Archery Talk Forum banner

PSE (or hybrid cam) tuning tips

205K views 672 replies 191 participants last post by  kenzo25 
#1 ·
For some time I’ve been pondering trying to capture the basics of my setup methods for PSE’s in one location. I get a lot of PM’s helping guys trouble shoot and end up typing bits and pieces of it over and over based on their need at the time.
Let’s see if I can organize my thoughts and assumptions here and I’ll start by setting aside a few “universals” in how I tackle my own bows and I probably can’t do it without exposing my own politics on a couple of tuning concepts but I’ll try.

1. Draw length- My draw length is set to support my form and shot. That’s it. It is fine tuned to my pin motion and my own form of group tuning. If your draw length is off such that you contort your body to fit into the bow, you can’t expect tuning (or grouping) to go as it should. Later I may fine tune my draw length by pin motion and groups (misses).

2. Arrow selection- I am blessed with a longer than average draw length. I also don’t have a “need for speed”. My target arrows and hunting arrows are all built heavy. The lightest arrows I own are 433 grains. I don’t ever push the envelope to the weak side on spine. In my opinion, tapping into speed is the only reason to go light on spine (so you can use a lighter GPI arrow). So, I always choose a shaft that is “stiff enough” and may choose over time to break it down a bit with point weight. My arrow selections are based on quality and specs that will finish in a weight range that I want. I’m not going to fret over helping you choose the right spine in this write up. There are tools for that.

3. Grip- it will make or break your tuning endeavor. First and foremost, you must be able to repeat the grip over and over again. Then, you may find that you need to be able to alter it slightly to test the result of having done so.

4. Finishing the shot- like grip. Even when you can tune “perfectly”… it won’t make more x’s, 12’s or dead deer for you. Good shots make those. A good test would be to take one shaft and repeatedly punch paper or bare shaft, if you can’t produce identical tears or group with the bare shaft…. Tuning shouldn’t be your first priority. You’ll chase your tail tuning and your time could be better spent. When you can bare shaft groups and identical tears you’ll soon come to realize that the tune doesn’t make nearly as much difference in scores or groups as it is made out to. Good shots make good groups and good scores….not good tunes.

Now, I realize those things don’t make me “normal”. That’s ok but one thing I want to make clear, tuning is much easier with an arrow that is stiff vs weak. After much testing, the only time I’ve seen softer spines equate to better scores or groups are where a bow had nock travel I couldn’t remove (or chose not to pursue). During tuning, if we know our arrow is at least “stiff enough”, we have a safe assumption. The arrow is showing us nock travel that is in the bow, with minimal chance of anything else. We tune the bow to the arrow (remove the nock travel) and the end result is a bow that is very tolerant of a variety of spines.


5. Center shot and nock height- I won’t dwell on these things like most “tuners” do. Here’s why; I let the bow tell me what it wants during tuning and early in its life. Nock height to me is defined by the way the bow aims and tunes. Center shot is where it tunes…not a measurement. I do not use walk back or French tuning at all, ever.

a. If you think you need walk back tuning, I’m going to challenge you. Check your sight setup (2nd axis specifically). Check your shot…are you centering in the peep the same as distance increases? And lastly, set your windage at the long range first. Then move up and see if you still think you need to move your rest via “walk back” tuning. Walkback tuning implies that there is one magic location that a bow will not drift left or right with increasing distance. This is simply not correct.


So, those are the basics concepts that are always in my mind. Let’s assume I’m taking a new bow out of the box.

1. First things are to set the specs on the bow. Draw weight, draw length and synch are the most important. I generally set ATA at this time as well (mostly so that I have a record of a starting point). If I know the cam system/bow well, I may already have some personal ideas about how I set my timing and synch. With any hybrid cam, it is a safe assumption to synch the cams so that the top cam hits slightly ahead as a starting point.

a. Let me time out and explain a couple of dynamics at play with just about any hybrid cam system. The timing marks are almost irrelevant. They really are an indication of letoff and valley more than anything else. If the timing marks move towards the string, letoff and valley length is increasing from factory spec. If ATA is correct, it is also an indication that you are making a longer draw length than the module/stop would indicate. If they move towards the riser, letoff and valley length is decreasing and the opposite is true regarding draw length vs factory positioning. When the cams are synched perfectly (as defined by us during tuning and setup) the timing marks will probably not be dead on the cables.

b. Let’s talk about twisting and the effect of each move on a hybrid cam;
i. Buss cable- a twist in the buss cable advances the top cam (makes it hit sooner), it lengthens draw length, decreases ATA and increases letoff/valley (assuming timing was even before the twist).
ii. Control cable- a twist in the control cable slows down the top cam, shortens draw length. It’s effect on ATA, valley and letoff are dependant on the others.
iii. String- a twist in the string shortens draw length, valley and decreases letoff. It plays a role in ATA and draw weight but it is secondary to to the buss.
iv. All- a twist out produces the opposite effect.

c. Cable rod or flex guard;
i. You should preliminarily set this prior to moving on. This should be done to provide minimal clearance off the first obstruction. On most of the flex guard bows, it would hit the string stop first. If you aren’t running a string stop, it will be in your sight picture before it hits the shaft at full draw or most vanes on the shot. I eyeball mine to be at the edge of the riser at brace height (not on a Dominator) to provide relief but not put them in my scope housing at full draw. Your tolerance for this may vary from mine.
ii. The flex guard bolt will move. I highly recommend removing it, adding loc-tite and replacing it. After initial adjustment, mark it with a silver sharpie or similar.
iii. I also run a small rubber washer behind mine. It does quiet the bow and seems to assist in it not wanting to vibrate loose. Others use hard plastic washers with success.

So, at this point, I have set my draw length and draw weight and preliminarily set my timing. Since I’m in and out of the press during this time, I also pre-set my top cam pre-lean to be minimally like \ when viewed from behind. Lay an arrow on the side of the cam just to get a better visual of where it is. Don’t over think it. If the shaft touches somewhere around the nock point, its good enough to start. I also check the bottom cam but we’ll circle back to the both cams shortly.
Let’s tie the nock point in. The reason I don’t do this before setting my other specs is that adjustment to the buss and control cable move it. I don’t want to tie it in, do my twisting and then find it isn’t where I wanted it to start with and have to re-do it.

1. Nock height- I said I wouldn’t dwell on this and I won’t. I use a basic bow square and tie the top of my bottom nock set in level with the center of the berger hole on a new bow. After I know a bow and cam system, I may learn through tuning and shooting that a slightly different nock location works better.

2. Hard nocks- I use superglue and cotton thread to build my hard nocks inside my loop. Some say not to put superglue anywhere near a string but over the last 25 years or so, it’s never hurt one of mine or that I setup for others. I tie in my top nock allowing for a tiny amount of play over the nocks I use to reduce the severity of nock pinch. ~1 serving wrap worth of play.
3. Install your loop. I measure mine with a caliper. Generically, the inside spread of my loop is .575”. I do change this based on the release and the bow. You need to know this measurement so you can replace them easily and stretch to the same length as it is highly critical to your anchor and accuracy. I can absolutely feel .020” difference.

Now I install my rest.
1. Height- Nothing fancy. I eyeball it so that the shaft sits level or very slightly nock high. Tuning will tell me what it needs later on.
2. Center shot- I do this by eye generally as well. I don’t measure it. If I am inspired for whatever reason, I use the two-arrow method where one is laid against the riser face and the other on the rest and adjust the rest to parallel. The reason I don’t really bog down on this is….. wait for it…. It doesn’t really matter. As we adjust the cams, the center shot of the bow changes. I tend to start with my rest centered in the grip (or window in the case of a Dominator).
So, hopefully I haven’t lost you yet. I don’t even like discussing the above because it’s individual and doesn’t really matter. We want to tune the bow to ourselves. At this point, I like to put some arrows through the bow to settle the strings before I even start tuning. I may immediately feel a needed draw length tweak or timing/draw curve adjustment I want to make….might as well do as much of this as we can before we worry how the arrow is flying.


Tuning- 1. For most shooters, it’s going to be easiest to start in front of the paper at about 6’.
2. Maybe you get a bullet hole. If you’re a “paper tuner” I’m going to encourage you to shoot from multiple distances (say 6’-10 yards) to get a real picture of arrow flight. I might also encourage you to do the same with a bare shaft. It will show you more clearly what the shaft really wants to do.
3. I generally make sure that nothing is WAY wrong through paper and then step to our 20 yard range and start bareshafting. The two methods are really equivalent but the bare shaft more clearly illustrates the flaw. You can arrive at the same point and quality of arrow flight with either with some effort and understanding. Bullet holes don’t necessarily mean the best groups. Many target shooters prefer a tail high or high left.
a. Paper tail left = bare shaft right.
b. Paper tail right = bare shaft left.
c. Paper tail low = bare shaft high.
d. Paper tail high = bare shaft low.
4. Broadhead tuning is another equivalent to paper or bareshaft just illustrated differently.
a. BH left = paper tail right….
b. And so on…..
 
See less See more
#320 ·
This might have been asked on here but I couldn't find it.

I am changing out the 70# limbs on my Freak SP to 60# limbs. I read the instructions that came with the new limbs but I have a question On two of the limbs there is a white dot on the back side opposite from the limb numbers.

My question is do the limbs with the white dots pair up and the remaining limbs pair up? If so, which pair are the bottom or top limbs?
 
#324 ·
I have run the axles/bushings in ME cams. They are nice, they have a different feel but aren't "necessary." The bushing will last longer than the bearings.

I haven't seen the need to install Bomar rocker pins since 2012 models. The pins/pockets in the Max models do really well.
 
#328 ·
Hi everyone in the forum!
I'm new to to this forum, and I'd like to thank everybody, expecially tmorelli, for the information shared in this thread. After reading all of it, I found some information about my new bow, a PSE FREAK SP, which I bought second hand.
I'd like to ask about some issues related to it's tuning. My bow arrived with an ATA measurement of 38" 1/2 with the original set of cables and string, allready broken in. I shot some arrows, and tried to tweak it to bring it to specifications. I pressed it and verified the length of cables and string. I found them stretched and gave some twists to restore the required length, and put the re-twisted cables (brought back to PSE reccomended lengths), obtaining a better ATA measurement of 38" 1/4, with the white marks on the cam very close to the cables.
I tried to restore specifications without maxing out the limb bolts, which I read is not properly good, and time the bow using the white marks on the cams.
I have so many questions and a big mess in my head, so that I don't exactly know where I should start asking....
Let's start somewhere:
A – Is it possible to bring the bow to specifications just twisting the cables and string? Do I need to tighten the bolts and bring them back to my setup position, each time I veryfy/maintain the bow?
B – when measuring buss cable, the length of the cable is considered from the single loop to the longer or the shorter loop of the yoke?
C – there are white marks on the Drive cams, and on the other side of each cam, there is a set of 4 engraved marks. Which should be used to tune the bow?
D – flexible cable slide. On my bow it is very tightly screwed and I suppose the wear on the buss cable serving, where it enters the module, is due to excess of side tension of cable slide. May this be correct? How much should I loosen the flexible slide to restore a correct cable approach to the module?
E – numbers on limbs. I read a post of the thread, where a limb number sequence was exposed. The numbers are different from mine, but the sequence was different either!!!
My limbs are placed as follows (LEFT HANDED BOW!!)
top left 147 top right 152
bottom left 148 bottom right 148
is the sequence correct, or should i switch them? If I sholud switch them, where should they be placed?

Maybe these questions are allready too much, but I hope to have some answers from the you, in order to understand my new bow and tune it for outdoor season.

Thanks from Italy!!

Gianluca
 
#329 ·
Ok, a lot of your questions are theory/opinion related and the bottom line is, pick your method and use it with confidence. Here is some food for thought:

A- You don't "have" to tighten the limb bolts down... but I typically do when making an initial setup on a bow. This gives me a starting point, then, I back the limbs off as I see fit and measure ATA/DW/DL. This gives me my new "baseline" spec.... that way I have a record and during maintenance, I'm always working around that new spec. This may change, I may find that I end up varying things as I get to know the bow.... again, the point is that when you get it where you want it, take measurements and record them.... that way you can always go directly back there (not necessarily back to factory spec and then retrace each step to get where you want it).

B- I honestly don't know. The difference is about 1/8"..... not enough to matter. The factory spec is nothing magic.

C- I use the white mark on the bottom cam that is nearest the string. I generally start with the top cam so that the white timing mark nearest the string is positioned over the cable as well.... then, I use the control cable to bareshaft/creep tune. Once I'm done, I don't care where the timing mark on the top cam ended up. I put a new one on the top cam for a visual reference (that shortcut back to "my spec").

D- Flex gaurd- I think I addressed this in the original post. Remove the cables from the slide. Remove the bolt completely. Add Loc-Tite to the bolt. I also suggest using some type of spacer (rubber o-ring?) to compress under the arm when you reinstall the bolt. Put the cables back in the slide, adjust for minimal clearance off your vanes, mark the head of the bolt with a sharpie or similar. This adjustment is a valuable tuning tool for correcting left/right tuning issues.

E- Your limbs are perfect.
 
#332 ·
Question and some of my observations:

Shooting and tuning my Evo Max (and other PSEs) I found that syncing the stops gives a rather different feel of the draw, but more importantly, drastically changes how it aims on the EV cams (far more so than on ME cams).

While I like the firmer (Hoyt-like firm, not limbstop firm) stop against the wall of top stop advanced, it leads to an immovable hold: - my front arm gets fatigued aiming in the wind or aiming high. But when I apply back tension, it just holds. Like, no float, untill shaking. Out to 30 yards, it doesn't exit the gold.
When I first got the bow, I noticed that I had my bottom stop advanced. This was a softer but still acceptable wall (more single cam-like) but helped me in aiming tremendously. I could start from 2 feet under the target and bring it up to the 10 ring and shoot it with no fatigue. The float however just isn't as good, I'd say I sway a lot more.

I tended to use this as a kind of creeptune while shooting through paper. At top advanced 1/16th to 1/4th (!!) I'd have little issues with high / lows through paper, but at bottom advanced I get some nock highs, I'm not sure I could fix those. (Or that I actually care, but that is something else)
Top advanced also gave me a few extra FPS in speed, but not a big deal...

Now I wonder; is it just me? Does the sync really make a difference for others too in regards to the back wall, float while aiming and bow arm fatigue?
Does everybody just shoot the Evo cam with top advanced? (by how much?) Is there a happy medium between top and bottom synced that gives a reasonably hard wall and still aims swiftly without causing fatigue?

Or is there some other factor that I'm skipping over?
 
#336 ·
Well... you touch on a lot of things and they aren't all necessarily related.

Top cam advancement is basically adding holding weight. It firms the wall because it is preloading the control cable (removing the "mush") before the bottom cam touches the buss cable (which is under a lot of tension and therefore more "firm" from the start).

Now, synch affecting aiming is far from "just you". I'd say everyone who is established enough to have a "feel" and a "style" is going to know the difference of a half twist in either cable (and the resulting synch) especially on a bow with two stops.

The fact that you say your arm gets fatigued when aiming in the wind or "aiming high" leads me to believe that you have a form issue, not a synch issue. The shaking also doesn't sound like a synch issue, it is a mechanics issue in how your shot is developing....or a form breakdown.
 
#333 ·
I set my Evo cam to hit first. Only about 1/16".
Feels solid, no aiming problems for me (but I'm not a competition shooter).
It seemed to tune a little cleaner with top cam advancement.
 
#346 ·
Oh, I just talked to Braden and you're wrong. He is using offset stops. He synchs for holding weight and then cams the stops to hit even. So, his cam is advanced and the stops are manipulated to keep the feel he wants.

Nathan normally shoots drive cams. It is a single stop system but he uses a similar stop. It is drilled offset so he can tweak the valley, draw length and holding weight. He bare shaft tunes too.

Goza runs top cam advanced. He also bare shaft tunes.

Not sure how Gillingham synchs his cams. I think I've heard him say he creep tunes, I know he bare shaft tunes.
 
#358 ·
Then Braden is making false Youtube videos. As far as Goza and Gillingham I don't follow them. I sure thought Gillingham demonstrates poor archery form in the PSE catalog but what works for him.

I think it's pretty obvious if your cams outta synch that would have a delirious effect on nock travel
 
#353 ·
Too excited with the new toy to check initial measurements. Backed off limb bolts to 35# from max of 42#.

should I max it back out, adjust ATA at max DW, then back it back down, or just run with untwisted the buss 4 full twists, untwist control to synch and then twist he strings?
 
#361 ·
So, had an interesting development last night getting the new string/cable set tuned on my Supra Max. Just before I put the new threads on, I had swapped my spaces on the bottom cam due to a tail right paper tear, however I also then had POI keep dropping lower, lower and lower on me, so new strings. Anyhow, I had left tears now, so swapped the spacers back, things kind of worked, thought it was good, then started getting really bad right tears again (left hand shooter), but then would get a clean tear, then a left tear. I couldn't figure out what was going on. I went to double check timing and whatnot on the draw board, and then finally noticed my cable was getting into the string stop at full draw. I had the flex guard relaxed a little, not much at all, but it was still hitting. This is with factory bottom cam spacing.

I tightened the flex guard down all of the way and bam, clean tears. Based on this, I'm half tempted to take the string stop off completely, or maybe look for one that might provide more clearance.

Now, to get those outdoor arrows sighted in!
 
#363 ·
Hi everyone, how do I understand Drive Cams are in sync? From the marks on the cam? As top cam has no stop to sync with the lower, what is the reference for sync? I have tried tuning my Freak SP in these days, obtaining fair results, but I'm at the point where I get a low bareshaft at long distances (1 ft lower than the fletched) @ 40 - 50 yards, and I can't have it in the group, even lowering the nocking point; now blade rest is producing a bad vibration, I think due to the lowered nocking point. Is this normal or am I wrong in something?

The white marks are not on the cables, but slightly off the cables, in the direction of the string, evenly spaced from the cables (it should mean my DL is slightly longer than the module setup, if I'm not wrong), ATA is 38, and peak weight is 61# or near it.

I have also another question: what does it mean the top cam is advanced? does it mean the white mark should go towards the riser or towards the string?


thanks for your replyes!!
 
#365 ·
With a Drive cam (or TH, HD or MD cams), use the control cable to fix vertical tuning issues (along with nock point and rest height, etc)

Forget the top timing mark exists.... For a tail high (aka bare shaft low) remove twist(s) from the control cable. For a tail low (aka bare shaft high)... Do the opposite.
 
Top