# Tuning a PSE Primos STL



## bthomas67wagon (Jul 23, 2010)

(pics below... never mind it is stopping me without 5 post)

I bought a new rest (Tropohy Ridge Whisker B) and after being very unsuccessful in getting it tuned in, a major chain hunting store said they would straighten it out for me. 1 hours later they said that they were having problems getting it all lined up, so I left ticked and decided to tune it myself. I bought a couple levels and a bow mount.

1. I mounted the bow and got the string level.
2. I measured the point where the strings come off the cams and at 34 inches I mounted the knocking point at 17 inches. (about 1 inch higher then it was installed from "that store")
3. I mounted an arrow with the arrow level.

I have do have some questions...

1. should I be at 17 inches? Makes sense to me and thought I read that the half way point is where it should be?
2. Can I make an extention for mounting the Whisker B up front instead of behind the bow? (The slide is in the way when it is behind)
3. What is best way to align the side to side of the whisker b and the sight without the use of a laser? (Trial and error and taking to the field?)

Thanks
Brent (Ohio)


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## bassman409 (Jul 19, 2006)

How does it shoot? I would like to see the pics after you get 5 posts.


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## bthomas67wagon (Jul 23, 2010)

it shot fine with my old rest but wanted "better" and to not have my arrows drop off the rest, so i "upgraded". 

i havent shot yet as i am trying to get the setup "correct" first. 

since i havent cut my arrows yet having the rest 3-4 inch foward should be okay. 

Brent


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## konrad (Mar 29, 2009)

Start by following the instructions for mounting your biscuit.

Eastman Hunting has a cheap bow square that you screw one of your arrows into, then push your arrow onto your rest and then clip the square to the string. Slide the square up and down the string until the arrow is lightly resting on the black, bottom fibers and some daylight will be seen between the top fibers and your shaft. This will give you the “level” position you are seeking. This is a beginning place. If there is no “daylight” between your shaft and the top fibers, the biscuit is too small (the hole) and you will need a larger one for best arrow flight.

You are not really looking for the true center of the string but more importantly you are looking for the center of pressure generated by the bow. That may or may not be in the center of the riser (right/left) or the exact center of the string between the axles.

By observing how the arrows leave the bow (i.e. paper tuning) you can make fine adjustments ether to the rest height or right/left position or by adjusting your nocking point up or down.

Many folks find one sixteenth to one eighth of an inch above the level position works best.

Trial and error is the only way to do this fine adjustment.


PS
One easy way to find right/left is to screw a long stabilizer into the bow and then sight from above the bow downward and align the arrow’s position with the stabilizer.


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## bthomas67wagon (Jul 23, 2010)

I went a head and made a piece to hold the sight and to be honest it, it fits and I think it will work pretty darn good.

-Brent


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## bthomas67wagon (Jul 23, 2010)

Konrad - I hear you, but it just seems like there is a logical spot to start from and the string would be the place to start from.

IDK, it just seems that bolting the rest on in any old spot then working from there isn't the ideal spot to start?!

-BRent


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## bthomas67wagon (Jul 23, 2010)

"You are not really looking for the true center of the string but more importantly you are looking for the center of pressure generated by the bow. "

Yes, I agree!! That seems to be a great starting point!!

But how to determine it?

-Brent


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## bthomas67wagon (Jul 23, 2010)

Ah, look at that, I have posted 5 times !! 

From what I read some where, by measuring where the string comes off the cam to the other end (where it also comes off the cam), you can take the center and use that as the release/nock point. (of course, maybe it is different with certain cam designs?!)










... with a 1/4 inch piece of steel here is what I mocked up:


















Again, it looks really good (as far as alignment). 

See any problems I didn't think about?
-Brent


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## konrad (Mar 29, 2009)

One of the advantages of the Whisker Biscuit is that it aligns the biscuit hole with the Berger Button hole(s) by virtue of the mounting bracket. Many, if not most, bow manufacturers locate these holes at the “theoretical center” (vertically) of the bow.

Most folks are trying to obtain a balance between arrow speed and penetration. As such arrow length always becomes an issue (more arrow = more weight and stiffer spine to compensate for additional arrow length and slower time of flight = greater trajectory). If your bow has a large enough riser window, the shafts should be cut about an inch in front of the rest (so there is clearance for a broadhead). If not, the arrow must be cut so the insert is just beyond the riser at full draw (again for broadhead clearance). By moving the rest to the front of the riser, the arrow length must be extra long. To shoot a full length arrow requires more spine than for say a 29 inch shaft (like mine). 

If your WB does not fit because of mechanical interference with your cable guard/slide, the WB may not be correct for your application. You may be able to use it in the fashion shown in your pictures; however, I would verify that the spine chosen for your shafts is up to your poundage, tip weight and length.

http://www.eastonarchery.com/products/selection

A photo taken from the arrow side of the riser with arrow in place will show the shaft’s relationship to the mounting holes. It is not mandatory for the arrow to be in this position (some rests such as the Whammy make it impossible) but will produce the highest efficiency (energy imparted to the arrow vs. energy stored by the bow at full draw).
Making sure the arrow is 90 degrees to the string is a critical place to start tuning and you said you did that with your level.

It would be nice if your string measurement produced an arrow that perfectly covered the mounting hole(s). I would be surprised but pleased.

Don’t ignore the additional spine requirements of a long shaft. Even if everything else is perfect and you have a weakly spined shaft, you will never achieve the accuracy potential of your rig. If someone sold you lightly spined shafts to start with in the attempt to maximize velocity and then you don’t trim them to the expected length, there could even be physical danger involved.

PS

The photos you included first look like a tight fit between biscuit hole and your shaft. This may also lead to poor performance but this was a side view.


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## bassman409 (Jul 19, 2006)

Brent it looks good for a start. You need the larger insert for the bisquit with those arrows. Looks like you have the small one for carbons. I dont know about splitting the string for a nock point but in your case it looks close, this is only a start for tuning and either shooting thru paper or walkback and broadhead tuning will finish it. Shoot some and see what it does.


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## bthomas67wagon (Jul 23, 2010)

thanks very useful information. 

so over the last couple of days i have read simular things as you posted and i guess i wasnt understanding that the rest mounting hole is a close to center point. i guess thinking that the sting length and cam setup seems more logical, but because of the adjusting nature of how i made the rest extention, i lowered the string loop and the rest about 3/4 of and inch down to the top half of the rest mounting hole. 

now you pointed out concerns that have crossed my mind... 

(the rest and arrows)

i bought the dozen easton alum arrows because i needed more and because they were cheap (2419 xx78) and the rest whisker size because that was what i was told i needed. But, as i read more i see it is not and should have gotten a bigger whisker opening. 

soooo.... 
1. can i trim the top of the whiskers to allow some gap on the top of the arrow?
2. can i shot a 31 inch arrow vs a 29? ( doesnt seem luke 2 inches is going to create physical threat or anything?!)


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## konrad (Mar 29, 2009)

I thought those looked like big shafts. The 2419 at 31 inches is considered “heavy” in weight using a bow like yours with a 100 grain point and a draw weight of 79 to 84 pounds! 

Nope, you don’t have to worry about an arrow collapsing!
Carolina Archery says their large Whisker Biscuit is good for arrows up to 23/64ths in diameter. Your shafts are 24/64ths of an inch in diameter. That is why yours are tight in the hole. 

I suppose you could enlarge the hole but my suggestion is to return the arrows and the rest. Calculate the correctly sized arrows for your bow and investigate another full containment rest that will work with your bow. Perhaps a reconnaissance trip to the local archery shop would save you some time and grief. Bring your bow so they know what you are dealing with.

If you want to save money, when you find what you need, shop around on the internet. In many cases you can save money even when figuring in the shipping. At the minimum, you will see if your local folks are priced right.
Lancaster Archery and Keystone Country Store are two good places to start shopping.

Good Luck and remember…look at all how smart you are getting!


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## nccrutch (Feb 26, 2003)

WOW, i don't know where to start. 
-First, take the Biscuit off and install it on the back side of the riser (see the attached pic). You can also chunk that steel spacer deal, you won't need it.
-Now, mount the WB so that the arrow passes thru the rest mounting hole. You don't want the rest to be tilted up or down at all.
-Now you can put an arrow in the rest and slide the nock-end up or down until the arrow shaft is 90-degrees to the string. You can use your levels for that. Install your loop so that the arrow stays in that spot. All this will get your up/down pretty close.
-For centershot on that bow, start at about 3/4" from the face of the riser to the centerline of the arrowshaft. You just loosen that one screw and slide the rest lt/rt until you get there.
-Now check to make sure you got the right size biscuit. There should be a little play between the bristles and the shaft. If it fits in there snug, you're going to have problems. Always remember to shoot cock-vane "up". You don't want any fletch contact with those stiff black bristles on the bottom.
-Now you can start paper-tuning and tweak fron there.

Hope this helps.


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## bthomas67wagon (Jul 23, 2010)

(Conrad) 
I can't return the arrows or the rest as they were bought last fall and I had to glue all the nocks on "correctly" (bought from an internet company and regreted it) and the chain store I bought the rest from won't take it back once shot through. (according to the "bow tech" that took my bow apart and then told me he couldn't get it all lined up and to come back another time when the main person was working... I didn't go back !!!)

I would prefer to just buy another dozen arrows that would fit the rest better and would be lighter and stronger if it would allow for better grouping and a more consistant shot?

The two bow shops I found "locally" are both about 45 mins away and when I inquired last year they had a couple week waiting list. I guess I just figured I could tune it enough for a 30 yard deer shot, as I have done with other bows and equipment changes in the past. (even though I'm sure there is huge room for improvement. )

(nccrutch)
I can't install the Whisker biscuit on the back side of the riser because of the string slide. As described, I had to find another way to mount the rest and in front of the riser seems like a logical spot.

Yes, I have the basics setup concerning having it all level, the cock vane pointed up, etc.

as a quick update...

I lowered the nock spot on the string and the rest to cover the top half of the rest mounting hole, cut some arrows and threw a couple from 20, 30 and 40 yards out and after some sight adjustments, I'm feeling a lot better.

I don have some more concerns to work out before I can say i am ready for the field, but...

1. I think I'll trim the rest whiskers to loosen "the hold". (why not since I can't return it now)

2. It seems that the drop at 35-40 yards is a lot more then expected and might have to do with what konrad hinted at being too heavy?

3. I have my sights dropped as low as they will go, so I'll either have to change something (arrows, nock point, my draw location, ???) or just aim high. 

Also, I could see some my arrow either porpising or fishtailing and I'll have to take some time and see what it is doing?

(Ran out of time yesterday, but hopefully this week I'll get out and make some more progress)

TIA !!
-Brent


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## konrad (Mar 29, 2009)

http://www.thearcher.com/depot/resourceCentre/completetuningguide.pdf

The above is a link to Easton Technical’s Tuning Guide. Not all of the information contained therein is applicable to compound bow shooting; however, there is much gold to be gleaned regarding the setting up of a bow and arrows. 

Unfortunately (or fortunately for me because that is one of my favorite parts of the sport), there is no “short cut” to archery accuracy. If that were true, everyone would get instant success every time. I have to believe there is a full containment rest that will work on your bow. Maybe it won’t be a Carolina Archery Product but I bet someone makes one that will work for you. Perhaps you should contact P.S.E.? Tell them what model bow you have and they no doubt will have a suggestion for you on rests that will work. At least you won’t spend needless money in the search. They are good folks and have a tech line you can call.
http://www.pse-archery.com/contactus.php

I suggest before spending any more money or effort on this project that you read through the entire guide once, just to get a feel. Then go back and study the parts that are relevant to you and your system. You will get quite an education and be much better prepared to fend off the BS sometimes found in archery (and gun) shops fed to neophytes.

Then get your draw length properly adjusted on your bow. This allows you to determine the correct length for your arrows and is critical to consistency.

Next, accurately measure the peak draw weight of your bow.

Now you can use the Easton Technical Shaft Selector program to research which arrows will work with your system.

Then you can go look for the sales.

Be patient with yourself. The rewards will be great and you will have taken control of your destiny. OK, so I exaggerated a little. At least you will be able to converse intelligently when shopping for goodies.

Most importantly, remember to savor the journey and have fun!


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## bassman409 (Jul 19, 2006)

For 55$ you can get a dozen carbon arrows that will shoot 50-60 fps faster and will fit your bisquit. Just make sure to get the right spine! This will make your longer shots not dip as much as those heavy alum. arrows.


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## TAStech (Jul 23, 2010)

I don't know what to say about the clearance dilemna i haven't had that problem with a WB before. I'm just going to suggest getting rid of the metal string loop and get a synthetic one put on from your local "pro" shop. metal loops are hazardous to center servings and when the string is shot its motion continues past the static position and the metal loop can "nick" the cables resulting in broken strands in your cables.


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