Author Topic: Tillering issues  (Read 5585 times)

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Offline Calios

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Re: Tillering issues
« Reply #30 on: November 25, 2021, 06:54:26 am »
Do you think i should take some scrapes along the final part of the right limb or near the grip to even out that incorrect curve in the middle? In the photo the bow is being tillered at almost 3inc brace height, i will lower it then, thanks

Offline Calios

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Re: Tillering issues
« Reply #31 on: December 03, 2021, 01:44:14 pm »
Hi everyone, i've been busy lately, but I managed to carry on with the project. I've taken off a good amount of scrapes along the left limb and some others  from the final part of the right limb and near the grip, but i can't really see any significant difference in the tillering...what do you think?

Offline Del the cat

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Re: Tillering issues
« Reply #32 on: December 03, 2021, 02:30:05 pm »
Looking pretty good.
The tips are coming back far enough to brace now... be prepared for it to look different when braced, so don't just heave it back without looking.... exercise it and look at it carefully. (and post anoother pic)
Even if you can't see the difference it is probably there, an will show up as you stress the bow further (e.g by bracing it)
Del
PS. It helps if you always note (and state) both poundage and how far the string is coming back, as either of both may change. It's not always obvious to us when we look at a pic.
Health warning, these posts may contain traces of nut.

bownarra

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Re: Tillering issues
« Reply #33 on: December 04, 2021, 05:23:32 am »
Ok so the right limb is now looking good but your left limb is bending a little too much inner/mid limb.
as Del mentioned poundage and drawlength you are pulling in the pictures is very useful.
If you could take a picture of the bow unbraced at low brace on your tillering board (as per previous photos) that would also really help. If you could manage it also a picture at half draw. This is so we can see the progression from unbraced, braced, partially drawn and at your present full draw.

Offline Calios

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Re: Tillering issues
« Reply #34 on: December 04, 2021, 11:42:00 am »
Hey there, here's some pictures of the current state of the bow, at rest, braced at about 2 inches, half drawn and full drawn. I think that in the last photo it is around 27# at 27, braced at 2 inches as well. Thank you for your quick reply, have a good day ;D
« Last Edit: December 04, 2021, 11:52:35 am by Calios »

bownarra

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Re: Tillering issues
« Reply #35 on: December 07, 2021, 02:45:41 am »
Great :0
So mark that inner 1/3rd - 2/5th of the right limb and don't touch there at all. Remove wood only from the mid/ outer portion of that right limb. Remove wood evenly off the left to keep strengths relative to each other.
Once you've got it looking even you could heat treat it again.

Offline Calios

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Re: Tillering issues
« Reply #36 on: December 08, 2021, 12:21:28 pm »
I have taken some good scrapes off that mid to final part of the bow, but the situation seems not to be changing. I've then strung the bow to almost 5in and switched the position of the bow to look at it the other way too, as it is in the photo attached... no better results, hope to understand the mistake :-\

Offline stuckinthemud

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Re: Tillering issues
« Reply #37 on: December 08, 2021, 03:08:52 pm »
OK, so you are closer than you think. Del taught me a trick, which is to hold a circular item up to the photo on the screen.  Angle the round thing (I often use the rim of my coffee mug) until the arc of the limb aligns with it. This will clearly show the stiff and weak spots.

Offline TimBo

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Re: Tillering issues
« Reply #38 on: December 08, 2021, 05:10:08 pm »
You may need to draw the bow a few times (not further back than previously) to "exercise" it and get the changes to register.  Lots of times changes appear quickly, but not always, and you don't want to take off more than needed and have it sort of bulge out there later. 

Offline Calios

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Re: Tillering issues
« Reply #39 on: December 09, 2021, 03:07:31 pm »
Yes I had the feeling that removing wood in that final part had me buldge that inner 1/3 of the bow, but i doubt it, i'll try to remove some more wood from there and take some scrapes off the other limb, we'll see if it does survive, thanks for the help

Offline simk

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Re: Tillering issues
« Reply #40 on: December 10, 2021, 03:31:13 am »
the only real problem I can see on the last pic is: the right limb obviously is much too strong, especially first half after the fades. this stronger limb makes your bow tilt to the right and pulls the left limb into a stronger bend. limbs are not balanced...
good luck
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bownarra

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Re: Tillering issues
« Reply #41 on: December 10, 2021, 03:36:07 am »
Right limb is stiff but it does have a good shape. Take full length wood removals from it. The inner isn't too stiff - your tiller on this bow should be slightly eliptical.

Offline Calios

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Re: Tillering issues
« Reply #42 on: December 11, 2021, 11:20:11 am »
Current state of the bow. Yes the right  limb seems to have a good shape overall, I ve taken numerous scrapes along it. However the left one keeps worsenig as i remove wood from its final third, wondering if scraping that inner part of the right limb could balance it again, at least in a kind of eliptical curve, how would you proceed? Atb

Offline stuckinthemud

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Re: Tillering issues
« Reply #43 on: December 11, 2021, 11:27:47 am »
You need a tillering gizmo or straight edge and constantly monitor the curve as you work it.  Look at how the curve opens and closes as you slide the straight edge along the limb.  This will show the weak areas (deep curve) and strong areas (shallower curve)

Offline Calios

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Re: Tillering issues
« Reply #44 on: December 12, 2021, 11:08:23 am »
Should really get a gizmo, I'll think of making one. I'm going to monitor it with a straight edge for now, thank you