cam and a half

[geoffretired]

I always thought that two identical limbs, topped off with two identical cams would would give fairly straight line nock travel. It seemed that way in the days of round wheels. Then I bought an Oneida Black Eagle. They have identical cams with identical limbs but the cams are operating the limb they are attached to not the opposite one as in conventional compounds. They have an added feature which is a timing system that keeps the top and bottom limbs working in synch with one another. When I saw the cam and a half system recently, it seems that the same idea is in use although it looks different. One cable seems to keep both cams in synch so they both rotate together all the way through the power stroke. The Oneida system is over 20 years old so they knew something then, or so it would seem, about wheels/cams working out of synch.
I am not talking about wheel timing as set by the relative cable lengths. I think this is to do with the cams moving together all the time, not letting one get in front for a while then trailing later in the power stroke. I wondered if anyone could throw light on this. I wondered if it was the parallel limbs that made it more likely for one cam to get infront then fall behind. Or is it just that we have better equipment these days to show how the wheels/cams tend to lead then trail. If that's the case, how did Oneida get to use their timing system so much earlier?
I'm puzzled.

[Bald Eagle]

I'm puzzled too Geoff, puzzled that we don't see many Oneidas taking top places at shoots(target) I shot cam and 1/2 for a long time with good results but felt there was something not right, something lacking, then I got a Bowtech with binary cams! BINGO. The best bow for me, I feel so settled in the shot, I can relax into the draw, unlike cam and 1/2, it was pulling all the time and there is no vibration, just smooth straight line release. It is also very fast, my 2314 alloys come out at 240fps! I,ve yet to chrono my aces, also very smooth, I'm hooked.

[geoffretired]

Perhaps Oneidas are not that popular as the marketing is not very strong. It's a small firm I believe. If they don't sponsor top shooters people think top shooters don't want to shoot them etc etc.
They also have a very unusual power stroke and lots of noise. They can be modified- mine is as quiet as any recurve.
I've just changed my Mathews Q2SL for the hoyt Ultra tec.
I would describe the M as very docile and sweet where the H is very taut.
The reaction is more lively too.I think it is a very personal thing rather like beauty is in the eye of etc.
So what are binary cams?

[Bald Eagle]

Binary cams, in my opinion, are the smoothest, foolproof cam ever, they just don't go out of sync, they are a "mirror image" of each other, so even if the string stretches and they don't, they would still be in sync. The new 2006 models have modules for draw length, whereas mine is draw length specific.

[Marcus26]

Here is info on the binary cam

http://urbanarchery.com.au/binary.php

The Cam 1/2 system can go out of time and is actually quite sensitive to it. It won't produce as bad results as an out of time twin cam does, but can still cause you misses that you were not expecting.

While the cams are tied to each other, one is still attached to a limb, and should that length change, then you have problems.

The Bowtech cam has no cables attached to the limbs at all. This means that both cams work together. I have added 10 twists to one of my cables and still had perfect nock travel and perfect timing.

After a year of solid shooting I have yet to find a single problem with this cam design.

[Jerry Tee]

Most Oneida shooters are hunters, Oneidas have a very efficient cam system that transfers a lot of energy to the arrow and generally they work better with a heavier arrow. This means more chance of a pass through and a better blood trail to follow.The cam system has another advantage to the hunter. It produces a level nock travel as the cams are syncronised, as Marcus says this produces straight arrow travel and easy tuning but for a hunter it means that the shaft is directly behind the arrow on impact so the broad head is driven by the shaft like a hammer hitting a nail.For me the Pro Eagle is the most stable riser available, with zero reflex putting the throat right between the limb pockets. I like the smooth draw and the hard cam that you can still use off fingers I also don't have to worry about cam lean or a load of cables and guides on the back of the bow.

[geoffretired]

Thanks for the information,Marcus. So, winding the cables round the cams, in effect shortens the cables which in turn draws the limbs closer together to get them to bend?
I'm trying to guess how they are configured. Is one cable like an extended letter "S" while the other is more like an extended letter "C"?
The S keeps them in sync while the C wraps onto both cams drawing them together and the limbs?
They sound good.

[Marcus26]

Are you talking the Bowtechs here?

If so both cables are identical, in the S shape. The main string is as normal.
They actually look like the bottom cam of the cam 1/2 system, but on each end.

[geoffretired]

Marcus, thanks for the info. I was talking Bowtech. Two S shapes.mmmmmm
Is one reversed so the two work in opposition?
I imagine now, that the wind on end is winding on more than the wind off end in order to bring the limbs together. Three grooves on each cam?