Traders - What are your hobbies?

Discussion in 'Chit Chat' started by Pension_Admin, Jan 3, 2010.

  1. Arnie

    Arnie

    A 24 foot long MODEL?

    Can't wait to see how you tackle the wings.
     
    #121     Apr 25, 2011
  2. Lucrum

    Lucrum

    Not really a "model" per se as I'll be sitting in it.

    One piece spar,plywood shear web, spar caps from laminated spruce, ribs from solid spruce and a solid foam core covered with one layer of 1/16 plywood and then one layer of .009 thick S-glass. I plan on installing a Kruger leading edge flap as well.
     
    #122     Apr 25, 2011
  3. Both Mercedes and BMW (as well as others) use a flex disc or Guibo (guee-bo) between their transmission and their driveshafts. Most of the 6-cylinder ones are rated up to 3-400 foot pounds of torque but some of the bigger V8 ones and even the V-10/V12 ones from 7-series or S-class are rated up over 1,000 foot pounds of torque. They are about $50 from a BMW dealer and you can get aftermarket urethane ones too. It helps cut down A LOT on vibration.

    http://realoem.com/bmw/showparts.do?model=1413&mospid=47322&btnr=26_0023&hg=26&fg=10

    (realoem.com and then click on the "enter here" link to browse)

    They don't give you the bolt spacing but they come "compressed" with a steel ring (like a hose clamp) around them so you could walk into a dealership and ask to see the parts. Also - if you find something you may want to use I can get technical specs on them from a few BMW factory guys I know. The fancy, more modern ones come with a double-cup around the flex disc that bolts in place and prevents the thing from blowing up on itself if you were to ever exceed the 700-1,000 foot pounds of torque they are rated at.

    For vacuum bagging stuff you should look on craigslist or in your local newspaper for foreclosure auctions or medical supply house closures. You can get a brand new pump from a medical supply house for $400 and pick up a $700-$1k pump used for $50-$100 from a dentist's office that is closing or upgrading from single office units to a central vac system.

    http://www.jamestowndistributors.co...ct.do?pid=3755&familyName=Vacuum+Bagging+Pump

    I own that pump and its worth every penny of the $500 (I got it at cost but you can get used for like $50-$75).

    You are correct on the kevlar - it "pills" when you sand it and turns fuzzy - its a royal pain in the rear end to work with (need diamond blades to cut it, can't sand it, etc.) but its not bad to use as a middle layer in the lamination process. Kevlar doesn't splinter though - and its very impact resistant.

    Enough rambling on for now - I come from a world where cars have two-piece driveshafts and if you don't balance them together as one unit you'll be sorry... Just be careful balancing those individually. Get yourself a vacuum pump and play around with stuff - its a bit expensive to get into but once you get the hang of it you'll be able to use balsa core and carbon/kevlar weave and make it 10x stronger and probably 10x lighter as well.

    Cheers & keep the updates coming!
     
    #123     Apr 25, 2011
  4. Hiking and Camping are some excellent hobbies!

    There are so many benefits. Sights, campfires, friends...

    Not to mention the health benefits: Fresh air, moving your legs, a few days of peaceful relaxation.
     
    #124     Apr 25, 2011
  5. Shreddin' it.

    The year that I achieve 100%+ returns, I shall be sure to buy this beast below.
     
    #125     Apr 25, 2011
  6. Epic

    Epic

    Ahhh... for some reason I had imagined a straight cylindrical duct. Are you suggesting something like a 32" straight inlet, with a symmetrical taper down to about 24" exit. Or are you suggesting a longer duct that includes bends? I would assume you aren't going to use and bend in the duct so as not to introduce unnecessary air friction.
     
    #126     Apr 29, 2011
  7. Lucrum

    Lucrum

    Momentum drag is what I think it's called and yes there will have to be a bend in the duct. The inlet will be a rectangle with rounded inside corners, the exit will be round and about 27.5" in diameter. The transition will wrap around the shaft aft of the engine forming a round tube just in front of the face of the fan. I don't have a good drawing of it as I suck at 3-D but if you take two corners of a piece of paper and bend them toward each other that is roughly what the top of the transition will look like.
     
    #127     Apr 29, 2011
  8. Epic

    Epic

    Oh, I had assumed that on this aspect you wouldn't be getting as close to the F-16 dimensional specs, but it appears you are actually going to try to mimic the design more closely than I had anticipated..
     
    #128     Apr 29, 2011
  9. Lucrum

    Lucrum

    The basic layout of under fuselage duct inlet, blended upper fuselage to wing and mid wing placement, yes. It will not be to perfect scale though. For example the wing aspect ratio of the F-16 is 3.0 mine will be in excess of 4.0 the wing taper ratio on the 16 is .23 mine is more like .43 the 16 has a swept wing mine is double taper but straight and so forth.
     
    #129     Apr 29, 2011
  10. Epic

    Epic

    Lucrum,

    BTW, maybe I missed it, but what was the driver for using black walnut vs a lighter wood. I know that Balsa is used frequently in aircraft. I was under the impression that you were gaining most of your strength from the glass coating. Are you also relying on the strength of the wood core so much that you need to use such a dense wood?

    Not trying to criticize. Just really curious. :D
     
    #130     Apr 29, 2011