airnico Posted June 20, 2008 Share Posted June 20, 2008 hello canardians, I found this picture somewhere on the web and was attracted by the center section spar shape: it's not a box shaped spar like the long-Ez's, but it's a C section. I did not know this before so it was a surprise for me. do you know if this kind of center spar(C section) is used only on the velocity or if some other models have it? looking at it I can see the brown colour of foam(I suppose it's the foam's colour) so it should be a glass fiber/foam sandwich structure: am I right? do you know if it's a moulded part that comes prebuilt in the kit or is a home builded part??? Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
jprock Posted June 20, 2008 Share Posted June 20, 2008 That is the standard spar that comes in the Velocity kit. The foam is not brown, but the epoxy Velocity uses turns brown over time. The spar is a pre-molded part that is quite stout. Quote Link to comment Share on other sites More sharing options...
airnico Posted June 20, 2008 Author Share Posted June 20, 2008 so there is foam inside.... the horizontal faces look to be very thin: is there foam only in the vertical part or is all the structure a sandwich? do you know exactly how it is made?how many layers and what kind of fiber? I know they use biax fiber for the fuselage and not a lot of layers, can you give me more info about the velocity structure please? the way they build the center spar is attractive, it's of course easier and faster to be built and it gives more space for fuel: it would be really interesting to make a load capabilities comparison between this one and the Long-Ez's Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
airnico Posted June 20, 2008 Author Share Posted June 20, 2008 +9/-7 not bad...... Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
Steve Innova Posted June 20, 2008 Share Posted June 20, 2008 You wouldn't want a thinner spar for more fuel. Any extra fuel gained would be behind the CG, we don't like that. Quote Link to comment Share on other sites More sharing options...
jprock Posted June 20, 2008 Share Posted June 20, 2008 I don't know the details of the construction of the spar. I received it as part of the kit. Yes there is foam inside. I think they use this as a base for layering the glass. velocity uses Triax extensively for wings and structures, so I would assume it is several layers of Triax, but I've never seen it built. Jack Quote Link to comment Share on other sites More sharing options...
emteeoh Posted June 20, 2008 Share Posted June 20, 2008 I took a tour of their factory in February... I don't recall specifics of what was built with what, but I do recall being told that in some places, they used a fibre product that was sort of a glass rope, rather than the usual cloth. If I recall correctly, the spars were one place. I wish I could remember the name of the glass rope-like stuff for you. As I recall, they said they used it because it make it faster and cheaper to make those parts that way, it wasnt an appropriate technique for thin/short shapes, and I don't think he commented on if it made for a lighter,heavier,stronger or weaker product. (I wish I'd thought to ask at time, but I'd guess its strength neutral or stronger, but heavier) Quote Link to comment Share on other sites More sharing options...
airnico Posted June 20, 2008 Author Share Posted June 20, 2008 You wouldn't want a thinner spar for more fuel. Any extra fuel gained would be behind the CG, we don't like that. yes, we actually do not like that so much. I think it would be more or less 5 gallons each tank: may be it could be acceptable if you don't have already a lot of ballast in the nose..... I do recall being told that in some places, they used a fibre product that was sort of a glass rope, rather than the usual cloth. If I recall correctly, the spars were one place. I wish I could remember the name of the glass rope-like stuff for you. I suppose it was a glass roving used as a reinforcement with who knows how many layers of glass cloth.... I don't know the details of the construction of the spar.it would be actually very interesting to know it: does anybody know it?? does anybody know if this kind of center section spar has been already installed in a Long? Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
TMann Posted June 21, 2008 Share Posted June 21, 2008 does anybody know if this kind of center section spar has been already installed in a Long?No, it's not.The spar on the Long-EZ is plans built. Quote T Mann - Loooong-EZ/20B Infinity R/G Chpts 18 Velocity/RG N951TM Mann's Airplane Factory We add rocket's to everything! 4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done Link to comment Share on other sites More sharing options...
airnico Posted June 22, 2008 Author Share Posted June 22, 2008 No, it's not. The spar on the Long-EZ is plans built. 06-20-2008 10:57 PM yes, ok the spar on Long_Ez is plans built, but there are some guys out there building something that is not strictly per plans, may be one of those bad guys have already done this mod and it could be just another to add to the mods list.... Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
TMann Posted June 22, 2008 Share Posted June 22, 2008 .....what I mean by 'Plans built' is that these are wet layups done in your garage/shop. Example: The Berkut spar is pre-preg Carbon Fiber layered into a mold and autoclaved to high temperatures. Now you could try and do that but most of us do not have those types of facilities available to us. Also, what limitations would you acquire as a result. I'm building with the Infinity retracts ......... which I couldn't do if I deviated from the plans built spar. Quote T Mann - Loooong-EZ/20B Infinity R/G Chpts 18 Velocity/RG N951TM Mann's Airplane Factory We add rocket's to everything! 4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done Link to comment Share on other sites More sharing options...
airnico Posted June 22, 2008 Author Share Posted June 22, 2008 it would not be difficult to build a molded C-section spar and autoclave it, something else would be to build a box shaped spar: it would be difficult and very expensive. I like the solution they have found to produce an easier(and so cheaper) molded spar and the added fuel capacity resulting from it could be also a good thing. Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
Edge 513 Posted June 22, 2008 Share Posted June 22, 2008 If you are not concerned with CG- just put some holes in the front of the spar and partition it off, so as to hold fuel, and let it function as another fuel area in the strake/cell. Hey- its just experimental aviation! Just dont freak as you auger in... Quote Self confessed Wingnut. Now think about it...wouldn't you rather LIVE your life, rather than watch someone else's, on Reality T.V.? Get up off that couch!!! =) Progress; Fuselage on all three, with outside and inside nearly complete. 8 inch extended nose. FHC done. Canard finished. ERacer wings done with blended winglets. IO540 starting rebuild. Mounting Spar. Starting strake ribs. Link to comment Share on other sites More sharing options...
airnico Posted June 24, 2008 Author Share Posted June 24, 2008 If you are following Daves lead you can't go wrong. the micro shelf must be a Berkut specific method. on the berkut the forward spar face is set into the spar about even with the sparcaps and on the long /cozy it is 2" forward of the spar caps. I believe that is how Dave got back some of the fuel capacity and space taken up by the gear leg wells searching on the forum I've found this: is it not something like the mod I was talking about?? Quote Roads? Where we're going we don't need roads. (Dr. Emmett Brown) Link to comment Share on other sites More sharing options...
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