70% FT Racer
Link to full size plans
I recently retired my D.520 which was my smaller fast plane, and I need something to replace it. So instead I'm to build a 70% racer because the racer is said to fly very well and it has tons of good feedback (I just need that to translate into a smaller airframe
)
First thing I did was printed out the full size plans at 70% size, and widened the A and B fold cavities to 3/16 in. The fuse went together well but I had to widen the nose to accept the FT mighty mini power pod, and widen the tail section so the the vertical stab could slot into the fuse. The only changes made to the tail feathers were changing up the alingent slots a little bit. The wing was the same as the full size except I used a spar like the FT mini mustang, and I changed the cutout in the fuse so that it lied flush with the belly.
I also cut out a section of the top plate for a hatch.
Here she is decorated with black packing tape.
Overall I'll give it a Build Difficulty rating of 3/5 after you've scaled down a plane once, the process is pretty straightforward. The build itself took about a week of working on it for like 45 minutes a day.
Now I just got to install the motor and reciever, and fly it!!
Update:
I got out to fly it!!
It flies pretty good just a bit touchy, I launched in high rates so it was very squirrely right off the bat but once I got her trimmed out she was pretty docile over all. The flight difficulty was 4/5 due to the close call at launch.
Do's and Don'ts
I think that for anyone wanting to design their own plane, scaling down or upsizing an existing plane is a great way to start. It will give you a better understanding on how the folds work because you'll have to enlarge or shrink each one of them to get them to fold properly and there will almost always be a road block along the way so this should help develop skills to make changes to an airframe on the fly. And it also gives you a way to make a whole new plane by using existing plans.
