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Building Tips and technical articles. => Building techniques => Topic started by: taildragger-j3 on July 30, 2007, 03:43:34 PM

Title: Flying Model's Laird Solution Conversion
Post by: taildragger-j3 on July 30, 2007, 03:43:34 PM

I've ordered plans from Flying Models for their electric R/C Laird Solution profile bipe. I have ALWAYS loved this airplane.

As drawn it's got a 29" wingspan. I'm thinking about upsizing it about 25% to come out with about a 36" wingspan. Both wings ought to have a total area of about 500 sq inches by my guestimate. I was thinking about powering it with something in a .35-40 size engine. Too much or too little?

Since it is supposedly designed for electric R/C I'm guessing I'll need to reinforce some of the stress points - engine mount, wing mounts, etc. I plan to mount the bellcrank in the center of the fuselage and run the leadouts through the wing strut.

Does anyone have any suggestions for building a profile biplane that I need to bear in mind?

Thanks in advance

Title: Re: Flying Model's Laird Solution Conversion
Post by: Jim Oliver on July 30, 2007, 05:29:27 PM

Only comment I can make is that Bipes have lots of drag.

Jim

Title: Re: Flying Model's Laird Solution Conversion
Post by: minnesotamodeler on July 31, 2007, 12:39:11 AM

CG should be a little ahead of where you'd think.

Boy, that's pretty vague isn't it?  How about "A little behind the LE of the leading wing"?

Point being, bipes tend to be very sensitive, i guess all that wing area, or perhaps it's a function of all that LE--someone recently had some remarks about inches of LE per oz. of weight, a bipe would have lots!  I built some triplanes that required balancing 'way up, on LE of foremost wing IIRC, to tame them down.

--Ray

Title: Re: Flying Model's Laird Solution Conversion
Post by: taildragger-j3 on July 31, 2007, 07:57:12 AM

I'll keep the CG issue in mind. That's a VERY good point.  y1

Any other suggestions? ???

Title: Re: Flying Model's Laird Solution Conversion
Post by: taildragger-j3 on July 31, 2007, 10:35:21 AM

I didn't know there was scale racing. That sounds like fun!