Primitive Archer
Main Discussion Area => Bows => Topic started by: Selfbowman on December 09, 2020, 08:17:01 am
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If you shot 187-188-189 with one bow . Then shot another bow with the same arrow . It shot 198-199 -214 throwing out the 214 is the machine lying and and if so which bow is it lying on. Arvin
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That is well with the experimental error.
The difference in draw length and loose can easily cause that much discrepancy...
There is also the possibility of false triggering caused by arrow flex etc... e.g say the arrow is flexing and instead of the point triggering the first gate, it is just outside the sweet spot and the shaft 2" behind the point flexes into the sweet spot and triggers it.... then if the point itself triggers the second gate it will give a high reading ... as it's effectively been give 2" head start!
Poor lighting or strobing from the light source can also cause problems (florescents or LEDs can do that.. incandescents are ok).
Del
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So out of a gun they are more accurate. To many variables with bows. So back to what I said don’t matter how fast it gets there as long as it goes farther. Now that being said may be lots of wasted time and effort arguing about glass vs wood. Can wood be as fast I think yes. If it does not take set. There are more fast glass bows than there are wood bows because of set!!!!! It’s modern archery and there is a place for it when we set here and talk on a phone. I think you Del for that info you just put on here. It explains the different opinions. Arvin
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Arrows are tough at best to get consistant. Shot truck loads of shizzle thru a chronograph for work from BIIG bullets to missiles. Depends what type of chrono your using. Go get some good .22 ELEY Black box. On back of bow it has the lot and FPScode info for that lot. It will shoot very very close to that a 65-70 degrees out of a 22-25" barrel. That give you a base line of how your chrono is lying. Good Black Box runs 1035-1060fps it'll say on lot code.
You'll see right off if you machine is consistanly low or high. My guess over years of shooting thru them a little bargin unit will be a tad high.
Hope that helps Arvin
Hedge~
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If you shot 187-188-189 with one bow . Then shot another bow with the same arrow . It shot 198-199 -214 throwing out the 214 is the machine lying and and if so which bow is it lying on. Arvin
Am I reading this wrong? Of course a different bow will read differently.
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DC did the machine read one bow wrong when I got the higher speed ? If so why? Or where they both wrong and I’m wasting my time with it. I don’t explain myself very well sometimes. Is the second bow shooting faster? The machine said yes. The first bow has shot that arrow 239 yds. The second shot 246 at a shorter draw.both as close to 50# as I can get to meet flight weigh in. Arvin
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If you shot 187-188-189 with one bow . Then shot another bow with the same arrow . It shot 198-199 -214 throwing out the 214 is the machine lying and and if so which bow is it lying on. Arvin
Am I reading this wrong? Of course a different bow will read differently.
That’s what I was thinking DC. If they still read the same I would be curious.
Bjrogg
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I think to get the best result is to shoot a marble through the chrono instead on an arrow.
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In the Help me finish this recurve Thread Steve Questioned the speed of the bow thru the crono and I respect his thinking that’s all.but like y’all they should read different. I shot both bows within 10 minutes of each other.
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Arvin I just made the point that their have been wood bows that have shot 190 plus fps at 10 Gpp arrow weight. I have never came close to that with my bows. If I get 15 fps over 100 plus bow poundage I am happy. Personal best is Osage sapling sinew backed that shoots 165 at 25.75 draw at 45 lbs.. The machine that Mark shows his 190 plus has to be set up properly to get consistent readings. I am sure he knows how. Then their is shooter error. I shoot static. So that is the way I check my bows. Then their is Badger who bounces the string. Flight shooters know that stuff, and squeeze every fps they can out of their bows for distance shooting.
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I see what your saying now Arvin
The chrono would measure the speed as arrow leaves the bow. After that so many things effect it. Clean arrow flight probably the most important I would guesss. I don’t know much about tuning arrow for flight but I’m guessing you do. Could it be that the faster bow isn’t as in tune with the arrow?
Bjrogg
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The second bow would seem to be faster for two reasons. Why do you have a problem with that?
The question might be if the distance should be more given the additional fps.
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Pat don’t have a problem with it. Steve was questioning the speed but not my word. Again I respect Steve’s thinking to a great degree when it comes to bow making. At the end of the day if your coming to flats and expect to beat that bow you better shoot 250 yds if my bow hits its weight . Just saying.all contingent on Lord willing ! Arvin
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Simply pulling through the shot with a slightly bent bow arm will increase speed considerably. Most guys test bows with the same release they would use for hunting so in reality their bows are probably faster than they think they are. On the average without bouncing the string just making a clean release speed will usually come up between 7 to 10 fps. Powering a bow arm at the shot can boost speeds as much as 20 fps over what a shooting machine would get. I would never count a speed release as a bow test, it is simply how much can I get out of it test.
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Ok put that crono back up and keep building bows if you don’t know how to use them. Got ya guys. Been doing pretty good without it anyway. Thanks guys Arvin
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I believe you badger. Just making an observation. Saw Dave Mead on utube shooting static with a glass recurve, and then pulling through the shot ,and jumped speed of the bow by 15 fps.
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The second bow would seem to be faster for two reasons. Why do you have a problem with that?
The question might be if the distance should be more given the additional fps.
Funny how I missed that because my mind thought it knew what was going to be written and didn’t really read what was written.
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I have almost bought a chrono on many occasions. I will start using a cast test instead I think if I want to start tweaking a design. Honestly what has kept me from buying a chrono is worry that it will make a bow that I am perfectly happy with less than acceptable if I start focusing on speed numbers. I don’t build bows to sell, so I’m not awefully worried about the exact speed of a bow. I have bows that I know are dogs, and bows that I believe shoot pretty fast.on a good year I will make half a dozen bows, so I thank you guys that dissect the performance, because guys like me will steal your findings to improve the few I do make.
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If you shot 187-188-189 with one bow . Then shot another bow with the same arrow . It shot 198-199 -214 throwing out the 214 is the machine lying and and if so which bow is it lying on. Arvin
I'm still puzzled. What am I missing.
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I think to get the best result is to shoot a marble through the chrono instead on an arrow.
How do measure marble slingshot bore velocity? With the same chrono in question or do you have a marble shooter you've tested in a shooting tunnel with doppler.
So, you got the fastest self 50lb bow on the flats. Another guy has one 20fps slower (tested with a real chrono). You shoot into teeth of a cross wind and get 200yds. He steps up later and wind is directly into his face and he shoots 220yds. Howd that happen?
HH~
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I have almost bought a chrono on many occasions. I will start using a cast test instead I think if I want to start tweaking a design. Honestly what has kept me from buying a chrono is worry that it will make a bow that I am perfectly happy with less than acceptable if I start focusing on speed numbers. I don’t build bows to sell, so I’m not awefully worried about the exact speed of a bow. I have bows that I know are dogs, and bows that I believe shoot pretty fast.on a good year I will make half a dozen bows, so I thank you guys that dissect the performance, because guys like me will steal your findings to improve the few I do make.
Nothing wrong with reading and applying the new learned knowledge.
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I haven't done any real testing in yeasr but from what I have seen a really well made r/d self bow that didn't take much set and had maybe 2 1/2" reflex would seldom hit over about 176, a well made self bow recurve with about 2 1/2" behind the handle would seldom hit over 180 fps. Not talking hand shot bows here or super skinny strings. I think my fastest self bow recurve hit 184. That was before I was flight shooting. I have seen very few self bows pass 176 in an honest machine shot test although I know the Mark St Louis style will go well into the 180's as long as it hasn't taken too much set.
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I think to get the best result is to shoot a marble through the chrono instead on an arrow.
How do measure marble slingshot bore velocity? With the same chrono in question or do you have a marble shooter you've tested in a shooting tunnel with doppler.
So, you got the fastest self 50lb bow on the flats. Another guy has one 20fps slower (tested with a real chrono). You shoot into teeth of a cross wind and get 200yds. He steps up later and wind is directly into his face and he shoots 220yds. Howd that happen?
HH~
Did it?
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How do measure marble slingshot bore velocity? With the same chrono in question or do you have a marble shooter you've tested in a shooting tunnel with doppler.
I think the point was that the marble is easier for the chronograph to accurately pick up, compared to an arrow that is wobbling all over the place as it goes over the screens.
Mark
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If you shot 187-188-189 with one bow . Then shot another bow with the same arrow . It shot 198-199 -214 throwing out the 214 is the machine lying and and if so which bow is it lying on. Arvin
I'm assuming both bows pull the same draw weight. The efficiency of the bow would account for the difference especially if you're using lighter than 10 GPP arrows
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Thank you Marc. We where comparing one bow design vs another with the same off the wall handle being of the same length, wood. It looks like the recurve won the race. Both speed and distance. I am constantly moving that mass In the same length . Looking for the sweet spot. Using good wood from the same grove. It’s paid off with the help from this forum. Thanks guys. Arvin
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I'm pretty sure in the past I told you to just try a recurve when you were stalling a bit after perfecting your favorite design. ;)
Recurve guys know what's up despite people claiming increased strain will cancel it out. Maybe over time, but when you want to make one great shot, you'll use it.
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I think to get the best result is to shoot a marble through the chrono instead on an arrow.
How do measure marble slingshot bore velocity? With the same chrono in question or do you have a marble shooter you've tested in a shooting tunnel with doppler.
So, you got the fastest self 50lb bow on the flats. Another guy has one 20fps slower (tested with a real chrono). You shoot into teeth of a cross wind and get 200yds. He steps up later and wind is directly into his face and he shoots 220yds. Howd that happen?
HH~
Poor arrow flight.
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How do measure marble slingshot bore velocity? With the same chrono in question or do you have a marble shooter you've tested in a shooting tunnel with doppler.
I think the point was that the marble is easier for the chronograph to accurately pick up, compared to an arrow that is wobbling all over the place as it goes over the screens.
Mark
Exactly
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I'm pretty sure in the past I told you to just try a recurve when you were stalling a bit after perfecting your favorite design. ;)
Recurve guys know what's up despite people claiming increased strain will cancel it out. Maybe over time, but when you want to make one great shot, you'll use it.
Pat I am a Bit hardheaded to say the least. Pm me the recurve specs and I will attempt it . I am willing to try other things but not till I am convinced what I’m working on is short of the goal. Interested in new design always.any bow becomes a recurve at some point when flipping the tips. Explain to the country boy in simple terms why the deflex increased the distance? I’m also pretty dense like Osage.
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Just make the working limb less pure pyramid and your hooks more pronounced and a bit shorter.
As to how and why some designs shoot faster or farther despite what we may consider flaws, I don't really analyze that too much. I'm not an engineer or mathematician.
If something works, that's all that matters.
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A recurve has the mechanical advatage of a lower string angle. This lower angle through most of the draw bends a thicker limb for a given draw weight, thus storing more energy per # of work. Thicker limbs also have an inherantly higher frequency of vibration : eg. return speed. Generally that is offset by having to use a bit wider and thinner limbs on the recurve...gain here....lose there....the search goes on haha
Short and as sharp as possible, kerfed if necessary to make them near 90 degs.
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I think to get the best result is to shoot a marble through the chrono instead on an arrow.
How do measure marble slingshot bore velocity? With the same chrono in question or do you have a marble shooter you've tested in a shooting tunnel with doppler.
So, you got the fastest self 50lb bow on the flats. Another guy has one 20fps slower (tested with a real chrono). You shoot into teeth of a cross wind and get 200yds. He steps up later and wind is directly into his face and he shoots 220yds. Howd that happen?
HH~
What the wind is doing at face level and what it's doing 60 yards up may be entirely different...
Del
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Tell me about it. Jumped out of high performance aircraft for a living! Got that right but in desert what you usually seen AGL is what you got at 1000ft plus a little from my desert ABN Ops experience.
HH
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A recurve has the mechanical advatage of a lower string angle. This lower angle through most of the draw bends a thicker limb for a given draw weight, thus storing more energy per # of work. Thicker limbs also have an inherantly higher frequency of vibration : eg. return speed. Generally that is offset by having to use a bit wider and thinner limbs on the recurve...gain here....lose there....the search goes on haha
Short and as sharp as possible, kerfed if necessary to make them near 90 degs.
Got some pics of one of those fast recurves . I seen DC’s bow last summer. I started out with 7” radius hooks but could not get the string on it so flattened out the first part of the hook near mid limb. Then decided to test it against my record longbow for comparison. The bows are the same length how did that change the string angle much? Are you not sure it moved the working limb out toward the tips more. I will post a pic of the two bows side by side.
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Here is pics
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Pic
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Stacking those bows reminded me of pic up sticks.😁😁😁
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This is something I haven’t ever been able to wrap my head around, it’s an honest question, I have no trial and error experience on the subject, just the way my head understands bows.
Set robs performance. The more stress you can have in a design up until set happens the more energy is stored. All of the bows that I see that are built for performance have little working limb and stuff handles. The stiff curves add stress while their sole purpose is moving the limb tips forward? If you are going to limit working limb why would you not want the handle as part of the working limb? Would that not add a little energy without having to carry the limbs a long distance? Meaning if the handle doesn’t work till the last inch of draw, then it is pulling it’s weight to help, but not responsible for carrying the mass of the limbs. In my brain that would make up some for lost working limb real estate without adding length or limb mass.
I know you guys have made a science of this and been over everything with a fine tooth comb, I am just asking these things not to challenge what you are doing but learn why a properly working handle would not benefit a super stressed design.
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A recurve has the mechanical advatage of a lower string angle. This lower angle through most of the draw bends a thicker limb for a given draw weight, thus storing more energy per # of work. Thicker limbs also have an inherantly higher frequency of vibration : eg. return speed. Generally that is offset by having to use a bit wider and thinner limbs on the recurve...gain here....lose there....the search goes on haha
Short and as sharp as possible, kerfed if necessary to make them near 90 degs.
Got some pics of one of those fast recurves . I seen DC’s bow last summer. I started out with 7” radius hooks but could not get the string on it so flattened out the first part of the hook near mid limb. Then decided to test it against my record longbow for comparison. The bows are the same length how did that change the string angle much? Are you not sure it moved the working limb out toward the tips more. I will post a pic of the two bows side by side.
Arvin, recurring forces working limb to move towards the inner limb more, not towards the tips.
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Sleek which part of the limb moves the most? The otter limb right. The otter limb work harder but the maximum compression is at the fades. Yes or no? I think that the combination of both is where it happens. But what do I know this is my third recurve.😁😁😁😁
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How much narrower are limbs on the recurve? I was under the impression that they were more your typical limb profile but they look quite narrow.
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Pat it’s a happy accident I guess. That’s all the stave had in it. 1/12” on the recurve. 2-1/8 on the longbow.
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Sleek which part of the limb moves the most? The otter limb right. The otter limb work harder but the maximum compression is at the fades. Yes or no? I think that the combination of both is where it happens. But what do I know this is my third recurve.😁😁😁😁
With your pyramid shape all parts should have the same bend radius. As far as what MOVES the most, would be the tips, but thays only because of the arc of circle it travels. The Fades have the most control as a result being nearest the center of the circle. Id give a more descriptive answer, but I only vaguely understand your question.
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Pat it’s a happy accident I guess. That’s all the stave had in it. 1/12” on the recurve. 2-1/8 on the longbow.
I think just a bit wider would cancel your set.
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Mark, when I tested your bow I was using heavier strings. That same bow would have tested about 194 with a 6 strand fast flight.
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They are both pyramid in shape. The recurve is also diminishing mass In thickness from fades to mid limb or so then increases in thickness to tips . The longbow is pretty much the same thickness 5-7” out of fades to 5-7” from the tips at which it gets thicker at that point.
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Sleek which part of the limb moves the most? The otter limb right. The otter limb work harder but the maximum compression is at the fades. Yes or no? I think that the combination of both is where it happens. But what do I know this is my third recurve.😁😁😁😁
I was in a hurry when I replied before and I feel it was an inadequate reply. So, I'm gonna give it another try.
Yes the tips move the most, but you knew that The outer limb does not work the hardest, it actually works the least. The maximum compression could be looked at as being at the fades, but in reality, no. You want your compression evenly distributed across all the working limb area, if your fades have more compression forces per its surface area its overstrained, or the rest of the bow isn't strained enough, depending on which way you look at it. So, in short, the answer to the yes, no you ask is, no.
The reason I say recurves move the bending loads closer to the fade is that if you recurve a tillered bow, you will see the inner limb bend more with the mid and outer limb more straight. You will need to remove wood from those areas to bring the bow back into tiller, and that action will simultaneously bring the bow back down to its original weight by the way.
The bow coming back down to its draw weight at the same time the tiller comes around perfectly is what guides me to that perfect amount of mid and outer limb bend when I start with an already made bow. When I hit draw weigh I know I'm done. It also is a proof of what I said where the fade gets stresses pushed to it when you recurve a bow, and when you tiller it back out, you are redirecting those stresses to be evenly distributed again.
Did that clarify anything or help you out?
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Clear as mud. But I will read it again and again so maybe some will sink in. We can cover this more in person sometime. Arvin
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Made more than a few recurves. A far as working outter limbs elm worked best. They worked about 3/8th inch. Hedge bow recurves I have done, the quickest (by eye watching arrow cast) are pure statics both big hook and small. The fast one is long 68-69" and returns flat after shooting. Its not a pyramid and it carries more wood on outer third which adds limb mass. Its bends nice right into fade with a tad shorter riser than i normally do. It did not need string grooves but after a few years I added them just to take some weight off ends.
Think you either end up some set mid limb in a pyramis design but you prolly gain some speed back in lighter limb mass. In my shorter recurves do pretty close to a short 90 turn. I tend to leave outter third real stiff until I get it close. All these bows I hunt with and have taken whitetails with cleanly.
I may have a pic working up them elm.
HH~