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Old Feb 29, 2008, 10:41 AM
Shiok Lah
Ghostfit's Avatar
The little red dot
Joined Sep 2007
406 Posts
Build Log
KF Crossbow

On the requests of several bros, here's the preliminary Plans for the KF Crossbow.
(Thanks to Bill and anyairrc for the PDF file conversions options)

Note that the Jpeg Plans layout format is :
1 - 2
3 - 4
5 - 6

Acknowledgements
* Dick Kline (Dickeroo) - for inventing the airfoil.
* Tony (Tony65x55) - for creating the KF hammers.
* Joe Yap - for putting the challenge to me and then helping me fly the KFC.
* My Wife - for acompanying me to those slopes and shooting "dizzy" videos
* Bob Horowitz (rahdds) - for the motivation to put plans of the KFC here.
* Troy (tiretrax) - for the lovely "pushed me over the edge" Revert design.
* Bill Segraves and anyairrc - for helping me convert the files to PDF.
* And a whole lot of others - for the kind words and encouragement.
...this is dedicated to you guys !

Specifications :
Wingspan = 36"
Length = 18"
Height = 8"
AUW = 160gm to 200gm

Materials :
5mm Compress foam or Depron
5mm x 0.6mm CF strips

Version history :
01 Mar 08 - KF Crossbow II plans uploaded to RCG ...build log to follow.
28 Feb 08 - Preliminary Plans created ...KF Crossbow II is born.
26 Feb 08 - Elevons enlarged by 1/2" Root and 1/4" tip.
- Nose shorten by 2".
- Wing roots to nose joint changed to a smooth curve.
23 Feb 08 - Prototype KF Crossbow design successfully test flown at Sedili.
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Last edited by Ghostfit; Mar 11, 2008 at 09:53 PM.
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Old Feb 29, 2008, 10:44 AM
Shiok Lah
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The little red dot
Joined Sep 2007
406 Posts
KF Crossbow II Build log.

Pictures speaks a thousand words ! ...here's several thousand.

Notes:
* I used foam safe CA and kicker as I hate sitting around the whole day watching glue dry !
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Last edited by Ghostfit; Mar 02, 2008 at 02:35 PM.
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Old Feb 29, 2008, 10:45 AM
Shiok Lah
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The little red dot
Joined Sep 2007
406 Posts
KF Crossbow Post#002

Trimming and flying the KF Crossbow (Slope soaring)

1) The CoG is located about 10mm in front of the KF step measured as shown in the plans.

Trimming and flying the KF Crossbow (Powered)


* Here's the original KFC maiden video at Sedili.


http://www.youtube.com/watch?v=TfJC9yxwHyc
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Last edited by Ghostfit; Mar 18, 2008 at 08:49 PM.
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Old Feb 29, 2008, 10:46 AM
Shiok Lah
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The little red dot
Joined Sep 2007
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KF Crossbow post#003

General discussion

...these build logs are really targeted at the newbies and juniors, I'm sure the more experienced builders will have no problems at all bashing up a flyable KFC from these plans ...I've included some pictures here of the prototype KFC as a guide for the time being.

Happy building !
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Last edited by Ghostfit; Mar 18, 2008 at 08:50 PM.
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Old Feb 29, 2008, 11:52 AM
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Quote:
Originally Posted by Ghostfit
On the requests of several bros, here's the preliminary Plans for the KF Crossbow.
(I'm sorry for the Jpeg file format but when I save as a Pdf, the file size is like 25+mb per page ! ...anyone can help me improve it ?)

Note that the Plans layout format is :
1 - 2
3 - 4
5 - 6
...
Nicely done, Ghostfit.

If you're using a raster-graphics program, you'll get huge file sizes when you print to a PDF pseudo-printer (driver). Vector graphics don't suffer from that problem, except when they are converted to bitmapped graphics in the conversion process.

That said, it is easy to combine your images into a single mutlti-page PDF, using the PhotoAlbum tool in the iText Toolbox. Once that is done, the pages can be converted to a single-sheet PDF, with the interpage margins removed. The resulting single-sheet PDF can then be scaled to any size and tiled with ScaleAndTile, as well as some of the other methods employed by members of this forum.

I need to leave in a few minutes to run some errands, but I should be able to complete the above procedure by mid-afternoon, when I return from my errands.

Best regards,
Bill Segraves

[Edit 29Feb2008: I whipped up a quick-and-dirty untiled version of your plan, which can be easily scaled to full size and tiled with ScaleAndTile. Before I do that, please print a copy of the attached file, to see if my gap-elimination measurements were correct (I measured margins = 0.29 in. on your JPEG images. After you've confirmed the correctness of the combined PDF, I'll finish it and add descriptions of the steps I used. Cheers,
Bill Segraves.]

[2nd edit 29Feb2008: Here are the steps I followed to untile the PDFs:
1. Use iText Toolbox's PhotoAlbum tool to convert the images into a multi-page PDF, Crossbow.pdf
2. Use an iText program (currently under development) for untiling a tiled PDF. This program allows the user to specify the Input PDF file, the array dimensions for the untiling process, e.g. 2x3 for this example, and the inter-tile gaps for X and Y directions. The resulting untiled PDF is shown below.

Note 1: The procedure in 2. above works best for borderless PDFs/images. PDFs with embedded painting path operators (vectors), because there is no content in the margins. OTOH, PDFs with embedded raster images, as well as images that have content in the margins should, ideally, be cropped before untiling to eliminate the content in the margins.

Note 2: Anyairrc has already performed the necessary cropping, while he was arranging the six images into a single image. His PDFs, produced with ScaleAndTile3, appear in the next message. Nice work, Anyairrc. Thank you.
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Old Feb 29, 2008, 11:56 AM
Foam Master
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Here you go man, the file size is smaller and the lines aren't as crisp but it should work

updated to fix wingspan to 36"
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Old Feb 29, 2008, 03:06 PM
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Quote:
Originally Posted by anyairrc
Here you go man, the file size is smaller and the lines aren't as crisp but it should work
My, Anyairrc, you are indeed fast with your image-editing software and ScaleAndTile3. You had already posted your output PDFs before I finished running my untiling program.

Note to users of other tiling programs, especially those that use pseudo-printer based methods to create PDFs. If you use your procedure to tile the first PDF in Anyairrc's message, you may see that the file size for your tiled PDF is more than 6X the size of the input file. If this happens when you try it, it is likely because such methods require an independent copy of the input PDF/image for each page of the resulting PDF.

ScaleAndTile does not suffer from the aforementioned disadvantage of pseudo-printer-based PDF generators, as all of the ScaleAndTile-generated pages use the same copy of the any input PDF/image that is embedded in the PDF. This difference has major consequences when a large number of tiles are generated.

Best regards,
Bill Segraves
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Last edited by segraves; Feb 29, 2008 at 05:42 PM.
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Old Feb 29, 2008, 03:27 PM
My plans are in my blog
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Kotzebue, Alaska
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Neat plane, nice design.
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Old Feb 29, 2008, 08:06 PM
Shiok Lah
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Joined Sep 2007
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Thanks to Bill and anyairrc ! ...I'm hopeless at images conversion ! (still struggling to understand half of what conversions has being done)

...But as long as it helps the other bros use these plans to built a KFC, I'm really grateful for your efforts ! ...thanks again !


...OKAY, now lets see some pics or vids of the KFC fly in other parts of the world !
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Old Feb 29, 2008, 10:54 PM
Use whatcha got!
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Metairie, LA
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Ghostfit - thanks for the design, bill, any, thanks for the pdf's!

We've been having horrible weather here, but I think that we might actually be able to get some slope soaring done on the levees down here... This might be a good candidate.

Looks great too!

Thanks again,
mike s.
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Old Feb 29, 2008, 11:23 PM
skumgummi dave
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Has any one had a chance to check the sizes of these pdf files?

Thanks, Dave-
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Old Mar 01, 2008, 06:42 AM
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That was quick, thanks for the plans.

JimW
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Old Mar 01, 2008, 08:18 AM
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See Anyairrc's message for ScaleAndTile3-produced PDFs.

Quote:
Originally Posted by foamdave
Has any one had a chance to check the sizes of these pdf files?

Thanks, Dave-
Thanks for checking, Dave.

The untiled PDF I posted was not scaled to full size and tiled, as Anyairrc had already done the scaling and tiling. I have now scaled the untiled PDF to 36" WS and will post same in my message with the untiled version, after the designer has resolved the discrepancies noted below.

If you use ScaleAndTile to scale and tile the untiled PDF that I posted, you'll have to fill in the skips in the lines after you print the tiles. Note: If you use SF = 3.4 with my version of the untiled PDF, you'll get WS = 36".

[Edit 01Mar2008 7:29 pm: See Anyairrc's revised PDFs.]

Best regards,
Bill Segraves
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Last edited by segraves; Mar 01, 2008 at 08:18 PM.
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Old Mar 01, 2008, 08:23 AM
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Note to Ghostfit and potential builders

Ghostfit, et al,

Please check the dimensions in the specs and on the title block of the drawings, as the wingspan and overall length do not appear to be consistent with the actual image. Thanks to Foamdave for pointing out the discrepancies.

Cheers,
Bill Segraves
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Last edited by segraves; Mar 01, 2008 at 07:23 PM.
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Old Mar 01, 2008, 08:52 AM
Foam Master
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I have fixed the wing span to 36"; I updated the .PDF files in my earlier post. Sorry If you guys ended up wasting paper, I don't know what happened I used the source drawings above and I didn't change the scale.
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