Forums: Skydiving: Gear and Rigging:
My little project

 

First page Previous page 1 2 3 4 5 6 7 8 9 10 ... 12 Next page Last page  View All

ChrisD  (No License)

May 21, 2013, 8:40 AM
Post #126 of 299 (5022 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Smile

You would think that there is some kind of computor program that would enable you to understand the effects of subtle changes in canopy configurations?

There isn't.

Therefore, keeping safety foremost in mind, everyone's comments early on in your postings, the good, the bad, the rude,...all apply.

You might just stumble upon something new and for that:

once again I applaud your efforts!Wink


JerryBaumchen  (D 1543)

May 21, 2013, 12:29 PM
Post #127 of 299 (4977 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Hi Quag,

Something that occured to me: Why not spread the rib/support tapes where they top out on the rib? This might spread the load(s) somewhat for a smoother topskin. As they are, they are point loading where they intersect.

Just something to consider,

JerryBaumchen


Quagmirian  (A 110392)

May 21, 2013, 1:11 PM
Post #128 of 299 (4954 views)
Shortcut
Re: [JerryBaumchen] My little project [In reply to] Can't Post

JerryBaumchen wrote:
Why not spread the rib/support tapes where they top out on the rib? This might spread the load(s) somewhat for a smoother topskin.
From what I can gather, it seems to be a bit of a trade off. If I spread the tapes out too much, I think I will end with something like this:



Taking it to the extreme, if the tapes were infintely close together, ie one tape going straight up, it would look like this:



I have moved just the c1 and d1 v tapes back a few inches, so I should end up with something like this:



From my not very extensive studies, I have decided that I am more afraid of tapes being too far away from each other than too close. I'm sure you'll agree that all this isn't going to make too much of a performance change anyway, since I am working on relatively large, conservative 7 cells. Feel free to overrule me on this if you feel I've missed something.
Attachments: pd_reserve_small.jpg (30.7 KB)
  300652_small.jpg (27.1 KB)
  trango_small.jpg (29.6 KB)


JerryBaumchen  (D 1543)

May 21, 2013, 3:02 PM
Post #129 of 299 (4933 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Hi Quag,

Quote:
Feel free to overrule me on this if you feel I've missed something.

Nope, it was just a suggestion. Heck, I didn't even charge you for it. Cool

"Overrule you." Never, it is after all your project.

JerryBaumchen


Quagmirian  (A 110392)

May 21, 2013, 5:36 PM
Post #130 of 299 (4896 views)
Shortcut
Re: [JerryBaumchen] My little project [In reply to] Can't Post

JerryBaumchen wrote:
Quote:
Feel free to overrule me on this if you feel I've missed something.
"Overrule you." Never, it is after all your project.
That may be, but I'd rather you say something before I make any shitty design choices.


Quagmirian  (A 110392)

May 24, 2013, 6:44 PM
Post #131 of 299 (4745 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

I thought I'd share this little gem from Poynter's.


Attachments: slope_soaring.gif (167 KB)


Quagmirian  (A 110392)

Jun 10, 2013, 2:28 PM
Post #132 of 299 (4643 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Here's something I forgot to post a while back. While it is beyond the scope of this project to manufacture live risers, I have been making some for ground handling and launching. Here's my latest effort (it's actually quite old) compared to a bought, and I suspect rigger made, riser. My thoughts so far? Accurate three ring riser construction is difficult and best left to manufacturers. I will not be jumping home made risers, as I consider them part of the H/C system.



Recently, I have been doing a lot of 'thinking'. While I am very happy with the performance of the brown thing, I think I can do better, particularly in the flare department. I have redesigned my ribs with smaller nose inlets and smoother profiles, in an effort for better glide and flare power.

One other thing, from now on I will be building canopies with fixed aspect ratios and at recognised sizes. While in the past I have made wings with areas of 'about 160-170 square feet', I will now stick as accurately as possible to known sizes, as in 135, 150, 170, 190 etc.

Here are the redesigned ribs, both seven and nine cell versions, in this case for a 150 square foot canopy.






(This post was edited by Quagmirian on Jun 10, 2013, 2:40 PM)
Attachments: 150-2571_small.gif (12.5 KB)
  139-2362_small.gif (11.5 KB)
  3_rings.JPG (61.7 KB)


bofh  (D 13995)

Jun 13, 2013, 5:04 AM
Post #133 of 299 (4503 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Quagmirian wrote:
Recently, I have been doing a lot of 'thinking'. While I am very happy with the performance of the brown thing, I think I can do better, particularly in the flare department. I have redesigned my ribs with smaller nose inlets and smoother profiles, in an effort for better glide and flare power.

Have you seen Ozone's patent for SharkNose? It would be interesting to see how that concept would work on a parachute:
http://downloads.flyozone.com/...ne_shark_nose_en.pdf


Quagmirian  (A 110392)

Jul 11, 2013, 2:04 PM
Post #134 of 299 (4324 views)
Shortcut
Re: [bofh] My little project [In reply to] Can't Post

bofh wrote:
Have you seen Ozone's patent for SharkNose? It would be interesting to see how that concept would work on a parachute:
http://downloads.flyozone.com/...ne_shark_nose_en.pdf
Thanks for that. I think that sort of thing is out of my skill level at the moment. Maybe when I'm building a high end swooping canopy, I'll come back to it.

I have been doing some more thinking, and I have decided that I want to put a single fold on the loaded bottom seams, not because it's any stronger, but because it looks a bit more professional. I've also changed my trim, rib and stabilser panels again.





I decided to use my scraps of old dacron to replace and extend my upper steering lines. It wasn't too difficult and they're all the same length +/- 0.25 inches. Good practice and now I have nice looking control lines. Smile








(This post was edited by Quagmirian on Jul 11, 2013, 4:13 PM)
Attachments: AK1.JPG (73.3 KB)
  AK2.JPG (71.3 KB)
  AK3.JPG (80.1 KB)
  2742_rib_stab_flat_small.png (34.8 KB)
  2742_rib_flat_small.png (29.1 KB)


Quagmirian  (A 110392)

Jul 25, 2013, 1:35 PM
Post #135 of 299 (4114 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

No more production updates for the moment, as I am living in the countryside for my own health. I have found a few good ground launching spots though.




Attachments: DSCF1007_small.jpg (313 KB)
  DSCF1008_small.jpg (546 KB)


Quagmirian  (A 110392)

Aug 10, 2013, 8:30 AM
Post #136 of 299 (3876 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

I have done quite a few flights on this thing now, including a glide down a 500 ft high slope, which was great fun. I have come to some general conclusions about the canopy in its current configuration.

Glide ratio is nice and flat, around 2.5:1.
Front riser pressure is very high.
Rear riser pressure is low, with a small control range before the stall (about 4 inches).
Flare power on the toggles is very good for a canopy of this size and type.
Control range on the brakes seems to be decent, although I haven't stalled it on the toggles yet.


Quagmirian  (A 110392)

Aug 20, 2013, 2:41 PM
Post #137 of 299 (3691 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

I've been doing a lot more ground launching. I went flying yesterday and it was very windy on the hill, so I got a decent bit of air time riding the rising air. I even got so bold as to try and stall the canopy. It didn't fold back on me, but it didn't look very happy either.

I took the canopy flying today with a couple of cameras. Here are some frames from the foot mounted camera.







This frame was captured just before landing, with the canopy in deep brakes.


Moving on the the future, here's a comparison of the rib sections and planforms of my old design, current canopy, and new design.





Comments and criticism are always welcome.
Attachments: frame1.png (230 KB)
  frame2.png (196 KB)
  frame3.png (183 KB)
  frame4.png (184 KB)
  planforms_small.png (8.05 KB)
  ribs_compare_small.png (28.1 KB)


Quagmirian  (A 110392)

Sep 2, 2013, 5:41 PM
Post #138 of 299 (3484 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

I've been going backwards and forwards on a few little things, but I think I finally have a design to replace the brown thing. The main design difference is the rib section, which is slightly thinner and smoother, with a smaller nose cut. There are construction differences too, addressing structural and quality issues.

General canopy info
Cells: 7
Aspect ratio: 2.10
Area: 170 sq ft
Chord: 2.740 m (8.99 ft)
Span: 5.754m (18.88 ft)
Colour: Not yet known, orange perhaps
Lines: 600 lb Dacron

Rib section
Max thickness: 15.0%
Position of max thickness: 19.4% (same as brown thing)
Nose cut size: 8.54%
Nose cut angle: 142

Slider, standard
Chord: 0.44m (17.3 inches)
Span: 0.78m (30.7 inches)
Grommets: Brass, type 8

Line trims (mm)
A line 3108
A-B 66
A-C 216
A-D 458
UST 1200
LST 2716 Roughly
BK-TOG Don't know yet

Panel shapes (less seam allowance) and slider diagram


Attachments: parts.png (22.6 KB)


RiggerLee

Sep 2, 2013, 6:20 PM
Post #139 of 299 (3470 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

The "Orange Thing"? I'm sencing a trend here. Your doing well on your design and Ok on your construction, but you need to work on your marketing. Take my word for it. Cool names and half necked woman, you can sell any thing that way.

Lee


mr2mk1g  (C 103449)

Sep 3, 2013, 3:06 AM
Post #140 of 299 (3430 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Just so you know, whilst you might not be getting many replies recently, we are still reading and interested in your projects. It's great to read of someone 'mucking about' like this.


DHemer  (B License)

Sep 3, 2013, 4:06 AM
Post #141 of 299 (3426 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Keep it up
Enjoy reading the updates


shropshire  (C License)

Sep 3, 2013, 5:05 AM
Post #142 of 299 (3407 views)
Shortcut
Re: [mr2mk1g] My little project [In reply to] Can't Post

mr2mk1g wrote:
Just so you know, whilst you might not be getting many replies recently, we are still reading and interested in your projects. It's great to read of someone 'mucking about' like this.

Very true..... Keep going OP


skyturtle

Sep 3, 2013, 12:38 PM
Post #143 of 299 (3331 views)
Shortcut
Re: [shropshire] My little project [In reply to] Can't Post

Just out of interest, how did you work out the dimensions for your slider or is it just a temporary design?


Quagmirian  (A 110392)

Sep 3, 2013, 2:39 PM
Post #144 of 299 (3309 views)
Shortcut
Re: [skyturtle] My little project [In reply to] Can't Post

skyturtle wrote:
Just out of interest, how did you work out the dimensions for your slider or is it just a temporary design?
The measurements are based on the slider from a PD 7 Cell. When I get round to jumping this thing we can work out if the dimensions need to be changed. It's just a starting point.


Quagmirian  (A 110392)

Sep 6, 2013, 7:10 PM
Post #145 of 299 (3126 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

I'm happy with all the seams on the brown thing, except the loaded bottom seams. Even if I hot cut everything, stuff still sticks out and I don't like the look of the raw edges. Also, the flat seam looks a bit thin in places. I would fold or roll the seam but all the bulk at the leading edge makes it very hard for my puny machine to sew properly, so I've come up with a solution. When I apply the leading edge tapes to the bottom skin and rib, I pre-fold the edges so that the tape only has one layer of thickness. It's difficult to explain so I hope this diagram helps.



I've made an image of what the new canopy should look like based on the brown thing in flight.


I've also decided on a warning label design and stabilser logo panel.




Attachments: seams.png (10.4 KB)
  new_7_cell.png (20.2 KB)
  warning_label1_small.png (92.9 KB)
  canopy_logo_9a_small.png (23.0 KB)


pwilliams  (A 64668)

Sep 11, 2013, 12:55 PM
Post #146 of 299 (3020 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Love this thread, please continue to keep us updated Wink


Quagmirian  (A 110392)

Sep 12, 2013, 1:11 PM
Post #147 of 299 (2954 views)
Shortcut
Re: [pwilliams] My little project [In reply to] Can't Post

There are a few things I don't like about the brown thing. Firstly, the control range is a bit short on the toggles (it's a flat trimmed canopy), and secondly, the turns are a bit snappy after about half brakes. There's plenty of flare power and toggle pressure though, so I thought I'd try and solve these problems by moving the most inboard control line half a cell outboard, like this:



Any thoughts?
Attachments: new_ust_config.png (14.0 KB)


Quagmirian  (A 110392)

Oct 8, 2013, 4:57 AM
Post #148 of 299 (2682 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

I had a go at making a slider for my new project.


Attachments: AK000003.JPG (44.7 KB)


theonlyski  (D License)

Oct 8, 2013, 8:05 AM
Post #149 of 299 (2619 views)
Shortcut
Re: [Quagmirian] My little project [In reply to] Can't Post

Quagmirian wrote:
There are a few things I don't like about the brown thing. Firstly, the control range is a bit short on the toggles (it's a flat trimmed canopy), and secondly, the turns are a bit snappy after about half brakes. There's plenty of flare power and toggle pressure though, so I thought I'd try and solve these problems by moving the most inboard control line half a cell outboard, like this:



Any thoughts?

If I recall correctly, that's the exact opposite of the Triathalon mod (it goes from the "After" to the "Before" IIRC)


Quagmirian  (A 110392)

Oct 19, 2013, 5:21 AM
Post #150 of 299 (2407 views)
Shortcut
Re: [theonlyski] My little project [In reply to] Can't Post

That sounds about right.

I downloaded Javafoil and put my airfoil in it and I have no idea what I am supposed to be looking for.


Attachments: javafoil.png (94.2 KB)


First page Previous page 1 2 3 4 5 6 7 8 9 10 ... 12 Next page Last page  View All

Forums : Skydiving : Gear and Rigging

 


Search for (options)