January 18th, 2007, 04:25 AM
PSE Primos STL tuning problems
G'day all, I'm seeking advice on a problem with this bow. 2004 PSE Primos STL, 60#, 28", PSE Raptor prong-type rest, TRU-Ball release, 29" Easton Axis 340 Full Metal Jacket arrows. Hope that's enough info for starters.
I'm trying to be self-sufficient with the tuning and maintenance of this bow. For one thing, I live over an hour's drive from the nearest archery shop, and for another, the guys in the shop pay virtually no attention to any adjustments to the bow whenever I take it in there. Seems like they can't be bothered because I'm not a competition shooter. Frustrates the heck out of me, cos I've spent what I would consider to be a large amount of money with them, but I don't have enough knowledge to refute their claims of 'yeah, should be about right like that' with everything. When I bought the bow, the arrowrest was fitted to it straight out of the box, no adjustments made, "should be about right". I had a bus cable replaced a while ago due to a frayed end. I suggested that perhaps the Ato A and brace height might need adjustment as it had done about 12 months work since new. "Oh, it won't have moved much". Sorry for the rant, but like I said, it frustrates the heck out of me.
This forum has been a goldmine of knowledge thus far, so i'm hoping I can sort out what's up now. I've been trying to set up the centre-shot and nock height by paper tuning with a bare shaft. I have the centre shot pretty good, but to get anywhere near a bullet hole vertically, I'm finding I have the arrow pointing upwards when nocked at about a 10 degree angle, i.e. the nock point is nearly half an inch below the rest. Surely that can't be right? I decided I should start again with the rest adjusted so that the arrow sits at the same height as the bolt hole in the riser, and the nock point set just slightly higher than the rest. I get a huge vertical tear, and when i shoot a bare shaft from about 10 yards, it just about does cartwheels- ends up stuck in my foam target at about a 45 degree angle upwards.
Would all this be caused by the AtoA being way off? Or something else being way off? Can anyone tell me what the brace height and AtoA should be for this bow, and how to adjust them? Any other sugestions?
January 18th, 2007, 11:47 AM
Couple things come to mind for me. First, your arrows are probably a little on the stiff side, but that shouldn't be a major issue. I'm just mentioning it suggesting that could easily shoot a .400 spine.
Secondly, how stiff is the spring on the rest? Often you'll get a high tear if the tension is too stiff. It only needs to be stiff enough to keep the arrow up and full draw.
Another thing you might check is the tiller of the limbs, even before you move anything else. Two ways to do this and both are acceptable. One way is to bottom both limb bolts then back them out evenly till the desired weight is set. The other is to stretch a string from axle to axle and measure from the string to the back of the limb where it meets the limb pocket.
Is it a single or dual cam bow? If dual then be sure the cams are in sync, rolling over and hitting full draw at the same time. If single cam then check to see if the cam orientation (rotation) is relatively close to specs.
I can't say what the specs are for the bow. Maybe someone else will chime in or maybe PSE has it on their website.
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January 19th, 2007, 05:00 AM
Thanks for that, I have backed off the spring in the rest- i'll probably be able to back it off some more. I have the limb bolts maxed out, so guess that makes them even? I'll do the string check as you suggest. The bow is single cam. I have no idea how to check the cam orientation. I'll have a check of the PSE website, see what info I can obtain. Thanks again.
January 19th, 2007, 07:36 AM
Took a bit of searching, but I found cam timing info and AtoA spec. My AtoA is about 3/8" long, and the cam (single cam) timing looks to be about 5 degrees off. Would this have much effect on how the bow shoots?
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