Tiller Check - 57" maple pyramid (also have questions to fix)

[burtonridr]

I'm working on a pyramid bow.... And I'm pretty sure I've got a major hinge on the top limb right off the fades. But I'm having a really hard time telling if it is actually a hinge, or if it just looks that way because of the shape of the wood. The top hinge leaves the handle slightly angled towards the string. But the pics and the tiller jig seem to be telling me it needs some shaved off the mid to upper mid limb.

I have a couple questions,

-Can it be saved? I've already pulled back to full draw because at 20" everything was looking really good.
-What are the cracks on the belly? Compression failure?(see pics) They are right at the fades on the belly. I did heat treat the belly.
-Can the cracks be fixed? Will wrapping with thread and super fix this problem?

[burtonridr]

Here are the belly cracks

[penderbender]

Looks like it's toast. It's only bending in the fades. How thick are your limbs? Learn from it and build another! Cheers- Brendan
 

[loefflerchuck]

Upper limb near the handle is doing way too much work. You can save it if you reduce the weight in the bottom limb and get the upper half of the top limb bending. Then match the bottom tips.

[loon]

it's at least chrysalling, if not worse
did you trap the back?
r/d pyramid? Someone said r/d bows should have even width limbs for the first 1/3 or 1/2 

[make-n-break]

What did you use to bend the recurves? It looks like you have two indentations where the recurves start... maybe you used a hard corner of a work bench or something? My eyes could be playing tricks. She's firewood either way I'm afraid. Onto the next!

[BowEd]

I've never had any long term durability luck with a limb or limbs that have chrysals or compression fractures as you've got there.I'm not saying it can't be done but it'll be a lot lighter weight bow in the end.I'd say just to scratch it up to experience and start over.It got pulled too far to save now IMHO.Parallel limb widths to mid limb for an R/D next time too.Plenty wide also.Flat belly and a little shorter draw length too for the length of bow there.
If a pyramid is wanted an Ishi style bendy handle would work a lot better at the draw length you want for the length of the bow you got.Starting out very wide with a flat belly also.
Either style would work but combining them does'nt IMHO.At least not with maple anyway.Might hold up a while with osage but I would'nt bet on that either long term.Good learning experience though and just my two cents worth of experience.

[DC]

Well, look on the bright side, you've learned what chrysals look like and where they form. On to the next one.

[Springbuck]

I'm afraid she's on her way out.  Not a terrible effort, though.  I see what you were going for in the strung profile.

Strictly, the minute you flipped those tips to reflex, it was no longer a pyramid bow and required a different tiller.  If you started with pyramid "specs" like an even side taper and essentially even thickness, that little reflex in the tips pushed all the strain, and hence the bend, toward that inner limb right off the fades.

I've done the same a couple times (at least) early on. Next time, if you keep that front profile, you have to adjust thickness along the limbs, going much thinner mid-limb, say the middle 50% of each.  Currently, all the bend is right off the fades, in the first 25%, and concentrated in the first 15%.  Right where the frets are.

Keep it up, though!

[burtonridr]

I'm afraid she's on her way out.  Not a terrible effort, though.  I see what you were going for in the strung profile.

Strictly, the minute you flipped those tips to reflex, it was no longer a pyramid bow and required a different tiller.  If you started with pyramid "specs" like an even side taper and essentially even thickness, that little reflex in the tips pushed all the strain, and hence the bend, toward that inner limb right off the fades.

I've done the same a couple times (at least) early on. Next time, if you keep that front profile, you have to adjust thickness along the limbs, going much thinner mid-limb, say the middle 50% of each.  Currently, all the bend is right off the fades, in the first 25%, and concentrated in the first 15%.  Right where the frets are.

Keep it up, though!

Crap that is exactly what happened.... And explains why it tillered out so nice until the very end (when I flipped the tips).

I took all kinds of measurements and just could not figure it out, everything was real nice and even. I was concerned to start shaving off to much mid limb, I've been to hasty in the past and suddenly had a bow 20lbs under weight real fast. I didn't realize that by flipping the tips I would increase work on the lower parts of the limb and completely mess with the tiller. I figured the upper limbs would still be working through the draw as before, just a slightly different shape. I will keep what you said in mind on the next one and reduce the limb thickness accordingly.

I really appreciate all comments, at least I know what happened. I will experiment with this thing until it fails, maybe learn some more in the process.

Good thing I still have the other half of this log to work with, and I like building them almost more than I like shooting

[burtonridr]

I've never had any long term durability luck with a limb or limbs that have chrysals or compression fractures as you've got there.I'm not saying it can't be done but it'll be a lot lighter weight bow in the end.I'd say just to scratch it up to experience and start over.It got pulled too far to save now IMHO.Parallel limb widths to mid limb for an R/D next time too.Plenty wide also.Flat belly and a little shorter draw length too for the length of bow there.
If a pyramid is wanted an Ishi style bendy handle would work a lot better at the draw length you want for the length of the bow you got.Starting out very wide with a flat belly also.
Either style would work but combining them does'nt IMHO.At least not with maple anyway.Might hold up a while with osage but I would'nt bet on that either long term.Good learning experience though and just my two cents worth of experience.

Thanks, this helps. I will keep this in mind on the next one and keep the limbs wide out to mid limb.

I'm not a fan of pyramid bows, this is my third try at one.... first one broke, second came way under weight, this one fractured due to poor design and planning. lol, not my cup of tea.

[burtonridr]

Looks like it's toast. It's only bending in the fades. How thick are your limbs? Learn from it and build another! Cheers- Brendan

They are a little over 1/2" thick for the entire length

it's at least chrysalling, if not worse
did you trap the back?
r/d pyramid? Someone said r/d bows should have even width limbs for the first 1/3 or 1/2 

I'm not sure what you mean by trap the back?

What did you use to bend the recurves? It looks like you have two indentations where the recurves start... maybe you used a hard corner of a work bench or something? My eyes could be playing tricks. She's firewood either way I'm afraid. Onto the next!

I used a piece of the log I cut this from.... I heated the portion with my little buddy propane heater with a wet piece of paper towel draped over it for about 5 to 10 minutes, bent a little, then repeated until I got it where I wanted it.

[Jim Davis]

I like pyramid bows best. But if you do leave them the same thickness all the way to the tip, the limbs will always bend more on the fade end that at the tip. It's because we can't actually taper the width to a point. So, we have to thin the limbs from about the middle to the tip, tillering as with parallel limbs.

Your thickness was probably about right, but longer limbs and more thinning as I said would have helped.

It's possible to cure chrysals by replacing the wood, but not worth the effort on maple unless you just want the practice. Here's a picture of replaced wood on the belly of an Osage bow.

[JW_Halverson]

You could try peanutbutter and jelly on it, because as it has been said by others, it it toast. On the other hand, it's a lesson learned.

I had real problems with my first half dozen pyramid bow, too.  And it was all pretty much what you are looking at here...top much bend too soon out of the fades.  I now use a machinist's caliper to carefully measure thickness down the limbs with a goal of keeping everything within 10-15 thousandths of an inch until the limbs begin to bend a little for floor tillering.  At that point, I thin the tips a little and start long string tillering.  The bow starts out whip tillered when you are beginning to tiller on the tillering stick or tillering tree.  Each inch of added draw as I tiller movesme to take wood off closer and closer to the fades. Clear as mud?

[burtonridr]

You could try peanutbutter and jelly on it, because as it has been said by others, it it toast. On the other hand, it's a lesson learned.

I had real problems with my first half dozen pyramid bow, too.  And it was all pretty much what you are looking at here...top much bend too soon out of the fades.  I now use a machinist's caliper to carefully measure thickness down the limbs with a goal of keeping everything within 10-15 thousandths of an inch until the limbs begin to bend a little for floor tillering.  At that point, I thin the tips a little and start long string tillering.  The bow starts out whip tillered when you are beginning to tiller on the tillering stick or tillering tree.  Each inch of added draw as I tiller movesme to take wood off closer and closer to the fades. Clear as mud?

Your description helps a lot, it sounds a lot different than tillering the two bows I built that didnt break. They werent pyramid style, one was an ishi paddle bow and the other is a standard r/d long bow. So, how the heck do you know you are going to hit your goal weight? at least in the beginning, say first 10 to 15 inch of tillering? It sounds like it would be super light out to about 10 inches, does it stack different?