PeterSripol Ultralight RC Build

_{PeterSripol’s Ultralights have gotten a lot of attention and it’s easy to understand why.Peter has taken his mechanical and RC scratch building skills to create not one but two actual full scale aircraft. I’ve been a fan of Peter since day one and so I thought it would be an interesting challenge to try recreating his second airplane into an RC model made of foam board and balsa.} 

_{Here is the result.}

_{It’s not a 100 percent accurate replica, but it’s pretty close I think, and most importantly, it is completely unmistakable.} 

_{The Build}

_{I originally wanted to get this plane done before Flite Fest, but I ran out of time. I didn’t take any picture as I went along, but it’s really easy to see how this plane is built because it’s so skeletal.} 

_{I made the whole thing from an enlarged single side profile and looking at Peter’s various Instagram videos and pictures. It is 36 inches long from nose to rudder.}

_{The fuselage is primarily foam with a lot of balsa reinforcement. I used this side view provided by Peter’s Instagram to get the fuse profile.} 

_{So then I traced the frame part and cut it out of foam. I ended up using two layers of foam to make it stronger. The nose is made like on the Otter and guinea pig.The landing gear is attached like on the FT flyer and others. My rubber bands are weak so I glued a skewer to make it tougher.}

_{The 3 cell 2200 battery goes up in the nose. The windshield is just clear plastic from some packaging like Peter shows how to do in the Otter build video. As you can tell I used as many Peter techniques as possible for this plane :D Then I added a bunch of balsa as you can see. It’s plenty strong for a plane this size, and it is very lightweight.} 

 _{Then I used the same side view  image as shown above to make the rudder and stabilizer. I had to make up the horizontal because Peter never posted a top view. It’s a bit short I think at 16” , but it works. I glued them on the back of the fuse and mounted the servos like this.} 

_{I had a good idea of what the wing chord would be, but less of what the span was. It ended up being about 47 inches with a 10 inch chord. Much wing area there is...} 

_{The airfoil and spar are really basic, very similar to most earlier FliteTest designs. There is a bit of dihedral like on the real one. The spar is three layers thick and there is no wood, but the wing doesn’t seem to need it because of how lightweight the fuselage is.} 

_{The motors DJI knock offs a bit bigger than Powerpack B with 30 amp ESCs. The nacelles are just powerpods stolen from my guinea pig, which someone’s race wing (I think)  annihilated it during combat at Flite Fest. No hard feelings though it was an EPIC mid-air :D}

_{The powerpods are just glued to the bottom and the scale ailerons are mounted to them. The ailerons are balsa and are actually very simple, using only one outer hinge per aileron proved to be strong enough.} 

_{The servos and receiver are mounted right on the bottom of the wing for easy access.} 

_{The CG is about 3 inches back from the leading edge.. With that determined it was maiden thyme} 

_{The maiden went GREAT!! All that wing area combined with the literal ultra light fuselage (and highly substantial differential thrust) made for a stable and easy flying aircraft.} 

Beautiful day to fly!! 

I hereby claim to be the first one to build a RC of Peter’s ultralight, that is unless the comments prove me otherwise. Sadly I can not provide direct plans for this model but you should be able to create your own by using the dimensions provided. I hope to keep this plane around for a while and bring it out to any events I may go to. 

This project was really interesting because of how unconventional this plane is. Again, I encourage you to build a plane like this if you haven’t already! It’s a great learning experience and really rewarding in the end.