Forward and Rear flanges built into ribs - Possible/Practical???

[Derrick]

Good Morning,

I looked for a "Stupid questions from beginners" section, and this seemed to be the most appropriate place... so here goes:

I am getting ready to start building rib blank forms and flange forms and researching the different methods that others use. I notice that on a number of other aircraft the forward and rear flanges are built into the ribs. Is there any reason this couldn't be done on the Bearhawk?

• The biggest issue I can think of is that a number of ribs have varied lengths, which would mean making the biggest first, then cutting down the template, to the next... and so on.
• A second issue might be alignment at assembly, if the flange is built in, you won't have the "wiggle-room" to shift the rib fore/aft before riveting the rib to the spars.

[Chris In Milwaukee]

Those are all good observations. Also, given that the spar thickness steps down the further out toward the tip you go, you'll have to account for those differences in your rib lengths. Then you have less flexibility in the case a rib gets screwed up. Makes it harder to just "grab one from the stack" (I created extras for this purpose). The "wiggle room" for final alignment is also at stake, as you mentioned.

[Scout]

I believe the way Bob has engineered it like he has , adds more strength to the spar web with out adding weight of having to use a thicker spar web I believe would be needed if the shim and angle was omitted. ???

[Derrick]

One of the reasons I was looking at this was to remove a very large number of angles needed (not to mention drilling, riveting, and deburring). It isn't a big deal, just noticed that others have this type of construction and are rated to higher G levels (ie RV's).

[S Lathrop]

I had asked the same question years ago. One reason I was given for using separate angles was to improve the accuracy of the wing structure. After building my wings, I am convinced that the way Bob designed the wings gives really good results.

[Chewie]

I agree with all of the above. The angles are pretty easy to crank out as you get a rhythm going, especially since you are making stiffeners on the ribs anyway which are basically the same thing.

[way_up_north]

Good Morning,

I looked for a "Stupid questions from beginners" section, and this seemed to be the most appropriate place... so here goes:

I am getting ready to start building rib blank forms and flange forms and researching the different methods that others use. I notice that on a number of other aircraft the forward and rear flanges are built into the ribs. Is there any reason this couldn't be done on the Bearhawk?

• The biggest issue I can think of is that a number of ribs have varied lengths, which would mean making the biggest first, then cutting down the template, to the next... and so on.
• A second issue might be alignment at assembly, if the flange is built in, you won't have the "wiggle-room" to shift the rib fore/aft before riveting the rib to the spars.

I`m working this idea right now.

Its been in the back a few builders minds.

I`m calling it the magic rib..in that it makes all the sizes of that type...so one nose rib to make all the nose ribs...etc..with the angles included as you describe

I`l start a thread here on it and ask for other builders input...to see if this is a good idea or not...

[whee]

Seems like it’s more trouble than it’s worth. Those separate angles make it really nice when you have to make an adjustment.

Now if you want to make the wing really slick and easy to build then design an build the wing like a Luscombe. Those wings have 4 ribs in each wing. Stamping out the hat sections would take a couple hours. Think of how big the fuel tanks could be if there weren’t ribs in the way!😁

[way_up_north]

You have a good point there...

the more I think about it the more the way Bob does it makes sense...

when I talked to him about it ... he listed other planes and their construction methods ... so he knows all the different ways to put a wing together...he has thought this plane out very well.. and the factory uses the wing jig and angles... if anyone knew of a more efficient way to put a Bearhawk together it would be them

so I might be over complicating it..

but I thought I would try and see how far I get...in the end if it doesn’t work out... the worst that will happen is I’ll be cutting flanges off and going back to the tried and true way

along the the way I welcome yours and the other members input....

[Bcone1381]

We are rooting for you developing CAN/CNC files for prepunched wing parts. With that, the design makes some sense to reduce sports count and simplify the build. But when forming and drilling by hand difficulties are different.