Tuning question

Blandry

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Hoyt RX-4 Turbo.. I'm still getting a 1/4 tail right tear with the rest moved all the way left to the edge of the shelf. I assume I'm going to need to yoke tune a bit. Will a full twist right/remove one left take care of this? Half twist?

I ordered a synuum press today (Hoyt ZT cam) and plan to do it myself this time.
 
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Blandry

Blandry

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28'', 65#, day six 300 spine cut to 27'', 125 head, 593 gr total arrow weight. Second arrow is maxima red 250 (350 spine), 125 head, 453 gr total weight. I might be a bit overspined with the 300's but they're still falling within the spine chart at 27'', 100gr outsert and 125gr head.

Both are punching paper exactly the same from paper tuning distance.
 
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28'', 65#, day six 300 spine cut to 27'', 125 head, 593 gr total arrow weight. Second arrow is maxima red 250 (350 spine), 125 head, 453 gr total weight. I might be a bit overspined with the 300's but they're still falling within the spine chart at 27'', 100gr outsert and 125gr head.

Both are punching paper exactly the same from paper tuning distance.
FWIW qSpine shows you're probably pretty close to "optimal" at 300 spine. I don't know how you're getting to 593 gr TAW though with a 125 gr head and 100 gr outsert unless you have a lot of weight on the rear.

Bow inputs: 350 fps IBO, 65# DW, 28" DL, 31" ATA, 5.875" BH, 80% LO
Arrow inputs: 27" C2C, 125 gr head, 100 gr outsert, 9 gr nock, 3 vanes at 7 gr each
Screenshot_20220616-001156_qSpine.jpg
 
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Blandry

Blandry

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The day six are four fletch and 11.2 gpi. I’m thinking about building the next ones with a 340 spine and three fletch to drop a little weight and increase FOC.

I kinda figured I might need more than one full twist but will start there. Thanks for the info!


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Blandry

Blandry

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Something must be a little off. My scales calibrated. Ironwill field point 125 gr. Maybe I’m forgetting my in/outsert config. I have some ss alum and titanium alum. If I recall they’re within a few gr of each other.

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Blandry

Blandry

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Ah they’re not the same. I must have these configured with ti outserts and stainless inserts for a 125gr ‘centric’ system. I guess I shouldn’t be doubting a computer program ;).

27f5502133aeeea91b5f4efdafc73dd2.jpg




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I would do what mighty mouse suggested. Also consider nock tuning, fletch contacting your rest, your rest not dropping at the right time, or maybe it's the nut behind the handle (which it often is).

I shoot similar setup with a helix turbo and had same issues. Nock tuning ended up working great. But since you have two different arrows that is probably not helpful. But do check rest clearance and make sure your form is good and not gripping the bow.
Good luck.
 
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Blandry

Blandry

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Yeah I did consider those things as well. I’ve been shooting compounds since my first bear at 12 years old so I’m sure I’m not torquing it and checked fletching clearance with some powder on the vanes.

A local bow shop set center shot and tied in my peep and dloop so that should be good.

I purchased this bow to replace a PSE full throttle I’d been on for years off an eBay seller (bow shop) new/old stock at a 30% discount. He mounted the QAD integrated rest and ‘supposedly’ timed it. I’d been shooting it and the arrows stabilize.

I’m fairly sure it just needs some yoke tuning. Otherwise I LOVE this bow!


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nphunter

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The newer bows with high let-off are super sensitive to face pressure and grip pressure. It really doesn't matter how long you have been shooting a bow, each bow is different, each release changes your anchor slightly, each string angle is different, and the list goes on. Shoot a bare shaft and see what it does, your center shot is definitely way off if it's moved clear out, I set my center shot by running an arrow parallel to the back of the aluminum plate on the riser and then one on the rest. They should be the same distance apart at the tip of the arrows and at the rest, this sets the center shot centered to whatever the strings (yokes) are set to. That is where I start yoke tuning and getting my bare shafts to fly correctly at about 5 yards and slowly back up to 20+ as I fine-tune. Every bow I have tuned has been slightly different, I can tell you on my RX4 when shooting bare shafts perfect, if I have any face contact at all, have my anchor hand slightly twisted, or don't follow through properly with my release my bare shafts do not fly straight.

I only make adjustments on shots that I feel are very well executed.
 
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Blandry

Blandry

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I mistyped on the second arrow too. I have both 250 and 350 maximas. The specs were for the 350s

I’m going to use your guidance nphunter to reset my center shot.

92b994d63cb5339aaee7f77a81ba4fd9.jpg



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nphunter

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Here are a few pics I sent my buddy to set up his new RX3, obviously if you have a bow vice this isn't necessary.

Find a level wall.

4B95D275-2BA1-48A8-8728-63B91AEC108D.jpeg

Top limb against level wall.
CA179213-5F93-479D-A1F5-253757490659.jpeg

Bottom limb against level wall.
DF604ECC-A07B-4884-AD45-2E7F8EF293FA.jpeg

Set rest/nock height so that it is level or slightly high, see bubble. Slightly less than 1/8". I set the bottom of the arrow running through the center of the Berger hole or as a starting point.
4287BA7B-E1DC-478A-84C9-77CD1CADD4F4.jpeg
 
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nphunter

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The plate on the back of the bow should be square with the bow on most bows. If you're running a regular QAD, RIP cord, or other you can rest it above the bracket on the plate as well.

4FAC6B33-7091-4538-B5BD-336FAD6C8BAB.jpeg

Hold an arrow tight against the back of the bow.
492299F2-3E0C-42C1-B61B-ED598E48ED17.jpeg

While holding the arrow tight against the back put another arrow on the rest.
6342C5D9-281D-4108-9481-E2F9B78E7CD7.jpeg

If your by yourself a good way to measure is to lay a ruler or small metric rule on the top of the arrows. It's easier with a helper measuring.
9D107468-AF1E-469F-8065-C4B8F2BBC53A.jpeg

Measure against the riser and at the tips or close to the tips. If someone is helping you can measure behind the rest, the further apart you take the measurements the more accurate you can get this.
9ED804DF-138F-4A2B-AE33-AA1BDF8CFE3B.jpeg

The # doesn't really matter, it will depend on where your yokes are set and arrow thickness, what matters is that they are the same distance apart from each other, as close to parallel as possible.
 
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nphunter

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When you yoke tune this is a good way to check lean/pre-lean in the cams. Hold an arrow square to the flat side of the cam, and tip down.
2808B871-F26B-4E5B-8221-068523D91783.jpeg

I like to have the edge of the arrow just crossing the edge of the string to start with, sometimes it ends up further times less, the end result really depends on a person's form and how you have to manipulate the bow to shoot how you want for you.
0279E4B7-2BF0-45CC-969A-D5E126699749.jpeg

After making all of the starting settings I then start shooting, normally I just shoot the bow for a while to get used to the new bow before shooting bare shafts. I typically don't shoot at all through paper, I will just shoot a bare shaft or two with fletched arrows until I get this result at 15-20 yards, this is in the back of my shed and I'm shooting from out in the driveway. I pay more attention to left or right errors than up-down, with a bare shaft unless shooting a target that is exactly the same height as the arrow leaving the bow. It should be close but if you a 1/4" in either direction you are tuned well. If your shooting a target lower than your arrow leaving the bow it should land slightly tail high, if you were shooting uphill it would be slightly tail low, this is due to no correction in flight.
C4BB397E-1AC7-4D21-8D57-EA6B2811ECE7.jpeg

I also set my brace height, ATA to factory specs, and the draw weight where I like it prior to setting the bow up. Set everything up as shown in the previous posts, shoot and adjust so that I am happy with the result. If I'm shooting tail left I start by tightening the left yoke 1/2 turn and loosening the right yoke 1/2 turn, once I am really close I will only do one side or the other but that is for super small adjustments.
 
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Blandry

Blandry

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Thanks nphunter. Re set my center perfectly but def got some cam lean. The arrow is clearing the peep.. may not appear like it in the photo.

ca32b0b2cb0bc97c520a7e4e5ac38fe9.jpg


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nphunter

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Your welcome, I run my arrow in the left hand or rest side of my cam. The back is not square on the regular RX4. I would say I have about 1/8” or less lean from the cam to the center of the loop.
If you have as much lean as it looks like in that picture it would explain the nock right. You will be able to adjust and see results pretty easily once your press arrives, IMO your going to be much better going this route vs trying to make up for that with the rest.
 
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Blandry

Blandry

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Oh yeah, absolutely. Looking forward to getting my press and tweaking it. Should be enjoyable to get it right and have done it myself. Thanks a bunch.
 
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Blandry

Blandry

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So I got my synuum press, which btw is nice! Perfect for small tuning jobs like this.

I had to put 2 full turns into the left and 2 out the right to get the cam lean corrected. Now it’s perfectly aligned with top cam at full draw and the arrow against the cam lines up perfectly.

At full draw it was like the center pic but about 1/2 as bad as the lean in the pic below.

98ca5c126a3f98fe0e2fe2fa5c0c2d14.jpg


Micro adjusted the rest and it’s a nearly perfect bullet hole now.

a3433b620fbc4fcaae0547e7526f2d28.jpg



Before the yoke tuning…

1a2c51b4b1be6b102c0da04260a01880.jpg


My only other issue is I have to anchor perfectly and pull hard into the stop to ensure I’m not inducing lean. I’m on a #2 cam which maxes out at 28” draw and I’m actually about 28.5”. I might swap to #3 cams to get my anchor a little further back but hate to lose that 7fps from the #3 :).

Anyway thanks for all the tips guys!! It was fun to get it right myself and know what’s happening via test/tune.


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