippery at all. I'll see if I have get some specs.

Funny you should say that Twardo... http://www.youtube.com/watch?v=Hfz34gy15tw Tow lines and closed end cells. A good idea never dies eh?

Bill Booth believes magnetic riser covers will save lives.

I got my grommets set in my slider but they're not spurred and not size 8 like I asked for. Ho hum. But apparently "they won't fall out", so that's alright. Luckily they weren't expensive either. I think I may just take them out and get a rigger to put some proper ones in. I still have a few more thoughts about seams at the leading edge. When I sew the topskin down onto the non loaded rib, the leading edge of the rib wants to sit perpendicular to the rest of the rib, right? This means that when I join it to the bottom skin, the leading edge of the rib is sort of twisted. Is this a problem. Also the extra reinforcement at the leading edge. I'm worried that a bartack may not be enough, especially with how I'm lining up the pieces. How about a Para flite style tab which wraps around the entire seam and then is sewn with a dense stitch pattern?

Yeah, I had a quick look and it may be more trivial than that. I may have been just not routing the upper thread through the tensioner at all...

The stitching on the slider is really shit in some places. As in the thread loops under the material. Upper thread tension too low? I think my tensioner's broken, lol. I know sliders are relatively easy to modify/cut holes in/replace entirely etc so I won't lose sleep over it. To clarify, the tape does go all the way to edge and folds over but in some places there's fabric on top so it looks like it's too short. I've had my inklings about extra reinforcement at the corners but I didn't know for sure. On the subject of grommets, are plain grommets and washers acceptable at all for sliders? The 800 lb line was relatively cheap at £0.70/metre and I've used it to make the lower steering lines. The main suspension and upper steering lines will be 600 lb Dacron. You mentioned earlier something about seams not lining up correctly, where should they line up? As in where does the rib meet the panel? On the load bearing stitch row (what I've been doing), on the second stitch row etc? Diagram may help or just confuse more. [inline bottom_seam_non_loaded.png]

Yeah, I've stabbed myself once already. If anybody wants to know, I managed to separate out the harness, backpad, main and reserve containers without destroying anything. I now have lighter ground launching harness I suppose. Good news is that I managed to source some slider tape, so I made my new slider. Bad news is that the thread tension is really fd up and I may just take it apart and try again on a proper machine. [inline HPIM4342small.jpg] [inline HPIM4347small.jpg] Also got some 800 lb Dacron for the brake lines, so I had a little practice and measured shrinkage for the first time. [inline HPIM4340small.jpg]

Remember to be honest about your currency and skills as well, even at 100 jumps and a lower loading I wouldn't want to jump a 150.

Not really related, but my old container may have been attacked with a stitch ripper. Maybe it's losing weight and turning into a ground launching harness, maybe it's turning into a future rigging project, who knows. [inline HPIM43382.jpg]

I think when you have automatic bar tackers and a machine for every task you stop being a home builder and start becoming a factory. About the loft I'm planning to use, there aren't any puller or folders but there are double needles which is a step up from what I'm used to. This also means I can go with neater seams as well. I'm thinking something like Nick's construction method should work well. And yes, I am going to modify my design slightly so that the rib lines up a bit better with the bottom skin.