Primitive Archer

Main Discussion Area => Bows => Topic started by: MM2 on June 01, 2020, 05:46:55 am

Title: Tiller check, please!
Post by: MM2 on June 01, 2020, 05:46:55 am
Ave, great and glorious Bowyers!

I'm working on an oak board flatbow, and need some help. I have never built a bow so long
 - 72 inch - and I'm a bit unsure of the tiller. Is this shape good or not?

The bow pulls 35 pounds at 22 inch presently, my aim is 35-38 pounds at 26.

(The grid not precise because the wall as flat and even as the surface of the Moon.)

Any suggestions would definitely be welcome!

Thank's in advance!

Michael
Title: Re: Tiller check, please!
Post by: BowEd on June 01, 2020, 05:53:10 am
Good even bend on both limbs.Bring it to a high brace of 6 to 7 inches to the back and continue on taking even amounts from both limbs.
Title: Re: Tiller check, please!
Post by: Del the cat on June 01, 2020, 06:09:54 am
Looking good. I think the inner limbs are fine, just get the mid to outer coming round a bit more.
Del
Title: Re: Tiller check, please!
Post by: RyanY on June 01, 2020, 08:53:49 am
If it's a pyramid bow the tiller looks good. If the limb with is parallel from the fades out, then it's bending too much in the inner limb.
Title: Re: Tiller check, please!
Post by: bownarra on June 01, 2020, 12:18:22 pm
Being a longer bow it should be slightly elliptical even if a pyramid. If parallel width for a decent portion of the working limb then the mid to outers need to come round more.
Watch the set.
Aim for non inner limb, a little mid limb and rest out to the tips. If your set is right the tiller is right :)
Title: Re: Tiller check, please!
Post by: MM2 on June 02, 2020, 04:03:52 am

Thank's a lot for your help!  :)


Del the cat, Ryan Yoon, Bownarra:

My first question:

I can't understand something. I use the legendary tillering gizmo very diligently - this is the first time, and
it's fantastic!  :D .
Presently the gizmo shows approximately even bend. If I give more bend to the inner and the outer limbs, there will be problems with the gizmo.  :-\

Second question:
If the limbs are parallel up to the middle, why should be the mid and the outer limbs more round?
(The limbs are parallel.)

Sorry for my poor english, it was years ago since I last spoke.
Title: Re: Tiller check, please!
Post by: Del the cat on June 02, 2020, 04:38:56 am
If you use the gizmo, and the gizmo says it's good, then just draw it some more and check again.
You say the gizmo shows "approximately" ... well maybe work until it shoes exactly? Does the "approximately" show the mid to outers stiff or weak?
you have to ask and answer your own questions  ;D
My opinion, was just an opinion based on what I could see in the pic', maybe what I'm really seeing and saying is draw it more and see how it looks.
Del
Title: Re: Tiller check, please!
Post by: MM2 on June 02, 2020, 05:53:38 am
Hi, Del!

Thank's for your answer!

"Approximately" means: it seems almost good.  :D (I find the weakest spot very hardly.)

Present situation (with 6,5 inch brace).

Thank's again!
Title: Re: Tiller check, please!
Post by: willie on June 02, 2020, 09:33:12 am
Quote
Second question:
If the limbs are parallel up to the middle, why should be the mid and the outer limbs more round?
(The limbs are parallel.)

a pyramid limb, if strained equally along it's length will bend in a circular arc.
a straight side limb, if strained equally along it's length will bend more like a quarter segment of an ellipse.

If we wish to not strain the limb equally, as bowanarra suggests, then keeping set lower near the handle makes both shapes types of limbs more elliptical.
Title: Re: Tiller check, please!
Post by: MM2 on June 03, 2020, 03:42:22 am
Greetings, great and glorious Bowyers!

Thank's for your help!

I think I start to understand. (Or I hope at least. :D)

I shaped the mid and the outer limbs a bit more rounded.

Here is the present situation.
The bow is 38 pounds at 24 inch (with 6,5 inch brace)

Thank's again!

Michael
Title: Re: Tiller check, please!
Post by: Pappy on June 03, 2020, 05:40:42 am
Left limb looks good, if anything right limb from about 3 to 6 on your board looks a little flat, over all looks great.
 PAPPY
Title: Re: Tiller check, please!
Post by: Pat B on June 03, 2020, 08:18:57 am
For me, both limbs look pretty good but on the left, from about the second black tape in to the handle looks a bit stiff.
Title: Re: Tiller check, please!
Post by: MM2 on June 09, 2020, 04:15:44 am
Greetings, glorious Bowyers!

I'm very grateful for your help!

I think this is the final lap. (I'm very excited.  ;D )

The bow pulls 40 pounds at 27 presently, which is absolutely enough for me.

I'm afraid to voice loudly, but... is the tiller right?

(I don't know why, but the limb on the right side always looks a little flat. If I flip the bow the right side limb looks flat again... Perhaps a trick of the camera or an optical illusion.)

Thousand thank's!

Michael

Title: Re: Tiller check, please!
Post by: Pappy on June 09, 2020, 05:23:44 am
Looks very good to me.Nice job. :)
 Pappy
Title: Re: Tiller check, please!
Post by: PaSteve on June 09, 2020, 06:24:13 am
Good job! Enjoy your new bow.