While I'm sanding on bows or sitting on a log, I get way too much time to think! Being the curious type and not easily satisfied with "the way it's always been done", ideas and questions cloud my little brain. Below is some of the research and development projects I've been working on. With my backlog, I don't get as much time to work on these projects as I'd like, but over months and years, they finally get done. I really enjoy the R&D, wish someone would pay me to do it! (I guess they are!) Here are the latest projects that has resulted in lots of head scratching and 4 letter words......

A little history first.....Having tested many of the best bows made, the performance difference between the very best is small! But the difference between worst and the best is HUGE! It's was apparent we've pushed limb designs about as far as physics, modern materials, and conventional building techniques will allow. By paying very close attention to detail, a Bowyer can gain a half percent here and half percent there which begins to add up into a bow with more efficiency than other bows by a few percent...What does a few percent got you?? 10% would allow you to get the same performance with the same arrow with 5 pounds less draw weight. 10% would let someone with a 26" draw length get the same performance as another drawing 28". 10% results in a lower trajectory at all ranges.

After months of contemplating and testing to determine what was holding the performance back, it became obvious the mass in the limbs was the culprit. The very best conventional designed bows are running 80% efficient and 95% of that 20% loss, is coming from the mass weight in the limbs. That leaves a lot of room for gains. Now the question became, how can the mass be reduced but keep the stiffness? Normal construction methods of increasing stiffness is to increase the thickness or width of the materials. Both methods increase the mass weight in the limbs at the same time.... Catch 22, This explains why performance has not significantly improved much in the last 40 years between the best bows. You could try to find lighter materials for limb construction but each material has pros and cons that have to be dealt with so...more limitations.

The Concept: I have found a way to increase the stiffness of the limbs and decrease the mass weight at the same time. Most folks are aware switching from a Dacron string to a DF-97 or FastFlight string will increase the speed by 5 to 10 feet per second. The difference is about 50 grains between the Dacron and the FastFlight string..What if you could take 500 grains out of the working part of the limbs? Especially the outboard 10" that travels the furthest?

The Adcock Cross Section "ACS" (US Patent# 6,718,962)

Conventional limb construction is laminating flat materials in a flat form. This results in a flat limb that is either rectangle or trapezoid cross section when finished. Any engineer knows if you want to make a flat piece of material stiffer, without adding weight (mass), bend it! Instead of using thickness or width to vary stiffness, I am using the cross sectional shape. You can see the concept by holding a piece of paper or cardboard flat by one end, now place a mass weight on the other end. Not very strong is it?? You can add more layers and make it stronger but you are adding mass in doing so. Now curve it, it's MUCH stronger and you did nothing to the mass weight. The radius varies from a few inches at the tip to infinity at the fade-outs. Doing so, for a given draw weight/length bow, I'm having to reduce the thickness of the materials by about 15%-40% This equates to several hundred grains of mass reduction and the energy it took to move that mass, now goes into the arrow where it belongs.

In testing, the ACS longbow is out performing all other bows from 5-20% and that includes the very best recurves. So, what does this mean? Are you going to see 5-20% more speed? Not necessarily.. Efficiency is determined by how many foot pounds you put into the bow compared to how many foot pounds are in the arrow. A 10 feet per second increase at the same grains per pound arrow weight is only about 5% in speed but about 10% in energy. That is huge for a bowhunter looking for penetration especially those with short draw lengths or those that can not draw heavy weights. Bottom line is I have yet to see a recurve that will out perform the ACS longbow at any draw length or arrow weight! Compared to other longbows, a customer said "It's like they are not even from the same planet!"

What to expect the first time you shoot an ACS limbed bow?

The first thing you will notice while stringing the bow, it will "feel" different. As you draw it loads up quick, lots of early draw weight. As the draw comes back, it stays at a nice smooth increase in weight, and less pounds per inch than bows that don't load up early. During the shot, it will be absolutely dead in the hand, no shock at all...And the arrow is GONE! In most cases, you could drop down 5 to 10 pounds in draw weight over most other designs and keep the same performance. Or, go up 50-100 grains in arrow weight and still shoot the same speed but greatly increasing penetration. In testing against other bows, the D/R longbows are beating them all (recurves included) at any arrow weight and at any draw length.

For people that can not draw heavy weights or that have short draw lengths, this will help level the field. When you are on the edge of adequate, 5-20% more "oomph" is a lot!

Update as of 03-24-05: Testing continues and lots is being learned. We've evolved the materials from glass over a single carbon layer, to glass over a double carbon later, and the latest generation is the ACS CX (Carbon Xtreme) which is pure carbon front and back with a laminated bamboo core. These are the highest performing and most efficient to date. Please see the testing results from Mr. Mullaney on the 66" 3 piece. We are experimenting with a different composite core materials that have potential. Many old beliefs and wives tails are being blown out of the water and in some cases, I'm not sure what to do with all of it! In a nut shell, the ACS bows are getting even better.

Bottom line, stay tuned, it only gets better and better......O.L.

Update as of 10-01-06 Anyone interested in target bows?? Check this out....O.L. Apogee ACS Target bow