Reinforcing the Glass Strut Fabricating NG-30 Installing Worm Drive Assembly Box Assembly
Nose Floor & Sides Rudder Pedals Master Brake Cylinders Completing Nose Gear
Pitot & Static System Closing the Top Nose Door
Pitot Tube at the Nose |
The pitot tube per the drawing construction method is pretty flimsy and I prefer a more beefy one. There were plenty of discussion on the Cozy Forum regarding alternatives. I liked the one Wayne Hicks used and I ended up getting the same from Aircraft Spruce ($27). I marked the pitot tube extension location at the nose carefully with my lasers and opened it up with a drill and Dremel grinding wheel. Since the pitot tube is husky and I plan to extend the tube out the nose by 1 1/2" only, I see no reason to make it removable. Hence, I put a groove onto NG-31 such that I can seat and flox the pitot tube in place. I will eventually have to cut the pitot tube shorter and put a thread at the cut end for the fitting. The picture showed the original pitot tube and the groove on NG-31. |
Preparing the Pitot Tubing |
I cut the 1/4" aluminum tubing from Aircraft Spruce to 38" & 6" per plan. Then I drilled the necessary holes through F-0 and F-22 and threaded the tubing up hill along the left side wall. The tubing was easy to bend. I just bent it by hand and it hugs along the side wall readily. I had to get a flaring tool (McMaster-Carr) to connect the tubing to the blue fitting. I hope we will be using a lot of tubing down the road because the flaring tool set me back $90+ for one shot ... so far. |
Here's a close look of the pitot tube after Jamie cut it to length and threaded it for the fitting. Jamie owns a machine shop close by and he had been providing machining support for us for the past 16 years. I have gained tremendous amount of knowledge in material properties and its machining processes from him - a very talented person. He also helped me with my rudder pedals in Section 6 of the Chapter. You can see Jamie can get a bit artistic with his work sometime ... Note the groves and dimples he added onto the surface for floxing. He even buffed the exposed tip, just for appearance !!! |
Pitot tube extending out the center of the nose cone. |
Static Port |
The 6" aluminum tube cut earlier is for the static port. I pinched one end of the tube with my rivet squeezer (it worked well). I made a simple bending fixture and bent the aluminum tubing to shape.
I had a lot of difficulty clearing all the foam between the glass layers with a drill bit and not going through the outside wall. It looks like I have to put 2/3 of the tube (i.e. 4") inside the foam - I can't see how a drill bit can do that. Matter of fact, I did put a small hole through the outside wall ... I made a small hole digger and it didn't work very well. After hours of struggling with it , I finally gave up. See the top half of the slot? |
Instead, I took the Fein tool and cut a strip of the glass out, dug out the foam and was ready to bury the static tube in a matter of 15 minutes. The wider hole at the top part was from the 1/4" drill bit and the lower straight part was from the FEIN tool. See that small hole I put on the outside wall with the tip of my 1/4" drill bit - at the middle? |
I marked the pitot tube position on the outside of the fuselage (with the help of a flash light), made some wet and drier micro. I partially filled the cut out with wet micro first, then I inserted the aluminum tube, making sure it is set tightly against the outside wall of the fuselage. Then I sealed the rest of the slot with the drier micro. Once it cures, I patched it up with 2 BIDs of glass and all is well. |
According to the plan, the nose cone compartment is used for lead ballasts - to keep the plane's center of gravity (cg) in check. Since I put the landing light in the nose, I need the opening (at NG-31) for replacing / removing the landing light if required. However, I still wanted to make the best use of the remaining space for the ballasts - I need to figure out how I can keep the lead ballast from falling through the hole. In addition I need to figure out how much weight/space I need? A removable 'floor' is required...
I found my answer through Rick Maddy's search engine (Newsletter #84 per Nat Puffer). Based on the weight of Nat's plane and his weight (160 lbs), he showed how he determined the amount of ballast needed for his plane - a total of 24 lbs at the nose. I would expect my plane will be somewhat close to his, but I am about 20 lbs lighter than he is. With a moment arm of 2.5 (per the Newsletter), I need a total of 32 lbs at the nose (its simple calculation if you read the Newsletter).
I also learned that lead is ~0.41 lb / cu. in. The 32 lbs can be in the form of a bag of lead pallets or in a 2" x2"x19.5" block. Since my nose cone door and space would not allow a 20" long block, I just have to make shorter blocks. I cut up a bunch of 2"x2"foam blocks and did a trial fit. The 4 longer blocks are 2"x2"x4" and the shorter ones are 2"x2"x3". I can fit 22" of blocks that equates to ~ 36 lbs of ballast. - giving me a small margin of flexibility - just in case I lose some more weight ... If I add one more 4" at the middle, it will make it 42 lbs of ballast. |
As noted above, the removable 'floor' over the landing light access hole consists of two aluminum strips mounted across the landing light access hole. The 3/4" and 1 1/2" wide aluminum strips are being held down by 4 bolts and nut plates built into the NG-31 floor. I had to notch out the wider strip to fit under the L bracket to provide some freedom for the landing light. An alternative is a wire mesh / net of some kind... if I come across something better. If I stay with the aluminum strip approach, I will drill a few holes through the aluminum strips and up through the lead blocks, stick a long threaded bolt through them (vertically) and secure the whole assembly with a wing nut at the top. That will keep them somewhat secure during flight. I also added a nut plate on the top of F-0. This will be used to hold an L bracket, which in turn holds the top end of the threaded bolts for the ballast. |
Here's a picture of the pitot tube floxed in place. I also sealed off the hole at F-0 where the aluminum goes through with silicon sealant. |