Hand shock .. Slot in limbs

[Bradford]

I have an idea, but I am sure it has been thought of before.  To help reduce hand shock, I was thinking of routing a slot in the limbs about 8" long x 1/8" wide.  Then you can put in rubber limb savers to help absorb shock and make it quite.

Has anyone tried this, or seen this?

I think the limb would retain it's over all strength, being that it will be fiberglass with epoxy..  

Thoughts?  Comments?

Part of this stems from the fact that I have arthritis in my hands, and any hand shock really hurts.  So I am designing a arthritic freindly traditional bow.  I know, call me krazy!  But designing something is half the fun!

[Aznboi3644]

hand shock is left over energy in the bow.

I'd go with a heavier arrow to absorb more energy.

[Bradford]

I have not built the bow yet.  I am just coming up with design ideas.  I see that most compound bows are some what designed with slots in the limbs and was wondering if it can be done with a recurve

[John Scifres]

I'm sure it could be done but I've never seen it.  Experimenting is fun.  Try it.  Report back on the progress.  In the meantime, if you haven't already, do a search on "handshock".  There are several tricks and techniques to minimize it.  Good luck.

[beetlebailey1977]

Mr. Bob Jones from here in SC has been building recurves like that for years.  If I can get some pics I will post them.  He doesn't use them for limbsavers though.  I suggest shooting heavier arrows.

[Bradford]

That is encouraging.. like to see some photo's.  
Again.. this is for research.. idea's.  I know you can shoot heavier arrows, but trying to see what "else" can be done.. invented.. designed.

Thanks all..

[Aznboi3644]

I had noticeable handshock on my last few bows.

Once I started narrowing my tips down to about 1/4 inch wide I haven't had any handshock issues.  I was hesitant to make my tips that small in fear of the bows breaking but 1/4 is plenty strong as long as there is enough depth.

[bjansen]

I would love to see it. I expect you would make round ends for the slots and use ULS glass and even a uniweft core to ensure if would not try to split up the limb.

[John Lipinski]

I'm not exactly getting the picture here--I have an idea, but could you draw out what you have in mind?

[Bradford]

Sorry about this pic.  I dont have a scanner to draw and copy a pic, so had to use Microsoft paint.

Yeah, I am going to try it after christmas.  I have been reading up on limb technology and what makes a smooth and fast limb.

 

Yes.. rounded ends as well as the whole slot edge rounded off for stability... yes on the glass.. core, maybe not so much.  I was thinking of adding epoxy to the edging for added strength.  

We shall see!

[PEARL DRUMS]

What will the added weight of the rubber do? It seems the wood removed would weigh less that the rubber added? I would think doing it lower on the limb would work better, just to keep extra weight off the tips.

[Bradford]

The rubber was just an idea.. I am now finding out that those can just be stuck on with an adhesive backing.

But rubber shocks put aside, I am now thinking this might add performance because it will lighten the limb.

But I am sure I will loose some #'s with it as well.

And yes, putting limb savers down toward the base would still help with dampening shock and should not affect performance.

[Schmidtster]

I use the stick on rubber limb savers on an X200, I noticed a difference. But also I'm sure you would be able to integrate it into a limb, I've seen many bows (selfbows) a couple on this site wear knots have been removed on the limbs leaving holes the size of a quarter through them and they are completely functional. Just a thought, remember you could come up with something awesome just by giving something different a try!

[Bradford]

Leave it to my Canadian neighbor to answer another burning question...  Thanks Schmidtster!

I was actually thinking of small holes as well.  A way to lighten and accent the limb... maybe let air pass thru for more speed????

I just LOVE coming up with all these ideas.  How fun!  Can't wait to try them.. come on Christmas, I need more money

[canopyboy]

The limbs are structural beams.  The outer fibers carry the load, one side in compression and the other in tension.  The core carries the the shear, or essentially keeps the two outer surfaces appart.  Putting holes through the face of the limb is essentially narrowing the limb by the diameter of the hole at that point.  Structurally, it's the same as cutting two semi circles in the outside edges.  In short, I think it would be a bad idea as you'll have weak spots in the limb at each hole.  You could drill through the core very carefully from one side to the other, preserving the faces and possibly get some benefit theoretically.  But that would be a lot of work for minimal gain.

On a selfbow, working around the knot (and any resulting hole) is possible only by leaving extra wood in the area (both in thickness and width) to make up for the loss.

Trying to save weight and going back to beam theory, you could go narrower and thicker limbs. The stiffness of the limb is dictated by (width*height^3)/12.  So since stiffness is affected by the cube of the thickness, a little thicker and a lot thinner will have the same effect, assuming you haven't reached the strength limits of your material.

[bjansen]

An old ad attached.  I would like to see how the nocks are and what the brace height is....but interesting to say the least.

 

[Osagetree]

Seems like there would be allot of tension on the belly out at the tips. Interesting, I've never seen that!

[don s]

would this be the same principal as a harmonic dampener that some wheelie manufacturers use.
                                     don

[Aznboi3644]

Doesn't matter if its tension or compression on the belly...its glass.

Some one over on PaleoPlanet reconstructed an actual horn wood sinew bow with slotted limbs.

Looks interesting though.

[hova]

i love that! looks like it might be a good candidate for a recreation here...