Posted by Aeromister |
Dec 25, 2015 @ 10:20 AM | 1,858 Views
I received the 75% Sporty 40 short kit early this week so I thought I would get things started. Time is limited between all the Christmas and New Year’s activities but as you can see things went together pretty fast. The Short kit (cut by Balsaworkbench) was pretty complete, the wood was nice and light, and the cutting was right on the money with the reduced copies of the plans. For the most part I followed Ken Willard’s construction article sequence. I also measured and cut the cabanes to length – the front cabanes are slightly longer which gives the upper wing a slight positive incidence to the lower wing and stab.
With the Saito being a little longer than a typical 2 stroke, I was originally going to extend the fuselage but decided to just move the firewall back. Since the firewall had been cut to the height for the original position, I had to add a small piece of spruce to the bottom. The fuselage went together really fast as you can see in the pictures below. I got the landing gear plate cut and fit, but decided to wait to glue it in until I get the lower wing built so I could predrill the holes for the hold down dowels.
One thing to watch out for, if you build one of these is when you move the firewall back you limit the room for the fuel tank. I had to cut a hole in the former at the back of the fuel tank compartment to accommodate the length of a 4 oz slant tank. This was no problem since I wanted to be able to install and remove the fuel tank from the...Continue Reading
Posted by Aeromister |
Nov 16, 2015 @ 10:44 AM | 1,905 Views
Here's the story - I was considering reducing a set of plans by around 80% for a 4-40 bipe (for a Surpass 26) when Balsaworkbench (Rob) suggested I look at reducing a Sporty Forty by 75% instead. While I really dismissed the notion at first, I changed my mind when I printed out a 78% and an 82% reduced set of the 4-40 plans and started trying to place the engine, servos - and especially the fuel tank. The upper wing mounts looked a little tough to get set right. Proper wing alignment in a Bipe is an absolute must as well as getting the wing incidences set correctly. To top it off, the reduced ribs look like a real pain and cutting all that small sized spruce out... well it made me take another look at the Sporty Forty.
After printing out the Sporty Forty Plans on my home printer (set at 75%) I glued up the sheets to get some idea of the potential fit for a Surpass 26. This design really looks like a very easy conversion. The wing area will come in around 510 sq in (taking account for the Fuse). There is generous room for the radio gear so I can still use full size servos - although the Hitech 225's are almost an exact fit. The wood sizes are easily converted (1/4 converts to 3/16, 1/2 converts to 3/8, etc.). The more I looked at it the better I liked it.
Disclaimer – If you are following along, do not get discouraged if I occasionally take a leave for a week or so. I have a lot of irons in the fire and have to prioritize a bit.
You will notice I now have a Saito 30 in place of the Surpass 26 on the pictures - just trying to stay consistant with Ken Willard's thoughts in his orginal construction article.