Aids HIV FAQ

Tiller and Nocking Point Adjustments

Question:

Greetings fellow Archers! I have a general question for all of you hard core bow physicists I have been shooting a Jennings Mag-T (New replacement is on the way for those of you who respond "God! that’s old!") for alot of years now, and have picked up just enough information on setup and technique to be truly dangerous on the target course One of the bow setup rules that appears to be etched in stone concerns the initial placement of the string nocking point.  I have seen and read in numerous texts that the one should start tuning with the knocking point placed in such a way as to provide approx 1/4" of clearance from the bottom of the arrow knock to the centerline or 90 degree formed by the bowstring and the pressure point of the rest. As such this places the arrow nock above the 90 degree measure with the arrows tip pointed at a very slight angle down…  My question is, What are the physical forces involved that make this a n advantageous setup, or am I misreading the texts and mistaking only what archers consider a good starting point for tuning?  Does a particular type of arrow flex associated with the forces of a compound bow on release have any bearing? Another question concerns a setup instruction that came with my Mag-T, actually it was sent to me long after I purchased the bow by a very nice lady at Jennings named Tracy, in the instruction they state that the tiller of the lower limb need be approx 1/8" shorter than the top limb.  Again, this was mentioned as a started point to tuning and could be a different number, but my question is again, what forces involved in the loosing of an arrow from a compound bow would be advantaged by having less tiller on the bottom limb… Thanx to all Archers in Advance! David Obando

Response:

those tiller and nocking points are only a guide for setting up. setting up your bow is a personal thing, I shoot fingers and have even tiller, and nocking point 3/32" above square. it all comes down to personal preferance. to tune your bow in you should adjust the nocking point and tiller up, down, left, right, in, out, round and round and inside out untill you find what shoots right for you, remember you can always set it back to shop-standard if you cant get it Grott.

Response:

The reason that you must offset both the tiller and nocking point is because you are not drawing the arrow at the center-line of the bow. The top of your bow hand is at or near the center line of the bow while your arrow rest is significantly higher than the center-line of the bow.  The offsets required in tiller and nocking point height compensate for the assymetry introduced by hand placement and arrow rest placement. I have included below, the text of a presentation on tiller tuning  I gave at Vegas one year.  I hope you find it of some value. Good Shooting! Perry Tiller Tuning, By Perry A. Ratcliff Tiller tuning methods described elsewhere require an archer of exceptional abilities to produce consistently good results.  The following tiller tuning procedure should be useful to a much larger segment of archers. My tiller tuning procedure is a simple two-step process.  In the first step, you adjust the tiller to where you can best aim the bow.  In the second step, you fine tune the tiller to where the bow is most forgiving. Step 1 Shoot as many shots as necessary to determine whether the bow is pulling you down below the spot or the bow is drawing you up above the spot.  Drawing "on the spot" will help you best determine what direction the bow is pulling you.  If the bow is pulling you down below the spot, decrease the weight on the bottom limb or increase the weight on the top limb.  If the bow is drawing you above the spot, increase the weight on the bottom limb or decrease the weight on the top limb. During this part of the tuning process it is not critical that you continue readjusting the nocking point for good arrow flight.  You are only interested in getting the bow to aim with the greatest ease. After you have adjusted your tiller, continue shooting the bow to see how well it aims for you and adjust the tiller as described above until the bow consistently draws on or near the spot. When you have the bow aiming well, readjust the nocking point (and peep sight height) to obtain proper arrow flight. Step 2 You now have the bow adjusted for the best "feel" in you hand and can begin tuning for best grouping.  For this part of the tuning process it is necessary to evaluate how well you execute each shot.  If you bow is tuned properly all of your "Good" shots are going to group together. What you need to do now is identify what happens to your arrows when you shoot an arrow that has been aimed well but execution was flawed. Disregard all shots that are not well aimed (did you do a good enough job in step 1).  If tiller is not yet adjusted perfectly, your questionable shots will tend to go consistently high or consistently low.  These high or low shots are what you will be looking for when fine tuning your tiller.  If your tiller is adjusted correctly, some of you poorly executed shots will group a little high and some will group a little low. If your poorly executed shots consistently group low, decrease weight on your bottom limb or increase weight on your top limb.  If your poorly executed shots consistently group high, increase weight on the bottom limb or decrease weight on your top limb. This fine tuning process should not be completed in only two or three ends because you are making adjustments based on where you poorly executed (but well aimed) shots are going.  During this fine tuning process, make adjustments on only one limb and never make adjustments of more than +/- 1/4 turn from your initial setting of step one.  I generally make my fine tuning adjustments in 1/16 turn increments. Unlike most tiller tuning methods, this procedure works well at even short distances.  I generally do my tiller tuning at 20 yards.  At 20 yards, I try to determine whether my poorly executed (but well aimed) shots consistently drift high of the spot or low of the spot and adjust accordingly.  

Response:

I would like to make a minor correction to my earlier post.  Tiller tuning also aids in compensating for miss-matches in the angle of the grip verses the natural angle of you bow hand. While on the topic of "hand feel" I have replaced the grips on all of my bows for years with PSE Rubber Grips and used a Dremel Tool to reshape the grip for a more natural vertical alignment of the grip for my hand.  Unfortunately, PSE no longer manufactures these grips. If you find it difficult to hold steady on the target despite extensive work on tiller tuning, you may need to look into the angle of the grip.  If the vertical alignment of your grip is significantly different from the natural position of your bow hand, you may have problems holding the bow as steady as you need to in competition. Good Shooting! Perry

Response:

Thanks again Perry! The grip on my Jennings Mag-T is a molded, thus indigenous to the riser. There are no mounting locations in order to place after market grips, so the only thing I think I can do to alter the grip geometry is to do something interesting, like adding tennis racket grip tape… This question will prove to be academic though, since my new bow will have accomodation for different "bolt-on" grip choices… As for holding steady on the target, At this time it seems that a very clean release is my best ally so far.  The sight still dances quite a bit (particularly when I’m fatigued), but I’ve found that using a consistent mental trigger helps in this regard… If I make sure to recite the trigger in my head exactly the same way each time, I think it allows my muscles to settle down to a "steady state" which, although still shaky at best, is shaky the same way each time With alot more practice, I guess I’ll develop the muscle groups I need for a steadier hold…. Thanks again, David Obando – Hide quoted text — Show quoted text -> I would like to make a minor correction to my earlier post.  Tiller > tuning also aids in compensating for miss-matches in the angle of the > grip verses the natural angle of you bow hand. > While on the topic of "hand feel" I have replaced the grips on all of > my bows for years with PSE Rubber Grips and used a Dremel Tool to > reshape the grip for a more natural vertical alignment of the grip for > my hand.  Unfortunately, PSE no longer manufactures these grips. > If you find it difficult to hold steady on the target despite > extensive work on tiller tuning, you may need to look into the angle > of the grip.  If the vertical alignment of your grip is significantly > different from the natural position of your bow hand, you may have > problems holding the bow as steady as you need to in competition. > Good Shooting! > Perry

Response:

I have two comments regarding your follow-up post.  I too have tried adjusting the feel of a grip with grip tape.  Unfortunately however, I was never able to keep the tape from  rolling /creeping on the grip creating more problems than I started with.  You may have better luck, just thought I would share my own experience. The second point is regarding holding steady on the target.  The best way to train your muscles is  with eyes closed shooting.  You will develop better feel for your good shots, much more quickly with eyes closed shooting than you can with eyes open.  Stand about five yards from the target and let your muscles work on instinct.  Without your eyes forcing you to try and zero in on a spot, your muscles will have an opportunity to learn the most efficient and consistent way to pull the bow back and anchor.  I also like to alternate between eyes open and eyes closed shooting to feel the difference between shot execution via both methods.  You will be surprised to find how big a difference there is in the feel of a shot between eyes open and eyes closed. Good Shooting, and remember…         Practice doesn’t make perfect.         Good practice makes perfect! Perry – Hide quoted text — Show quoted text ->Thanks again Perry! >The grip on my Jennings Mag-T is a molded, thus indigenous to the riser. >There are no mounting locations in order to place after market grips, so >the only thing I think I can do to alter the grip geometry is to do >something interesting, like adding tennis racket grip tape… >This question will prove to be academic though, since my new bow will have >accomodation for different "bolt-on" grip choices… As for holding steady >on the target, At this time it seems that a very clean release is my best >ally so far.  The sight still dances quite a bit (particularly when I’m >fatigued), but I’ve found that using a consistent mental trigger helps in >this regard… If I make sure to recite the trigger in my head exactly the >same way each time, I think it allows my muscles to settle down to a >"steady state" which, although still shaky at best, is shaky the same way >each time >With alot more practice, I guess I’ll develop the muscle groups I need for >a steadier hold…. >Thanks again, >David Obando > I would like to make a minor correction to my earlier post.  Tiller > tuning also aids in compensating for miss-matches in the angle of the > grip verses the natural angle of you bow hand. > While on the topic of "hand feel" I have replaced the grips on all of > my bows for years with PSE Rubber Grips and used a Dremel Tool to > reshape the grip for a more natural vertical alignment of the grip for > my hand.  Unfortunately, PSE no longer manufactures these grips. > If you find it difficult to hold steady on the target despite > extensive work on tiller tuning, you may need to look into the angle > of the grip.  If the vertical alignment of your grip is significantly > different from the natural position of your bow hand, you may have > problems holding the bow as steady as you need to in competition. > Good Shooting! > Perry

Response:

All of these points you have talked about are only starting points for properly tuning a bow.  Because every bow throws an arrow differentely every bow is going to need a slightly different adjustment.  Paper tuning has always worked best for me.

Response:

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