[Sid]

There is a southafrican mountain bike company that changes the distance between the backwheel axel and the pedal axel depending on the size of the bike. They advertise this like its something special.
Makes you wonder what other non-changing parts are used to simplify production processes.
Take a hh style longbow. With it being flat. Cutting the tips back doesnt effect the reflex of the limbs.
So one former can fit all bow lengths.
But on reflex deflex... thats not the case. Cut a reflex deflex back and you get more deflex when unstrung. Ie less preload for any set BH.
So lets look at td recurve limbs.
Its possible to do the same with recurve limbs. Cutting the limb back. But that makes the recurve smaller.
Its also possible to have different formers for each limb length.
Just read a coment about another bowyer that tweeks the limb to work at a set draw length...
So ways to do this would be increase the fadeout. Or change the core tapers. Or change how much you make the limb work and where you make it work.
The next question is. When making a set of limbs how accurate are your weights. As most probably knows all bowyers miss limb weights. And with glass limbs you can rub the faces. Which changes the amount of glass to core.
0.010" glass each side and a thick core. Can make the same draw weight as 0.040" of glass and a much thinner core. But these would be different bows.
Its also possible to skinny a limb down to meet a weight. As in the 1.75" limb blank can be whittled down to a slender 1.5". And still be called the same bow model.
Since 2005. We have changed the widths of our limbs inkeeping with what we are finding works better.
So inline production changes also take place.

How would these kinds of bow changes effect bow tests.
The quote on another bowyer indicates that there might be a change to the dfc on a set bow length. So that means no on 62" brand X bow will be the same.
This excludes tiller changes during production

Without knowing the tricks of the trade on making different bow lengths. How do you know what the bow is going to be like?

 

[Sid]

Sorry folks... new phone and its jumping about on me... mods
Can someone delete the duplicates... :-(

 

[Todd the archer]

The old trial and error method and keep lots of notes on what works and doesn't.

Todd

 

[Grantmac]

In my experience Hex limbs like to be shot about 1 size shorter than conventional limbs. Could you just adjust them so that someone would use the same length conventional and Hex limb? I know I prefer a 68" bow even though it's borderline short for my DL.

-Grant

 

[Hank D Thoreau]

I guess we are not going to be able to eliminate variability until we start 3D printing from a standard limb, and that assumes that our printing materials are consistent. Otherwise, we will be back thinning and narrowing to make weight.

 

[Larry Hatfield]

hank, that also assumes that the materials are constant. in my experience, that simply does not happen. the closest you could come would be with an all woven construction, but that may be self defeating.
personally, i am of the opinion that an absolute system of evaluation in archery products is virtually impossible, and while interesting from a scientific and mathematical perspective, is largely unusable in the real life use of the equipment.
i had the opportunity to work for around 200 hours a year at battelle northwest with their top material scientist for a 4 year period and we tested literally hundreds of ways to quantify design/speed, design, material/speed, design, material, configuration, speed and smoothness and on and on.
i learned how to maximize design for a r/d longbow in the process but we did not come up with a formula that would take into account even slight differences in fiber/resin loading and distribution in comparing recurve bows and td limbs.
bottom line i think is the fact the smoothness, "shootability", and factors like that are mostly personal in nature and not likely to mean the same thing to any two archers.

 

[Hank D Thoreau]

Okay Larry, that sounds like interesting work. You have just given me a teaser. I am interested in what you tried and how it turned out. I used to work as a material scientist way back in the late 70's. I was doing R&D on optimizing the cure cycle of graphite epoxy composites for large parts...really large parts.