Reducing tips and such for speed

[avcase]

There may be a couple of things happening here.  You minimized mass in the tips of the bow which should help performance, but if it reduced the stiffness of the limb near the tips, which may may have losing most of what was gained by the reduced mass.  I have experienced this many times. I even had a bow or two show worse performance after a tip reduction because the tips would start to flex and deform at the end of the shot, which interferes with the bow effectively converting limb kinetic energy to arrow kinetic energy at the end of the shot.

Alan

[Marc St Louis]

  Tim Baker ran a test many years ago using lead tape on the tips. I don't remember much about the results except it took a lot to make a difference. I still keep mine slim at about 3/8 but the 1/4" tips I reserve only for light arrow flight bows. Lighter arrows do benefit more from lighter tips than hunting weight arrows.

The test Tim did was nothing more than a rehashing of the test done in Archery: the technical side

I was going to say that light arrows benefit more from light tips

[DC]

I did some machine shooting.
Bare finished bow, no serving 5 shots average 174
11 grams of lead on lower limb average 170
11 grams on upper limb av 169
11 grams on each limb 163
Then I shot the bare bow again av 172
Served the center of the string, + 4 grains av 171

So the bow relaxed a bit while testing, it is still fresh, but at least I could see some change. You have to take off quite a bit of wood to make 22 grams. I only managed to take off 10 grams when I made the bow. I was pleased that I could see a 4 grain change. It was closer to 1.5 fps but it was definite. These chronos are amazing things. In all the five shot groups the biggest difference was 1.5 fps. I noticed afterwards that the fletching wrap was getting worn from where it was snagging on part of the machine. That may have caused a variance. Fixed now

[DC]

  DC, you are ignoring the biggest factor, you don't loose all the energy it takes to accelerate the limbs, most of it goes back into the arrow. I said a few posts up that a well made bow only has about 150 grains of virtual mass and about 50 of that is string mass. Your limbs weigh about 2,000 grains a piece, if it wasn't going back into the arrow your bows would have almost no power at all. 100 grains off your tip is more like 10 grains off of an arrow.

I'll have to spend some time figuring this out. After my testing I can see that you're right, I just have to wrap my head around it.

[Badger]

  That was a cool test you did, simple enough but something most of us never get around to doing.,  Think of the arrow as getting heavier as the string angles get lower, not as much weight pushing against it but the now heavier arrow is more effectively slowing down the limbs, as it slows them down it sucks the kinetic energy back out of them.

[BowEd]

Ditto DC.....Your experimenting has shown something here for all to pay attention to.Thanks for doing that.Personally when I converted over to FF string from B50 I noticed the most significant raise in fps in the past.
Badger...Good analogy as to getting someones' head around what's going on.
I measured my serving weight once on the latest string[never did before]and it was 12 grains.Things dooo all add up when chasing fps.

[Selfbowman]

Well this is interesting but one thing for sure big tips equal shock
In my findings and that is not good to me. At some point mass has to count on the tips or the worlds slowest bow would not have won the contest. arvin

[Badger]

   Arvin, I think the outer limbs do make a big difference if you are talking grossly overbuilt as opposed to already slim and then just making them scary slim.

[bradsmith2010]

thanks for the info, really makes since the ways you guys described it,,

[Selfbowman]

Yes Steve what I did when I first started was 3/4 inch wide tips a 1/2 inch thick.  my bows were slow and full of shock. That been said I often see bows built the same. We all start somewhere. I was enjoying the builds none the less and that is what counts when first doing this crazy hobby. As the works get better and appreciated by some folks you can now figure you are doing it right.
We don't ever quite learning and forums like this make the learning curve
easier. Don't know what this was like till about 3-4 years back. But it has been very
helpful to me. Arvin

[bradsmith2010]

I just kept thinking about this thread,, back in the day, I would take off wood,, weigh it then see if the speed increased it,, as stated, on very wide tips it willl make more of a difference,, but as you get narrow seems there is a point of diminishing return,, just like when the arrow gets lighter, there comes a point where the bow wont shoot faster,,even with a lighter arrow,, thanks again for all the positive input,, I enjoy learning how to make my bow better or more effecient,,or at least having the options to try different techniques,, 

[Del the cat]

I think you nailed it with the law of diminishing returns.
Del

[Marc St Louis]

I just kept thinking about this thread,, back in the day, I would take off wood,, weigh it then see if the speed increased it,, as stated, on very wide tips it willl make more of a difference,, but as you get narrow seems there is a point of diminishing return,, just like when the arrow gets lighter, there comes a point where the bow wont shoot faster,,even with a lighter arrow,, thanks again for all the positive input,, I enjoy learning how to make my bow better or more effecient,,or at least having the options to try different techniques,, 

With wide tips you also have to factor in air drag, one thing narrow tips don't have a problem with.  When we were kids we would snap off a twig and swish it through the air when going for a walk in the bush.  The air drag was noticeable but leaving a leaf on the end would increase that drag considerable

[DC]

Maybe if I get bored I'll try taping cardboard to the tips and see what happens. I've always wondered about this.

[bradsmith2010]

hmmm,, didnt think bout that