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Discussion Starter #1
Picked up a leftover CT5 and need some help getting it setup. 80lb, 29" draw. Trying Black Eagle Spartans in .200 and .250 at 28.5", various point weights and 75 gr brass inserts. Using a Hamskea Trinity Hunter Pro. I don't have a scale but the limb bolts are currently maxed out so assume it's at 80 lbs for now.

When I set arrow/rest center shot per the Prime manual, I get the following nock left tears with bareshafts:

CT5 Paper.jpg

If I move the rest to the right (closer to the riser) a fair amount, like 3/16-1/4", I can almost get bullet holes with the .200 spine/100 gr point/75 gr insert set up...still a little nock left though.

That seems like a long ways to move a rest to get it shooting proper, but I'm new to tuning so I don't know much. One thing that caught my eye is the cable running through the string donut isn't even and stuff kind of looks crooked up there. Could that be causing it?

CT5 Top Cam.jpg

My press just showed up today so I can start fiddling around. What would be the best approach? Adjust the Flexis AR? Adjust the cables or yokes? Other ideas? Thoughts are appreciated.
 

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I would start from the ground up.

-Max out limb bolts
-check ATA (35 +/- 1/8) and brace. Check draw weight. Add or remove cable twists to get the poundage spot on.
-Sync cams. Line up the 4 sync dots with a straight edge via cable twists for static timing and move the draw stops all the way out. Many arguments are had over the importance of the sync dots but I can tell you if they align then your dynamic timing will be spot on or extremely close (it’s a starting point).
-reset centershot at 7/8 horizontal and vertical
-tighten flexis all the way down to start.

After you are set shoot through paper and take one co diction out at a time. For vertical tears twist the uptake cable on the A post. Twist the upper cable for a nock low and the lower cable for a nock high. Once you have a purely horizontal tear move to the flexis. Loosen for a nock left. Tighten for a nock right. Don’t loosen more than 3.5 turns. Once the flexis adjustment is maxed out start for adjust your rest in 1/16 increments. RECORD EVERYTHING.
 

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What kind of rest are you using? Rest timing is another condition you need to check. Ensure the rest is dropping in the first inch as the string moves forward with a cable. Limb is a lot easier in regards to timing.
 

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What kind of rest are you using? Rest timing is another condition you need to check. Ensure the rest is dropping in the first inch as the string moves forward with a cable. Limb is a lot easier in regards to timing.
This! I had trouble tuning when found out this was the issue. Even a 350 spine at 77#/29.5” was showing stiff. Checked the rest timing and it’s good now.

I have gotten it to tune before that mess with 200-300 spine arrows. Currently shooting 200 spine X impacts with 100gr focos and 100gr points. Previously shot 250 spine rampages with 75gr insert.


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Discussion Starter #5
Using a Hamskea Trinity Hunter Pro. Seems to be ok? The rest is all the way down when it's not drawn back.
 

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So your 250 spine always tears low left and the 200 always tears high left. If you rotate the nock does the tear change?

On that bow you don't have as many options as some others for tuning out lateral nock conditions. The first thing I'd try is bringing in the Flexis guards towards the arrow, just watch out for fletching contact. If that doesn't change anything, I'd go to shimming cams but I don't think that's an option on this bow either, at least not without making a purchase. At that point, I'd rotate my grip hand counterclockwise to put more pressure on the left edge of the grip. A couple degrees of rotation should make a big change to your nock condition. We sometimes have to remember that not all bow designs will lend themselves well to the same grip.
 

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Using a Hamskea Trinity Hunter Pro. Seems to be ok? The rest is all the way down when it's not drawn back.
It’s the internal spring tension you need to look at. My guess is rest is dropping to fast as I had similar issue and that was the problem.

Blade being all the way down is not indicator of proper timing/tension adjustment.


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Discussion Starter #8
Ok here's where I'm currently at:
ATA = 35.25", so off by at least 1/8"
Brace = 6"
Sync dots seem lined up near as I can tell
Center shot is 7/8
Arrow height is 0.850". The manual says set it at 0.850" but the Prime Tech Sheet says 7/8, don't understand the discrepancy but oh well.
Flexis AR was tight.
Yoke/Cam Gap Top = 0.9185"
Yoke/Cam Gap Bottom = 1.1395"

So based off of the above it looks like I should shorten the ATA and cam timing is off according to the yoke/cam gap measurements?

Shot a fletched arrow w/ some chalk on the vanes and had no rest contact.

Started fiddling around with the spring tension on the rest. When I reduced the tension I got a big tear that looked like someone punched the paper. At one point when increasing the tension I got the following results:

IMG_20200623_202359~2.jpg

You can see shot #1. Horizontal tear gone! Good deal. So I shot another arrow (all of these were the exact same arrow). Shot #2, horizontal again but not too bad. Shot #3, right back to where I was. That leads me to think that I actually just suck and I'm the problem. My other bow is an old Bowtech Commander with 7"+ brace height. My concern is that my form is such that I can't shoot a 6" brace height bow. TBD I suppose. I cannot begin to fathom what I did differently on those first 2 shots that were much better. I sure hope this thing isn't so finicky that I can't even discern alterations to my form that can impact the shot like that.

I fiddled around the the Flexis AR. In, out, somewhere in the middle. Never made a difference in the tears. Also tried playing with my grip, that didn't seem to make much of a change either.
 

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Ok here's where I'm currently at:
ATA = 35.25", so off by at least 1/8"
Brace = 6"
Sync dots seem lined up near as I can tell
Center shot is 7/8
Arrow height is 0.850". The manual says set it at 0.850" but the Prime Tech Sheet says 7/8, don't understand the discrepancy but oh well.
Flexis AR was tight.
Yoke/Cam Gap Top = 0.9185"
Yoke/Cam Gap Bottom = 1.1395"

So based off of the above it looks like I should shorten the ATA and cam timing is off according to the yoke/cam gap measurements?

Shot a fletched arrow w/ some chalk on the vanes and had no rest contact.

Started fiddling around with the spring tension on the rest. When I reduced the tension I got a big tear that looked like someone punched the paper. At one point when increasing the tension I got the following results:

View attachment 7187755

You can see shot #1. Horizontal tear gone! Good deal. So I shot another arrow (all of these were the exact same arrow). Shot #2, horizontal again but not too bad. Shot #3, right back to where I was. That leads me to think that I actually just suck and I'm the problem. My other bow is an old Bowtech Commander with 7"+ brace height. My concern is that my form is such that I can't shoot a 6" brace height bow. TBD I suppose. I cannot begin to fathom what I did differently on those first 2 shots that were much better. I sure hope this thing isn't so finicky that I can't even discern alterations to my form that can impact the shot like that.

I fiddled around the the Flexis AR. In, out, somewhere in the middle. Never made a difference in the tears. Also tried playing with my grip, that didn't seem to make much of a change either.
Check tension again. Did it loosen up by chance? Had same issue with mine. But like I said even a 350 spine at 29.5/77 was tearing same as a 200.

Only thing to note is my limbs were already profiled. Have seen others say that was an issue. Do you have a blade rest to try? Then finally might need to shim the cams.


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Discussion Starter #10
I can check the cord tension. The internal spring tension is held by two screws, so that shouldn't have changed.

I have a QAD drop away on my Commander. I'd rather not have to take that apart, but maybe I'll end up having to.
 

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Having you watched Shane Chunnings video on How to grip the centergy? Applies to the logic as well. It seems you have a grip issue that is compounding a tuning problem. Take the vertical tear out. Add 3 twists to the bottom A post cable to start. Report back.
 

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Discussion Starter #12
Having you watched Shane Chunnings video on How to grip the centergy? Applies to the logic as well. It seems you have a grip issue that is compounding a tuning problem. Take the vertical tear out. Add 3 twists to the bottom A post cable to start. Report back.
Thanks for the tip on the grip video, hadn't seen that. I'll definitely play around with it. Got the press put together but haven't pressed it yet. I end up having like 20-30 mins a night to fiddle around with this thing. Never pressed a bow before and taking my time to make sure the bow is in there right so I don't explode it. Hoping to press it and adjust cables tonight. Those 20 minutes go by fast.
 

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I can check the cord tension. The internal spring tension is held by two screws, so that shouldn't have changed.

I have a QAD drop away on my Commander. I'd rather not have to take that apart, but maybe I'll end up having to.
Correct. Have seen a few replaced at my shop where internal spring is/goes bad. I don’t know if that’s your problem but just an option.


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I would say most tuning issues with a prime are from grip. If everything is in spec i would experiment with different grips and see the results. I had to change my grip when i switched from a Hoyt to a Prime to get a bullet hole. I was going crazy moving the flexis, rest, and still had a bad tear that never changed unless i moved my rest way out. It is your grip I would bet
 

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Discussion Starter #15
Ok here's where I'm at. I rechecked my center shot and it was 7/8". Decided to check and see how parallel it was to the riser, which I hadn't done before. Definitely off. So I made some rest adjustments until it was as close to parallel as I could get. Paper tears were much improved but still there.

Then I decided to add some twists to the bottom cable on A post as suggested. Put it on the draw board I just built and the timing/sync was off. Top limb stop was hitting before the bottom and the cam/yoke gap on the bottom was larger. Being new at tuning, I wasn't bright enough to put it on the draw board before doing all of this. Tried adding a few more twists and things didn't improve. Due to a toddler intervention, I lost track of my twists at this point. Decided to take that cable off and see how long it was and basically go back to scratch. Cable was shorter than spec, so I adjusted it until it was as close to 41.4" as I could get it and put it back on. Back onto the draw board and the top cam limb stop is still hitting sooner than the bottom by a good bit. Picture below of the bottom cam when the top cam stop is making limb contact.

IMG_20200628_084715.jpg

Will definitely start writing stuff down from here on out.
 

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Discussion Starter #16
Ok after my above post and putting that cable back into spec, everything measured up basically where it was when I started.

ATA = 35 3/16"
Brace = 6"
Top Cam Gap = 0.9405
Bottom Cam Gap = 1.119"
Timing off

Added 3 twists to the bottom cable
ATA = 35 1/8"
Brace = 6"
Top Cam Gap = 0.9320
Bottom Cam Gap = 1.110
Timing still off.

Seems like I need to add a whole bunch of twists to that cable to get things synced up? Am I missing something? Firebomb the current set of strings and cables and get new ones and start fresh?
 

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Ok here's where I'm at. I rechecked my center shot and it was 7/8". Decided to check and see how parallel it was to the riser, which I hadn't done before. Definitely off. So I made some rest adjustments until it was as close to parallel as I could get. Paper tears were much improved but still there.

Then I decided to add some twists to the bottom cable on A post as suggested. Put it on the draw board I just built and the timing/sync was off. Top limb stop was hitting before the bottom and the cam/yoke gap on the bottom was larger. Being new at tuning, I wasn't bright enough to put it on the draw board before doing all of this. Tried adding a few more twists and things didn't improve. Due to a toddler intervention, I lost track of my twists at this point. Decided to take that cable off and see how long it was and basically go back to scratch. Cable was shorter than spec, so I adjusted it until it was as close to 41.4" as I could get it and put it back on. Back onto the draw board and the top cam limb stop is still hitting sooner than the bottom by a good bit. Picture below of the bottom cam when the top cam stop is making limb contact.

View attachment 7190161

Will definitely start writing stuff down from here on out.
Use a straight edge. Follow this graphic and add or remove twists from each respective cable until the sync dots align. This will get the limb stops hitting darn close at full draw. Both are just a starting point. If you want to fine tune it to get a little closer then put it on the draw board and add twists to the cable whose limb stop is hitting first.

Then begin to shoot. If you are stuck on paper tuning then shoot through paper at whatever distance you choose (I take my first shot at about 5 feet) and add twists to the cable you want the nock to travel. If it’s nock low add twists to the top uptake (A post) cable. Nock high add twists to the bottom cable. Then you can move on to the horizontal. One condition at a time.
 

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I would say most tuning issues with a prime are from grip. If everything is in spec i would experiment with different grips and see the results. I had to change my grip when i switched from a Hoyt to a Prime to get a bullet hole. I was going crazy moving the flexis, rest, and still had a bad tear that never changed unless i moved my rest way out. It is your grip I would bet
Couldn’t agree more, I had issues with left tears on paper and consistently hitting left of target when gripping my Rize the same as my Vertix, added a slight amount of pressure to the left side and problem solved
 

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Discussion Starter #19
Thanks I found that chart in another post as well. Super handy for sure. I was hung up on the limb stops being off, not realizing that the cams are different sizes so that's a piss poor way to time/sync. My wife is due with a baby any day now so things are crazy, if I can ever find 10 minutes of free time to put it back on the press I'll get the dots back inline and go from there.
 

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Discussion Starter #20
Ok, finally got things back in order last night. Had to take a bunch of twists out of the cable that connects to post A on the lower cam and a couple out of the cable that attaches to post A on the top cam. The timing dots are fairly close. The inner dots are barely high when a straight edge goes through the middle of the two outer dots. When I put it on the draw board, the overdraw posts hit the cables about as close to perfect as one can hope for. Didn't bother to measure ATA and have been ignoring the cam/cable gap.

Still had a low, left nock tear, like 3-4" tears. So I moved the rest in toward the riser and took out 1.5 turns on the flexis (was all the way in) until the left tear went away and had a straight vertical tear. Moved the rest up until is was pretty close to shooting bullet holes. Could use a bit more tweaking but it was late when I finally got there last night. Before I moved the rest, I tried adjusting my grip on several shots and that had no impact on the arrow flight.

So now the center shot is about 0.725" from the riser, which is a pretty long ways away from 0.875". It doesn't look like I'll have vane clearance issues, but it might be close, still need to check. To be more specific, the arrow isn't parallel to the riser either. When I measure from the arrow to the front edge of the riser it's 0.695" and to the back edge of the riser is 0.745".

So now my question is, is center shot too out of whack or should I just be happy that it's shooting better? Basically, did I take the batteries out of the smoke alarm by moving the rest so far? Should I reset center shot to spec and be looking at making yoke adjustments? It doesn't seem like making further adjustments to the cables is smart since the timing/sync seems to be good. But then again I'm not that smart.

I'm by no means hell bent on bareshaft paper tuning either. It just seemed like a logical place to start when I could see the arrow flying sideways though the air.
 
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