Friday, August 4, 2017

Estes Nova Scout Ship #1392 Scaling Questions

I have a client who wants a Starship Nova and it's sister ship the Nova Scout Ship built.
Now that Estes has re-released the Starship Nova with the drop-down nose cone, the Nova Scout Ship can be cloned.
I posted on TRF and YORF but so far, nobody has a Nova Scout Ship to check the fin dimensions. All I really need is the root edge of the main wing fins and everything else could be sized.
If I can't get sizes from an original kit, what is the next step?

The instructions can be found on - CLICK HERE
There are fin tracings but no 1" reference square. I printed the fin patterns but am not sure they are the correct size when printed out. They seemed large.
PLEASE: For the benefit of all the rocket clone builders out there, please draw a 1" reference box on all submitted fin tracings!

Catalog and face card pictures are usually taken at an angle, not very valuable for fin sizing.
On page four of the instructions there is a decal placement picture, two shots, straight on. While the resolution isn't great, I can get an idea how close the fin templates are.

I copied the page and dropped it into my Corel Draw software.
A box was drawn with a height of .976" or the outside diameter of a BT-50. The rocket picture was enlarged until the body tube was the same height (diameter) as the .976" high box.
This also enlarged everything else in scale and gave me close to the top intake tube length at 3.5" long. That also gave me the standoff length, close to 2.7" long.

The overhead view is a second chance to get more sizes.
Again the picture was enlarged to the body tube diameter of .976". That enlarged the main fin root edge to 4.17".

These approximate sizes were a double check to see if the PDF sizes were close. They weren't! I'll have to cut off about 1/4" from all sides.
The wing fin at the bottom shows the outline closer to the correct size.

You can use this method to get an idea of the original fins sizes when you clone a model rocket. (If the online PDF doesn't include a 1" reference square) While it may not be exact, it's much closer than what the PDF printed out.

EDIT: BAR Geezer pointed out something obvious in his comment below. The top fin root edge is the same length as the 3.5" long tube at the top rear. I didn't see this and it would have made my scaling problem much easier!
I loaded the art into Corel Draw and reduced it until the root edge of the top (rudder) fin was 3.5" long. Done! 


  1. The root edge of the longest triangular fin (the one that goes on top of the secondary engine tube) should be 3.5" long, the length of the tube. My pdf printout was about 1/8" too long. Cheers.

    1. Hi BAR,
      Check my EDIT on the above post. Thanks for pointing out something I should have saw!

  2. I haven't visited your site for a few weeks or I would have noticed this and commented much sooner. I started a Nova Scout Ship clone a few years ago, and I still have my original from c. 1983 when I was about 7 y.o.; probably the second oldest rocket I still have). I can't trust my old rocket's fins sizes (too much sanding), so I just now reprinted the fin pattern image file from Gimp as a test to compare to my clone-in-progress. The fin patterns are 200 dpi, and I tend to trust what the image properties say, as most people who scan or trace this stuff don't play with those settings after the fact. Also, if you print either the traced pattern or the balsa scan directly from the PDF file at 'actual size' you end up with something that matches the print from the image file.

    I wouldn't worry about that 1/8" overlap due to the very acute angle at the root/leading edge vertex. I think perhaps it was designed as deliberately oversized due to the inevitable material loss when sanding such a sharp angle. Something else to consider is that the wing decals are actually too long for the wing and will probably need to be clipped at the trailing edge (compare the left wing decal graphic with the B&W view of the left wing from the kit instructions). Having a bit of extra material may keep you from also having to clip the decal at the leading edge.

    Note: I also have the decals ready to go in CAD for whenever I finish my Nova Scout Ship, and a set for a Star Ship Nova clone that's had a coat of primer on it waiting since last year (my rocket building free time has been pretty limited, you can probably tell). If you'd like a copy of the decal CAD files, you're welcome to use them. I shared EPS format version of both decal sets with Mark Hayes of Stickershock a few years ago (though I don't know whether he's actively using them for his vinyl decals or not).

    Josh T.

    1. Hi Josh,
      This build will be for a customer and I want it to be the original sizes. I have printed fins from online sources before and have had oversize results before. I just wish available files had a 1" reference for scaling before I end up cutting them out.
      The client wants something other than the kit decals. Thanks for the offer of the decal file.
      In the past I've had to trim many decals to fit stock fins.