Biplane struts and covering.

Forgot how I used to do mine Ron, so I went to pictures.

rsv1cox wrote:Forgot how I used to do mine Ron, so I went to pictures.

are the struts permanent or removeable?

happydad        

Permanent, epoxied in then covered.  

Two in background turned out well done several years ago.  Uncovered one not so.  

rsv1cox wrote:Permanent, epoxied in then covered.  

Two in background turned out well done several years ago.  Uncovered one not so.  Recent shaky hands not conducive to fine work.  

The title says it all. Oh and add close friends. I love to build, rebuild. Don’t get to much time to actually fly, shhh, that is why I fly micr quad copters indoors. The blade have guards so if I bump into anything, no harm. I buy-rebuild-resell those also. Will upload a picture later. Haven’t had lunch yet. It’s 4:10p.m. PST now
LUNCHTIME

Happydad.          

The Sterling C series kits were nice kits in terms of scale appearance, however some of the critical fits were pretty poor such as wing connections and firewall mounting. I've built two Stearman bipes and a Great Lakes Trainer. The one Stearman is almost ready to go.  Where the struts enter the wing, they offered a square piece of balsa that had a small notch out of it about a 1/4"x 3/8". This is where the strut entered the wing. The fit is similar to a round dowel in a square hole it's that bad. This is due to the fact the struts are on a splay and you also airfoil the strut by sanding. Technically, your not supposed to airfoil the entire part just the visible area.  The instructions had you glue the top wing on and from the top side where the strut entered the wing, you were to glue that area top side numerous times to build a fillet on top of the notched piece of balsa they provided.. This way even if the initial glue joint failed, the glue on the strut wouldn't pull out. Keep in mind these were also the days of cellulose and yellow glues.

                   Today's epoxies would be superior.  In theory, it worked but if you took the time to make properly fitting parts this wouldn't be a problem. The Flying Fool is notorious for it's top wing shedding. The key to covering first is to have full contact of covering around the strut and not just a rib. In order to do so, installing planking flush with the ribs in the entire strut bay. This way it offers the covering something to attach too. Obviously covering a wing prior to it's installation is much easier to do vs when assembled.

Obviously covering a wing prior to it's installation is much easier to do vs when assembled  

My thinking too Ken, but I always opted for a secure wing and put up with the seams that are unavoidable when you cover after the strut's are installed.   I like to see where the epoxy is going.  

My son found this old Guillows Stearman in an antique shop for me.  The struts were positioned wrong and the top wing was hanging on by a thread.  I had to change things around and completely redo the struts.  I just dabbed some epoxy on the struts and hope for the best.  It's sturdy enough but I haven't flown it.  Came with a brand new Babe Bee installed.

I see something very concerning in regards to the leadout exit at the tip on the Guillow model. The leadouts should be exiting at the same elevation as the bellcrank position. I know when I fly foamie combat models, the leadouts exit on the top of the wing with the bellcrank only slightly higher maybe 3/8" higher. This causes the outboard tip to pitch up in level flight. I slightly warp my outboard tips up to bring the wing back down. Seeing how much the guide is lower than the bellcrank on the bipe suggests to me that your bipe would probably fly outboard tip high by several degrees which would automatically cause a total loss of line tension.

Your right Ken. I think the wires were supposed to go through a horizontal placed on the struts like the Nieuport. I'll have to move them, gives me something to do this afternoon.

rsv1cox wrote:Your right Ken.  I think the wires were supposed to go through a horizontal placed on the struts like the Nieuport.  I'll have to move them, gives me something to do this afternoon.

Be careful. If you run wires THRU the struts the stress will increases who knows how much, but a lot.  Try building a piece of wood like the wing with a weight on the end equal to the weight of the plane and run the lines, temporary, thru the struts and see what happens. Pop, crack. Before you try it on an actual expensive plane, please try it on a dummy plane. I don’t believe the struts themselves can handle the stress. If you meant between the struts, ??, then what?? You would move your exit point around.
   I agree something is wrong with The way the lines exit the plane and go thru the end of the wing.
   Think before you leap or the wing will be ripped apart.
   If you decide to use the struts as an exit point for the lines, make sure it is very sturdy.

Happydad      

Hi HD

No, I will use a cross member over the struts like you see on the unfinished Nieuport 28.  It worked well on the original 28 I built and flew years ago and is kind of standard for biplanes with mid level lines.  But, I have thought of using two cross members one on either side of the strut to strengthen it and install a long brass eyelet guide through both.  

Another one of my favorite Bipes.




Some of us built these from kits years ago that was provided by a member here.  You probably remember it.  

Bob

rsv1cox wrote:Hi HD

No, I will use a cross member over the struts like you see on the unfinished Nieuport 28.  It worked well on the original 28 I built and flew years ago and is kind of standard for biplanes with mid level lines.  But, I have thought of using two cross members one on either side of the strut to strengthen it and install a long brass eyelet guide through both.  

Another one of my favorite Bipes.




Some of us built these from kits years ago that was provided by a member here.  You probably remember it.  

Bob

now that is support!  is that the baby ringmaster biplane from nitrosmeller? isn't Ron's son starting one of these with a built up wing?

happydad      

I believe it was Roger Harris that did the kits on a laser printer.  They were nicely done and packaged and included plans.  

I know that Eric (getback) built one, but there were others.  I modified mine into a Stearman trainer with a back seat and changed the cabane struts around.  Roger did the Snoopy figure too.  

Ron, you still in here or are you fixing your Son's Xbox............?  

Bob