hdmx

I got mine from a local boating supplier (they use Divinycell for building yachts). You can also call Divinycell directly and request a quote. They were a bit expensive because they charge repackaging fees if you buy fewer sheets instead of a whole pack - Aircraft Spruce was still more than twice as expensive

I would not use polyurethane foam in place of PVC foam. Buying these materials from Aircraft Spruce ist extremely expensive by the way. There are other suppliers that offer the same materials for a fraction of the price. You can also get H250

absolutely, however I would introduce new loads by mounting a retractable landing gear on the forward face of the spar. The original spar was designed to take loads introduced on the aft face and it does a good job doing exactly that - it was never intended to take loads introduced in the front face

Thank you very much for your reply. I think your answer boils down to: Basically the center section spar is strong enough as is to accommodate all forces given in the original design. Adding more complexity would not make the spar better. The aft section will take most of it and the front is not as stressed so altering the design might not even have a significant impact for the original design. I fully agree with your conclusion here. I plan to incorporate a retractable landing gear which will be bolted onto the front face of the center section spar. This changes the loads for this part. I thought about possible load paths - the forces would need to be transferred to the thick spar caps so this glas-to-foam connection will be stressed significantly in comparison to the original design. Altering the connection probably isn't enough to take the landing loads but I feel like this change from glas-to-foam to glas-to-glas makes sense in addition to introducing some thick layups that will transfer the loads to the aft spar caps. So, condensing it down to two sentences: would you think that this change makes the spar stronger but was not done by Rutan because it's simply not needed? Or can you think of any reason why this change might even have some negative side effects and shall be avoided? By the way I have not really worked with composites so far so this is new territory for me

Hello everyone, I got a question regarding the composite construction of the center section spar. According to the plans you fabricate the box and the lid. The "large box" has a U-shaped cross section. It is laminated with glass inside, the glas is then trimmed after curing. The fat red line represents the inside layup - see first attached picture. Then the laminated and cured CS4 foam panel (forward foam) is bonded to the U-shaped box with micro slurry. You nice see it in Ary's well documented build log (great read by the way): - http://www.aryjglantz.com/2015/01/spar-interior-layup.html - http://www.aryjglantz.com/2015/01/spar-lid-cs4.html So my questions are the following: 1) Why is the inside layup trimmed which results in a simple and weak tee joint? Wouldn't it be better to overlap the inside glass layup (see second picture) and peel ply it so it the CS4 will not get bonded to CS2/CS3 foam but directly to the inside glass layup with a much larger surface? It doesn't add any noticable weight, it doesn't add any extra steps, it's not more work - what do I miss here? Even if overlapping has negative side effects, why not at least use a floxed corner for a better connection between glas on CS4 and glas on the U-box? 2) According to the plans, CS4 is bonded with wet micro to the U-box. Why not flox, which is supposed to be structurally stronger? Maybe there are very simple and obvious reasons that I might have overlooked. Thanks for any insights

Yes, the projected area is is increased roughly 8% in comparison to the original canopy and nose. The shallower angle of the canopy might be an additional problem regarding visibility. What are the results of your analysis with directional stability? I just don't like the looks of the original canopy/nose

I worked a bit on my model. Included some significant modifications so it can probably not be seen as a "stock" Long EZ anymore. However most of the structure (Fuselage, most of the center section spar, most of the wing) stays the same. I plan to include blended winglets, a rounded nose, streamlined canopy, and maybe a retractable landing gear. To actually confirm the measurements and models, I intend to build this project beginning next year. This will also include building jigs and models (for example to fabricate the new canopy). If someone is interested in building a similar project, it might be possible to re-use these jigs and models

Slowly but steadily... Pretty busy right now so it's going to take a while, however some parts are already finished. I'll probably do more modifications than originally anticipated. That probably limits the number of people interested in my project but maybe someone likes my mods and ends up building something similar. By the way does anyone here have the installation instructions of the infinity retractable landing gear? I'd be very interested to see how it's installed to the structure and how the structure might be beefed up locally in order to take the large shock loads from a rough landing. Unfortunately I wasn't able to find any technical details

@Jon Matcho thanks for the feedback. Some points are indeed a bit problematic. I fully intend to publish all CAD files. Of course everyone will be able to check and verify or give feedback. Point 2 is what will be most problematic. It's not a "stock EZ". I will modify the plans according to my needs. Some materials have changed, for example I'm only able to get the PVC foams in metric thicknesses and my drawings will reflect that. Personally I'll be using CATIA V5. Certainly not the most user-friendly nor the cheapest piece of software. Exporting to a neutral format is probably the only way of sharing the models

Yes, I've already talked to Ary. His builder's log is great and explained a lot, is has been really helpful to understand the plans and drawings. Unfortunately he does not want to share the 3D model for liability reasons. Maybe the US has much stricter laws regarding liability, I don't have this problem in my country so I'm pretty relaxed and don't see any potential issues in sharing my models and drawings. Just wanted to check first if someone is interested because preparing the models, drawings, and documentation is quite time consuming - there's a huge difference between creating models just for myself and creating models that can be used by other people too

I know this thread is pretty old but I wanted to ask whether there is still a general interest in having CAD models of Long EZ parts? Or if someone actually made a complete model after all this time? I plan to build a Long and for proper planning and manufacturing I'd like to have a full model of the entire aircraft. Already started working on a model myself and if there's a general interest in such a model, I'd consider making the files public