Let’s build something crazy! Ash Wing Bow (EXPLODED)

[RyanY]

The trailing edge of the wing will have a concave back along that chamfer. I use pencil to help see where I will be removing wood and a centerline between the edge and the previous chamfer line.

I use a gooseneck scraper to create the concave effect. I was surprised how much wood it removed. This was a good experience to help me consider doing a hollow limb design at some point.

Last pic is the roughed out chamfers.

[RyanY]

I then use a scraper to round out the last few edges on the back and then go over it with 80 grit sandpaper.

As expected, I lost quite a bit of draw weight doing this. Currently pulling 33#@28". The design doesn't seem as stressed as I was expecting. Next I'll heat treat it a bit to try and get a few more pounds out of it. Tiller looks a bit better with the left side being a bit stiff to my eyes.

[Mad Max]

Nice

 

[bownarra]

See is looking pretty cool
To get the very sharpest and longest lasting burr on your scrapers make sure the face of your scraper is polished like a mirror before trying to raise the burr Makes a big difference

[Digital Caveman]

If this doesn't work you could make another with the opposite orientation, cut them in half, splice them together, and put the result on the front of a piper cub. 

[Digital Caveman]

I see your crazy plan and raise you one wacky. (or whatever that phrase is)

[JW_Halverson]

With the setback in the handle and the recurving at the tips, you have a profile that is known as "dihedral". This dihedral wing shape is common on soaring birds such as raptors, particularly in vultures and condors.

You are really taking the inspiration of natural dynamics into this bow, Brother Ryan. 

https://images.app.goo.gl/Rdngsiq2RL3sS9mf6

[RyanY]

Bownarra, I'll have to keep that in mind. I find of the 4 edges I usually get one good one, 2 okay, and 1 that doesn't do much. 

TCM, It's amazing how much these are starting to look like wings. Maybe I'll add a body/fuselage and see if it'll glide! 

John, Definitely going to see how far I can push it to a degree. Always appreciate your extensive bird knowledge!

Got the heat treating done today. Heated the tips, handle, and limbs separately. This bow is relatively thin so I made some modifications to my setup. Usually I hold the heat gun 4" away from the belly and go pretty dark. For this one I'll go 3" and go for a lighter color. I couldn't use my normal jig due to the width of the limbs so I had to hold the heat gun. Helps to have some youtube videos to watch on the tablet.

[RyanY]

Added just a hair of reflex to the limbs as I feel it helps more with the heat treating process than no reflex at all. I know before I said 3" seemed like more reflex than I wanted...... Maybe I'm a glutton for punishment.

[RyanY]

Next I'll start finalizing the shape of the profile. Because of the design, I'll be putting in a lot of work into this bow before it's technically tillered out after heat treating. Not ideal but part of the challenge. I taper the tips closer to my desired 3/8" width. Next, I shape the handle to it's final width. I'll then start shaping the handle along with some chamfers along the belly to help complete the 'airfoil' limb cross section.

[RyanY]

I want to mention that I have crowned the back of several board bows. This is primarily for aesthetics. Theoretically I think it operates similarly to trapping and could help in compression. This would be good for this bow considering the curly grain. I also wonder if adding a crown may help get away with some level of grain runoff due to the curved surface as it seems many breaks along the grain must start at the edge where it runs out of the limb. This would help the edges experience less tension.

The chamfers on the belly will certainly concentrate the compression strain to a degree but this bow is built more for aesthetics than performance. I will consider it a failure if I get compression fractures though. Still needs to be a bow!

[RyanY]

Finished the 'airfoil' limb profile. Certainly not the shape needed for lift but something that would feel interesting and help thin out the trailing edge. It's hard to take a picture of the actual limb so I drew a quick sketch of the steps I took to get the shape. Now it's time to draw the "feathers" on the limb and start cutting them out. In retrospect I should have waited to round the trailing edge so it would be easier to draw on the limb but no biggie. I'll start by roughing them in and then will get the bow bending before spending all that time shaping and sanding them. Till now the bow has not been braced due to the limb being too wide near the tip for my tillering string. Feels pretty stout still with floor tillering so hopefully I'll have some room to get the bend the way I want it to. Fingers crossed!

[Pat B]

Interesting, Ryan. Looking forward to the end results. 

[Will B]

Very cool build!  Thanks for the detailed description of your build and the step-by-step photos. If it can be done your the guy to do it. Good luck

[Mad Max]

Interesting, Ryan. Looking forward to the end results. 

Yep