handshock and string vibration?

[Jesse]

Limb timing and tiller are important contributing factors to me. Timing and tiller are not the same.
Also, limb mass. Too much mass for the design will add shock.
Yes, indeed, a bow that bends TOO much in the handle will shock.
Jawge

You said timing and tiller are not the same. I agree with that but what is your description of timing? I see it as simply an imballance from top to bottom limb where they fight eachother and rob energy from where it should be going. Imbalance puts energy back in the bow instead of the arrow.
Thats just how i visualize it. I could be wrong. That said on the type of bow i make which is mostly r/d longbow shot 3 under. I make the top and bottom exactly the same with no bend in the handle and shock is not an issue. If they are off a bit the chronograph shows it as well.

[Marc St Louis]

You would have to be a pretty poor bowyer to tiller a bow out with bad limb timing but I'm sure it can be done.  Limb timing and tiller are related but there are other factors you would have to screw up to affect limb timing. 

Some people describe limb timing as a bow with limbs that come back to rest at different times.  For that to happen the bow you would have to have limb tips with vastly differing mass and a cockeyed tiller

[Jesse]

You would have to be a pretty poor bowyer to tiller a bow out with bad limb timing but I'm sure it can be done.  Limb timing and tiller are related but there are other factors you would have to screw up to affect limb timing. 

Some people describe limb timing as a bow with limbs that come back to rest at different times.  For that to happen the bow you would have to have limb tips with vastly differing mass and a cockeyed tiller

  subtle diferences do affect the performance though. I dont know how to post pictures anymore now that photobucket doesnt work. I have pictures where you can not see anything wrong with the tiller by eye but when traced at brace the limbs have slight differences. After correction the performance goes up as confirmed by the chronograph. Its Such an easy way to fine tune the tiller because the lines show exactly where the limbs are different. You can fine tune it to the point that when traced with a mechanical pencil you will only see one thin line.
 

[DC]

If you have one limb that is narrow and thick and one that is wide and thin but the draw weight and mass are equal could it be "balanced"?

[Jesse]

If you have one limb that is narrow and thick and one that is wide and thin but the draw weight and mass are equal could it be "balanced"?

i would think so . I have made mostly tri lam type bows where its easy to keep everything matching perfectly.

[redhillwoods]

This is why I love this forum so much. In the past, I have only had TBB 1-4 as a guide. They're  an incredible foundation  to learn from, but the opportunity to just ask a question and receive so many insightful answers from so many competent bowyers  is an absolute revelation. I don't have a problem with handshock in my bows however I have noticed differing degrees of it from none at all to a certain feeling of it and I wanted to learn as much as I could so as to minimize it as much as possible. I will continue to post questions/queries and remain in utter appreciation to everyone for the answers and feedback. Thanx everybody. Dave

[willie]

I have pictures where you can not see anything wrong with the tiller by eye but when traced at brace the limbs have slight differences. After correction the performance goes up as confirmed by the chronograph.

interesting. just to clarify. Are you observing tiller at full draw? on the tree or in a pic?
And when the chronograph shows an improvement, can you notice a difference in handshock?
thanks
willie

[Badger]

   It has been my experience with handshock that very often the most perfect looking tillers are the worst offenders. Unless you know what you are looking for.

[George Tsoukalas]

Jesse,
timing to me is when both limbs return at the same time but not necessarily together depends on the wood's character of lack of it.

Good tiller is when each part of the limb is doing its share of the work but yet working harmoniously with the other limb.

There are times (character bows) when the tiller may appear off  but, nevertheless, the tiller is right for that particular bow...different limb entry points in the handle, one limb reflexed or deflexed, the presence of knotted areas which should not bend much in relation to the rest of the limb,etc....Here well timed limbs may not end up in the same place relatively but that is ok.

Let's take the situation where one limb is reflexed and the other is not. The reflexed limb needs to bend just as much as the one that is not reflexed. It will stop higher than the other...timing good...tiller good but appears off.

With flawless staves, a good tiller means the limbs will be timed properly.

Tired now. Not sure I am getting my points across.

Thoughts?

Jawge

[Philipp A]

I make most of my bows with 1" difference in length between the top and bottom limbs. All my bows are bendy handle HHB bows with an elliptical tiller and most are around 67" length n/n. Even though I have relative thin handle sections (both in width and thickness) I have few problems with hand shock and if I feel a bit of it during tillering, I thin out the limbs a bit more and it goes away. I am however using relatively beefy string silencers that are between 2.5" and 3" long from grey fox and lynx that have relatively long fur.

Now to the Questions: Other than having an elliptical tiller, do the string silencers affect hand shock and to what extent do they affect speed? Also does your shooting style impact it? I shoot mediterranean style and hold the handle comanche style with the thumb upright on the belly.

[Tuomo]

Watch this - it seems that limbs are working in unison, right? Are the limbs timed well or not. Tiller is way off but has it really any kind of meaning?

https://www.youtube.com/watch?v=6iHEiBa7zMg

There is a bit handshock (see my fingers) but nothing special. Every bow has that kind of forward motion. Look this video - a lot of handshock because of no arrow:

https://www.youtube.com/watch?v=od8e1MqS_w8

Here is the last example (and my first slow motion video...) - bendy handle bow with shorter lower limb. Seems that limbs are workin in unison but right after brace height, they are NOT vibrating in unison. What really is happening there? Is the reason different limb masses?

https://www.youtube.com/watch?v=T9EUraxn82M

[Selfbowman]

Hand shock comes from lots of things. B50 is a Hugh cause. Believe me I argued with Rick Barby for a year about this. Two much extra mass around knots and crooked limbs and such. To much mass on the tips!!! Flipped tips that don't bend especially when real wide. Little or no handle. Yes heavy arrows help cover up hand shock but now you have made a slow bow slower. When talking about hunting speed is not everything for sure. A well placed slow heavy arrow will get it done. Heaven bows have more shock just cause . From my experience the two big contributors are b-50 and too much mass on the outer limbs! Arvin

[Jesse]

I have pictures where you can not see anything wrong with the tiller by eye but when traced at brace the limbs have slight differences. After correction the performance goes up as confirmed by the chronograph.

interesting. just to clarify. Are you observing tiller at full draw? on the tree or in a pic?
And when the chronograph shows an improvement, can you notice a difference in handshock?
thanks
willie

I tiller on the tree but then when it looks right by eye i go to the bench . At full brace height I lay the bow on its side on top of paper so i dont mark up the bench. Then i mark an index at the start of the fade and another at the string groove on one limb. I then trace the limb profile onto the paper between the marks. Next i switch to the other limb and line up the two points on the bow to the previous index marks and then trace the limb. If its off there will be 2 lines instead of one. The part where the lines are furthest appart is what needs work. I sand then exercise on the tree and re check. As far as this improving speed yes. As for shock its a bit harder to say because the bows i make do not have a problem with this generaly.  the more i think about this i think its probably a combination of things that add up in the bows that are really bad.
  Thanks Jawge great explanation on timing.

[burchett.donald]

   My biggest culprit in the beginning was the fact that I did not tiller from "MY" fulcrum point...Letting the tree depict to me the tiller, once I learned to tiller in the hand the last 3-4" by using a camera or a mirror and especially the feel in my own hand 90% of the vibration, noise, bow kick stopped...
    The interesting thing is when it feels and looks good in the hand it can look like crap on the tree when final weight and tiller is achieved...
     I have seen so many beautiful bends on tiller tree pictures and then the final draw in hand is so different...
    You see so many variables in shooting stiles...Heel down, high grip or whatever...My fulcrum point gives me my final tiller and balanced limb timing...It's very easy to see, take pictures of your bow drawn heel down, mid handle and a high grip and compare the change in the photo's...A tiller tree is NOT a human being...
                                         Just my 2 $ , Don

[Jesse]

That's a good point to bring up. If your shooting fulcrum point is not the center of the bow or the deepest part of your grip like on the tree it will be an issue.