Bamboo-maple-horn, 98#@28"

[Badger]

   I don't know how you keep the handle from popping off at that heavy weight? Is it pinned?

[Tuomo]

No, just glued with SmoothOn.

In fact, I don't know if it will stay or pop. I am not able (yet) to shoot this bow, so it is not really a problem yet.

[Pat B]

Generally speaking, when a handle pops off of a self bow, at least, it's because there is movement(bending) in the handle and no amount of glue will prevent that. You might try wrapping it with sinew or another strong thread. I've been successful at doing that. On your next one try adding a power lam to prevent the handle area from bending.

[Tuomo]

This bow has an osage power lam. I use a power lam in every laminated bow — it’s a nice detail and also helps prevent the handle from popping out. A thin and long strip between the belly and the handle piece is also a good option. Most problems occur when the handle piece is ipe or another very rigid material, because it doesn't bend with the bow.

[JW_Halverson]

I think it is right and proper that the VERY FIRST new Bow of the Month Award goes to an absolutely exemplary showpiece of mastery of the art and craft.

No, this isn't my cup of tea, but in this case, I am no fool. I cannot help but admire the fine lines, the clean glue lines, the aesthetic and functional choice of materials blended together into something this side of perfection. I look back at the other comments, and I am pleased that most are from bowyers far better than I with knowledge and skills well beyond my abilities. They recognize the workmanship, too, they that are far less likely to be fooled by looks over execution.

Tuomo, you have earned some bragging rights with this bow. Congratulations.

[Tuomo]

I chronoed this bow. With a light 463 grain arrow (about 5 gn/#) the result was 256 fps. Quite ok, I am happy. Shot with a shooting machine, witnessed by my friend.

[Badger]

I chronoed this bow. With a light 463 grain arrow (about 5 gn/#) the result was 256 fps. Quite ok, I am happy.

  That is good speed!

[sleek]

256fps is certainly on the HOT side of things. Thats fast! Especially with a 460 grain arrow. Id like to see what it will do with a 320 grain arrow.

[Badger]

256fps is certainly on the HOT side of things. Thats fast! Especially with a 460 grain arrow. Id like to see what it will do with a 320 grain arrow.

  It should do around 300 fps. Maybe a little less.

[mmattockx]

256fps is certainly on the HOT side of things. Thats fast! Especially with a 460 grain arrow. Id like to see what it will do with a 320 grain arrow.

Based off of energy storage the 320gr arrow will go ~308fps if the bow efficiency stays the same. It will likely drop a bit with the lighter arrow, so figure on a bit less.


Mark

[Badger]

If he is storing 100% of draw force it would put his virtual mass at about 200 grains. Giving him around 285 for 350 grains. If he is storing less energy he would have a lower VM and have a higher speed.

[mmattockx]

If he is storing 100% of draw force it would put his virtual mass at about 200 grains. Giving him around 285 for 350 grains. If he is storing less energy he would have a lower VM and have a higher speed.

It doesn't matter how much energy is stored because it is the same for both arrows. To get the velocity for the 320gr arrow you simply equate the kinetic energy of both arrows and solve for the velocity of the lighter arrow. That assumes the efficiency stays constant, which it likely doesn't, so the lighter arrow won't quite get to the calculated speed.


Mark

[Badger]

      You are wrong the best predictor of speed over an assortment of different weight arrows is virtual mass, which is based on stored energy and efficiency. The lower the virtual mass the less drop in ke as arrows get lighter.

   I would guess that this bow probably stores about 93% or in that area. In that case his virtual mass would be lower and his arrow speed might be closer to 300.

[sleek]

I chronoed this bow. With a light 463 grain arrow (about 5 gn/#) the result was 256 fps. Quite ok, I am happy. Shot with a shooting machine, witnessed by my friend.

Do you mind solving a debate and making a 320 grain arrow to chronograph?

[Badger]

  There is no debate because we don't know how much energy the bow stores; we can only guess at this point. Using virtual mass to predict arrow speed is not debatable; it has been used for decades. Now, just for fun, if he shot, say a 700-grain arrow and then let us guess the speed of the 320 it would be fun. I thought you said 350, I will go back and figure it at 320 with 160 grains VM and see what it comes to.

 Ok my official guess is 292