The Bad With The Good

[adb]

I have to admit it's been a while (no arrogance intended), but I made firewood today. I was tillering out a new warbow. Hickory back, yew core, ipe belly. 74" NTN. 1 1/4" wide at the center, 1 1/8" deep, tapering evenly to 1/2" nocks. I had it tillered to 125#@29". I only intended it to be tillered to 30", and I was looking for 120-130#. It had <1" of set.

I asked my wife to come and snap a few pics at full draw. I exercised it well, pulling it multiple times to 120#, no problems. To get a full draw pic, I had to hold it for 3-4 seconds to give my wife enough time to center the shot and let the camera focus. Catastrophic failure. After autopsy, I could see it blew a tip off. Top tip. I've been making my tips lighter over the years to improve cast and reduce handshock, but I definitely went too far and didn't leave enough meat on these.

Looking at the full draw, I can see the left limb (would have been bottom limb) is a bit stiff especially in the outer third. I would definitely have fixed this had it survived.

First pic: full brace
Second pic: 125#@29"
Third pic: my wife caught it just after it exploded. You can see flying chunks!
Rest of the pics: autopsy

Without the bitter, there is no sweet.

[paulsemp]

That sucks! Better on the tree than in your hands at a 120lbs. A lot of good action shots lately!

[adb]

I wouldn't have to worry about it exploding in my hands! I can't fully draw 125# anyway. I can shoot 100# comfortably, but even 5-10# above that is impossible. The difference between 100# and 120# seems logarithmically different.

[ravenbeak]

Wow,

I heard an explosion recently and thought they were blasting up the road,  now I know what it was!

Tough one,   I too am consistently playing the how small can tips be game.  I guess the rules get exagerated with draw weights that heavy.

All in all a good lesson in more more woops too much,

[Easternarcher]

ADB, what were the dimensions of your tips? they look fine to me....but point of reference is not there.

[adb]

Wow,

I heard an explosion recently and thought they were blasting up the road,  now I know what it was!

Tough one,   I too am consistently playing the how small can tips be game.  I guess the rules get exagerated with draw weights that heavy.

All in all a good lesson in more more woops too much,

Yup! Scared the HELL outta my wife.  She hit the deck! "OMG!! WTF???" Made a helluva bang! I won't be bringing this one to the shows Jamie... sorry!

[adb]

ADB, what were the dimensions of your tips? they look fine to me....but point of reference is not there.

I'll take a pic of the tip and post it later. Way too small for the weight, obviously! I think the problem was more the thickness than the width. I took too much off in the string groove, basically cutting it too deep. Live and learn.

It's a bit confusing in the picture. That's the top tip. It actully has two grooves. The top groove you can see in the picture is the stringing groove. The String nock is below that, and that's where it failed... in the string groove.

[nineworlds9]

What a bummer man 

[adb]

ADB, what were the dimensions of your tips? they look fine to me....but point of reference is not there.

I'll take a pic of the tip and post it later. Way too small for the weight, obviously! I think the problem was more the thickness than the width. I took too much off in the string groove, basically cutting it too deep. Live and learn.

It's a bit confusing in the picture. That's the top tip. It actully has two grooves. The top groove you can see in the picture is the stringing groove. The String nock is below that, and that's where it failed... in the string groove.

Pics of the broken tip.

[adb]

Remember, that's the top tip, and the groove that's intact is the stringing groove. I'll leave a bit more meat next time!

[Easternarcher]

I see now....ya, tiny to start with, and the grooves musta been real thin....

[adb]

Yup... I know where the tip size limit on heavy bows is now!

[Ian.]

The positive I would take away would be, its been glued well to break in that fashion. How about full nocks next time though 

[adb]

The positive I would take away would be, its been glued well to break in that fashion. How about full nocks next time though 

Yup... I've never had a glue line failure. My nocks will have more meat on the next one! I doing the glue up for it today... same combo.

[toomanyknots]

That sucks about the brake. The tiller was very nice.