Hazel mollegabet in progres

[Ricardovanleeuwen]

Im working on this hazel stave, its 3 inch wide at the widest point its 70 inch in lenght. It will be my first mollegabet style bow. Anny tips or tricks?

[Mafort]

A lot of mass to remove there. Keep the stiff ears light and narrow. And it should be pretty quick

[Ricardovanleeuwen]

Yea i know, i will do that as the last part, im planning to only heat threat the working part till i finished the tiller. Then, i will narrow the levers till they just start to bend minimal, then i will heat threat them so they are stiff again. Atleast, this is what sounds logic to me

[Ricardovanleeuwen]

Did annyone evver tried to make the lever the same shape as a airplane wing for less wind drag?

[bownarra]

Steady you might take off when you shoot it....
A straight taper is all you need
Hazel is great wood but be careful of the pin knots as they can start a limb folding chyrsal.
70" is long, what drawlength have you got?

[Ricardovanleeuwen]

Somewhere close to 28 inch. I did read that most of them where 65 70 inch and that did seem logic to me since the working limb is smaller

[Del the cat]

Did annyone evver tried to make the lever the same shape as a airplane wing for less wind drag?

I'd suggest that shape wouldn't be rigid enough. I reckon a triangular or T cross section gives good lightness with rigidity.
Remember to have some thickness taper on the working section, because they are short it is important to get a good tiller to avoid hingeing.
Del

[DC]

Did annyone evver tried to make the lever the same shape as a airplane wing for less wind drag?

Quite a while back I was messing around with the chrono and wind resistance came up. I taped a couple of pieces of card roughly 2"x4" to the tips of the bow and shot it through my machine. It made no difference whether the cards were on there or not. I should try it again on one of my newer bows

[Ricardovanleeuwen]

As i am getting it thinner and it is starting to bend slightly.. i think it will end up paper thin in the working area. Are there down sides of having a thin and wide working limb instead of a more narrow but thicker limb?

[DC]

A wide thin limb will have the more mass for the same draw weight so theoretically a narrow thick limb will be faster. But, a wide thin limb is harder to tiller because each scrape lakes off more draw weight. Think I got that right. If you think your limb is getting too thin(a judgement call) you should think about side tillering.

[Ricardovanleeuwen]

But when is too thin? And i am right that wide and thin dont take as much set as thick and narrow?

[Del the cat]

But when is too thin? And i am right that wide and thin dont take as much set as thick and narrow?

Yes, you are right... but it's a matter of balancing to the wood and the draw weight. There's obviously a point where it gets so thin that it's too twitchy to tiller without creating weak spots and hinges.
If I had to put a number to it I'd say I wouldn't like to go much thinner than say 1/2" ... maybe 3/8"
Just measured one of my Hazel bows (not a molle') it has a crowned back (just the under bark surface)
1.75" wide x 0.65" thick.
Dunno if that is any help.
Del

[mmattockx]

There's obviously a point where it gets so thin that it's too twitchy to tiller without creating weak spots and hinges.

I can't speak to hazel, but my current hard maple pyramid bow project has limbs that are around 0.385" thick and taking very light scrapes of 0.001-0.002" (at most) made noticeable differences in the tiller when I was at the end of tillering. I worked the limbs down using a caliper to measure how much I was taking off and keep the sides even and I was surprised how little wood removal was noticeable near the end. I plan to continue using the calipers to keep an eye on things as they worked great for keeping me from going too far in one shot.


Mark