I have managed to get quite a bit done on my Mig29 V4 NAMCV3 build the last day or two... :)
I dry fitted what I have done to this point to perhaps show the subtle differences between the NAMCV2 and V3. I should have taken a picture with the stock plane to show the real difference in length, but will when it is complete. The V2 is already about 1/2" shorter than the stock Mig and this V3 is about 1" shorter than the V2
In the following two pictures, you can see the significant difference in distance between the wing trailing edge and the horizontal stabilizer on the V2 and the V3.
You can also notice in this picture below that I put the angled/bevelled part of the rudder hinge and the carbon fibre reinforcement on the outside of the vert stab/rudder setup in order to keep the area in the prop wash as smooth as possible.
Carbon fibre reinforcement installed in the wing, back plate and elevons shown below. I used 4mm carbon rod for the main wing spar, the two pieces along the leading edge of the wing, the piece on the back plate and the elevons are all 3mm carbon tube as is the piece above in the vert stab.
In planes where I am going to be using the NTM Prop Drive (which I eventually will on this plane after it's first series of test flights), I like to have a little more strength in the back plate to reduce torsional flex in turns and rolls. The reinforcement in the vert stab also helps those stay nice and strong in the prop wash and with those big rudders it helps to have a good strong surface for them to hinge from.
In the picture below you can also see the ailerons I am going with. They are very similar in shape and size to those that I like on the NAMCV2 Mig although the trailing edge is not completely straight to accommodate the slightly different shaped wing of the Mig35. The total span of the aileron is equal to roughly 60% of the wing length from root to tip.
In the picture below, you can see the small angled cuts at the front of the intakes, this will allow me to bend the bottom of the intake up a bit to make a more rounded front edge like the front of a ski similar to the FRC Su35 MK2. I find this helps prevent such abrupt stops when the plane touches down and since it will be a bit heavier with the NTM eventually, this hopefully will help reduce structural stress when it slides a bit better after touchdown.
Next up I need to sand the leading and trailing edges of the elevons, prop slot, vertical stabilizers and rudders and the trailing edge of the wing. I find this much easier to do before assembly. Once the sanding is done, airframe assembly should be pretty quick. I will probably finish up the nose later today so that the glue on that can set up over night before I handle it too much for assembly.
It appears the weather might let up a bit by Friday, so since I am not going to paint this before maiden and initial test flights, I am hoping to have it flying on Friday, work shop and weather Gods willing... :)
More to follow... :)
Cheers,
Scott
Scott, I've copied your use of extra carbon fiber in other RCP planes and will do so again in the Mig V4. Your placement of the carbon fiber is an art form. You are minimizing flex at each location of the biggest bending moments. Very nice work!
ReplyDeleteThanks very much for the kind words, Dave... :) The build above is probably the most comprehensive reinforcement plan I would ever use. I knew I was going to be putting the NTM Prop Drive motor in this plane and wanted the extra strength to put up with the stresses of higher wing loading and 100+ mph speeds.
DeleteFor a lighter setup like with the Focal Price motor or other light to medium weight setups, I don't usually put in the piece on the back plate or in the vertical stabilizers and have not noticed any weakness or problems, that saves a bit of weight.
When I built my very first Mig V4 I had a bit of suspicion that the wing would be a bit flexible without the two reinforcements along the leading edge as there was a lot of foam without reinforcement out near the tip and behind the main spar. That is why I went with those and have in every MigV4 variant I have built. Using KF4 airfoils I think also helps give the wing a bit more rigidity.
I have been paying close attention to the wing on this in high G turns and maneuvers on this NAMCV3 plane with it's higher weight and wing loading and thus far I am happy to report that I don't notice any movement in the wing tips that would indicate it is flexing too far.
I have also been having good luck with using 4mm carbon rod as the main wing spar. It is twice as heavy as 3mm carbon tube, but much stronger and stiffer, so that coupled with the 3mm carbon tube along the leading edges and the KF4 airfoils makes for a pretty strong wing.
Good luck with your MigV4, I look forward to hearing about your Mig experience. It is the best stock built park jet I have ever flown. Obviously Stephan and I have pushed the envelope pretty hard with our modifications and testing, but if I could only build jets stock, the Mig V4 would still be on the top of my list... :)
Thanks again for your kind words.
Cheers,
Scott