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Discussion Starter · #1 ·
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I am working on tuning a Mathew’s Switchback after a string change. I have been working on removing a nock left bare shaft. I am right handed. I’ve got my bare shaft grouping with my field points, but my broadheads are impacting about a foot right. In the photos the broadhead hit is indicated by the blue arrow. I know I still have a very slight nock left but I’m not if that is enough to cause the broadhead to be so far off. It’s been a long day of shooting, hence the open 20 yard group!
 

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I am working on tuning a Mathew’s Switchback after a string change. I have been working on removing a nock left bare shaft. I am right handed. I’ve got my bare shaft grouping with my field points, but my broadheads are impacting about a foot right. In the photos the broadhead hit is indicated by the blue arrow. I know I still have a very slight nock left but I’m not if that is enough to cause the broadhead to be so far off. It’s been a long day of shooting, hence the open 20 yard group!
Drop the draw length 1/2-inch shorter. Stand up more vertical (less leaning backwards).
Unbend the left elbow. Move arrow rest 1/16th inch to the right, to move fletched to hit closer to broadhead.
Adjust sight windage, to recenter the fletched arrow group and broadhead group, with new arrow rest position,
more to the right, 1/16th inch to the right,
along with the shorter draw length.
 

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Discussion Starter · #3 ·
Thank you so much for your help. I’ve moved the rest to the right 1/16” and adjusted the sights. The group was shot at 20 yards. The arrow with the broadhead is the flyer and it also corkscrewed to the target. My sights and rest are almost maxed out to the right. I can still move the launcher arms to the next bolt hole. I’m not sure how to reduce the draw length without purchasing a new cam. Is there a way?
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I'm assuming you have a press. ?
Is the bow timed correctly?
What's your center shot measurement?

Lay an arrow along the top wheel on the left side and run it down the string, where does it cross ?

Probably as simple as putting a few twists in the top left yoke to bring it all together.
 

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I don't know....how you shot a bareshaft that straight, and then had a broadhead hit that far away...especially at just twenty yards. And how you did any of that...with the rest that far into the riser. That's pretty amazing. I have never seen that before. Not sure how you are getting fletch clearance. I am thinking the fletch contact is not bothering the target point arrows as much and you set the sights to accommodate that ,and the broadhead arrow is planing right after the fletch hits the riser. Could be I am not seeing things in the photo correctly. I have never messed with a switchback. The grip puts the power stroke to the right of your hand. if it was me....I would move the rest left to a more normal centershot position, resight to get fletched arrows hitting with the pins. Make sure you have fletching clearance and make sure the rest is timed right, looks like the cord is tied too high from photo but again maybe photo. Then I would shoot a broadhead and see where it hits, if its better, than you are on the right path, and probably need to correct your power stroke / nock travel instead of trying to adjust out a problem with the rest and sights. At least all that is easy and only takes a minute and you don't have to press the bow and maybe it will help, I would watch my grip carefully too and make sure I was not torquing it . Sometimes you need a good backstop with broadheads just incase you do something to send one way off base, especially when you get further out. You always want your broadheads hitting good at thirty and forty too....not just twenty. The further out you get, the more problems you find with your broadhead flight, or prove its good when they stay behind the pin.
 

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Discussion Starter · #6 ·
I'm assuming you have a press. ?
Is the bow timed correctly?
What's your center shot measurement?

Lay an arrow along the top wheel on the left side and run it down the string, where does it cross ?

Probably as simple as putting a few twists in the top left yoke to bring it all together.
I do have a press. Not sure about timing on a solo cam? The arrow along the idler is parallel to the string. Center shot as seen is way off!
 

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I do have a press. Not sure about timing on a solo cam? The arrow along the idler is parallel to the string. Center shot as seen is way off!
Arrow along idler parallel to string, at BRACE is no good.
Want arrow pinched to LEFT side of idler, if a RH bow
want the arrow to cross under the string, like this much.



Broadhead missing LEFT is cuz the LEFT side yoke leg is TOO long.

Press your bow, ADD two twists to the LEFT yoke leg, to shorten left yoke leg.
BH will hit closer to fletched.

Then, ADD another 2 twists to the LEFT yoke leg
and bump the arrow rest another 1/16th inch to the right.

THICKEN the grip, by adding a layer of grip tape. THIS will reduce the draw by the thickness of the grip tape.
Yeah, even 1/16th inch GRIP tape, will make a difference is BH hitting closer to fletched.
 

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0321
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I do have a press. Not sure about timing on a solo cam? The arrow along the idler is parallel to the string. Center shot as seen is way off!
Can you take a pic of your bottom cam both sides ? There was a timing mark on those cams if I remember. The arrow when laying on the left side of the top wheel should cross the string around your nocking point. So you basically need to put some twists into the left yoke.

But before you do that I'd reset your center shot. And check the cam timing. I can't remember if the center shot on those was the typical 13/16.
I'd eye ball it. Then with an arrow in your rest lay another arrow along the inside riser and make your arrow on your rest run parallel to the one on the inside of the riser.

There is your center shot.
Time your cam. The bottom cam has a timing mark.
Twist your left yoke so when you lay an arrow on the left side of the wheel it crosses the string around your nock point.

Then thats your starting point then shoot some broadheads and see where your at.

Also assuming your rest is timed correctly.
 

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I didn't read anything about paper tuning and walk back tuning ? 2 things I would not miss for all the money in the world in order to tune a bow to my liking.

That pepr and walk back let you know whats going on.
 

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Discussion Starter · #10 ·
I didn't read anything about paper tuning and walk back tuning ? 2 things I would not miss for all the money in the world in order to tune a bow to my liking.

That pepr and walk back let you know whats going on.
It paper tuned a bullet hole. As I backed up and went to bare shaft it developed a hard nock left. Worked that out, had bare shaft with fletched but poor broadhead flight. I will make adjustments tomorrow and go from there
 

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Did you start with 11/16th center shot? How does the idler look at full draw . Same arrows and everything as before?
 

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Are you using the same broadhead every time? Was it spin tested? If the broadhead isn't straight on the arrow it won't fly straight.
 

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Discussion Starter · #13 ·
thanks for everyone’s help. This is the first bow I’m attempting to set up and tune myself. I have twisted the yoke cables so that when an arrow placed along the side of the idler wheel crosses the string at the nock point exactly like Nuts & Bolts photo. I have also moved the tie in point for the rest lower on the string. I have adjusted the rest to a more normal center shot position as well. My first shots put the broadhead slightly low of the bare shaft and fletched shaft group at 10 yards. Unfortunately it’s 17 deg outside, so tinkering will be in short bursts today!
 

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Discussion Starter · #14 ·
I was shooting after making some adjustments and all of my arrows are on the target in a loose group. The bow is 70# @ 29.5. I’m shooting 29.5” 340 spine arrows with 125 grain tips. On a whim I decided to try a 100 grain point. I had better arrow flight with the bare shaft. Unfortunately I do not have any 100 grain broadheads to test. I do have some 300 spine shafts that I can cut down and try. I’m thinking I’m under spined along with the other problems.
 

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I was shooting after making some adjustments and all of my arrows are on the target in a loose group. The bow is 70# @ 29.5. I’m shooting 29.5” 340 spine arrows with 125 grain tips. On a whim I decided to try a 100 grain point. I had better arrow flight with the bare shaft. Unfortunately I do not have any 100 grain broadheads to test. I do have some 300 spine shafts that I can cut down and try. I’m thinking I’m under spined along with the other problems.
Your definitely not under spined with a solo cam. They can shoot a pretty weak arrow.
Did you figure out the cam timing on the bottom cam ?

Is your rest coming up the last inch or so in the draw cycle ?
Do you have a draw board ?
 

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thanks for everyone’s help. This is the first bow I’m attempting to set up and tune myself. I have twisted the yoke cables so that when an arrow placed along the side of the idler wheel crosses the string at the nock point exactly like Nuts & Bolts photo. I have also moved the tie in point for the rest lower on the string. I have adjusted the rest to a more normal center shot position as well. My first shots put the broadhead slightly low of the bare shaft and fletched shaft group at 10 yards. Unfortunately it’s 17 deg outside, so tinkering will be in short bursts today!
Single cam bow. The Mathews bows (single cams) have reference holes for the single cam STARTING rotation position at brace height.

Example. My Apex 7 has two dimples, instead of a reference hole for rotation position at brace.



I painted the reference holes GREEN, so the two reference dimples are easier to see.
The idea is that the factory recommends, you ADD or REMOVE a twist or two from the BUSS cable,
to change the position of the single cam, to a reasonable STARTING rotation position.

BUT, a SINGLE cam has no TIMING. Yup.
So, that's why I go to ALL this trouble, to call it the SINGLE cam starting rotation position at brace height.

When the SINGLE cam starting rotation position is not IDEAL for YOU,
broadheads will miss LOWER or broadheads will miss HIGHER than field point groups.

So, a simple HALF twist or ONE twist adjustment in the BOTTOM end loop
of the buss cable, will bring your Broadheads to hit HIGHER, with the fletched field points.
YOu have to figure if you need to ADD more and more half twists, to the BOTTOM end loop of the buss cable.

YOU have to figure if you need to REMOVE more and more half twists from the BOTTOM end loop of the buss cable.
 

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Discussion Starter · #17 ·
Ok, so after lots of twisting and adjusting my broadheads and field points are impacting as a tight group. However the bare shaft is still off. Should I just let it go for now? I have shot a few different broadheads with the same results… VPA 3 blade, Magnus Stinger, and Thunderheads. I am tapping the rest a hair back and forth and cannot get the bare shaft in the group.
 

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Yep.....especially if your broadheads are accurate to forty. I have no answer on the bareshaft, it makes no sense. But it is irrelevant if the broadheads shoot accurately and hit behind the pin out to about forty, then the arrows have to be flying like a dart pretty much. You do not even have to have the field points hit exactly with them, as long as the sights are set for the broadheads and they hit where you aim, its a plus though because you can practice with both and expect the same point of impact. Even if I am 90 percent sure I will be shooting 25 yards or less, I want my broadheads doing well out to forty, thats sort of a magic spot. Seems like if they do good to forty they are good beyond. Sometimes between thirty and forty can find a little tune more needed when they maybe hit a little one way or another. And if I really get a good shot at that distance and it all sets up well, I want to be able to take it.
 

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Discussion Starter · #19 ·
Yep.....especially if your broadheads are accurate to forty. I have no answer on the bareshaft, it makes no sense. But it is irrelevant if the broadheads shoot accurately and hit behind the pin out to about forty, then the arrows have to be flying like a dart pretty much. You do not even have to have the field points hit exactly with them, as long as the sights are set for the broadheads and they hit where you aim, its a plus though because you can practice with both and expect the same point of impact. Even if I am 90 percent sure I will be shooting 25 yards or less, I want my broadheads doing well out to forty, thats sort of a magic spot. Seems like if they do good to forty they are good beyond. Sometimes between thirty and forty can find a little tune more needed when they maybe hit a little one way or another. And if I really get a good shot at that distance and it all sets up well, I want to be able to take it.
I appreciate it. I haven’t sighted the bow past 20 yet. I bought it as a back up in rough shape and decided that I would learn how to do a set up and tune on it as well. I had a switchback from 05 until last year when it blew up. Love the bow and am going to figure it out!
 

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Ok, so after lots of twisting and adjusting my broadheads and field points are impacting as a tight group. However the bare shaft is still off. Should I just let it go for now? I have shot a few different broadheads with the same results… VPA 3 blade, Magnus Stinger, and Thunderheads. I am tapping the rest a hair back and forth and cannot get the bare shaft in the group.
If the broadheads and FP's are hitting together you are good to go. The bareshaft may just be an outlier or needs nock tuned or may just not play well with others. Sometimes you just have 1 or 2 out of a dozen that just wont shoot with the rest of them.
 
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