Finished with speed testing.

[Buemaker]

I have finished this bow, but I have to wait a bit before putting a finish on. However I did some speed testing. I am posting a few pics.
Shooting machine with two speed testers set up in a tandem configuration. Why I do this can be seen in the build along section on top.
I have made this model before with better speed results, but it just shows that you should never change more than one thing at a time. With this one I made the the riser section 3/4 inch longer, the reverse taper in the ends 2 inches longer and one thing that I think is the reason. I used Uniweft instead of Stabil kore and by that made the limbs heavier. The bow is 66» ntn. 56,3 pounds at 28» draw.
Will continue with post in a few minutes

[Buemaker]

Here are some results, not bad I think. It is a bit of a hazzle to get arrows with an excact weight of 9 and 10 grains pr pound bow weight and right stiffness, but with the use of small washers between insert and point and grinding of points it works out. I tested with  16 strand Fast Flight plus string at brace height between 6 3/4 and 7 inches. I also tested with a 24 strand Mercury string. Did not see any difference. I used aluminum arrows with 5 inch helical fletched turkey feathers.
56,3 pounds at 28 inch draw, arrow weight 565 grains which is 10 grains pr pound bow weight. Speed was 183 feet.
I then used the same arrow at 29 and 30 inch draw.
59,4 pounds at 29 inch draw arrow weight 9,5 grains pr pound bow weight, speed was 191 feet.
62,6 pounds at 30 inch draw arrow weight 9,02 grains pr pound bow weight speed was 200 feet.

With 503 grain arrow, 56,3 pound bow weight, as close as I could get to 9 grains pr pound bow weight the arrow speed was 191 feet.

[Mad Max]

 
183 with 10gpp is good Bue

[Roy from Pa]

 

[kennym]

Above average speed Bue!  Very good!

[Crooked Stic]

I would be happy with anything in the 180s with 10 gpp.

[williwaw]

I am impressed you can get good speed without very much reflex. How many bows of this pattern have you built off that form? You vary the taper and reverse wedge, but keep the same R/D?

[Buemaker]

Williwaw. I am mostly a wood, sinew, bamboo bowmaker. When it comes to glass bows I make one once in a while.
I have made a few on this form with same RD and lenght and have changed tapers, riser lenght and reverse tapers.
The fastest glass bow I have made was the take down recurve I made as my trade bow to Woodcarver 2 two years ago. It tested at 28 inch draw 197 feet with 9 grains pp.

[Shredd]

  I feel for yah Bue Man... It's tough making a bow at a slower speed when the last one was ripping...  I personally think you had the magic recipe for that design on your last bow... It's tough trying to go past 190 fps... But we get sucked into, 'If I change just one more thing I can suck another 2 to 3 fps out of her... You did break one of the basic rules... 'Only change one thing at a time'...  Been there, done that...  At this stage of the game you probably know that a few thousandth's of an inch can effect performance...   My swap bow was shooting 185... I did not like the way she was shooting and I adjusted the tiller, now she is shooting 183...  Sometimes you can't have your cake and eat it too...

  Better luck on the next one...  Like the boys said, 183 aint too shabby... 

[Buemaker]

Shredd. Even though I know better, just change one thing at a time. I sometimes tend to be too impatient. I am going to make one more like this last one, but go back to the Stabil-Kore instead of the thicker and heavier UniWeft. Working my way backwords, that is. If no improvement doing that I will go back to the old recipe that I know is good.

[Shredd]

Sounds like a plan...   I know all about being impatient...    

[Roy from Pa]

Impatient???

No not Rich?

LOL

 

[Stagmitis]

Bue great job!

On a side note  one thing I learned when testing strings was to weigh them.  Difference in HP string speed had more to do with physical weight than material type- A heavier string in essence is like increasing arrow weight...

[Buemaker]

Stagmitis thank you. I did weigh the strings. The 24 strand Mercury was 0,7 grams heavier than the 16 strand Fast Flight. I called BCY and they recommended 24 strands for this bow. I have seen that Blacktail use a 15 strand Mercury with reinforced loops and Centaur use 20 strands with reinforced loops. I’ll try something like that next time.

[Mad Max]

That is a Liability answer Bue 

[williwaw]

I have made this model before with better speed results, but it just shows that you should never change more than one thing at a time. With this one I made the the riser section 3/4 inch longer, the reverse taper in the ends 2 inches longer and one thing that I think is the reason. I used Uniweft instead of Stabil kore and by that made the limbs heavier.

I am going to make one more like this last one, but go back to the Stabil-Kore instead of the thicker and heavier UniWeft. Working my way backwords, that is. If no improvement doing that I will go back to the old recipe that I know is good.

Bue, do you place the Uniweft or StabilKore just under the belly glass, or somewhere else in the the stack?

[Buemaker]

On this last one I put the Uniweft on the belly ramps. Just because the Uniweft was in 36 inch lenght. Before when using Stabil Kore which I had in full lenght I placed it between lams on the back of riser. To prevent twist I do not think it matter.

[Buemaker]

Here is picks how I did it with Stabil Kore

[Roy from Pa]

Very nice, Bue..

I think ya have the pictures fuggered out too:)

 

[williwaw]

the old recipe that I know is good.

Has neither Uniweft or StabilKore?