lever length experiment (not for bom) finished pics with bullsnake skins

[ken75]

this was an experiment with lever length versus working limb length that was inspired by a conversation with rich r. hickory 58 inch tip to tip ten inch working limbs and 15 inch levers 44lbs at 28 2 inch fades down to 1 1/4 at lever fades. guessed on the tiller profile , and ill flight shoot tomorrow after my midnight shift. keep in mind this was just an experiment to see what improvements to cast lever to limb ratio would make

[ken75]

more

[oat]

kooi (1996) predicted that the bow with longer "ear" may show a better force-curve, but the efficiency could be lower and hence the final results are not much different. It woud be nice to hear that someone doing the wet experiment on this matter.
The "ear" angle, however, was predicted to play more role on the final result.   

http://www.bio.vu.nl/thb/users/kooi/kooi96.pdf

[Frode]

Ken,
I'm looking forward to your results!  Nice looking bow!
Frode

[half eye]

Ken,
    That brace and full draw pic both look about too good. Looks to me that the levers being longer makes the workin limb bend less to get the same draw length.......cant wait to see how she does on cast, guess that will be the true indicator. Also like that low brace height maybe the longer power stroke will give some more distance too.
    Hell man, get 'er shot.....the suspense is killin me.
That whole bow is just way sexy looking.
rich

[AncientArcher76]

Ken very unique expiriment!  How does it shoot???  I would assume cast would either be fair or it may be kinda like the turtle bow as not much kinetic energy is being made with the short bending limbs.  It looks cool let us know what happens

AA76

[medicinewheel]

Well, since the bending portions of the limbs taper, there is a very small segment, that stores the biggest part of the energy...

[Badger]

     I will speculate that cast will be fair but not great, as said above stored energy and fdc will be good but efficiency will suffer. As the arrow approaches brace height the weight of the arrow increases dramaticaly as far as the bow is concerned because of leverage angles. The arrow is trying to stop the limb tips from mving past brace. A long stiff lever carries quite a bit of momentum on it's own and the arrow cannot slow the tips down as effectively, this might manifest iteself in handshock or just some energy lost to limb vibration. Now take that same bow with a very heavy fishing arrow for instance and it would likely outperform one with shorter levers, the heavier arrow would be better able to control the limb tips. Steve

[hillbilly61]

I like it. It has that look of deviance. Don't look like it would do much, but we know it has that hidden energy. My first one that turned out to be a hybrid. Is a very hard shooter. Working on the next, but my bandsaw blade broke 3" from having the limbs cut.
 Rich has given me allot of info on these and it keeps me intrigued. Good luck on the shooting session. Can't wait to hear the results

[PatM]

 It may be worth visiting the "Hickman stiff limbed theoretical bow" thread over on Paleoplanet

[Keenan]

Very good to see experiments that we all can learn. I like Steve's prediction and would have to agree. Often where we increase advantage in one area, we will suffer in another. It is always a balancing factor.

[jwillis]

That is a really cool looking bow. It will be very interesting to see how it shoots. Here's a idea... since this is an "experiment" bow anyway, wouldn't it be interesting to shoot the bow with a 10 gpp arrow and measure the performance...possibly even take a chrono reading and make a FDC...then shorten the levers some and test it again with a 10 gpp arrow...then shorten it some again and test it again? If you do this, I'm thinking that you would want to shorten the levers from the mid-outer limb instead of piking it. Jim

[ken75]

alright first of all thanks for all the input im glad others are interested . as i said the tiller was a guess if you look at the blown up pic by Frank the working limb bends like a mini regular limb i think u have to ignore the levers and watch the workin limb JMO.

the only thing i truly disagree with is the comparison to the turtle bow , which for those that dont know was a log with a bow in the center, these levers are 3/8th to 5/8th and hardly like Hamm's turtle bow that if memory serves me made it 21 feet !

i did the flight shoot with it this morning in not so fare conditions rainy and foggy, however 460gr arrows with ma2 broadheads had a 148 yrd. four shot average.
this one was 17 lbs lighter than the bow with 15 inch working limbs and 11inch levers which got 183 yrd average. so i think its fair but not as good as it could be . Rich has said before that equal lever ,limb length ratios were optimum and i agree after this expirement.
 
i would start removing lever length but that would require retillering down to 44lbs each time to get proper judgement of effiency, limbs are less than a 1/4 so im done with it , thanks everyone !

[ken75]

few pics

[Badger]

  Thats decent performnace, I bet you could thin out the thickness on those levers and get a bit more out of it without changing the tiller. Steve