• Welcome aboard HomebuiltAirplanes.com, your destination for connecting with a thriving community of more than 10,000 active members, all passionate about home-built aviation. Dive into our comprehensive repository of knowledge, exchange technical insights, arrange get-togethers, and trade aircrafts/parts with like-minded enthusiasts. Unearth a wide-ranging collection of general and kit plane aviation subjects, enriched with engaging imagery, in-depth technical manuals, and rare archives.

    For a nominal fee of $99.99/year or $12.99/month, you can immerse yourself in this dynamic community and unparalleled treasure-trove of aviation knowledge.

    Embark on your journey now!

    Click Here to Become a Premium Member and Experience Homebuilt Airplanes to the Fullest!

Search results

Advertise with us
Find deals on ebay
Find deals on amazon
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
  1. Birdmanzak

    How about this way to reduce induced drag:

    HPD is asking (as I read it) how to get CL (coefficient of lift of 3D wing) from Cl (coefficient of lift of 2D foil) and wing geometry.
  2. Birdmanzak

    Software for Design

    Kind of off-topic and not helpful for anyone looking for software right now, but FreeCad is worth keeping an eye on. It's free open-sourced 3D CAD, based on the pretty much FOSS OpenCascade. Does a whole lot of not much so far but in a couple of years should be a reasonable option for...
  3. Birdmanzak

    If you were going to design a cockpit...

    My guess is that the album it's in is "Private" not "Public". Either change the album to public, or make a public one and copy the image there.
  4. Birdmanzak

    Blunt Trailing Edge Question

    [thread drift] Yeah, not like that open-cut coal mining... :ponder: As far as I know, the noise is an issue because people don't like the turbines near their homes. The low frequency noise, particularly that with wavelengths near to the lengths of people's rooms in their homes, causes...
  5. Birdmanzak

    Help deciphering Raymer...

    Question 1: From the same place you measured Xwing. Question 2: Measure it from "wherever you're using as a datum", which is arbitrary or entirely up to you. As in, see Question 1. You should be able to use the wing leading edge, the front of the spinner, or some point metres out in front...
  6. Birdmanzak

    AN hardware versus SAE for homebuilts

    This is the clincher for me. I was involved in Formula SAE, building a little open-wheel racecar. We used SAE fasteners because they were available, affordable, and metric (major plus!). Coming from an airline, where I'm used to AN and NAS fasteners being available in all the different grip...
  7. Birdmanzak

    Composite wing spar design: Shear web/spar cap interface

    The thing is, if you've got a circular rod of diameter D which is strong enough to take the load, and you change it for a square rod of side length D, the square rod will also be strong enough (27% percent stronger than the circular rod), AND it will have 27% MORE surface area available to react...
  8. Birdmanzak

    Composite wing spar design: Shear web/spar cap interface

    What? mz- is right. For a rod with a cross-section of 1 square Unit of Length, the perimeter of: A circular rod is 3.54 UoL (ie. sqrt(4*pi)) A square rod is 4 UoL, and A 2:1 rectangular rod is 4.24 UoL (ie. sqrt(18)). The rectangular rod has the MOST surface area per unit length for...
  9. Birdmanzak

    Steorn's Orbo Motor - Cutting Edge tech for aviation?

    Depending where you draw the system boundary, a 100% efficient heater is possible :p.
  10. Birdmanzak

    M0.7~0.85

    It seems you're joking again. From above: Force x Velocity = Power Given the numbers in your drawing for thrust and torque, and assuming consistent units, AND taking "torque" as a force since you've given it a velocity rather than a rotational velocity. Tu-95: Thrust: 0.97 (force)...
  11. Birdmanzak

    M0.7~0.85

    Actually, Force x Velocity = Power. Force x Distance = Work. And to be proper, it's actually Force x Displacement = Work. Also, while those equations do break at the extremes, I'd say those limits don't apply until you're talking about subatomic or interstellar effects.
  12. Birdmanzak

    Starman's plane

    I know this completely off-topic, but please tell me you're talking about Guy Savelli, with the staring-at-goats thing. As for "while the next best one jammed at 3500", a little Googling reveals the Ruger SR9, which manages 12000. Back to your plane; I have a question, too. If...
  13. Birdmanzak

    New Electric Motor Technology

    How is the Liquid H2 kept liquid? Pressure or cryogenically? Either way sounds like a lot of work (and mass)...
  14. Birdmanzak

    Tubular rivets (not blind rivets)

    There's a bit in Michael Niu's Airframe Stress Analysis and Sizing on tubular pins (I bought my copy from Darcorp through Amazon, or you can find scans on the web - about 39MB). I've attached a PDF of the relevant pages (well, I had to split them into two files because of the file size...
  15. Birdmanzak

    NACA 23015 or equivalent

    Xfoil (here) and XFLR5 (here - also does 3D wings) will give results for whatever Re you want. The accuracy will drop off at ridiculous values, I'm sure, but it should help.
  16. Birdmanzak

    Starman's plane

    Rogallo hang gliders had a L/D ratio of about 4. That's pretty terrible - about the same as a parachute.
  17. Birdmanzak

    Starman's plane

    Starman: Please stop taking things said on this site personally. Raymer (whose books I also highly recommend) puts it well when he says That's from his site. I know you're getting a lot of recommended reading but allow me to add that page. It's not directly applicable to you but...
  18. Birdmanzak

    gearing toward long leg flights

    On that, I write most of my posts - particularly the long ones - in notepad and then copy/paste them into the site. That way, departures from controlled interweb connectivity don't matter and you never (cat on keyboard incidents aside) lose a post.
  19. Birdmanzak

    Structural honeycomb Panels

    Best "tap tester" I've ever used is a 50 cent coin (Australian). It's a similar size to the US half-dollar, but about 35% heavier (thanks, Wikipedia!). The US coin would do a fine job. Good enough to sign a 767 inspection off with, anyway. Cheap, too.
  20. Birdmanzak

    What software do you use?

    I've recently moved from Pro/Engineer to Solidworks. I had a couple of weeks of unlearning the Pro/E way of doing things, but after that I'd say I'm far more efficient in Solidworks than I ever was in Pro/E. It's easier to use, and everything from 2D sketches to assemblies are much more robust...
Back
Top