All fired up

[onetone]

Thanks for that explanation mattocks.

[Mad Max]

0.29 or .0029?

[mmattockx]

0.29 or .0029?

That's a good question and needs clarification. I shouldn't have said 0.29", that wasn't correct. The ratio is actually the ratio of strain, which is the amount of change per unit length. Poisson's ratio for steel is indeed 0.29, but that means the lateral strain will be 0.29 x the longitudinal strain. So if the longitudinal strain is 0.1% then the lateral strain will be 0.29 x 0.1 = 0.029%. To get the actual measured amount of lateral deflection you would need to take the width you are measuring and multiply it by 0.00029 (0.029% converted to a straight decimal). If the width was 10" then the change would be 10 x .00029 = 0.0029".

I will go back and correct my last post.


Mark

[Mad Max]

I will measure the width braced and I’m braced just for fun

[Kirkll]

I’m sorry… you guys lost me going down that mathematical rabbit hole. But to put this in such a way to wrap my head around I think of a tape measure with the cup shape holding it’s shape as it’s extended.

If the cup is turned upside down it folds over instantly….. It does the same thing on a bow limb and increases the strength a lot as it’s drawn. but…. looses vertical stability proportionally, so the geometric shape of the limb from butt to tip is very important to balance it out. Also the width profile is critical to have both limbs bend the same…

I had no idea the limb actually flexed along the cross section like that… Why did you have to go and tell me that? Now I’m going to have to check this out myself.

So on these Turkish style bows you are building with glass, what type of width profile are we looking at?    Kirk

[onetone]

1 1/8” wide w/ a slight taper only at the beginning rigid levers.

[Mad Max]

1 1/8” wide w/ a slight taper only at the beginning rigid levers.

Yes that is what it is, James told me it was a test for me to make it, I passed  then he told me to make one 1" wide, 1" is how  wide it suppose to be. One day I will try again. fingers crossed.

Kirk the gap at brace is tiny but there, maybe .010

[mmattockx]

I had no idea the limb actually flexed along the cross section like that… Why did you have to go and tell me that?

 


Mark

[mmattockx]

I would not say that fiberglass bows are more radical.

I missed this in my replies...

I didn't say that FG bows are more radical than the sinew/horn bows. I agree they aren't for the most part. I was just saying that FG can withstand much more strain than either sinew or horn and it should be possible to make a more radical bow design using FG instead of the natural materials. In doing that I suspect the main problems would be keeping the core wood from failing and keeping the string on the bow.

We don't use anywhere close to all the capacity of FG in our bows. Long before we get close to the limits of the material strength we hit stability problems with the narrow, deep limb sections that FG lams allow.


Mark

[Mad Max]

I would not say that fiberglass bows are more radical.

I missed this in my replies...

I didn't say that FG bows are more radical than the sinew/horn bows. I agree they aren't for the most part. I was just saying that FG can withstand much more strain than either sinew or horn and it should be possible to make a more radical bow design using FG instead of the natural materials. In doing that I suspect the main problems would be keeping the core wood from failing and keeping the string on the bow.

We don't use anywhere close to all the capacity of FG in our bows. Long before we get close to the limits of the material strength we hit stability problems with the narrow, deep limb sections that FG lams allow.


Mark

Did you read this link I posted earlier?

http://www.manchuarchery.org/bows

[mmattockx]

Did you read this link I posted earlier?

http://www.manchuarchery.org/bows

I have seen it before. The one comment about modern composites isn't very valid because he is comparing different bow designs, so it isn't apples to apples. Make a Turkish horn bow design using modern materials and I expect it will outperform the natural materials.


Mark

[onetone]

This a recent redesign of a sapahi or Turkish horse bow. 38” between the string nocks unbraced with
10 1/2” of reflex from line between the string nocks to the belly of the riser. This is the first draw with a trial string and the hook wasn’t quite centered. Initial DW @ 28” is 52# Hoping this version proves to be more durable. Included a pic of the concave distortion on the back of the bow when braced.

There have been questions and comments re bracing these extreme reflex bows. As Max mentioned it can be done with the leg through method which is quick and direct. However, it is necessary to pay close attention to the process so bow doesn’t snap around between your legs, if you get my drift. Also it is important to be careful not to twist the limbs while bracing as these bows are more subject to misalignment during bracing. The horse archers of old had many methods to brace their bows, some of which could be done while riding a horse!

Max thanks for the video of the Vegh bow being brutalized. That removed any remaining doubts I had about fiberglass being able to stand up to the stresses exerted by these rad reflex bows.

[Kirkll]

These are very cool bows…. I read the article on the Manchu bows designed for heavy shafts and heavy draw weights. I have NEVER seen a DFC chart like that before.   If you gotta draw it to 80 pounds before it starts letting  off, I’m in trouble…. Those days are gone for me.

But I really like the looks of the Turkish design…. You guys are killing me here. I’m getting  the itch to try one of these real bad.   Kirk

[Mad Max]

I see 52# make a larger gap/cup, way to go

Kirk

[onetone]

Yeah Kirk, you make one of these Turks and next thing you know you’ll be wanting to get a horse!

[Kirkll]

Yeah Kirk, you make one of these Turks and next thing you know you’ll be wanting to get a horse!

I spent 30 years raising my own beef and never owned a horse. When my youngest daughter was first wanting a horse at a young age, I took her to a stable, and had her mucking out stalls, learning about grooming, feeding, and taking care of the tac. Then she learned the required exercise the horses needed whether the were riding them or not…..and the daily attention these horses need.
I told her that her papa was not going to take care of Her horse…. She had to do it.

She quickly got over her desire to own a horse, and I always preferred a quad myself for the ranch. I put gas in it to run fences and chase cattle. Changing oil once a year, beats taking care of horses, and they don't eat as much either. Horses are expensive animals to own too.

Oh I didn’t a bunch of riding in my early 20’s . I spent a lot of time working at a riding stable in Denver Co. including round up, and getting the horses tamed down a bit before the urban cowboys and girls came out to ride them. It’s amazing how much spunk those horses get being out on the range all winter. Saddle bronc riding wasn’t uncommon. 

I even did a bit of rodeo riding in 80-81. I always wanted to ride a bull, and I did a few times too.trust me….. It’s a bit different than those mechanical bulls they had in the dance halls.

But ….. I just turned 67, and I doubt very much the seat of my pants will ever touch a saddle again…. But the horse bows I can do on the ground just fine.

So there is my horse story…. Kirk

[onetone]

Yeah there is all that with horses. I started riding at about five, my family had a couple of horses and my older brother was all about competitive riding. Been thrown and scraped off on clothes lines and low hanging tree branches enough that I have never wanted to have horses as an adult. I prefer walking at 73. Didn’t mean to get your dander up 

[Kirkll]

Ya didn’t get my dander up at all bro… I rode a lot of horses years ago, and motor cycles too…. But I was smart enough to never own either one of them.

The motor cycles are fine for some guys. But Me…. I always preferred full throttle on the dad burn things, and almost killed myself a few times doing it…. I had a buddy that had a Suzuki 900 RM with a turbo that was almost the death of me. He told me to take it easy until I hit the freeway before opening her up, or I’d get myself in trouble….. So I did…. When I hit the freeway on-ramp, the traffic was non existent that morning, and when I hit the throttle on that baby she stood up on her rear wheel and almost threw me off from the gate…. By the time the front wheel hit the pavement again I was coming past 95 mph…… WOW! What a rush!

I lived through it, thanked him kindly for the experience, and never got on a big bike again for many many years. That damn thing was a crotch rocket!   

In my late 40’s to early 50’s I almost bought an old Harley sportster though… that was a nice road bike I liked the feel of… but I passed once again. I chose wisely too.

I repaired a guys roof on a ranch one time in exchange for using a trail horse to go hunting with for a week one time…. That was a fun trip, but the horse was a pain in the ass at times. That was a solo trip I took. Go ride the high lonesome sort of thing…. I trailered that horse for 160 miles up into the mountains by myself. Learned a bit about trailering horses too. Lol

I figured out that horse had never been close to much gun fire before too. I shot a grouse with my pistol while still in the saddle…. Don’t ask whether I hit the grouse, because I couldn’t tell you. The next thing I know that horse took off like a race horse through the trees and raked me off in the first 50 yards…. I had to walk back to camp…. Luckily the horse got hungry and made its own way back to camp later in the day and all my gear was still in the saddle bags and the rifle in the scabbard….. That was my last horse adventure, and about the same time I got into archery hunting.

A couple  of my nine lives were given up on crotch rockets and horses… lol

[Mad Max]

A couple  of my nine lives were given up on crotch rockets and horses… lol

This is all I saved from that long post . 

 

[Kirkll]

Aw come on max…. You know you love my stories…..

But…..If I had been packing a horse bow instead of that 357 mag, I’d have probably saved some knots on my gourd that trip.