Spotted gum self bow help

[pdccr]

I just got back from the shed with some photos of the tiller of my new bow. Its a 71" tip to tip and 69" nock to nock bow. Its unbacked and has a glued on riser.

Here it is unbraced

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A little bit further

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Here you can start to see the hinge that appeared in the right limb. It appears fairly often and i just picked up on it.

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Here it is and the left limb is stiffer than the right, found out that the limb was a 2 mill wider than the other.

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I shaped the nocks with a small knife and a file.

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I decided to put the bow the other way around and on a different background. The hinge still appears to be there on the left limb and the right is slightly stiffer.

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At the end of the day it was drawing #25 at 14". Any help on the tiller would be greatly appreciated. I dont care about how good this bow will be thats why i made it fairly long, all i was aiming for was to let me practice my tillering and stay in 1 piece for longer than 100 shots. The dimensions from memory were;

- 38mm wide at handle
- tapering to 24mm wide at tips
- 19mm thick from edge of riser to 8mm at tips, didnt want to go thinner. Taking almost no set at the moment but i am sure it probably will.

Also found this branch on a sheoak tree, trimmed it down and it pulled 36# at 25". I was pretty damn surprised.

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[Glenn]

Toby the main reason you have what looks like a hinge in the left limb is because the limbis not bending coming off the handle section, it is very stiff there, you need to get that area working and get the right limb bending to suit the left limb before you go any further...Glenn...

[pdccr]

Ok so work alot more on the handle area?

[Glenn]

Toby, when you start to work your limbs down to make them bend get them to bend from the handle section first, thry to leave the last third of the limb towards the tips until last. A well made efficent selfbow will bend the whole length of the limb but it will bend the most coming off the handle and will gradually bend less as it nears the bow tips. A bow made like this will store more energy and have less hand shock and it will also take the least amount of string follow...Glenn...

[pdccr]

Ok thanks glenn. Going back up to the shed on thursday and will try to get the handle working.

[Glenn]

I might not have written that very well Toby. What I ment was to get limbs bending coming off the handle section but keep the handle stiff...Glenn...

[pdccr]

Yer no sorry i didnt say that very well, i knew what you meant by get the handle working I meant by shaping the limbs as they come off the riser.

[greybeard]

Hi Toby,

With board bows using a glued on handle, the handle section needs to be at least 12" or longer at the glue up stage. This allows you to control the way the limb bends off the handle. You can obtain a better transition from a rigid handle to a flexable limb by the length and profile of the fadeout area.

Daryl.

[Glenn]

That's a good point Daryl, you see a lot of glued on handles that are too short and the transition into the bow limb is too abrupt as the handle needs to be faded into the limbs. Some of the early one I made popped off and I made many handles built up out of 5mm thick laminations to get the height I wanted. I found this helped a lot as well and I have never had a laminated handle come off...

[pdccr]

Yer, i think i may have made my riser to small, the fadeouts are extremely rigid and i am having trouble making them look smooth. I think it might fall because i couldn't get my hands on any titebond so i had to use whatever i could. Once i get my machinery up and running will give some laminated risers a go.

[Glenn]

Toby if the handle pops off that's no problem as you just reglue another one on and next time make it longer. What I have done in the past also is to dish out the handle section slightly on the stave. I rasp the handle slightly the length of the handle and then do the same on the stave. I have found this to work best of all and have never had a problem doing it this way...Glenn...

[pdccr]

Ok, if i cant get any titebond have you had any success with other glues?

[Glenn]

I have only used techniglue myself but a lot of people sware by titebond 2 & 3. You should be able to buy titebond from the hardware, it's an industry standard these days. The titebond 3 is waterproof...Glenn...

[pdccr]

Ok, will have a look around.

[ichiban]

i use titebond 3 but if i was going to make complex compisites i would go with tecniglue, but for backings and handles titebond 3 is cheep, easy and water souluable when wet (god knows i couldnt be trusted with better glue i always am sticking myself to something)