Lay up order

[rodlonq]

Hello All,

After looking at the many excellent home brew bows on this forum I notice one aspect that all seem to follow with longbows. Any bows made with 4 core lams seem to have 3 lams at the back of the bow and 1 lam at the belly side of the handle.

Perhaps someone could explain why this is the case, because my logic tells me it would be advantageous to have the very fine fade out parts of the handle on the neutral axis of the bow (with 2 lams behind and 2 lams in front) to nullify any stress that might be in the fade outs. Perhaps it is preferential to have the fade outs in a state of compression rather than tension so moving them to the front of the neutral axis does this?

Thanks and cheers...... Rod

[Stickbow Hunter]

I do it simply because I like the look of it Rod.

I really don't think it makes much difference to be honest. A lot of bows have been made with just the glass on the belly side of the riser. One thing it does effect is how deep you need your riser wood to allow you to get your desired handle depth (back to belly).

Jeff

[rodlonq]

Hi Jeff,

Is there any disadvantage to only having three lams per bow instead of four (two at the back and one at the belly)?

I made a little bamboo board bow (with camo cloth back and belly) for my son and it should have been thick enough to come in at around 30# but it only went about 15# (only just moved the bow scale at 24" draw) and took about an 1 1/2" of follow. It only shoots my 450 grain arrows abot 40 yards I am thinking of adding 40 thou of glass to it both sides to bring up the weight. I will use clear so you can still see the camo cloth. Mikey is stoked with the bow but he has just outgrown a 30# wheelie bow and I wanted to get him into trad for his next bow. This one is just too weak.

The experience with the board bow tells me the more rigid glue lines there is in the bow, the stiffer it will be. Am I on the right track?

Cheers, Rod

[Stickbow Hunter]

Is there any disadvantage to only having three lams per bow instead of four (two at the back and one at the belly)?

The one problem that you can have (when your draw weights get up a bit) is the belly lam will be thicker with using only three lams and this can make it difficult to get the lam to bend well around the belly of the riser. In this case the lams is already glued now though.

The experience with the board bow tells me the more rigid glue lines there is in the bow, the stiffer it will be. Am I on the right track?

That isn't what we (a mate and I) have discovered with testing. We found the three lam bows to shoot faster than say five lam bows.

Adding .040" glass to back and belly of that bow will jump the draw weight up by a considerable amount mate - maybe more than he could handle. I would give it some more thought if I were you.

Jeff

[rodlonq]

Thanks Jeff,

I might just add a strip of glass to the back of the bow to begin with. I am looking for about 20# gain in draw weight.

Cheers...... Rod

[Stickbow Hunter]

I might just add a strip of glass to the back of the bow to begin with.

Rod, If you do that you will jusy over power the belly bamboo and cause it to fail under the compression forces IMO. I honestly would leave that bow the way it is and build another.

If you really wanted to use the bow perhaps you could add a wood lam on the belly or even back and belly rather than the glass. This way you can easily adjust the core thickness to adjust the draw weight.

Jeff

[rodlonq]

Hi Jeff,

I think you are right, and thanks for your comments. I can just make up some super light arrows from 1/4" dowel and it would be OK for little fellas to have a go at a long bow. I will take some pics of the bow and post them so you can see why I wanted to maintain the camo backing look.

Cheers...... Rod