Author Topic: Fixing stingalignment (Read 9001 times)

gmc · « **Reply #15 on:** November 29, 2009, 05:10:38 pm »

Tbod:
I wouldn't risk using steam at this point on a bow that far along. I like to use steam early on when there is plenty of wood left for major corrections. Besides, steam has a tendency to dry the wood as well as wet the wood lifting grain or even cracks from further drying (1.5 hours of steam is extreme). I'd use dry heat with the back of the bow protected. Heat the zone between the arrows with more focus on the handle area. I'd hold the bow fixed at the white arrows and apply pressure at the yellow arrow. As already posted, you will need to take the correction a little past center and hold it. I would heat correct and temper all at the same time if thats what you are after because once you've corrected, any heat added later on will erase what you had. I believe string alignment will be a problem if not reduced. You ask for input, there is mine.

artcher1 · « **Reply #16 on:** November 29, 2009, 06:06:14 pm »

The amount of dry heat needed for tempering to hold your alignment is more than sufficient alone for straightening. So why even steam? But steaming alone will correct your problem, even at this stage. Steaming and then heat tempering will work also but is more involved and unnecessary in my opinion.

If previous straightening attempts have failed you then you simply didn't over correct and bring back to straight. ART

TBod · « **Reply #17 on:** November 30, 2009, 03:14:46 am »

Thanks for the response!

Appreicate the effort you made guys! Good explaining gmc, a pic is easy to understand.

I have fixed it with dry heat now . Don't know what I was I going on about really.. Was a bit off my self..Still is probably

George. The handle is 1,25" times 1,25" maybe it looks narrower because the limbs are 2,75" wide ate fades. If doing the wood reduction strategy to the fix the alignment that you and Pat suggests it would have meant not following the grain. I may be off again.. My orientation of the grain is the small drying cracks that covers the back of the bow. So I followed the cracks lying out the bow and ignoring the off alignment.

If I understand what you are saying I should have ignore the grain(cracks) and compensate for the alignment instead? Is it ok not follow the grain at the tips and the handle?

If I didn't have the cracks to follow I wouldn't have any idea of the grain orientation. It's Maple and I don´t split with wedges and axe I use my chainsaw device, thats not right but I like it.

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TBod · « **Reply #18 on:** December 01, 2009, 10:55:40 am »

The bow exploaded!

I'm trying to understand why. It's kind of interesting. Here's my own conclusions:

1. 2" of reflex on a 62" bow with 28" draw when tempering makes tiller process more crucial.

2. I think it it was a tensionbreak(s) not much set before braking. The pic shows that the top of the crown had a straight break and the edges were more intact. The top of the crown do more more work than the edges, especially on a high crown.

3. The bow was 2# underweight according to massprinciple.

4. Tiller wasn't perfect.

Don't think it was to dry, it's about 50% air humidity where I stored it.

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Pappy · « **Reply #19 on:** December 01, 2009, 12:03:05 pm »

To bad,Looks like dry rot to me,where did you get the wood and how was it stored before you started your bow

Hickory is bad about that if it isn't handled right during the drying process but is almost indestructible when it is treated right. I had several stave's do that once when I was storing it in an open end shed,I checked several pieces and it all would break under tension so I cut it all up into fire wood.

Pappy

TBod · « **Reply #20 on:** December 01, 2009, 12:58:04 pm »

Yes I did not t handle it correct during the drying process and stuff. Nowadays I usually rough a bow out green If I have the time.
You say it's a tension break right Pappy?

The pictures of different breaks in tbb1 is really dark a hard to understand for me.

George Tsoukalas · « **Reply #21 on:** December 01, 2009, 02:08:24 pm »

Tbod, that's too bad. But I broke a couple (hundred). 28" for a 62" bow is pushing the design limit. That's too short. What I was saying was a crooked, twisted, character stave is not my choice for a pyramid bow. One reason is because on character bows I leave the handle wide and the nocks wide so I can adjust them to track the string. If you want I can describe how I do it. You absolutely did the right thing by following the lateral grain. That's not the issue. You can still leave handle wide and nocks wide until you string the bow for the first time. Jawge

gmc · « **Reply #22 on:** December 01, 2009, 08:29:40 pm »

Darn! I hate to see that. Man it sure has the MO of being too dry. A bow under weight on the mass principle would also support low a moisture content in the wood. How long did we wait after our heat gun session?

gmc · « **Reply #23 on:** December 01, 2009, 08:31:32 pm »

Jawge, why are you breaking that many bows?

TBod · « **Reply #24 on:** December 02, 2009, 01:41:20 am »

Jawge!

Please explain how you do that alignment stuff with the handle and tips. I am very confused on that subject..I wanted a short bow so I could practice inside my house with it. That induced reflex did the job of breaking it I suspect epically if it has been weakend by bad drying like Pappy says

gmc. I waited a couple of days after heat gun. I kept monitoring the weight and knew I was underweight from massprinciple. Still I pushed it on, I could have done something to get back on massprinciple track. Like go for a 25# draw instead and lower the drawweight from 50# to 45# or not put in the reflex. Massprinciple is great gave me a warning but I chose to challenge it anyway. The MO ought to be 8-10% in the bow since it has been about 50% inside, outside extremely high the last month. Don't have a MO meter for wood though. The ring count is 6/inch on that Maple. Really the opposite of dense if I am right. Thats why I made it so wide.

Thanks!

Pappy · « **Reply #25 on:** December 02, 2009, 05:07:24 am »

I usually don't bend them in the handle[to much wood to move] I tweak the tips or somewhere along the limb.It is easier to bend and seems to hold what you do to it better.

For some reason I thought it was Hickory[Should read closer] I am with George ,that is pretty short for maple and 28 in. draw.

Buy the way gmc he has broke a lot of bows because he had made a bunch of bows. I have broke a bunch also.

I have broke 2 or 3 in row several times.That just kind of goes with it.

Pappy

gmc · « **Reply #26 on:** December 02, 2009, 07:00:29 am »

I know Pappy, I was trying to poke at Jawge a little.

Tbod:
MO = Modus opernadi (method of operating)

Time to start your next project.

Pat B · « **Reply #27 on:** December 02, 2009, 10:09:47 am »

Hickory is very strong in tension so when we see a hickory bow break across the back we know from experience that the wood was not cured properly or handled properly while curing. The break in your bow is definitely a tension break.
Lately there have been quite a few bows that have really blown(one of mine included). These catastrophic explosions have been rare in my bow building career. I have had one limb break, both limbs fold over simultaneously or just bend badly but to see a bow blow into many pieces on both limbs is rare IMO. Sorry your bow broke but if you have learned from your experience it is not a failure.

TBod · « **Reply #28 on:** December 02, 2009, 12:14:45 pm »

Ok now I know what MO means, IMO= in my opinion? There's something I learned..

Hope I learned something else. We will see on the next bows.

Sure wish I had the blow on a movie, it was pure destruction.

I have had three explosions and one bendover break so far, seems like I am more of a explosion kind of guy then a bend over..

Thanks!

George Tsoukalas · « **Reply #29 on:** December 02, 2009, 03:21:19 pm »

Tbod, I am happy to do that. So let's say you are working on a character stave that you suspect may have alignment issues. Leave handle full width and nocks a good inch wide. That is when strung the string may be off to the left side. Leave the handle full width. That way you can remove wood from the right side when shaping the handle. Brings the string back to center very easily. Also, if the string is off to the left, as it is in our example, cut the left side of both nocks deeper. Brings the string to center. Later when you shape the nocks you can remove wood so that the grooves are even. You can even remove a little more wood with your rasp to even everything up. Please ask questions.

Jawge

Primitive Archer