One more try at 50#Bamboo

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Graeme K · #1 Post by **Graeme K** » Fri May 12, 2006 3:39 pm

Yep giving it one more try. Put a bit of shape on the back of the handle this time, not really trying for deflex just do not like the flat on the drawn profile caused by the straight handle.

Graeme

#2 Post by **Stickbow Hunter** » Fri May 12, 2006 5:11 pm

Graeme,

You will automatically have deflex in the limbs when shaping a riser in that fashion IMO.

All the best with it mate and I hope you make the weight this time. I look forward to your reports as you make progress.

Jeff

Graeme K · #3 Post by **Graeme K** » Fri May 12, 2006 6:03 pm

Yes Jeff -- But just a little bit -- more for style than design

Graeme

gilnockie · #4 Post by **gilnockie** » Fri May 12, 2006 6:18 pm

Hi Graeme,

I think you will find that you have a Hybrid bow on your hands. If you do, consider yourself fortunate.

Keep up the good work.

archangel · #5 Post by **archangel** » Fri May 12, 2006 7:47 pm

Graeme

Looking forward to seeing how it turns out. You will have seen from some of my efforts that this deflex/reflex design works really well with tri-laminate bamboo. I like the look of the laminated riser as well: are you using jarrah with light veneers? The shaped handle on one of your recent bows has an excellent looking grip. Best wishes for this one.

Graeme K · #6 Post by **Graeme K** » Fri May 12, 2006 8:01 pm

Hi David

The handle is Babinga that I got out of the rubish bin at a timber place I was buying something and the light veneers are some sort of cypress that a tree lopper friend gave me

Graeme

Graeme K · #7 Post by **Graeme K** » Sat May 13, 2006 2:50 pm

Stage 2 of glue up --- belly lams. Some difficulties as the belly lams are 6mm thick which makes it hard to get them to conform to the handle fades

archangel · #8 Post by **archangel** » Sat May 13, 2006 3:15 pm

Graeme wrote:

Some difficulties as the belly lams are 6mm thick which makes it hard to get them to conform to the handle fades

As you found in making your original bow, tapering the riser end of the belly lamination allows a much easier operation, without sacrificing any bow weight - the rigid riser takes care of that. Great work on your post Graeme, this bow continues to look like a real winner.

Graeme K · #9 Post by **Graeme K** » Sat May 20, 2006 5:23 pm

A couple of photos of tillering the bow.
What is interesting about these photos is that the uneven shape is a direct result of the increase in thickness of the raw bamboo where it runs up to the nodes. At this point I have not done any tillering and when you mark the spots that are stiff then measure the thickness you find the extra thickness is ramp up to a node. I have now tillered for even bend and an currently gluing a lam of black Bowtuff on the belly to overcome the string follow problem. I hope the bow making gods are smiling on me

Graeme

#10 Post by **Stickbow Hunter** » Sat May 20, 2006 5:42 pm

The Bo-Tuff will bump the weight up mate. What was it at full draw in the photo? The Bo-Tuff might stop the reflex coming out also.

Jeff

Graeme K · #11 Post by **Graeme K** » Sat May 20, 2006 6:11 pm

Hi Jeff

I realised the glass would up the weight so when I fixed up the tiller I dropped the weight from 50# to 35#. No way of knowing if that was the correct amount so only time will tell--- let you know tomorrow

Keep your fingers crossed for me

Graeme

#12 Post by **Stickbow Hunter** » Sat May 20, 2006 7:04 pm

Yeah mate it is a bit of an unknown. I hope it turns out good for you.

Jeff

archangel · #13 Post by **archangel** » Sat May 20, 2006 8:27 pm

Graeme

This will be interesting to see how much the bo-tuff affects the weight and tiller of the bow. Your comments about the unpredicable nature of bamboo especially around the nodes certainly makes this an intriguing material. I am currently working on a short composite recurve, using bamboo on the belly rather than the back. I have based its construction on the wedge/binding technique as the picture below from the Atarn site.
http://198.66.52.119/phpBB2/viewtopic.php?t=395

Will post a thread later this week when I can get some pictures taken.

Graeme K · #14 Post by **Graeme K** » Sun May 21, 2006 12:24 pm

The Answer is that 50 thou of glass makes it too strong.
Photo shows bow drawn using long string with tips down 11.5 inches and load is 100#. The tips would need to come down another 1.5" to give 27" draw. Given that with the long string 22" of draw gives 100# then the average is 4.5# pre inch so with the string starting at 5" brace height and assuming that the average draw weight will be something more than 4.5# say more like 5# then the weight at 27" will be about 110# .
Anyone out there with really strong arms?

#15 Post by **Stickbow Hunter** » Sun May 21, 2006 4:55 pm

WOW that is some increase!!!

Jeff

Graeme K · #16 Post by **Graeme K** » Sun May 21, 2006 5:17 pm

I have now reduced the width to 30mm at the fades and 12mm at the nocks which is about a 25% reduction in width and the draw weight is 74# at 27" which as you would expect a 25% reduction in draw weight . Still a bit heavy and the tiller is uneven being a bit stiff in the LH limb so I am going to sand down the thickness of the glass on the stiff limb to try and get about 60# at 27"

#17 Post by **Stickbow Hunter** » Sun May 21, 2006 5:21 pm

Graham,

At least that is a start. I hope you can get it down to a useable weight for yourself.

Jeff

erron · #18 Post by **erron** » Sun May 21, 2006 5:46 pm

good effort Graham, I too hope you get the weight you want. Seems to be the really hard part of bow-making, from what I can work out

At any rate, it looks the goods

Erron

jindydiver · #19 Post by **jindydiver** » Sun May 21, 2006 6:52 pm

The whole process sounds as easy as pie, just glue up laminates and make a bow, till it comes to actually getting something you can use. I am sure my first effort would be either 20# or 200#

Thanks for sharing your efforts with us Graeme

Graeme K · #20 Post by **Graeme K** » Sun May 21, 2006 7:44 pm

GOING---GOING ----GONE----65# @ 27" -- Proof that you should never give up. And that nearly all things are possible. But I have to admit I had my doubts.

Not much of my 2" wide glass left . I reckon of the $30 dollars worth Ive got about $5 worth left on the bow but you have to admit I got a lot of pounds for my dollar.

But seriously it has turned out really well and I am very happy with the result. I flings arrows with such aggression that I will have to find something new to make a target out of because the arrows go straight through it.

Graeme

#21 Post by **Stickbow Hunter** » Sun May 21, 2006 7:51 pm

Great outcome mate. So glad all seems to be well and it is a good shooter. Been an interesting project for sure!!!

Jeff

yeoman · #22 Post by **yeoman** » Mon May 22, 2006 9:56 am

Mate, the bow looks absoloutely fantastic. I especially like the grip portion.

Well done,

Dave

tracker · #23 Post by **tracker** » Mon May 22, 2006 3:00 pm

Matey.. that is a nice looking bow.. well done.

Mick.

Poppy · #24 Post by **Poppy** » Mon May 22, 2006 6:44 pm

Nice bow mate. Its great to see hard work and determination pay off
Cheers
Paul

Lou · #25 Post by **Lou** » Tue May 23, 2006 7:27 pm

Very nice outcome Graeme, the bow looks realy nice, nice eaven tiller too

.
Lou

jaselpool · #26 Post by **jaselpool** » Tue May 23, 2006 10:36 pm

Fantastic looking bow mate congrats! Well in for sticking with it Ã¢â‚¬â€œ it looks great

Jase

NCArcher · #27 Post by **NCArcher** » Wed May 24, 2006 10:12 am

It sounds like it shoots as good as it looks. Great job.
Is that a vinyard I can see through the shed door

Graeme K · #28 Post by **Graeme K** » Wed May 24, 2006 12:57 pm

NCArcher

Hi Tony
Well spotted -- yes that's my vineyard, and that's what I do for a living I am a winemaker which is why I have plenty of time to build bows. This is my quiet time of year but I have to start pruning in the next couple of weeks.
As for the bow it really shoots beautifully, I found out something about tillering that seems to make a big difference. It probably should have been self evident but never occurred to me until now. It is also looks real nice which is always a bonus. I would like to chrono it as I suspect the very slender light limbs probably make it quick. Have not been able to use it as much as I would like as I am not used to the weight and also it fires the arrows straight through my target which tears off the fletches--- need different target!

Graeme

NCArcher · #29 Post by **NCArcher** » Wed May 24, 2006 2:22 pm

Hmmmm, a field course set amongst the vines could be fun.

Perhaps a little wine tasting after the shoot

Trad bows and wooden arrows only of course. Wouldn't want to sour the wine with that aluminium taste. (***slowly uses foot to push aluminium arrows under the bed out of sight***)

Back to the bow...what glue are you using and would the increase in weight have been as large if the glass was on the back instead of the belly?

jindydiver · #30 Post by **jindydiver** » Wed May 24, 2006 2:45 pm

That bow sure does look sweet

Ozbow

One more try at 50#Bamboo

One more try at 50#Bamboo

new design

bo-tuff