Ok bow gurus...tuning questions
Massachusetts
I am going to re-tune my Bowtech Old Glory ( I think I did 12 years ago, but not sure). It is a binary cam bow, so I am not sure I can adjust for any cam lean, not that there is much. I ordered a boat winch so I can whip together a draw board and check for it, as well as timing.
After I have timing taken care of, what steps do you guys go through? Since I probably cannot play with cam lean much, am I limited to nock and rest adjustments?
Pete
I am no expert but can't you manipulate the twists in your string to adjust cam lean? That is how they do it at my shop but maybe your bow is different?
I learned my bow was not correctly tuned right before this last season when I shot my first fixed blade arrow and it shot much higher than my target points,.. rather than get into trying to tune it right before the season start I switched to a mechanical,.. that flew great.
I plan on spending some time tuning (adjusting my rest) this year so I plan on following this thread.
I have always shot mechanicals as well. However, I thought it would be fun and worthwhile to learn how to do this correctly, and also be able to shoot fixed blades.
I do not have a yoke on my bow. The cables are slaved to the cams. I suppose I could always try to shim it if needed, assuming I could find shims.
I always wondered if my slightly off shots when shooting field tips was me sucking or possibly a tuning issue........ I'm going with tuning :)
I would try the nock and rest adjustments first. Set up for a paper tune.
nock and rest , peep and pins , Arrow spine and broad-head weight.
Tune it all according to what you will hunt with. I have two sets of fixed blades . One set is target the other hunting.
(Disclaimer - I'm not an expert. I am a guy who loves hunting, and went through a "Phase" where I thought I could become an expert in archery and tuning etc. but to many other hobby's won out, so... I know enough to be dangerous :))
Why?
Not being a wise guy... But I'm curious. If it's shooting well, I'd not mess with it.
Below is what I did with the Allegiance, Guardian and 82nd AB I've owned which all use versions of the binary system.
If you really want to check it all out. Search the web for the timing specs. they vary a bit based on your draw stop post (on the cam) setting (believe I'm remembering the OG system well - so take this with a grain of salt for darn sure). likewise, check the timing to make sure you have that on track (same number of engraved lines on the cam flush with the limb).
You can mess with cam lean via twists of the cables. I know there have to be youtube vid's on this.
Point blank, all that stuff I leave for the shop. They can press it, some will put it through the hooter shooter etc. It's a big plus to have someone with ALL the tools you could need on hand to do that stuff. It's one of those: You can do it... But someone who's done it a zillion times can do it better. situations to me.
Regardless of how you do it, once that's set now you get to the stuff we all can do at home smoothly - tuning.
I used to paper tune any time I got new arrows. Then I found that some times, I'd be sending fixed blades down range like darts but have a weird tear, and some times I'd have a bullet hole but couldnt group fixed blades. So, while I think it can tell you you are in the wheel house, and I know some folks love it... I just dont do it any more.
Ill start with walk back tuning. Use a good sized target, put a bull upper third in the middle and hang a bit of paracord with a plumb bob on it down the center of the bull. Now shoot 3 arrow groups at 20, 30, 35, 40 out to 50 or 60 if you are not going to miss the bottom of the target.
What you will see if your center shot is off, is that the arrows will drift in a diagonal line away from the bull (aim at the same bull for all shooting). each time you see the arrows are "off" from center (IE, lower than the aim point but along the plumb bob line), move the rest a smidge to get things in line. Repeat as noted above as far back as you can go and, again, not miss the bottom of the target.
Once that's done, I follow the instructions from the Easton Tuning Guide for broad head tuning (that's a must have for all archers). http://www.wvac.asn.au/docs/TuningGuideEaston.pdf
Once that's done, so far, I've been able to screw on any fixed blade I have OR mech, and get point of impacts which are close enough I cant see a difference between BH and field points at any distance I can shoot.
That said, I dont do all that often. Last time I did it was probably 5-6 years ago actually. I have not seen any changes in my bow's tune, but, I'm also not a guy who shoots a zillion arrows a month all year.
Will, great post, thanks. That gives me a bunch to work with.
Not sure on your exact binary cam, but you would most likely need to swap out the shims. I've watched videos on youtube on how to do it with Obsession bows and it's not that hard. Lancaster Archery sells shim kits. Honestly if it's not that bad I wouldn't bother. Cam lean isn't that big of an issue and if the bow tunes and shoots you will be ok.
using the cable rod to introduce or remove cam lean in a binary cam system is the easier than shimming. Adding/removing twists on a binary cam will have minimal affect on cam lean and leads to other problems with DL, DW, BH and cam timing. After 12 years my first suggestion is a new set of quality strings and cables. Set rest height to 90 degrees, centershot to mfg spec or straight down the center of the riser, rotate cable rod so your vanes just clear and go from there. Will mentioned walk back tuning and it is definitely effective, the one thing you have to remember is to use your 20yd pin as you move farther back...and THAT 20YD PIN BETTER BE DEAD NUTS FOR WINDAGE. If it is off just a bit at 20 yds it will get worse the farther you move back...giving you a false positive result that your centershot is off.
Thanks Shawn. New strings put on this past September. It is one of the reasons I figured it made sense to tune. Twelve years ago I think I knew this stuff, or at least I had all the tools. I opened up my bow box this weekend and could not believe all the stuff I have. Portable press, nock tools, squares, serving tools, solder looking thingy to melt d-loop ends, fletching jig, etc. Heck I even found a arrow saw that I built in my cellar. I must have done this stuff in the past, just been so long.
Peter - do what Shawn says. Exactly. He know's this stuff inside out, backwards, sideways etc.!!!
Didn't the old glory just have a straight cable rod? I don't think moving it is gonna do anything.
X2 what Will said! Shawn is one hell of a Archer!
Murphy, good memory. Yes it is.
Full disclosure; some changes are planned for the bow. My rest is gonna go. I use an old drop away but provides very little arrow support. It does not like angles, and I have to be careful that the arrow does not fall off. LimbDriver Pro will be ordered soon. Next is my sight. I have used a Timberline No-peep coupled with a Copper John, probably for fifteen years. Love the no peep. The sight is a bit temperamental. I am really liking the Perry's No-Peep. Leaning toward the Perry No-peep and sight combo or just his no peep, then getting one of the more popular sights. I also have been shoot off the string for the past ten years, but I always get serving separation. So I added a D-loop. All of these things add up to major changes, so might as well start from scratch and tune away.
Will showing your age with the eastern tuning guide that's about twenty years old unless they put it out again
Winch and scale have been ordered from amazon. Will have a draw board ready sometime next so I can begin my endeavor. Then I will begin to follow Shawn's steps.
So next question: I got to get me some arrows. My last batch of twelve arrows lasted me ten years. I am down to three. 61 lb draw weight, 30 inch draw length. Help me cut down on a bunch of reading and lead me in the right direction. I think the IBO is/was 315fps on my bow. Arrow choices are dizzying and like every other freaking activity I do, I always seem to fall right in between manufacturer recommendations. I shoot 100 grains up front, always used 4inch vanes with right helical, but very tempted to go to those short things everyone is shooting these days. Oh, and damn arrows are expensive. Cabelas Extreme Stalkers appear to always pop up high on recommendations and don't break the bank as much. Are they good? Pete
The draw board is complete, although I am still waiting on the scale. What a neat little tool to have in the arsenal. Well, now I know why my forearm has a bit too much bend. 28.5 inch draw length out of an E5 Bowtech cam. So I did a wingspan measurement to figure out where I should be theoretically. I came up with a 29 inch draw. So I added some twists to my cables and got very close to 29. The E5 cam is supposed to be 30 inches. My brace height is a bit shy of 7.5, and the ATA is 37.5, so I am pretty much at spec. I do not really notice any cam lean, and while I do not have any timing marks on the cams to go by, my eyeball says it is pretty much dead on. I may take a few twists out of the draw string to see what happens. I am close to perfect on length. It just felt a bit short since I put the new strings on there.
For the life of me I cannot understand exactly what the cables do on a compound. I know they build energy because they are the small gear in the system (thinking of bikes). Can someone help me understand these things? Why does shortening increase draw length? Thanks in advance. Pete
It pulls the axles closer together. It'll also increase your draw weight and brace height. Taking twists out does the opposite. Pulling everything towards your riser.
Captain - I know right... But, it's still the best written thing I've seen on tuning...
Peter - try PM'ing Shawn if he has not checked in here again in a day or so (or just do it). The guy is a guru with this!
Will, I certainly will try to reach him. I ordered the new rest, and arrow shafts. I also played around a bit with the cables yesterday. It was pretty interesting because one of the sales pitches for the binary cam was they are always in sync. Well, I quickly figured out that with a few twists of one cable, it is easy to knock them out of whack. By playing with the cables, I am finally beginning to understand exactly what they do.
When you put twists in the cables you lengthen the draw length, decrease A toA, and increase BH. Although the shortened A to A and increased BH play a small part in this, the primary reason for the increase in BH is because you are "over" rotating the cams allowing more string to pay out before hitting the draw stops. When measuring DL on a draw board the correct measurement is nock point to throat of grip Plus 1.75". So an E5 cam should measure 28.25" from nock point to throat of the grip. As for the straight cable rod you can do 1 of 2 things...1)replace it with a bent cable rod or 2) try a few different cable slides...some of them have "deeper" grooves than others allowing the cables to sit closer or farther from the arrow. The bowtechs I have helped people with over the years tuned pretty easily. THe best starting point is still to run arrow at 90 degrees or a touch nock high and down the center of the riser and shoot through paper at like 6ft and at like 15-18ft. a very small tear at 6ft could be cleaned up by 15-18ft or it could be worse by 15-18ft depending on if its caused by tuning or fletching contact etc.
Shawn - as noted above, I've ditched paper tuning... You have me curious though. If one was to do it, and the 6ft tear is better at 16ft, is that likely fletching contact... but a bullet hole at 6ft and tear at 16 would be a spine or tune issue?
Really creative on the slides having different grooves.
Will- that is exactly right based on my experience. Now with quality drop away rests fletching contact is almost a non-issue as long as the rest is timed properly. The BIGGEST issue I've seen with people is in their grip on the riser AND grabbing the bow. Case in point...I recently setup a friend with a new to him target setup. He is a newer archer and willing to put in the work and take advice. He has a huge hand and it was tough for me to see exactly where his pressure point was on the grip or if it was consistent from shot to shot. I spent some time adjusting his hand on the grip and also made him start using a finger sling. once his hand placement was consistent and his hand was relaxed his point of impact shifted 2.5" to the left at 20yds...that tells me he was torquing the bow a lot...he would have NEVER gotten a bareshaft to tune. Speaking of bare shaft tuning...unless you have VERY good and repeatable form (read expert level), do not mess with bareshaft tuning...it will do nothing more than frustrate you.
Very interesting stuff Shawn. Thank you!
Shawn, interesting point. I am sitting here waiting for my new limbdriver rest to show up. I think I have my draw set up fairly well at this point, the cam timing is as close as I am going to get it and I even did a tiller measurement (and made almost a quarter turn adjustment to one of the limbs). Not sure tiller matters much, but hey might as well tweak and learn. It feels more balanced, but that is probably just in my head. I guess at this point I have a base line to start from.
So you are scaring me away from bare shaft tuning. I may try it just for fun, but now I won't sweat it if I can't get it perfect. So should I start with a paper tune to get the nock height right and get close with rest alignment, then go to walk back tuning? Also, should I do it with both the field points and a broadhead?
One more thing. I stumbled onto a problem I was never aware of; the wrist sling. I always had it set so it was snug. However I shot with a broken wrist and palm against the grip (I know I know, bad form). I see that the preferred way was to have the knuckles at a 45%, but for the life of me my hand would not rotate like that when I drew the bow. It was the damn sling. So I have it set loose now, so I can get the hand just right. Much more comfortable and much easier to not torque the bow. My saving grace in the past was the I use a Timberline no-peep, so I can pick off when I am torquing, at least prior to the shot.
Thanks Pete
Wow! This thread could be written in Chinese and I would understand it about as well as I do right now.
Shòuliè yú huáxu chúsh
W? xi?ng wèi n? xi? zh?ngwén
H?o
Ji?ng
(Dang - my attempt is mostly foiled, with the ? replacing some text for some reason once I posted it...) (Apparently with google translator you can convert English to Chinese. Above: Hunt Fish Ski Cook I wanted to write in Chinese for you Be well Will Ha ha ha! To much time on my hands tonight!
You can broadhead tune, but usually if you paper and walk back tune. They will be flying right. If you bare shaft tune. You really shouldn't have to worry about broadheads.
Hahaha! Nice Will! Do you actually speak some Chinese?
HSFC.. only via google... And some epic kung fu movie impressions :) Perhaps ironic given some of my favorite books have some historical bases in various Chinese thinking (philosophy's) like Zen, Buddhism etc. But no, I cant speak a lick of Chinese!
Peter...skip the bareshaft IMO, good catch on the wrist sling...that will definitely cause torque issues. Get a good paper tear close and far as a starting point then move to walk back. Make sure sight is level especially 1st and 2nd axis. There is a variation called reverse walkback tuning that I feel is better. Long explanation but I'll try. Set up target like you would for regular WB tuning (dot near top of target and plumb bob string hanging straight down. Use 20yd pin and shoot at the dot at 20yds just to make sure you are close. Then move back as far as you can (40-50yds) and shoot at the dot w your 20yd pin. Adjust your SIGHT windage L-R until you are hitting the string. Then immediately move up to 20 yds and shoot at the dot w your 20yd pin. If your sight is level and you are not canting your bow, your windage should be good at 20yds if your centershot is correct...if it is not then move the rest ever so slightly and start again. THis eliminates the false positive results I talked about due to sight windage errors in my post on 1/3/18.
Thanks. I found kitchen sink tuning, a lengthy PDF online. It was a good read. I finally understand what you are talking about here; it actually makes perfect sense, and it is fairly straightforward. The rest came today, as well as the arrow shafts. I ordered new fletchings, Blazers. Damn those things are tiny. I'm trusting everyone that those things work. I am even going to spine the arrows. I have a big ass quick grip that I can put them into. I will nock both ends and insert a point in each, put in the quick grip until it bends. Again, not sure it matters, but might as well give it a shot.
Shawn that's a cool approach I've not heard of before. If my increasingly weak spine relative to buying a bow finally breaks and I splurge on a Halon, I'm going to do that!
Man, too bad it is raining today because it is perfect temp to go outside and tune the bow. I made up three arrows with the new shafts and decided to at least paper tune it in the basement. I had to push the rest almost as far as it will go to the left, and I also almost maxed out the height. I think the end result is good (pic below) but I do not like to be at the extreme ends of my adjustments. The up/down fix is easy; move my nocking point and readjust the rest. However, I am brain farting on the windage.
Shawn, help. It is probably a cable twist, but I'm just not seeing it.
I'd put it back to center shot and shim the cams. It only takes like 5 mins. Moving the rest doesnt fix the problem. It only compensate s for it. If its not just a tiny rest movement. You're better off just yoke tuning (which you don't have), or shiming the cams.
Hi Murphy31,
I dug around on the web regarding this issue. It appears that the bend in the riser is quite a bit more than other bows, which is probably why they were able to use a straight cable guard rod. Most people were setting center shot at 1 1/16 to 1 1/8 (pretty much where I am as well). I also remembered that 12 years ago I had to order a special extended rod for the drop away rest I was using.
As soon as weather permits, I will begin to walk back tune, then BH tune. I will lower my nock a bit though, so I can bring the rest more in line with the Berger hole. I'm a tad higher than I probably need to be.
Sorry for all the posts here but I am kind of using this thread as a log for future tuning.
Went out to the club to do a bit of walk back tuning. It was a bit challenging with the wind and 15 degree drop in temps in 45 minutes, but it went fairly well. The paper tuning got things very, very close. The rest only needed to be moved to right about a 64th inch. And this correction really did not become obvious until I was at 40 yards. (I did remove the D loop earlier in the morning and put it back on about a 1/4 inch lower; also lowering the rest by the same amount. Then I paper tuned again).
Then I went back to 20 yards and put on a fixed blade BH. At first I had a couple of flyers. I could see the weird flight as it left my bow. Well, it was me. I learned a valuable lesson. Any tension in the grip hand is going to cause problems. So I relaxed the hand and I got the BH flying just like the field points. I ended up cutting the string on my make shift plumb bob in half at 20 yards. For me, that is quite an accomplishment. The BH was still flying true 30 yards. Did not get to test at 40 yards because I started to freeze my balls off.
I will continue to tune it once I get some better weather, but I have never had the bow shooting so well. Heck, I never could get a fixed blade to fly without major changes to my sight, so I always used mechanicals. I also never had my field points flying so well. Almost speared an arrow today, but fortunately, I only snapped off the nock.
Been a long time since I had so much fun with a bow. Pete
Sounds like you got it all figured out Pete! Congrats!
Pete - that's awesome! Thanks for starting this thread, and to you and Shawn for so much good info here. It's been a good one to learn from and I'm going to refer to it in the future I am sure.
More data for my future tuning. I played around with some serving nocks inside the D-Loop. I tried a pair first. Top had 20 wraps, bottom had 10. Next I removed the top one and just used the serving nock under the arrow. I liked the single nock better. It is one less thing on my string, can't notice any nock pinch and the arrow flight seemed the same with one or two nocks (maybe even a bit better). Not even sure I need one, but I like having it there so I can replace my D-Loop without having to figure where the loop should be re-tied. I cut off the D-Loop and put a new one just to test it out. Bow shot the same. Shot 20 muzzy BH again today at 30 yards and the thing is dead on. I am shooting without a peep, just relying on consistent anchor points. I am still blown away with the the flight of the arrow when compared to ones with field points.
The final part of all of this will be to get to archery range so I can test the BH out to 50 yards and to climb a tree and practice shooting them from various awkward positions. If that works, mechanicals are dead to me, and one other possible point of failure in my hunting setup will be eliminated. I will never shoot a 50 yard shot (or 40) while hunting, but if the BH gives me good accuracy out to 50 then I know the system is perfect. At that point it comes down to consistent form. Been working hard on reworking my grip. I finally am able to get my knuckles at a 45 degree angle, with the bow basically resting on top of the soft part of the area around the thumb and pointing fingers. Fingers are not gripping the bow and I got rid of the hinge in the wrist. Note to self....... Come back to this thread often and read the previous two sentence over and over.
Just adding more tuning info to this thread for my future reference.
Started to paper tune my daughter's boyfriend's Bowtech Tomkat. He had to buy a new module to fit his draw length, which is a bit over 30 inches. He also purchased new strings. We installed the modules and the bowstring, and went to work. We would get close but could not get bullet holes. So I started to play with the cam lean on the top cam. I was able to get a little lean out, but I was still chasing the bullet hole ghost.
So then I had an idea. What if I reversed the cable guide slidy thingy so that the cable pulling on the top cam was closer to the arrow? That 1/8 of an inch, while not a great distance, must add quite a bit of extra tension. So I reversed the way the cables over lapped. Started to shoot and after one final adjustment of the rest we had bullet holes.
Even on binary cams, cam lean seems to cause issues at times. Later this week we walk back tune it then see if it will shoot the broadheads true.
More tuning info for my future tuning needs............
Have new bow. Bowtech Realm X.
Set up centershot by measuring outside arrow shaft from inside of riser, in front and back. Make sure it is the same. Then bareshaft tune through paper and use yokes to fine tune. I.E. left tear then add twists to top and bottom left yokes.
There is not a lot of room for my vapor trail drop away so fletching position is important. Also was getting mixed messages with fletched arrows. Found that rotating nock made a difference. So lesson learned... bareshaft tune each arrow shaft through paper, then fletch and paper tune each arrow, adjusting nocks as needed. Mark the nock and shaft relationship once it works perfectly.
