Wednesday, September 18, 2013

New Project!

I have a new project that I am very excited about.  I have started scratch building a semi-scale Yak 52.  Now you may be asking, "Why scratch building?", "What is this semi-scale thing?", and "Why the heck a Yak 52?".  Well, let me start off with the easy one. What is semi-scale?  I've come to find out that in modeling this generally refers to something that is built like something but not exactly, and usually built larger or smaller than the original.  So, for my project, I started with drawings and pictures that I got from the Internet.  These drawings and pictures, though reasonably accurate, are not to scale.  In my project I have taken one of the drawings and "scaled" it up to the size I want to build.  So, although I have accurately scaled it up from a drawing, the drawing was not accurately scaled to begin with.  Clear as mud?

Flite Test swappable Nut Ball airplanes my daughter and I built
Why scratch built?  Well, I have enjoyed modding my existing planes and building some simple scratch built foamies like the ones at Flite Test (Check them out they do some really cool stuff with DollarTree foam board).
Then I hooked up with Daniel Madrigal on YouTube.  Check out his site!  This guy builds some really cool foamie jets completely from scratch.  Now I have the bug and I want to move on to my own scratch built planes.

On to the big question that everyone has, why the heck a Yak 52?  Yes, we can all see building a Yak 54, these planes are all over the place as one of the best aerobatic planes, but a Yak 52?  Well, it really comes down to the first time I was really exposed to this plane, and that was in one of my, and my oldest daughter's, favorite movies: Resident Evil: Afterlife.  In the beginning of this movie Alice (Milla Jovavich) along with Claire (Ali Larter), flies a Yak 52 from Alaska to Los Angeles and crash lands it on top of a sky scrapper.  First you may ask, "How did I even notice the plane with Milla Jovavich and Ali Larter?  Well I did and I fell in love with Milla,.. I mean the Yak 52 and have liked this quirky plane ever since.  I most likely would not be scratch building this plane except that it's really hard to find a Yak 52 kit, especially for electric.  So, I'm building my own.

How am I starting?

Like Daniel suggests, I'm starting with a "three view".  This is like it sounds, a drawing with three views of the subject.  I found several just by searching the Internet for "Yak 52" and "drawing", "plans", "three view", etc.  After selecting the one I liked the most, I had to figure how big I wanted to make it and how I was going to scale it up.  I could have used Daniel's technique of finding all of the "joints" and scaling and transferring  all of these measurements to a larger sheet, but I have laser printers and computers at my disposal and decided to use them to scale the drawing.  I started by deciding that I would like to make mine 5 times larger than my drawing.  This would give me about a 33 inch wing span.  The drawing I had was already sized for an 8.5 x 11 sheet of paper so once I opened it in my drawing program, I selected a custom paper size of 5 times 8.5 x 11 ( or at least 42.5 x 55 inches in my case).  Then I expanded my drawing dimensions by a factor of 5 in height and width.  From here I saved the new drawing as a PDF file.  From my PDF document viewer I had the option to print on multiple sheets of letter paper or, "Poster" print.  This then gave me a bunch of sheets that I cut out and taped together.

My enlarged drawing "Poster" printed and all taped together

Now, on to the build!

I started the same way that Daniel did with his planes that used bulkhead sections.  I started with a fuselage base to attach sections to.  I also started by normalizing and straightening some of the dimensions.  By this I mean that I took out some of the subtle curves and contours and also adjusted some of the dimensions to even increments.  The width of the fuselage base in the photo was set to an even 3 inches instead of the measured 3 and 1/16 inches.  I also had to estimate where the firewall would go and what I would make it from and how thick that would be (I decided on 1/8 inch plywood).

Then I started drawing out bulkhead pieces and shaping them down to compensate for the 3/16 inch foam skin I'm going to wrap it in.  I had some nice sectional views to work with that you can see in the previous photo.  These helped greatly in getting the shape right.  If I did not have these I would have been tempted to just make it completely round the whole length like I have seen other do.

 Here I have all of my sections cut out and trimmed for the skin and the center section removed (the lines through the middle in the above photo) to compensate for the fuselage base thickness.  You can see too the bottle of Fabric-Tac glue that I will be using.  I was going to use hot glue for ease and speed, but this was suggested by Daniel Madrigal and others as being lighter and stronger.  The tackiness does help with assembly but it does take overnight to really set up good.

Here we are with all of the bulkhead pieces glued in place ready to start putting in stringers from the nose to the tail.  I'll be using 1/8 x 3/16 basswood strips for this.  I was going to use balsa wood, but the selection I had seemed too soft and flimsy.  I opted for heavier but more strength.

That's all for now.  I'll have more soon.

Thanks for stopping by my blog.  Please feel free to post comments, good or bad, and be sure to come back and check for future posts.

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