Author Topic: how fast can you really make them  (Read 7071 times)

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Offline bradsmith2010

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Re: how fast can you really make them
« Reply #30 on: August 17, 2019, 02:28:41 pm »
I think the glued in profile had less mass

Offline Selfbowman

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Re: how fast can you really make them
« Reply #31 on: August 17, 2019, 02:36:32 pm »
Brad maybe easier to control the mass. If you don’t have to deal with knots, humps and such. Arvin
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Offline Selfbowman

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Re: how fast can you really make them
« Reply #32 on: August 17, 2019, 02:41:54 pm »
Maybe a engineer could assist me . 470 gr. arrow 230 yds from a 50# selfbow at 28”. I don’t live and die by chrono.
Well I'll say!!  Osage is king!!

Offline timmyd

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Re: how fast can you really make them
« Reply #33 on: August 17, 2019, 02:48:10 pm »
So the backed bows that are getting faster speeds is that due to the glued in reflex or is it because they can be lighter made  in term of physical weight.

Its both. Reflexes limb causes the physical mass of the limbs to be less when achieving tiller. This in theory causes faster speeds because it takes less force to move a lighter limb. There are tradeoffs to everything and in this arena it's a tradeoff between speed and reliability of the bow. If you design a bow strictly for speed it won't last long. If you design it to be bomb proof it will underperform. This has been proven over and over in the glass bow world. It is worse in self bows

Offline Marc St Louis

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Re: how fast can you really make them
« Reply #34 on: August 17, 2019, 02:55:21 pm »
For me so far there is a big difference between backed(Bamboo or Maple) and self bows. The best I've managed with a backed bow is 193FPS@10gpp. The best I've gotten with a selfbow is in the high 170's. I'd be interested in what others have gotten with selfbows. I don't think they should be compared to one another.

  The 10gpp is arbitrary but it does eliminate a variable when comparing bows. In the end though, the ultimate quest is cast and that requires both a bow and an arrow.

I've done low 190's with a couple of selfbow but it's usually mid 180's.  Not too hard to do low 190's with a backed bow.  All this of course with 10GPP on a 28" draw
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Offline DC

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Re: how fast can you really make them
« Reply #35 on: August 17, 2019, 03:10:43 pm »
For me so far there is a big difference between backed(Bamboo or Maple) and self bows. The best I've managed with a backed bow is 193FPS@10gpp. The best I've gotten with a selfbow is in the high 170's. I'd be interested in what others have gotten with selfbows. I don't think they should be compared to one another.

  The 10gpp is arbitrary but it does eliminate a variable when comparing bows. In the end though, the ultimate quest is cast and that requires both a bow and an arrow.

I've done low 190's with a couple of selfbow but it's usually mid 180's.  Not too hard to do low 190's with a backed bow.  All this of course with 10GPP on a 28" draw

I've got some work ahead of me then ;D ;D

Offline Nasr

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Re: how fast can you really make them
« Reply #36 on: August 17, 2019, 11:20:52 pm »
 Mid 180 with self bows that's incredible. I got a long way to go.

Offline Badger

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Re: how fast can you really make them
« Reply #37 on: August 22, 2019, 02:50:44 pm »
  Several years ago I posted an experimental bow on here. My idea was to try and incorporate all the things into a bow that make it fast and then try to figure out how to best mitigate the issues that extreme designs create. I decided on a reflex deflex with huge  rounded recurves with the tips about 12" behind the back of the bow. A design like this would normally be very unstable as it would have an unusually large amount of string contact with the limbs and very low string angles for most of the limb as well. My remedy for the lack of stability was to use a very small working limb section just outside the fades. That put a lot of strain on a very small area so I had to make it about 4" wide.

   I knew the bow would break down fairy quickly but I just wanted to see if I could get a few shots off before it broke down. I only tillered it out to about 22" and extrapolated to weight to be about 50#. I hooked it up to my shooting machine with a scale inline and started shooting. The first shot right at 50# shooting a 500 grain arrow hit 212  and started dropping in speed and weight with each shot. After about 10 shits it had leveled off at about 38# and hitting 157 fps with a 500 grain arrow.

   On the first shot it had stored about 125% of energy in relation to peak draw force.  The last several  inches of draw had a slight let off with no weight gain. Some of that was because of the geometry of the bow and some of it was most likely due to the bow taking set as I drew it further.

Offline DC

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Re: how fast can you really make them
« Reply #38 on: August 22, 2019, 03:50:38 pm »
So was this almost a Turkish horn bow made of wood?

Offline sleek

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Re: how fast can you really make them
« Reply #39 on: August 22, 2019, 04:26:34 pm »
Maybe a engineer could assist me . 470 gr. arrow 230 yds from a 50# selfbow at 28”. I don’t live and die by chrono.

I'm really hoping someone will be able to answer this. That's an astounding shot.
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Offline Badger

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Re: how fast can you really make them
« Reply #40 on: August 22, 2019, 05:13:10 pm »
So was this almost a Turkish horn bow made of wood?

  There were a lot of similarities but the hooks were larger and rounder. Most of the Turkish bows I have tested seem to run about the same speed through the chrono as the top wood laminate bows do. I have never tested one to hit over 184 with 10 grains but have seen reports from accurate sources that were a bit faster.

Offline Badger

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Re: how fast can you really make them
« Reply #41 on: August 22, 2019, 05:15:47 pm »
Maybe a engineer could assist me . 470 gr. arrow 230 yds from a 50# selfbow at 28”. I don’t live and die by chrono.

I'm really hoping someone will be able to answer this. That's an astounding shot.

  The chrono will tell you more about the bow, the distance you shoot is about the bow, the arrow and the shooter, how clean it comes out has a lot to do with it. I have hit 242 with a self bow and 252 with a backed bow but not official and only official really counts. An arrow that comes out clean  right from the start can add a lot of yardage.

Offline Selfbowman

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Re: how fast can you really make them
« Reply #42 on: August 22, 2019, 05:59:07 pm »
Thanks Steve we will see how it does in about a week. I think my shoulder and pinched nerve are on the mend. At least I hope so. CBD cream seamed to help a lot . See ya at Wendover. I am at Smith Creek now. Arvin
Well I'll say!!  Osage is king!!