Primitive Archer

Main Discussion Area => Bows => Topic started by: backtowood B2W on May 02, 2022, 05:41:06 am

Title: HLD Layout and tiller question
Post by: backtowood B2W on May 02, 2022, 05:41:06 am
I was wondering what tiller profile should go along with parallel limbs. More elliptical or circular ? Because of the taper in thickness you end up with higher sidewalls towards the grip. Imagine to press down the limb until flat - It would be pyramidal.
This 66" Elder HLD is straight when resting, 40#at25", has been drawn and shot to 48#at28" :'(, Should be at 40#at28" when finished. It's my first Elder and messed up a lot and had to learn a lot
What would you do - should I go more towards circular?
Thanks for your input!
B2W
Title: Re: HLD Layout and tiller question
Post by: BowEd on May 04, 2022, 08:13:04 am
Looks good to me as it is.I wish elderberry grew that large here.
Title: Re: HLD Layout and tiller question
Post by: backtowood B2W on May 05, 2022, 02:33:19 pm
Looks good to me as it is.I wish elderberry grew that large here.
Worked a bit on it today. Got some weird string alignment issues. Shot some arrows but on each side, up or down left or right, I can get out an arrow without smacking the handle ::). Now it is a bit more working towards handle. Still a bit room for adjustments.
This one measures 1,5" in width and was just a bit too young,5or 6 years, when harvested. Wish I wouldn't have gone for 50#....To find a good piece here is also not so easy as it likes to twist a lot. But a nice bowwood and a hole in the handle just looks so cool...
Title: Re: HLD Layout and tiller question
Post by: bradsmith2010 on May 05, 2022, 04:50:09 pm
I have been going more toward circular,, cause I like the way some of Marcs bows look,, but if it shooting good,, I just think its your preference,,
Title: Re: HLD Layout and tiller question
Post by: Jim Davis on May 05, 2022, 11:06:05 pm
The way you have it is best. Thicker wood near handle should bend less than thinner section at outer limit of parallel part. Thickness should decrease and bend should increase from fades to beginning of side taper.
Title: Re: HLD Layout and tiller question
Post by: bradsmith2010 on May 06, 2022, 04:39:42 pm
cant see any reason the thickness could not be reduced near handle and handle,,
Title: Re: HLD Layout and tiller question
Post by: backtowood B2W on May 09, 2022, 11:09:03 am
Thank you guys for your input!
Straightened out the ends a bit with the heat gun and worked at the fades and inner limb.
Resuming to the other HLD thread this is also a semi HLD - the half moon is too thick, to get the benefit from flattening out.
Funny, I also had a very similar bow explosion like that.
Still some alignment issues or maybe it just needs longer arrows. Or more weight on the tip ::)
Title: Re: HLD Layout and tiller question
Post by: bradsmith2010 on May 09, 2022, 04:09:18 pm
you can probably narrow the arrow pass a little,,
Title: Re: HLD Layout and tiller question
Post by: backtowood B2W on May 12, 2022, 02:54:44 pm
All in all, not much wood I removed. mostly at the handle, fades and inners, doesn't work much more there but enough to prevent more set.
She ended up at 42#@27". Didn't go for the extra inch, as she started to take set again, and I really want to see through that handle!
My draw is 27" so its OK.
Did some quick and dirty paint job today. Curios if your going to like this...
First finish coats tomorrow and some pics for you...
Title: Re: HLD Layout and tiller question
Post by: bradsmith2010 on May 12, 2022, 03:16:43 pm
a little set is ok, it doesnt look so hot in a photo,,, but really from a practical standpoinit,, its not that much of an issure,,
for shooting or accuracy,, my go to bow has bout 2 inches of set,,but I shoot it the best so I dont care,, its accurate and heavy enough to be very effective,,
Title: Re: HLD Layout and tiller question
Post by: bownarra on May 13, 2022, 02:47:21 am
cant see any reason the thickness could not be reduced near handle and handle,,

with a parallel width limb design it shouldn't bend much near the handle or else it will take set there and handshock will raise its ugly head. Jim describes correct tiller for this width profile above.
Tiller logic - in the the trad bowyers bible.
Title: Re: HLD Layout and tiller question
Post by: backtowood B2W on May 13, 2022, 09:04:42 am
cant see any reason the thickness could not be reduced near handle and handle,,

with a parallel width limb design it shouldn't bend much near the handle or else it will take set there and handshock will raise its ugly head. Jim describes correct tiller for this width profile above.
Tiller logic - in the the trad bowyers bible.
Hm, canīt feel handshock , or lets say, not more shock than before. Maybe I had just enough to play with. To relieve some strain from the outers was a good move, because i have a fret at a knot in the outer, and the other outer started to get too much set.

Iīm not sure if I was clear enough about my thinking that an HLD with parallel width design acts more like a pyramid.
I drew a sketch - sometimes a pic tells more than 1000 words...
The typical stave for HLD is a small diameter sapling which tapers mostly from one end to the other - to get parallel width you have to trim let, say about 3/4 from the stave length. This results into higher sidewalls towards handle - at least in my bow.
Title: Re: HLD Layout and tiller question
Post by: bradsmith2010 on May 13, 2022, 01:03:44 pm
   I think it could bend a bit more near handle,,,, in theory, I agree with bownarra
I was friends with Jim ,, have that book,, there is room or interpretation on some tiller logic,,
Jim taught me how to make a bow ,, 30 something years ago,, I did some things he told me not to do ,, and they worked,,but in general he was right,, and I still follow his teaching to this day,,
and thats kind of how bow making is,, not all rules are definitive,, or there might be some room for variation,,

   
Title: Re: HLD Layout and tiller question
Post by: bownarra on May 14, 2022, 02:33:02 am
Well I've never made one of these hld designs and I don't think I ever will! BUT tiller logic is simply another way of saying that wood at a given thickness has a given strain or bend it can take. Thicker can't take as much bend, thinner can take more. The wood doesn't care what design it is in. All that matters is strain levels. Our job when making different designs is to find that perfect strain level - it is dictated to us by wood species and thickness, watching set and its posistion will always give you the right 'answer'. As I've said many times draw the orginal profile on a wall/tillering boards etc. So you have a definite reference to check back to during tillering........the wood never lies about what it thinks of your tiller :)
Title: Re: HLD Layout and tiller question
Post by: backtowood B2W on May 15, 2022, 03:17:30 am
Well I've never made one of these hld designs and I don't think I ever will! BUT tiller logic is simply another way of saying that wood at a given thickness has a given strain or bend it can take. Thicker can't take as much bend, thinner can take more. The wood doesn't care what design it is in. All that matters is strain levels. Our job when making different designs is to find that perfect strain level - it is dictated to us by wood species and thickness, watching set and its posistion will always give you the right 'answer'. As I've said many times draw the orginal profile on a wall/tillering boards etc. So you have a definite reference to check back to during tillering........the wood never lies about what it thinks of your tiller :)
Would love to see a HLD Bow from you! Maybe sometime you will be in the mood for it. But I understand; This is my 4th - and I broke two. And this are all not real HLD more semi HLD - so the "flattening out effect"  is not noticeable. Not the easiest build in bow making...
About tiller logic I totally agree with you. Also, I do draw the orig. profile to a paper roll for reference, but more with the curvier ones - this one is so straight you can detect set easy. I think the tiller is still quite elliptical - and set is distributed better than before .
It took 18mm set going back to 4mm when resting. ;D
you can probably narrow the arrow pass a little,,
That and some adjustments at the nock sorted out this string alignment issue. The bow is a tiny bit twisted.
Title: Re: HLD Layout and tiller question
Post by: backtowood B2W on May 15, 2022, 06:07:28 am
presentation of the finished bow:
http://www.primitivearcher.com/smf/index.php/topic,71438.0.html