I was putting a couple twists into the new string to bring everything back into spec, now that they have plenty of shots through them and doing a bit a yoke tuning. I had shifted my rest a bit to bring the broadheads closer to field points at thirty yards. I didn’t really like that as I’m pretty careful about keeping my rest “centered”, so I thought I’d verify that in as many ways as possible.
First was to eyeball the string, limb center and arrow from behind.
Then arrow shaft alignment with rod screwed into stab bushing.
I measured the distance between the shaft and riser, front and back.
Then something I’ve not done before. I ran a string around both limbs so I could center the shaft between the two limbs.
I did all this after setting the top cam to zero lean. If I lean the cam (yoke tune) then with the rest being the fulcrum, that will change the centring of the shaft between the bow limbs (string around limbs)
So can I just yoke tune? Or should I be tweaking the rest to maintain that perfect center alignment every time I lean the cam a bit? Will they come to an equilibrium at one point?
Once I get the bullet hole, I go back to 10-12 ft and check again. After that I shoot it out to longer ranger, then try broadheads. I'm usually having trouble from not too perfect form if I try this early in my pre-fall shooting. Once I'm in good shooting shape its easier and more reliable.
Good luck. I don't have a press so I don't mess with yoke tuning. If I think something there is out of whack, I go to a bow shop....
Right now some of the blame is form which could be suffering from shooting three different recurves quite a bit. And I blame that on a few trad guys that I respect ( and probably envy a bit) for making me want to shoot another bear or two with a single string this spring.
Once I used the following method, tuning my (& buddies) solo-cams was a breeze. This always got my FP & BH hitting the same at 50 yards. I only hunt to 30 yards so all good for me. >>>
Start with bow is spec and at max poundage. Set rest so center of arrow is 13/16" (at berger hole) from riser. I never move the rest left/right. Twist/untwist idler yokes to get perfect arrow flight. ie: If you have a right tear you need to move the nock left (using yokes). Someone told me think of it as getting the nock directly behind the BH.
Idler lean should NOT be straight at brace. It should be straight at full draw - have some stand behind you and look if you don't have a draw board. BUT if the bow shoots good, it might not be perfect.
Mine aren't straight at brace, OR full draw. Somewhere in between.
I changed my grip a bit last year to put a little more intentional pressure on the bottom of the “life line”. Also straight (locked elbow) bow arm.
Many folks confuse "locked" with hyper-extended. Not the same thing. When the arm bones are "in-line" with the least amount of muscle use, it will actually look bent from that over-head angle.
Matt
I’m a 74” wingspan. 29” bow, very short D-loop and release trigger is at the second knuckle. Shouldn’t be over DL.
I just retied my loop to make sure there is no pinch. Retimed the QAD rest. According to the group I just shot at fourteen yards, my bare shafts are a bit nock right and impact a bit left of fletched.
Matt
Then shoot some big fixed blades.
If you have a draw board, you can experiment with that nock travel as you draw the bow. A sharpie in the string loop drawing a line on freezer paper as the bow is drawn. Play with the limb bolts until that line is as straight as possible.
GG, setting your cam lean first on a draw board, then fine tuning with the rest is (I think) the opposite way around than must archers? But it must work for you.
Well it's a crappy, snowy day out today, so won't be shooting. I took my draw board apart two summers ago because I wanted the winch for another project. I did pick up another winch and cut up most of the parts for a more sophisticated model last winter but never got around to putting it all together. Great day to put it all together. Only item I can't find is the roller I had for the grip to sit in. Also, when I cut the mainframe tubes, I didn't allow to put a scale between the d-loop and the winch. I'll have to draw and hold just before break over and have my wife mark the arrow. Plotting the nock travel will be interesting too.
Hopefully by late afternoon I'll have the new draw board up and functional.
Horizontal travel is the amount of side to side travel of your nock as it moves in the draw cycle. If your sharpie is positioned to just touch the paper, then horizontal travel would make a thicker or thinner(maybe pull away from the paper) line as it moves.
Think of it this way.... standing behind the arrow and looking directly down the shaft... vertical nock travel goes up and down while horizontal nock travel goes left and right.
In theory, the forward travel should be straight as far as horizontal travel is concerned through a shooting machine. Hand torque is what causes horizontal travel.
But: I set up a piece of cardboard under the nock loop and traced a line through the draw cycle, moving it over about an inch each time and graphed five lines. Each line made a slight consistent curve over about eighteen inches. The middle of the curve dropped about 3/16". I couldn't detect a "bump" in the line.
With yoke adjustments, I ended up setting the cam lean between brace and peak weight to the average of both. I shot one group of three fletched and three bare shafts at twenty five yards and the groups were within two inches of each other horizontally. Then I wiped out hard on the ice coming back from the target and figured that was enough till the rain, snow and nighttime freezing quits. It's been raining all morning, so I decided I might as well add a foot of length to the draw board (for a scale) and a winch rope guide too.
You may never get the bare-shafts to group with the fletched arrows, if you're shooting a straight locked bow arm, because the only direction your follow-thru can go is left.
Also, per your earlier question, all of the top level competitive 3D archers, that I shot with back in the day, set cam lean first, then tuned the rest. I've never heard of trying to tune cam lean to a fixed rest position.
Matt
GG, that’s basically what I’ve done now. A straight edge alongside my idler (top cam) comes to exactly the same place on my bottom cam, at brace and peak weight. All indicators say my rest is centred. I’m going to use form correction for the fine tuning.
X-man, my draw board is portable and can go horizontal or vertical. All my stuff is homemade and has no permanent home and so is designed for such. I did put it “crossbow like” for easier graphing, but it’s understood that vertical and horizontal are with the bow in shooting position.
I am going to graph again, paying special attention to the peak weight hump to valley portion of the draw. I’d like to find that bump you described.
Miserable weather again today and two days left of isolation, so it’s a nice diversion :)
I was starting to wonder if I was overdrawn so I shot a few with my release on the string instead of the loop and that was definitely too short. I was 1/8" too long on my axle to axle measurement. so I put that back to spec and the bow became it's jumpy self again, waiting to take off if I relaxed even a bit. I asked X-man in a PM about twisting it up a bit to shorten the draw length and he recommended against that on the solo cam. So I took my spare, matching release and shortened it in 1/8" increments. I'm convinced I'm not to long in the draw length.
I did end up moving my rest 1/16" to the left to bring bare and fletched together.
I believe my grip on the grip may be partially to blame. Strongly considering buying a Shrewd grip.
I can always grab my old Drenalin if I have to. I always say we are a perfect match; a little slow, a bit sloppy, a spongy back wall, but we’re good enough to get the job done :)
But at five feet, fifteen feet and twenty yards, bare shafts , field points and broadheads are hitting the line :).
Can’t get farther out than that until some ice and snow are gone from my range. And that’s not looking like anytime soon :(
