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Building Tips and technical articles. => Building techniques => Topic started by: Jim Thomerson on September 30, 2006, 06:08:08 AM

Title: I-beam derivative
Post by: Jim Thomerson on September 30, 2006, 06:08:08 AM

I have built a couple of I-beamers except that instead of an I-beam, I used the same amount of wood to build a box spar tapered both ways.  I think it was much more rigid and stronger than a comparable I-beam.  I really like the I-beam and similar building methods.  Lots of fun.

Title: Re: I-beam derivative
Post by: Bill Little on September 30, 2006, 10:12:54 AM

Hi Jim,

The "box" beam is a great idea and is stronger.  I haven't done one that way "yet", as I wasn't sure I could get it as light as a solid piece of wood when counting in the glue....... ???

The solid piece of 1/4" in a regular size I-Beam is plenty strong enough, but I do know the box would be even stronger and more twist resistant..  y1

Bill <><

Title: Re: I-beam derivative
Post by: Bill Sawyer on September 30, 2006, 10:39:23 PM

BOX BEAM ? Where have I heard that before? Oh yes, the Playboy kits have them! Much stronger and not much heavier. And they come prebuilt in the kits.

Title: Re: I-beam derivative
Post by: phil c on October 02, 2006, 02:55:36 PM

look up the plans for the Moody Mooney.  Very innovative, with a thick wing and a huge box beam out of 1/16 in. balsa.  More work than I could imagine when I was a kid.

Title: Re: I-beam derivative
Post by: Randy Powell on October 06, 2006, 10:39:49 AM

Most of my planes are modified I-Beams. They have I-Beams that are actually built, a piece at a time, into the wing after the ribs are installed. It's a sort of Warren Truss based I-Beam. Some have partial sheeting, some not. It's an interesting process.

Title: Re: I-beam derivative
Post by: Warren Wagner on October 06, 2006, 04:03:51 PM

Quote from: phil c on October 02, 2006, 02:55:36 PM

look up the plans for the Moody Mooney.  Very innovative, with a thick wing and a huge box beam out of 1/16 in. balsa.  More work than I could imagine when I was a kid.

Phil,

Though the "Mooney" looks like an extremely interesting project, that "box spar" construction looks daunting to me, and I'm not a kid.

The small plans are difficult to read, so actual construction of the "box spar" is not clear.   Perhaps a full scale plan would make it obvious, but it looks like a very tricky build, that would require extreme care and workmanship.

Wouldn't it be interesting to get Al Rabe's opinion on just how viable a stunt ship the "Mooney" would make.   It certainly would be unique, and not easily confused with any other design.

Cheers.

Warren Wagner