Looks good so far bud. First I have a request and I will PM you my email address but I would love to have a file of just where you have the engine drawn up. Would be a big help when I finally get my 55cc edge profile from paper and into CAD. Now my little bit of input on what you have drawn so far. First are you going to do a wood frame fuse or do like I did mine and do foam core sheeted with balsa? I believe it can be built lighter doing wood framing but the sheeted foam makes it really rigid and wont have any tail twist when rolling (the 55cc profiles that WWRC sells have horrible tail twist, never broken in flight but they twist bad). Next the placement of the wing looks perfect. I would suggest bring the stab down into the same plane as the wing as well as lowering the engine down so the center of your thrust line is right on the center of the wing and stab. Also I think it would look better moving the engine back so the prop is only a 1/4" or so in front of the nose of the fuse. Also I recommend incorporating a carbon fiber or fiberglass tube into the fuse to make it stronger as well.
Hi “Balsabust” thanks for the reply. I am not home right now. You are welcome to a copy of the cad drawing of the motor. It is copy or should say the exact out line of a DA50. Spent a couple of days measuring it and then making the drawings of it. Makes life a little easier when drawing up something new.
Thanks for the input.
1. I started laying it out in foam because I have vacuum bag equipment and have some foam cutting wire. But after laying it out and adding in all the supports it just did not look good and really I was starting to add more weight than I would like so scraped it and started on a wood frame.
2. Will look into lining up everything and see if my wood frame still fits and all the hard points still work. Will let know.
3. Made the fuselage 90 % of the wing span.
4. Will extend the nose closer to the propeller or 1/4 from the propeller.
5. Question on a 50cc profile with a gas engine how thick did you make the stabilizer. My stabilizer will be glued into place.
6. One more important question is fuselage to CG ratio. What I mean if you measure the length from the back plate of the spinner to hinge line of the rudder, and then the length from the back plate of the spinner to the Cg. The Cg measurement should be about 27 to 31 %. Of the spinner to the rudder hinge line measurement. I hope you get what I am asking. I checked the PDF you sent and it was 29%.
I will get a picture of the wood fuselage soon and let you see it. Still needs a lot of work and numerous changes till I get to where I think it will work and not twist as much as the first one I drew. I am also having trouble getting the landing gear fit and not weight a ton. Went from flat aluminum gear to piano wire it is lighter and easier to lock into fuselage. Does not look as good but I believe functional. The is being built to teach me to 3D. When I am half decent at it I will get my Viper ST into the air.
.
