Degree of reflex at the tipps

[Thorsten]

Hey folks,
I came across that question while reading through hundrets of pages of bowyers and bowmanufacturing…
How do you judge the degree of reflex when you'r going to bend the end (missing the s , due to the rythm ;-)
Is there a calculation, or contruction ahead?
In took screenshots of a couple of bow's, latest was Dano by Marc Louise, and played with circels and ovals, but couldn't find out the "why this circel, why this oval that long"?

Maybe you can light up the dark corners of my inner head…

Cheers Thorsten

[Eric Krewson]

You are over thinking this stuff a bit, most of us just grab an object close at hand that has a pleasing arc like a paint can to trace out a pattern for a future bending form. I have a lot of bending forms; none were calculated arcs but there are probably bowmakers out there that do have carefully crafted forms that were created for the maximum gain in limb efficiency.

[George Tsoukalas]

I don't have a form. I use my vice if I decide to add some reflex.
Forms are a  relatively new and I am relatively old.
Jawge

[bradsmith2010]

If you make a form similar to a bow you like,, its a good starting point,, then modify as needed on your next,, if you make the bend and you not happy,, then you can change it,, till you get what you want,,
or degree of angle,,some guess work involved, ,like all bow making,,or experimentation,,I just copy the best and go from there,,no need to re invent the wheel,,,

[sleek]

Hey folks,
I came across that question while reading through hundrets of pages of bowyers and bowmanufacturing…
How do you judge the degree of reflex when you'r going to bend the end (missing the s , due to the rythm ;-)
Is there a calculation, or contruction ahead?
In took screenshots of a couple of bow's, latest was Dano by Marc Louise, and played with circels and ovals, but couldn't find out the "why this circel, why this oval that long"?

Maybe you can light up the dark corners of my inner head…

Cheers Thorsten

Glad to see a guy out here asking questions about what seems to be a process that not many think about. I like to think the parts that are over looked are where advancement can occur.

First I'll say that a circle or oval is the least efficient way to make a recurve. A Siyah is the best. The point of the recurve is to make the string angle at the tips more acute.

With the shortest distance between two points being a straight line, a siyah accomplishes that, vs a curve that has more mass, and we all know mass at the tips is something to be avoided. The construction of a siyah however is tricky and adds mass in the need for the joint. So really  it may be a wash.

In the end, just make your recurve to the height you desire and make it with as little curve as possible to keep the mass down. I Hop that shed some light on the subject.


Edit: after reading reading your question, I may have misunderstood you. I thought you mentioned reflex the tips, you seem to mean the limb in general?

[Selfbowman]

Just get a six foot 2x4 count it 70” long . Use piece of metal or thin laminate and ftrace one end . Cut that radius .  Flop it to the other end trace it . Cut then smooth the cuts. Your done. Here is a good design. Or something close.

[Selfbowman]

That caul is used for 67-69” bows

[bambule]

You are over thinking this stuff a bit, most of us just grab an object close at hand that has a pleasing arc like a paint can to trace out a pattern for a future bending form. I have a lot of bending forms; none were calculated arcs but there are probably bowmakers out there that do have carefully crafted forms that were created for the maximum gain in limb efficiency.

That‘s it!

Greetz
Cord

[superdav95]

Hey folks,
I came across that question while reading through hundrets of pages of bowyers and bowmanufacturing…
How do you judge the degree of reflex when you'r going to bend the end (missing the s , due to the rythm ;-)
Is there a calculation, or contruction ahead?
In took screenshots of a couple of bow's, latest was Dano by Marc Louise, and played with circels and ovals, but couldn't find out the "why this circel, why this oval that long"?

Maybe you can light up the dark corners of my inner head…

Cheers Thorsten

Glad to see a guy out here asking questions about what seems to be a process that not many think about. I like to think the parts that are over looked are where advancement can occur.

First I'll say that a circle or oval is the least efficient way to make a recurve. A Siyah is the best. The point of the recurve is to make the string angle at the tips more acute.

With the shortest distance between two points being a straight line, a siyah accomplishes that, vs a curve that has more mass, and we all know mass at the tips is something to be avoided. The construction of a siyah however is tricky and adds mass in the need for the joint. So really  it may be a wash.

In the end, just make your recurve to the height you desire and make it with as little curve as possible to keep the mass down. I Hop that shed some light on the subject.


Edit: after reading reading your question, I may have misunderstood you. I thought you mentioned reflex the tips, you seem to mean the limb in general?

I agree with this.  Good siyah design still be less mass in the end.  For steamed or boiled tips I do use a form made of wood 2x10 hemlock and just traced the curve from an old gallon paint can.   Best of luck.

[Thorsten]

Suprise suprise…
I did expect mathematic formulars, physical explanations, drawing of any kind, even some kind of mystic spell - but - no it's much easier!
Thank you!

@sleek; no i was after the tips only and by now I did it! But I had no luck as you wished me. My first attempt to bend a hickory tip by heat treating ended up with two (2!!) cracks… Turned it around and tryed the other end straight away. Oiled it this time and made it!
Inspired by all the repairs Del does on his site I even managed to repaire the broken end - glueing a preshaped thin layer of hickory onto it - thanks Del for inspiration!
When I get into upload and this stuff , I'll send some pictures.

But still there is this kid in my head that's asking question after question:
@Eric Krewson; where does "maximum limb efficiency" come from? In the sense of bending tips away from the archer?!

@George; I started shooting arrows in June 2021, finished my first bow the same winter and it's long time ago that I was 25  :-) Being curious, isn't a question of age …

[Eric Krewson]

I don't know what it would it would take to get maximum efficiency; I am a simple-minded guy who only wants to make bows that are great shooters and not speed demons. I bet the flight shooters would have a leg up on achieving maximum efficency.

[bradsmith2010]

its just a bend, try and adjust as needed,, its not rocket science

[Del the cat]

Like most bow building...
Make it more and more extreme until it explodes or screws up the stability or lengevity.
Then make the next one a bit less extreme.
Del

[Buckeye Guy]

Like most bow building...
Make it more and more extreme until it explodes or screws up the stability or lengevity.
Then make the next one a bit less extreme.
Del

ya gotta love Del's answers !

[Pat B]

"ya gotta love Del's answers"

What do you expect from a retired engineer?