The Ins and Outs of Bow Presses

If you want to be a compound coach, do you need a bow press or at least need to know how to use one? I think the answers are “yes” and “yes.” Compound bows were invented before the bow press. In those early days (the 1970s and 80s), it was the practice that to work on a compound bow, you slacked the string and cables or even dismantled it by backing out the limb bolts. This was a clumsy process which could be dangerous and, for one, screwed up any chance of finding your previous bow setup and tune accurately.

For those of you not in the know, compound bows use mechanical advantage to bend very stiff limbs, very short distances. In those early days, again, there were even kits to convert recurve bows into compounds: they involved cutting off the recurve sections and bolting on wheel hangers, etc. These bows, even without their springy limb tips were invariably weaker than purpose made compound bows, which used much heavier limbs (over 100 pounds of deflection force at a minimum).

Technicians in shops and manufacturers responsible for assembly, repair, and adjustment of these bows quickly realized the need for a device such as a bow press and voila!

The photo shows a couple of common modern designs, the yellow one was designed for older bows, the other for more modern bows. The yellow one worked until the past decade or so. The bow was placed so that the limbs rested on the outer rubber rollers, which were adjustable to make a correct gap between them. Then a winch pulled the riser, which was hanging below, downward, causing the limb tips to bend closer to one another, slackening the string and cables (see photo at bottom). The original presses were more like the yellow one, but they involved a single center pull (at the pivot point of the bow). It only took a few dozen bent or cracked risers (they were wood or cast, not forged, aluminum then) to suggest the improvement of having a double pull (note the two central rubber wheels on the yellow press), this perfecting the design.

That design lasted until compound bow’s evolved toward what are called “parallel limb” designs. These bows have limbs that are parallel to one another or even past that point. The original design of bow press no longer worked because the limbs didn’t stick out far enough to get bent; the bow just pulled through the outside rollers!

The other bow press has “fingers” that approach the limb tips on both sides of the eccentric on both ends of the bow (see detail left). Then a screw drive (powered or manual) brings those two ends of the bow closer together, getting the job done. This new type of press will work on newer and older style bows as long as the bow is short enough to fit between the fingers! In the early days of compound bows, the bows weren’t short like they are now. Instead of 30˝-38˝ axle-to-axle bows as are currently in vogue, they had 48˝, even up to 54˝, axle-to-axle bows. Modern bow press manufacturers are unlikely to make their presses accommodating of these very long compounds as so few still exist.

This press was my first press. I still have it as I have quite a few older bows.

Danger! Danger, Will Robinson!
Using a bow press is inherently dangerous, so be sure to get a seasoned veteran of their use show you how to use one. The forces involved are great (hundreds of pounds of force) and, trust me, if you make a big mistake, changing your underwear will be the least of your worries.

 

 

 

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2 Comments

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2 responses to “The Ins and Outs of Bow Presses

  1. Tom Dorigatti

    In the very early 1990’s, HOYT, USA accommodated the “pressing the bow” situation by installing grooved “buttons” at the riser end of the limb forks by replacing the standard limb buttons with the grooved limb buttons.
    You simply made a “bastard string” that you would hook on one end of the bow, have a friend (or try it yourself) draw back the bow to full draw, and then hook up the other end to “press” the bow so you could twist up string and cables (all synthetic fast-flite system, back then) for fine tuning, or get the string slackened so you could adjust the turn of the peep sight.
    The BAD thing about this was the sharp edges of those “buttons” would fray the bastard string, so you had to watch it very, very, closely.
    The answer was a “portable bow press” that was comprised of an adjustable length of steel cable which had, upon each end a short post that you placed into the limb fork. Then you could used the portable bow press and the cantilever to “press the bow.” These things were doubly dangerous, because they could break at the wrong time, AND…if you bumped the cantilever, the entire thing would come crashing down. I had a friend who got his fingers busted big time when he accidentally undid the canter lever while he was fiddling by the bottom eccentric reinstalling the string when the thing let loose on him.
    They still have those items around…but I wouldn’t ever use one again! Learned my lesson more than once with both the bastard string and the portable bow presses.
    I don’t have any photos of these sinful items to post. Besides that, I wouldn’t want any of you readers to get “ideas” and try to make one of these highly dangerous devices.
    One other means of pressing a bow in a dire emergency is to get the bow drawn back and insert a screwdriver or strong solid object thru the cams at each end and then slowly let the bow down so the limbs hold the screwdriver in place and the bow can be relaxed…BUT…you are asking for potential marring of the limbs and with some thin cams potential cracking of the cam(s).
    Better off to spend the money and get a high quality bow press you can rely on.

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  2. Tom Dorigatti

    Here is a link so you can look at photos of various “portable bow presses” that have been out there for years:
    https://www.google.com/search?q=photographs+of+portable+bow+presses&rlz=1C1CHFX_enUS529US532&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj_25qG9dvUAhWK7YMKHV6uCH0Q7AkIQA&biw=1280&bih=894
    Enjoy…but do NOT try to make one yourself. You are asking for trouble.

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