Primitive Archer

Main Discussion Area => Bows => Topic started by: IrishJay on March 08, 2020, 09:47:30 am

Title: Limb Cross Section for Elm
Post by: IrishJay on March 08, 2020, 09:47:30 am

I'm roughing out an elm stave, it's 75" long, 1" thick x 1 1/2" wide at center stave, with 5 1/4" of natural reflex. I'm planning to keep this one really simple, no cut in shelf, no glued on lams, no additional reflex or deflex added. I'm thinking of making it an ELB, but I'm not sure how elm behaves with the crowned belly. What do you guys think, flat belly or ELB?

(https://i.imgur.com/zfKlwNO.jpg)

(https://i.imgur.com/H8DQyeG.jpg)

(https://i.imgur.com/UAvj4Tn.jpg)

Title: Re: Limb Cross Section for Elm
Post by: PatM on March 08, 2020, 09:55:09 am

A slightly flatter oval is a good compromise with Elm.

Title: Re: Limb Cross Section for Elm
Post by: IrishJay on March 08, 2020, 10:09:45 am

How much should I round the edges of the back? How much of a concern is violating a ring when rounding those edges?

Title: Re: Limb Cross Section for Elm
Post by: Pat B on March 08, 2020, 10:47:09 am

I think a rectangular cross section. It won't be totally rectangular because of the crowned back but basically rectangular with a flat or slightly rounded belly. Rounding the edges has more benefit because it helps to eliminate the chance of lifting a splinter plus the edges are basically dead weight and don't add to or take away from the performance. Elm reacts well to heat treating the belly also so you might consider that.
 With 5 1/2" of reflex you will have to tiller carefully so you don't over stress the belly just trying getting the bow to first brace. Once there things should go smoother through the tillering process.

Title: Re: Limb Cross Section for Elm
Post by: IrishJay on March 09, 2020, 05:50:47 pm

Decided to keep it rectangular, getting one limb fairly well roughed out.

(https://i.imgur.com/uthQ4tU.jpg)

(https://i.imgur.com/5wkJ0vJ.jpg)

(https://i.imgur.com/HqsJqX3.jpg)