Making the perfect Trilaminate Longbow.

[SoulArcher]

Hi Guys. I hope this is the correct place to ask this question.

What would you guys recomend for the perfect woods to use in building a trilaminate longbow?

I am asking as I am importing various different ones with woods ranging from Osage Orange,Actionboo, Hickory, Ipe and Yew.

They all have their benefits and negatives but I am finding some are softer woods and assume the shape of the Strung bow after 1-2 hours of shooting. (when unstrung it will not return 100% straight instantly)

With harder woods like 100% osage orange or yew it ends up snapping.

Any Ideas what the perfect combination may be for durability?

Thanks all!!

[greybeard]

That is a difficult question to answer.

Firstly contact the manufacturer to try and find out why the bows are failing i.e. glues not suited to our climate. Is it a problem unique to Australia?

If the materials being used are first grade there should not be any problems.

The combination and positioning of the different timbers in the bow can affect the durability of the finished product.

Care needs to be taken to get the correct lamination thickness ratio to the overall limb thickness of the bow.

Incorrect limb cross section and the wrong timber selected for the belly.

Poor design.

Are the bows sourced from a reputable manufacturer and what sort of quality control do they have?

The majority if not all of the selfbows and laminated wooden bows do not return instantly when unbraced.

Generally all wooden bows will retain a certain amount of string follow.

Good design in tri laminate bows will help to minimise string follow if not eliminating it.

Daryl.

[greybeard]

Matt,

Can you post some photos of the broken bows so we can see what the break looks like? We may be able to determine if the break was a result of faulty timber or poor glue lines.

Do the bows with string follow show signs of compression faults on the belly?

I lifted the following photo off you web site, is the photo representative of the bows in question?

Trilaminate Longbow.jpg (17.19 KiB) Viewed 1499 times

Without shooting the bow it is difficult to know but the brace height looks too high, as a general rule I think they run the brace height at one twelfth of the n to n length for this style of bow.

Additionally the lower limb [right hand side] appears to be too soft in relation to the upper limb.

Personally I believe the upper limb has the better profile.

Daryl.

[SoulArcher]

Hi mate and thanks for the reply.

Yea that is the type of bow in question.

I have had no brakes with those. Only with 100% orange osage or Yew woods not trilaminates.

My photo is a little skewed so it looks like one limb is much shorter. It's hard to take perfect photos with limited space.

sometimes the limbs have a little twist going towards the nocks as well.

Thanks

Matt

[Fraser]

Hi Daryl, I have one of the Osage Orange bows in question, being a self bow it has some twist and turns. To my untrained eye the tiller is fine and the bow shoots accurately and consistently. I had the bow loaded up for a couple of minets while testing the weight at max draw, 123# @ 32", no noises or signes of problems with the timber. The problems I have had are with the bow nocks, they wheren't installed far enough on to the bow for a warbow, they where installed 20mm deep, the cones of the bows found on the Mary rose where 15mm in diameter at the base and 40mm long, they where also side nocked and the string grove penetrated through to the timber. My first attempt at replacement nocks lasted a couple of weeks until I discovered a hair line crack in the top nock on the belly side.

I hope I got it sorted for my next go at them.

Fraser.

[job]

Hi mate and thanks for the reply.

Yea that is the type of bow in question.

I have had no brakes with those. Only with 100% orange osage or Yew woods not trilaminates.

My photo is a little skewed so it looks like one limb is much shorter. It's hard to take perfect photos with limited space.

sometimes the limbs have a little twist going towards the nocks as well.

Thanks

Matt

If you are getting breaks with the Osage or Yew there's something wrong. They are both really good timbers. But like all selfbows they need warming up and shooting in and cannot be overdrawn cold by an orang-utan. For the trilams Ipe is really good for the belly, and Hickory makes a fair back. But my favourite by far is bamboo. It's wicked. For the strips for trilams you must have good grain, same as you need in a selfbow. a lot of these kits will break because the billets are not quarter-sawn/backsawn. if you have a good clean straight grain that runs the full length you'll be right. Also pays to taper the laminates. But in the end you will have 3 timbers with differing shrinkage rates, and in a hot place like Australia, I think a good chance of coming apart anyrate? Personally I'd stick with laminated bamboo.