May 26th, 2006, 10:06 AM
Yes... in fact to all hybrid cams with modifications... as the true Darton clones do not have a draw stop on the control wheel...
Originally Posted by acal
May 26th, 2006, 10:31 PM
Javi Timing Article
Thank you for your reply Javi.
May 26th, 2006, 11:01 PM
Trykon XL setup woes
Can someone give me some advice as to what I may be doing wrong here?
I have a Trykon XL 29" 70lbs. I read Javi's setup procedure regarding cam sync and draw stop timing. Does this apply to the Zephyr cams as well?
I followed the steps and everything seemed to be fine...I got the ATA 1/4" long and got the reference marks on the bottom cam so the bottom limb was dead center between them.
This is where I'm baffled...when I drew the bow back, the top cam was grossly under-rotated. Could I have untwisted the string "too much" initially as he said to back it off 10 twists or so? That's what I did but to get the bow to come back anywhere near normal, I had to twist up the string again and then adjust the buss and control cables.
Also, which draw stop hole should be used? I'm baffled as to why we make those initial cam sync adjustments just to then twist/untwist them to get the draw stop timing set.
One last thing...what is creep tuning?
Last edited by Archer1eroc; May 26th, 2006 at 11:08 PM.
May 30th, 2006, 01:12 PM
Go back and re-read JAVI's article again. In no place does it say to center or even use the reference marks, and this is the root of your problem.
Yes, the Zepher cams work just like the spiral cams, or the cam 1.5's, except they do not have the 1.5's draw length adjustment modules. I should let JAVI try to explain, but here goes anyway.
First, the reason for untwisting and twisting is to get the A2A set. You are correct in that you could just untwist the right amount to start with, but it has proven easier for most to untwist the 10 twist and than twist back a little at a time.
Second, re-read the part about twisting and untwisting again. This is a multipart thing that when done as JAVI said will get three things right, all at one time; It gets the A2A set, it gets the brace height set, and it gets the poundage correct. Most people have problems with the bows shipping with the poundage a little high (once in a while low), the brace height not correct, and most never even notice that the A2A is off.
Do not give up, the article is near perfect if you just follow each and every step JAVI gives. Do not read into it something that is not there, like centering the reference marks. When you have "timed" it on the flat spots of the cams as indicated, you will find the reference marks are not centered, but each bow will be different.
One last thing, the draw stop holes. The outermost one gives the smallest valley and the hardest wall. That is what most of us like, but some do not. If you like a little more valley and a little softer wall, use the inner hole.
Worse comes to worse, send it to Crackers, he can do it for you, and replace the factory strings, and you will not even need to worry about how to do it.
May 30th, 2006, 01:14 PM
Oh yea, creep tuning. Something that is better done with two cam bows than the hybrid and single cam bows. But if you want to know more about it, do an AT search for "creep tuning".
June 11th, 2006, 03:33 PM
Hey! muddog in iowa here. i'm a first time user, but from what i see, i love this site. i have one question about cam 1/2. i have a 2005 vtec. my upper cam is under rotated and my brace height is about a 1/4 in. low. i still have the factory strings, should i twist to retune or should i purchase aftermarket strings and start from scratch.
June 12th, 2006, 11:11 AM
I shot for quite a while with the factory strings, and if you don't mind re-tuning the bow fairly often the 05 strings will be ok and you can just time it per JAVI's instructions.
Originally Posted by muddog
Still, how many shots do you have on the strings. It would be worth your time to get a set of Vapor Trail or Winners Choice or ............. and set it and forget it.
June 19th, 2006, 07:00 PM
When it says back the string off ten twists is it talking about un-twisting the string or is it talking about backing out the limb bolts? Not sure my string is twisted ten times?
June 20th, 2006, 11:35 AM
The directions are talking about the string twist, the bow should have the limb bolts bottomed out for this tuning.
Originally Posted by ck92
What you have found is that the bows do not come out of the factory very consistent. Normally there would be enough twist to do this.
In your case, measure the Axel to Axel length and I'll bet you are too long. If so, jump to the next step and pretend you have already untwisted the string.
June 22nd, 2006, 07:50 PM
I have installed new strings and cables (winner's choice). The ata is 3/8inch longer than spec. The bump stop and cams look to be right. It is getting 68 pounds with the limbs bottomed out (60 to 70lbs. limbs) and the draw length is short. I am a little lost at this point. The last step reads to twist the string because the bow should be long and heavy, mine is the opposite. Any help from this point would be apprieciated.
June 26th, 2006, 04:15 PM
I'm not quite sure I understand what you are saying
You say the Axle to Axle it still 3/8" longer than spec. This should leave you at the 68 # draw indicated, and you should have a little shorter draw length (actual measured dl) than spec.
Originally Posted by ck92
If the AtA is indeed still too long, twist down both the control cable and buss cable (try about a full turn each), twist down the string two twist, and re-check the poundage, dl, and A2A.
If the cam's are already right, twisting the cables a total of two twist between them, and then twisting the string the same number, will return it to timed.
If the twist are too much, back off a half turn on each cable and one on the string. If the twist are still not enough, add a little more twist.
Keep in mind that the A2A is the least important of the bunch. If the dl is correct, the cams timed, than reducing A2A to increase limb pre-tension, or increasing A2A to decrease limb tension, is all you need to do.
I hope this helps, get back in touch if you need more.
June 26th, 2006, 07:19 PM
Archersteve, maybe you can help.
I've gone through and attempted to tune and time my bow a couple times following Javi's instructions. Each time, I've been able to get the cams right in tune, the drawstops perfect, the BH, ATA, tillers, and weight right on, BUT I always end up with the DL a half inch too long (27 1/2 instead of 27). Every time I try to go back and fix that, I end up really screwing things up and it takes me forever to get it back the way it was before trying to correct it. As it turns out, the bow was probably so out of wack that I was shooting an effective DL of 28, so being at 27 1/2 actually feels very comfortable and I don't feel I need to shorten it to shoot properly. I'm just wondering if having everything in spec except the DL creates any problems I'm not aware of.
BTW, if I were to try to shorten the DL, what would I do that wouldn't end up reducing the DW in the process, which has been part of the problem I encounterd before, and/or messing up the timing, etc.?
June 29th, 2006, 10:44 AM
Sorry it took so long to get back to you, I've been swamped this week at work. For starters, having the DL 1/2" too long will not impact accuracy or function of the bow at all, as long as the length fits you. In fact, it might (usually will) add a few fps to your velocity. Now, for the second part of the question.
Originally Posted by hunohio
You have me a little stumped to be honest. Without actually looking the bow over myself, my first thoughts are "are you sure of the DL - how are you measuring it?". If everything else is dead on, a half inch seems a little wacky.
One thing to remember is that specifications given by the bow companies, including Hoyt, are approximate. It is not all that uncommon for a bow to have a draw weight a couple pounds high when maxed out, or to have the A2A or dl a little off. The real issue is getting close and getting the balance. For me, my issues of importance are first, dl set correctly for me, second, cams tuned correctly, third, poundage set correctly (state hunting issues and laws that I don't want to go into), than an A2A and bh close.
If the dl is 1/2" too long, I would twist down the string a couple or three twist and see if the dl comes down enough. This will not change the cam timing at full draw, and will have no adverse impact on the performance of the bow (except drop a couple of fps), but it will change the peep and nock locations so re-sighting will be necessary. When the dl is correct, check the A2A and bh. On a parallel limb bow like the Trykons, the bh will not change very much at all. On less parallel limb bows, twisting down the string will actually increase the bh just a little. Now see what happened to the draw weight. Usually this little bit of a change will not impact it either way by very much.
REMEMBER, like you said, if the 1/2" extra length is not a problem, don't worry about it. If it is, try the above and get back to me. I often get to PM's faster than threads if I'm swamped.
July 4th, 2006, 06:20 PM
I read and reread the original on timing and I've got a question on the tiller.
I've got my bow at the set weight that I want to shoot and the brace height is right on. My upper cam (spiral cam) is under rotated.
I've taken 2 twist out of the control cable and the cam is almost there, probably one more twist and I've got it.
The problem is that my lower limb tiller is now 1/8" longer than my top limb.
The b/h is still dead on, am I still okay or do I need to go back and twist my buss cable. I haven't checked my d/w as I'm not able to where I'm at.
July 4th, 2006, 07:37 PM
If you twist the Buss Cable you will only length your draw length and it will take you backward on cam rotation.
Originally Posted by Steamin
My best advice it to set the draw stop timing when you have the tiller even, the bh dead on, the A2A close, and let the sync do what it will. I don't want to go into the physics of it, but cam sync is controlled by the same cables that control draw stop timing and draw stop timing is far more important.
July 4th, 2006, 07:52 PM
I got it straightened out, stupid mistake on my part , everything is @ spec. I went ahead and gave the buss cable a twist to help my d/l out. The spiral cam's longest cam is only 30" and I need closer to a 31" anyway, so it's a little more comfortable now (after shooting it too short for 3 yrs.)
The cam is rotating just like it should so I'm anxious to shoot it in the morning, it's always been a sweet shooting bow -- it ought to be even better now.
July 5th, 2006, 10:35 AM
You are not the first, and you will not be the last to have problems tuning a bow, any bow.
Originally Posted by Steamin
Keep in mind that most of us have only one to three bows, often with completely different designs, and we only need to tune them when we change strings or they are new. Simply stated, we don't get enough practice to get real good at it.
The directions JAVI gave are top notch, but if you skip a step or mis-understand a step, it seems that they don't work. Trust me, with very few exceptions they do, but trust me again, it is so easy to miss a step or mis-understand.
Glad to hear you got it worked out.
July 5th, 2006, 11:51 AM
One thing I'd like to point out. With my bow starting at 1/4" over on the AtA measurement was too much. I found I needed to start at 1/8" over AtA to get it to come out dead on. This, I would guess, had to do with limb angle and deflection rate....being a parallel limbed bow. I would figure that this (1/4") is not carved in stone and can vary from one model of bow to another. Anyone else notice this??
July 5th, 2006, 04:19 PM
It's a different bow!!!
I always thought that my Super tec shot smooth, man what a difference tuning makes in a bow.
Talk about smooth and no shock or vibration, I really always felt that those were virtually non-existent in my bow. I can say it's like shooting a different bow now.
I've got the nock height taken care of, it was high, and I was working on getting the biscuit left - right adjusted until we started getting high wind gusts this morning.
Thanks again guys
July 5th, 2006, 06:26 PM
Actually, you are dead on, and there is even more
Originally Posted by XP35
Different cam sizes will give different results. The 1/4" is just a starting point, nothing more, nothing less.
July 6th, 2006, 07:47 PM
Broadheads still to the left
I still can't get my broadheads to group with my field points, they are consistently shooting 2" to the left.
I've tried three different arrow combo's and I get the same affect on each one. Easton's tuning chart say's that I'm overspined, but by the selector chart and the three different arrows I tried, I disagree.
I've moved the whisker bisciut towards the riser until it started affecting my field point flight, then I moved it back to the original.
I'm getting frustrated and aggravated.
Any help would be appreciated.
July 6th, 2006, 10:43 PM
Take two turns off the limb bolts and shoot it again... if they move further apart then you are overspined... if them move closer together you are under spined...
Originally Posted by Steamin
July 6th, 2006, 11:00 PM
How do you adjust the A2A? Shortening it should increase bow weight correct? Can I adjust it without throwing off the bump stop and cam timing? I have twisted and untwisted all cables and string several times. I have had the timing marks in several equal locations and then did the bump stop timing. And everytime when I check the A2A and weight it is long and a little light. I am hoping to get it right by october
July 10th, 2006, 11:55 AM
Remember that there are so many little things that can be overlooked or that can be misunderstood. Just don't give up.
Originally Posted by ck92
To start off with, if the draw length is a little long, but everything else is on, than you need to either twist the string a little, or untwist the buss and control cables a little (the exact same amount for each). How much twist depends on how far the draw length is off. REMEMBER, twisting the string will not change cam sync or time so this is the easiest way to do it.
Once you get the dl correct, check the weight of the bow. If you are still a little low, than twist the string one twist and twist each of the cables one half twist. This is the trick in reducing A2A without messing up all of the hard work you have already done. Each twist of the string is worth one half twist done in both cables.
Of course you probably need more than one twist, but keep the ratio of one in the string per one half in EACH cable.
Now, if you are really sharp, you will tell me that the two to one formula only works if the string is the same length as the cables, and it is not, but for only a couple of pounds this works. When you are to where you need to be, recheck dl, confirm time, verify bh is close, record your new bh and A2A so you can go back to them if needed.
July 10th, 2006, 12:31 PM
First, go get a cold and maybe a little and relax. This is not the end of the world. Many people just resight for that when they shoot their broadheads so if the worse comes to worse you can too.
Originally Posted by Steamin
Second, the one area that I and JAVI are not in complete agreement on is arrow stiffness, so understand that you may find that the answser is not so simple that it is as clear as day and night. If it were, JAVI and I would agree completly on this as well. In fact, try what JAVI suggest first; I'll explain later.
Now, I will state up front that I am of the school that believes that an arrow cannot be too stiff, if you are shooting a release and you have near decent form. I simply have tuned too many bows to the point where I can shoot "too stiff" arrows well. Currently I shoot my Trykon XL with Arrow Dynamics .395 mags, PSE Radial X-Weave, Beman ICS Hunters, and Carbon Express CXL's. The only thing I need to do is change sight tapes on my Sure Loc and my left and right stay the same. I tune my bow for perfect flight with the PSE's or ICS Hunters and I find that the fatter shafts fly just fine for 20 yards. Buy the way, I can shoot NFAA field all day and drop a broadhead on either of my PSEs or ICS's and go hunting that evening.
Compare the above list of arrows, and you will understand that there is no way that any of the CXL's or .395 mags are going to be "properly spined" (always over spined).
Now, the Easton guides (and far too many other tuning guides) are old school, and have not been updated for far far far tooooo long. The left/right issues with spine were/are absolutly true for a finger shooter. Shooting with fingers creates arrow flight dynamics that demand that the arrow spine be near perfect. So, if you shoot fingers, the directions that JAVI gave you are the best ones to start off with. And think about it, if in this case you are over spined, it takes nothing to back your bow off a couple of turns and see if the groups get worse.
I see that you have already done what I would have first suggested with the WB. Remember, if you go too far, it can give you the same results and give you a false reading. Have you tried moving the WB to the left? Also, moving the WB, or any rest, to the right/left will change the location of the impact of the field point; this is normal. The broadhead will change much faster so when the two come together you are there, and you just resight. Just what do you mean by "moved the whisker bisciut towards the riser until it started affecting my field point flight"?
This is my concern. You have not mentioned what broadhead style you are using, but I assume you are using a fixed blade. You have your bow timed and tuned correctly, and it is shooting well. Now you have started to broadhead tune and found a problem I have seen this a lot. Often moving the rest a little WILL fix the problem by micro-tuning the bow/rest. BUT, when it won't, 9 out of 10 times the problem is shooter induced torque.
Remember that the little blades on the end of the arrow are acting like wings. If the arrow is moving left/right during the release the "winged arrow" will move to a different point that the "wingless" arrow.
If it proves out that Torque is your problem, you have time to fix it. Or, than again, if you are consistent each time (many are) than you can still resight for your broadheads.
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