I just recently tried to tune my 58" Centaur Chimera with new arrows. It is 52"@28 and I am drawing 27"s. I am shooting CE Heritage 150's cut to 29.5"s with 100 grain brass insert and a 145 grain point. I have 5" LW shield cut feathers and wraps on the arrows as well. Bow is cut to center and brace height is at 6 3/4 as Jim recommends. I have what I feel is good bareshaft flight although I cant get the nock high out of the arrow...the shafts are flying good left and right. I fletched them and it seems they want to barrel roll. I dont know what to do to fix this. I thought everything was fine but I guess not.
By adding fletching it makes the shaft a little stiffer.
Usually not enough that it isn't adjustable.
I'm not familiar with those shafts.
Suggestions.
First just try shooting a couple with the cock feather in towards the shelf. Sometimes this really makes a difference.
Then since it is rolling it indicates a nock change is needed.
So try that to see if you can get to only fish tailing.
You can check to make sure your brace height is good also.
If you get to fish tailing only, then try adjusting the side plate thickness.
Try all this before worrying about different shafts.
I am not sure how close your bow is cut to center. My initial thought is too stiff, but this is just a guess not having more info. If bareshafts are flying well you could play around w your fletch orientation -- cock feather in-- inverted Y etc. you've got a good amt of weight up front, but carbons really stiffen up quickly when you shorten them. Play around-- try less point weight/ more point weight etc. hope this helps.
Push comes to shove, try building up your rest with a crown shape located right at the deepest part of the grip about an 1/8" high. This will allow you to lower your string nock just a bit and still have shelf clearance.
Like others have said could be a clearance issue with the quill.
I mean the bareshafts are flying right where I want them but the fletched shafts are giving me trouble. Just havent encountered this before.
Sounds to me that your arrows are too weak! I'm pretty sure that CE 150's are a .600 spine arrow. I'd think you'd be better off with at least a .500, maybe even a .400 spined shaft. A .600 spine cut to 29.5" with 245grains up front is very similar to what I shot out of a 40ish# bow that was not cut to center. Also, a weak arrow can give you that nock high bare shaft that won't go away. Try cutting one of your bareshafts down to 27.5"-28" and try starting with a lighter point weight. You can always add more weight. You will probably find that you'll need to adjust your nock hieght to see the true results. A bare shaft test kit would be a wise purchase.
Try to play with different point weights to correct, the only time I have had issues with a arrow barrel rolling or cork screwing was with a stiff arrow but I would think your set up would be close. The Heritage 150 is a .487 spine deflection.
CE 150 are what others call 35/55. CE 90's are the 600 spine. The 250's are 55/75 unless CE has changed their specs these are what spines I was told by them.
It is also possible that if your fletchings are of contrasting colors, the rotating arrow is giving the "illusion" of barrel rolling. The only way to be certain is to shoot through paper.
I would try some different point weights?You have a lot of weight upfront.Double check your brace and nock height to see if something is different.I like to revalulate my arrow setup if I'm having issues.Carbon Express has changed their specs on Heritage spine.Older 150 were .487 and now the newer 150 is .495,old 90 were .530 and newer 90 are .588,old 75 were .608 and newer 75 are .670,old 250 were .373 and newer are .391 and they changed to woodgrain look some,the newer models the woodgrain has a lighter color similar to a GT Trad.
I started with a new bareshaft and I feel like so far, i have concluded my previous arrow was too stiff.
Kevin,
I have a 60" 52@28 Chimera drawned to 29+ and I would get some of the same symptoms you described. My fix was to do as Kirk suggested I built up the rest just a tad and I also shoot with an inverted "Y" arrow orientation.
I have my theory on why this is needed on my 2 Centaurs part of it being the way the riser shelf slopes in toward the plate. And can allow for shelf contact.
Anyway for whatever reason this has worked for me and I love my Centaurs. You sometimes have to find what the bow likes instead of the other way around.
Oh and by the way my arrow set up is GT 5575 (400's) 30.5 to BOP 50 grn brass insert and 175 grain points, 3 4" shield fletched. Total wt 535 grains.
If your shooting 3 under that's one I always had trouble with. I don't know what barrel rolling is? I'm assuming you mean porpoising. If you do shoot split try cock feather in twords the riser.
Any recommendations on material to build up the shelf?
Kevin,
I use velcro for my shelf material and what I do is place a 1/2 piece closer to the shelf and over the deepest part of the grip. Then I cut another piece that is full length and place that over the first piece but this one ride right along the edge of the riser shelf lip. This create a high spot and assist in clearing the shelf upon the shot.
Ok great. Thanks! I will give that a try. I appreciate the input.