I believe the 40 lbs, but we're only talking a beam that is cantilevered about .7" or so, aren't we? I'd figure the stress if I had my Machinery's Handbook handy or if I had worked with beam theory more recently. I just picked up a winch battery with two popsicle sticks under the handle and two fingers on each one (i.e. as you would hold a dlg). Seems like just a little thicker and it would do the job, and be very easy to streamline. Or is that too heavy? I've got to think it would be a fraction of a gram, or so my guesstimate calculations say (.06" X .25" X 1.5", 45lb/ft^3, .27g)
Joe & Jan Wurts wrote: > > By my calcs (and sore fingers to testify), a good launch > will get about 40 lbs or more of pull on the tip. It is really > hard to get wood to take this amount of loading. > > As to the lower drag solution of the streamlined shapes, > this is attractive, excepting that it is hard to do, and still > keep light. Low yaw inertia is very important in a DLG, > and the streamlined peg adds weight. > > Joe > ----- Original Message ----- > From: "Lincoln Ross" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, February 13, 2002 11:12 AM > Subject: Re: [RCSE] DLG finger pegs > > > > > I don't understand why everyone makes these things so strong! It only > > has to be stronger than your fingers, doesn't it? Why not wood (say, > > maple, spruce, bamboo)? And why not carved in a nice, low drag shape > > instead of the circular cross section which is about as draggy as you > > can get? > > > > I haven't made my dlg yet, tho. > > John Erickson wrote: > > > Rick, > > snip For the peg itself solid carbon > > > rod, about 3/16" D. seems to be popular. I've seen some that are a more > > > aerodynamic shape and if you are trying to squeeze everything out of the > > > plane, that is worth investigating. I did one where I crushed a 3/8" D. > > > aluminum tube in a vise and then put a rod on the inside for support, > and > > > filled the void with microballoons. Nice shape, but too heavy. You > really > > > don't want any weight out at the tips. > > > > > > You probably could also take something like the old 1/2" carbon wing > joiner > > > that you broke when you switched from Mode 2 to Mode 1 during a flight > (that > > > wasn't you? Oh yeah, that was me with my Edge...) and sand away till > you > > > get a foiled peg. Pretty messy job. Carbon fiber dust has to be right > up > > > there with asbestos as far as health quality goes. > > > > > > Maybe laminating some strips of pre-preg might work, too. I'm sure > there > > > are many ideas (and attempts) at a foiled peg. > > > > > > JE > > > -- > > > Erickson Architects > > > John R. Erickson, AIA > > > > -- > > Lincoln Ross > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" > and "unsubscribe" requests to [EMAIL PROTECTED] -- Lincoln Ross RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
