Primitive Archer

Main Discussion Area => Bows => Topic started by: stuckinthemud on September 01, 2022, 03:36:48 pm

Title: tiller help needed -full draw added plus questions
Post by: stuckinthemud on September 01, 2022, 03:36:48 pm
I always seem to get to a point where I can't really see what to do next.  Here is a wych elm short bow with tiny little recurves.  I think the outers might be a tad stiff, but I don't know if that is the effect of the recurves?? The centre looks a bit too stiff to me, what do you think?

(https://stuckinthemudsite.files.wordpress.com/2022/09/img_0220-1.jpg)
Title: Re: tiller help needed
Post by: bownarra on September 02, 2022, 02:22:00 am
Watch those areas about a 1/3rd of limb length out from the handle. They are bending too much.
Center is stiff and the mid to outer limbs stiff.
Before it takes any set trace the backs outline. Compare it everytime you exercise it and relax it.
Title: Re: tiller help needed
Post by: NicAzana on September 02, 2022, 03:46:06 am
Also, it would be helpful to at least have a pic of the unbraced profile, as well as maybe a pic of the front view profile!
Title: Re: tiller help needed
Post by: stuckinthemud on September 02, 2022, 04:56:16 am
I got clumsy, set already happened. There’s about an inch of set in each limb from where it bends too much in the limb centres  First photo is front profile, middle photo shows the pin knots along the one limb that are making things entertaining, last is the view from above.

(https://stuckinthemudsite.files.wordpress.com/2022/09/image0.jpg)

(https://stuckinthemudsite.files.wordpress.com/2022/09/image2.jpg)

(https://stuckinthemudsite.files.wordpress.com/2022/09/image1.jpg)
Title: Re: tiller help needed
Post by: stuckinthemud on September 02, 2022, 02:31:28 pm
Done a bit more scraping, it now looks like this at close to full draw on a long string hanging down 2 inches,

(https://stuckinthemudsite.files.wordpress.com/2022/09/img_0235.jpg)

Draw weight is in the region of 70lb without heat tempering.  How's it looking?
Title: Re: tiller help needed
Post by: George Tsoukalas on September 03, 2022, 11:02:46 am
What I used to d when I first started was, when I went to a shoot, I would just watch as other people shoot just to see how their bows bent and recovered. This forum was not around then.

Now, you can go to the Bow of the Month portion of this site and look at some nicely  bending bows.

Bownarra gave you good advice and  I see the same.

Jawge
Title: Re: tiller help needed
Post by: stuckinthemud on September 03, 2022, 04:32:36 pm
Thanks both, your comments are much appreciated.  I softened the tips a little and took a few mm out of the centre but it looks like I didn’t go far enough. I’ll have another go, haven’t used a gizmo yet as I’m trying to go for an ellipse/D-profile.  Ntn is 33”, draw length will be 10”
Title: Re: tiller help needed
Post by: bownarra on September 05, 2022, 02:20:22 am
The gizmo will still help.
For an elliptical tiller I simply wind the screw in as I move along the limb, with a bit of practise it will still show you stiff/weak spots on an elliptically tillered limb. I( use one on my elbs all the time and it doesn't get much more elliptical than the true elb tiller.
Title: Re: tiller help needed
Post by: stuckinthemud on September 05, 2022, 11:23:07 am
oooh, ok, I will give that a go, thanks!
Title: Re: tiller help needed plus other questions (at the end)
Post by: stuckinthemud on September 11, 2022, 05:45:31 pm
(https://stuckinthemudsite.files.wordpress.com/2022/09/img_0245.jpg)

How's it coming along?  This is full draw, I'm thinking to get it braced next then heat treated before a final tiller.  The profile now looks like this:

(https://stuckinthemudsite.files.wordpress.com/2022/09/img_0248.jpg)

It used to look like this:

(https://stuckinthemudsite.files.wordpress.com/2022/09/image1.jpg)

Photo is the other way up.  Most of the recurve has pulled out which is disapointing. 

When I heat treat this, how dark should I cook it, and should I set the handle back, or try to restore the recurve, or attempt to straighten it???  It will be under a lot of stress as it will be held at full draw for many seconds, as opposed to the fraction of a second at full draw for an archery bow so I'm thinking of a relatively gentle toasting - small colour change, heat soaking through 'til the back is warm to the touch - but leaving the profile as it is, but, I would really welcome your thoughts.

Draw weight is over 70lb at the moment.  Thickness taper is from11mm thick at the end of bending section to 18mm thickness at the centre.