Author Topic: Australian Eucalypt bow  (Read 23047 times)

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Offline WillS

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Re: Australian Eucalypt bow
« Reply #30 on: March 24, 2016, 11:02:25 am »
The big dreadnought rasps used for car body work are fantastic for roughing out bows.  They don't tear the grain, but work like a traditional bowyers flote and while you can hog off masses of wood if you want, they're also great at fine work such as chasing rings.  They even leave a polished surface if you use them at the right angle.

Offline ryder

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Re: Australian Eucalypt bow
« Reply #31 on: April 02, 2016, 08:05:17 am »
Made myself a hotbox to speed the drying. made it approx 75" long, 18" high and 12" wide, wired up 2 x 75 watt incandescent light bulbs in the bottom, connected to a STC-1000 temperature controller from my beer fridge. Kept it as 40 deg for almost 2 weeks, weighing the wood twice daily as I do not have a moisture meter. It was losing 10 grams a day, a few days ago I got frustrated and wondered if it wasn't getting too dry. Took it out and left it in the lounge room to check, and lo and behold it started gaining weight - grr guess I over did it. Still, it wasn't too bad, it stabilized after 2 days, only over dried it by about 10 grams on a 1400 gram stave.

Also have made myself a better tillering tree, one with a pulley system. I made it with 3 pulleys to give myself a mechanical advantage, and as such it only takes me 25 lb effort to apply 50 lb to the bow. Bought a spring scale for it too. Could use some paint perhaps, but it'll do for now



Have started to tiller the stave as well  ;D  having a few small challenges though.

I made the mistake of tapering the tips and roughing out the handle close to its finished size before the wood had fully dried. I  found that as it finished drying, one limb has warped sideways a little, and now with a tillering string on it the string is not centered down the grip. It's now about 1/2 inch off the center of the grip, but still inside the finished grip. The grip wants to rotate in the tillering tree as I work, I can stop it from doing fairly easily though.
Lesson learned - will not make that mistake again. Not sure if it will affect how the bow shoots, figured I'd just make that limb the top one and have the string close to the outside of the grip - will that be a problem? If so, the bow is pretty long (70 inch ntn, but as a bigger fella I do have a 30" draw), maybe I could shave an inch off each side and re adjust the nocks. Alternatively, I could make it say 64" ntn, and sinew back it?

The wood is very hard, and now its dry I have no bladed tools that work on it. Everything skates off the surface, or tries to bite in then make ripples, so I'm down to one rasp which works well but is frustratingly slow. Still, I am enjoying the process overall so its not a huge deal.

Also, the wood is a little snakey on one limb, not sure why as the trunk was as straight as you could want before I cut it and took the sapwood off it. Not a warstopper either, but it's first time I've worked on tillering a snakey limb. There's plenty of literature on how to do it though, so it's just a matter of me learning as I go and hoping for the best. The snakey bit at the fade is worrying me, because I don't understand the mechanics of it very well. Will probably post a few pics up for advice as I go, if anyone doesn't mind helping me.

Here's a pic of where I'm at right now



On the long tillering string, I have the limb tips moving probably 3-4 inches right now. Not enough to string yet, but hopefully will get there tomorrow afternoon!

Offline DC

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Re: Australian Eucalypt bow
« Reply #32 on: April 02, 2016, 01:04:26 pm »
Made myself a hotbox to speed the drying. made it approx 75" long, 18" high and 12" wide, wired up 2 x 75 watt incandescent light bulbs in the bottom, connected to a STC-1000 temperature controller from my beer fridge. Kept it as 40 deg for almost 2 weeks, weighing the wood twice daily as I do not have a moisture meter. It was losing 10 grams a day, a few days ago I got frustrated and wondered if it wasn't getting too dry. Took it out and left it in the lounge room to check, and lo and behold it started gaining weight - grr guess I over did it. Still, it wasn't too bad, it stabilized after 2 days, only over dried it by about 10 grams on a 1400 gram stave.

Sacrificing a beer fridge to dry wood---- you've got it bad >:D

Offline ryder

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Re: Australian Eucalypt bow
« Reply #33 on: April 02, 2016, 11:41:38 pm »
Lol would never sacrifice a beer fridge! It's a removable unit i can plug into my fermenting fridge when needed  :)

Offline ryder

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Re: Australian Eucalypt bow
« Reply #34 on: April 03, 2016, 03:57:29 am »
Had some time to work on it today, its drawing 13" at 36 lb atm (well, more like 12" in reality, that string is a bit stretchy). Have not drawn it further as i think it needs more wood off the midlimb first.

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Should get another hour or two on it tomorrow night.

Offline ryder

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Re: Australian Eucalypt bow
« Reply #35 on: April 06, 2016, 07:14:15 am »
Finished tillering!

Thanks to everyone who has given me advice on tillering and everything else. The bow is not done yet, but without your help im sure by now I'd have had a 50/50 chance of having a broken bow and feeling very discouraged.

After the advice on the tiller check thread, I had a crack at redesigning the fades and getting it to bend closer to the fades. Here is the result.



Maybe not perfect, but its the best I can do. Next one will be easier from the experience.

If the right limb looks a little odd, the wood was a bit snakey to start with but also i seem to have somehow made it exactly 1" shorter than the left. I wasn't actually going to own up to that one...

Bow finished tillering at 69" NTN, 30" draw @ 60lb. After a dozen full draws it had not lost any draw weight. After testing it on the tillering jig and by hand I immediately unstrung it, it had taken 1 1/4" set. Not sure what it has settled back to now.

I expect the draw weight will drop a little when i finish the belly, maybe 55lb? I was going for 50lb, but i find it comfortable to draw now so im just going to leave it. Tomorrow, I'm going to shoot it in once I make the bowstring, and I'll aee if I can con the missus into taking a full draw photo of it, assuming of course that it doesnt explode.

Also, the warping it did while drying seems to have almost completely vanished, so thats good.

Pretty amped right now, reckon I've earned a beer or two :)

Stringman

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Re: Australian Eucalypt bow
« Reply #36 on: April 06, 2016, 09:47:30 am »
Finally got around to reading this one, and I gotta say "Bravo"!! This can be a truly frustrating journey with patience being your biggest enemy. Reading this I am reminded of my early days in the hobby and how poorly I would sleep at night - waiting for wood to dry...  You did fine work on this bow and looks like you have a nice shooter to show for it. Congrats!

Offline ajooter

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Re: Australian Eucalypt bow
« Reply #37 on: April 06, 2016, 10:30:52 am »
Bravo is right man....well done!

Offline JoJoDapyro

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Re: Australian Eucalypt bow
« Reply #38 on: April 06, 2016, 01:34:46 pm »
If no one has posted it, it took a few seconds googling "Yew forest in australia" to come up with the location. Daintree Rainforest, only 2300 km from Darwin, a short 33 hour drive on A1 and national route 1!
If you always do what you always did you'll always get what you always got.
27 inch draw, right handed. Bow building and Knapping.

Offline cadet

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Re: Australian Eucalypt bow
« Reply #39 on: April 06, 2016, 06:23:38 pm »
If no one has posted it, it took a few seconds googling "Yew forest in australia" to come up with the location. Daintree Rainforest, only 2300 km from Darwin, a short 33 hour drive on A1 and national route 1!
Unfortunately:
a. "Southern Yew" is a Prumnopitys, not Taxus - anything (not sure if the timber is even comparable); and
b. I'm pretty sure we wouldn't get far wandering into a world heritage listed rainforest and tourist mecca with a chainsaw...
My wife is a heritage horticulture consultant; one of her best friends is an arborist; my brother in-law is a landscape gardener; I've definitely asked, but between them they can count very few mature, sizeable yews in SE Aust, let alone any that might have suitable staves in it, and then that I might be allowed to take something from.
But if anyone has any leads: I'm all ears!

Offline PlanB

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Re: Australian Eucalypt bow
« Reply #40 on: April 06, 2016, 09:42:13 pm »
Glad it worked out for you, Ryder. This is the same bow as in the "Tiller Check" thread, right? Just a suggestion for future tillering -- if you were aiming for 50 lbs from the start, pulling to 60 lbs was what gave you a lot of your set.

The usual advice is to pull to a little under your final goal during early tillering, and then at a certain point when late tillering pull to the goal weight. But not to exceed it. If you want to tiller to a couple pounds over to compensate for final sanding that's okay, but 10 pounds over is a lot.
I love it when a plan B comes together....

Offline ryder

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Re: Australian Eucalypt bow
« Reply #41 on: April 06, 2016, 11:13:00 pm »
Thanks for that, will keep it in mind. I only pulled to 60 lb when it was over 22 inches draw, and really only went as high as that because it seemed to be happy to do it. More than happy to have a 60lb bow, next time I'll plan that from the start though, perhaps make it a fraction wider?

In hindsight, I've made several mistakes with this bow. I think theres a little more draw than i need, I measured it at 30" on a method suggested by a member at the club, but now its complete, with an arrow nocked my draw only needs to be 29" for my thumb to reach the corner of my mouth. That probably added some set.

My poor tillering technique probably added some set too, making some areas strain more than they needed to before the other areas caught up. With experience i can fix that too.

Also next time i make one, I'll buy a scraper and try chasing the last few inches of draw with that to reduce any losses from sanding / scraping file marks off.

Still, there's 3 more staves from that tree to work with now!  Learned a lot from this one!

Offline WillS

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Re: Australian Eucalypt bow
« Reply #42 on: April 07, 2016, 05:42:54 am »
I've definitely asked, but between them they can count very few mature, sizeable yews in SE Aust, let alone any that might have suitable staves in it, and then that I might be allowed to take something from.
But if anyone has any leads: I'm all ears!

Go North  ;)

Offline Aussie Yeoman

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Re: Australian Eucalypt bow
« Reply #43 on: April 07, 2016, 07:53:19 am »
Ryder, well done on your bows.

It's always terrific to learn of another Aussie bowyer.

What's more amazing is that there's another person in Australia (heck...the world) that also does bend testing of wood!

I'm late to this piece so I have a few points:

Spotted gum has great potential as a bow wood. Problem is, like with many eucalypts, the trunk can look pipe straight and branch free, but the grain can still grow spiralled. So a board can have dead straight ring lines, but horribly violated grain. Best way around that is to back it with something, most commonly bamboo.

Red Gum has relatively short grain, in my experience. The shorter grain does not lend itself particularly well to making bows.

I am fairly certain there is not anywhere in Australia, a 'yew forest'. Zip. Nada. Not in the sense that yew trees originating in the northern hemisphere have been grown here in any sort of density above 'peculiarity' level. I've been making bows for about 18 years, and have been on the hunt for bow wood that whole time, and only in the last 12 months have I landed a stave of Yew. On the NSW coast Osage is listed as a pest, but there is not yew in any significant quantity. If there are bowyers in Australia making nice warbows out of Australia-sourced yew, they are not telling anyone here about it and theyr'e hiding the bows as soon as they're finished.

You can indeed make a bow from Blue Gum (E. Saligna). I've made a few myself and they worked really well. Most typically I use spotted gum and any of the ironbarks. When I lived out bush I'd use any acacias I could get my hands on. Do you have Brigalow scrub up there?

Back to you Ryder: You sort of are at a disadvantage being in Darwin - I don't know that there're all that many bowyers up there. On the flip side, you can consider yourself to be one of the very few pioneers of your region; you're the one that will light the way for NT bowyers who come after you.

The very best tool I've found for working Australian timbers by hand is the Shinto rasp. It has a course and a fine side, and can remove honking great piles of wood chips or fin dust depending on your pressure and levels of elbow grease. I could not recommend anything else for working wood bows by hand. I do envy the Northern hemisphere types that get away with using planes and spokeshaves. But them's the apples, I suppose.

For a scraper I use the long side of a chisel. The steel's excellent, and machined to a sharp edge that takes shavings off very well.

Keep up the good work on the bows.

D
Articles for the beginning bowyer, with Australian bowyers in mind:

http://www.tharwavalleyforge.com/articles/tutorials

mikekeswick

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Re: Australian Eucalypt bow
« Reply #44 on: April 07, 2016, 02:02:32 pm »
Good on ya!
Well done on making a very good first stave bow. You are obviously learning.
Sounds like you'll be making a few more and keep on with the bend tests ;)