I keep reading that the Brodak Profile Pathfinder has a fuselage that flexes and should be somehow modified to strengthen it against flex and weakness?

What is the preferred method for this?

I know a friend dopes light glass cloth to a fuselage.  Would that be enough to strengthen it?  Maybe actually glass it?

You are correct about the flexing issue.  The real fix is to full built-up fuselage.

I don't believe that any surface hardening will do the job.  The surfaces are too close to the neutral axis to do much good.

If you stay with profile, I might suggest 1/4" square spruce stiffeners on both sides.

Watching these planes fly, I see the rudder offset bending the body, thus leaving the rudder streamlined to the direction of flight.  Thus causes a control interaction  between the flaps & flippers.  Not good.

I have heard folks say it twists
I run mine with electric RSM 46 and AXI 2826/10
they fly incredible
I wanted to light it up so I use 1/2" 4lb balsa, Cored out with triangles, Case in 1/8" 4lb balsa and it is stiffer
than the original.  Do note that two new kits I have came with fairly stiff 1/2" - more so than the first kits - I don't use it because of the weight

Hi David

This issue of a profile fuselage twisting in flight has been beaten to death over the years and if you read the volumes of posts on here regarding this, the remarks all always the same and the discussion gets quite tiring and boring and no magic solution is ever found.   It is a profile and a profile is a profile and there are thousands of them out there going around in circles and bringing a lot of joy to a lot of fliers.  Ty and some of the other guys are right, it is a great flying profile.  When Brodak still made the ARF profile Pathfinder, I bought one and flew the Hell out of it and it flew great until it met its ultimate demise called pilot error.  Seems all of my models eventually meet that fate.  My advice is to not worry about the tail flexing a little, it aint going to fall out of the air because of this and you will enjoy flying it. 

Mike

I am at the point of writing it off as urban legend and glassing the fuselage.

Slap on the LA 46 and fly it.

Thanks guys.

I have flown a few of them, both ARF and kit built and all have flown great! The ground flexing seems to have minimal effect once it's in the air. They have done quite well in Profile and Intermediate competition here in NorCal. Somewhere on this forum there are a few things that Gordan has recommended for kit builders. The two I remember are; shorten the fuselage by 1 inch (cutting it off the back) and increase the thickness of the stab/elevator to the next size balsa sheet.  Definitely worth building.