First Lazair Nouveou Blog
So I'm very new to this blogging thing.
This site will be a tool to communicate news and info about Lazair Nouveou and the journey of resurrecting the famous Lazair ultralight.
Where to start - where to start......
The Lazair project is moving at an incredibly slow pace. Although some things are happening, any visible progress is invisible. We have obtained all the tooling, what there was of it, from Michigan (October 2010), and we have all the necessary rights and licenses in place to sell under the Lazair name (HUGE sales importance). We have been capturing the Lazair design in Solidworks (parametric 3D CAD software), and are updating a few items to take advantage of modern manufacturing techniques and materials. The end product will appear to be exactly like the Elite or Series III Lazairs, however there are several major differences; strengthened wing spars (for 350lb pilot), different main landing gear wheels and nosewheel with better brakes, relocated fuel tank (from behind seat to inside leading edge D-cells), Hirth F-36 engines, BRS recovery parachute, and rigid polyurethane foam for the wing ribs. It will be named the "Mark IV".
Design Issues
Ultraflight released very few drawings for parts (only tubes) to the public, there is some debate as to how much of the design was captured. In making Solidworks models of the Lazair parts everything is pretty straight forward and simple to model, although very time consuming to reverse engineer, except for the wing ribs. I asked Dale how he designed the rib profiles, his answer was he hand lofted them using parts of other ribs he was familiar with and developing the lines until they were pleasing to his eye. Very creative and yet another indicator of his natural ability as an aircraft designer. However this becomes a nightmare when trying to model the ribs in 3D CAD. So I had a couple of choices; I could simply model something that looked OK but wasnt really representative of the real airfoils, and therefore couldnt be used as a base for modern CNC manufacturing techniques to make templates, I could send the ribs out and have them Z-scanned and a point cloud for each developed and make models from that (really cool technology, but very expensive), or I could trace out each rib and graphically extract coordinates and get some useable data to start from (the old school method). I chose the latter course ( I never knew how important those kindergarten tracing lessons were going to be). I created large graph paper and layed each rib down and traced the profile. I then took a 6 inch scale and hand computed each coordinate in half inch increments. A labor of love to be certain, but when finished, a few months later, I had something that no one else on earth has, not even Dale, Lazair rib coordinates. I loaded the coordinates into my CAD software and "wah-lah" I had 3D models of the ribs. After some adjusting and smoothing for measurement inaccuracies I now have beautiful rib models that I can send out and get templates made (molds actually, explanation below).
Why move the fuel tank, and why that drives new rib material and the need for accurate rib models.
The decision to relocate the fuel tank is twofold. Firstly the traditional location is a pain in the back to refuel (literally), you either have to remove the fuel tank (which means lifting it back into the holder when its full of fuel ~30lbs), or contorting your self and holding a gas can at an awkward angle to refill, both of which are extremely hard on your back. Some folks developed special hoses and other things to make the job easier, but this means you have to take that stuff with you if you plan on refueling off your home field. The other reason is to reduce the total lift height from the fuel tank to the carburetors. Although a good pumper diaphragm carburetor will lift the fuel, any small leakage in the fuel line, primer bulb, or joint in the fuel line will cause fuel starvation. It was a significant problem as evidenced by the Lettair Service bulletins. Relocating the fuel tank to the leading edges makes it much easier to access and refuel and drastically reduces the lift height from nearly 24" to about 6" max. But what happens when gasoline is spilled into the leading edge when refueling? This is a major concern and has many facets to overcome. The largest problem to overcome is the fact that gasoline will melt polystyrene (i.e. the blue foam the original ribs were made from), and it could have and adverse effect on the tapes used to hold the covering material on. The design changes to overcome these obstacle are rigid polyurethane foam for the rib material, this is an excellent substitute for polystyrene, and scuppers near the fuel inlet to capture and absorb any spilled gas before it gets to the tapes. Polyurethane foam has the same density as polystyrene and is rigid. Polystyrene is semi-rigid but has very low compression strength. Polyurethane foam is inert to all chemicals, but is not UV resistant (easily overcome with a coat of ordinary inexpensive latex housepaint). Fabricating ribs from 2 lb density polyurethane foam was a bit of a head scratcher to overcome. Polyurethane foam boards in 1" thickness are available, but not locally and they are quite expensive. Looking around for a solution found expanding foam (often referred to as A/B foam) and is quite readily available and affordable from the marine industry. So a plan to cast the ribs from expanding foam was hatched, but to cast something you need a mold. I couldve just got a 1" thick board and made female molds by simply tracing the originl rib profiles, but that just didnt cut in my world. I wanted ribs that were accurate to the original Lazair ribs, but were repeatable if I ever needed to make new molds. So right now shiny new HDPE molds are being CNC cut from the hard work that was put into capturing the rib profiles in CAD and new polyurethane Lazair ribs will be available soon.
Whats the hold up? When will we have new Lazairs rolling off the assembly line?
This is the question I am asked all the time when someone gets wind of what I'm up to. And the answer is.....I wish I knew. I have basically everything needed to make new Lazair parts and whole ultralights except for a place to work in. My little town of Brooklet, Georgia and the larger Statesboro area has few offerings of spaces large enough to set up shop in, and what is available is priced far out of my meager budget. I am still vigilant looking for shop space, but until something comes along I will keep plugging away in the garage.
There will be more to come on the Blogspot page as I get used to this means of communication, check back from time to time. Until then email me at Fltofancy@gmail.com.
Later,
Gene
