Bamboo backed tri-lam ELB

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hunterguy1991
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Bamboo backed tri-lam ELB

#1 Post by hunterguy1991 » Thu Mar 26, 2015 6:55 pm

Started a new one today... a replacement for my other tri-lam which has crapped itself. Knew that Teak was hit and miss and this particular piece was a miss.

This new bow will be my first bamboo backed ELB and has a Red Ironbark core and American Ash belly. I really like the Ash as a bow wood, it just looks really nice and its great to work with.

The bow is 76" nock to nock, 30mm wide and the handle and will be about 26mm thick initially with 15mm dia tips.

I am also trying the bow put in reflex to gain some performance hopefully. I have glued the belly and core with 1 1/2" of reflex so far.

Tomorrow I will get the limbs to plan and then thin the bamboo toward the tips as is advised before gluing it on in the form. Hoping to have 1-2 inches of reflex when its all glued up depending on how far I push it in the form.

Photos when I get some decent progress made on it.

Colin

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Re: Bamboo backed tri-lam ELB

#2 Post by hunterguy1991 » Thu Mar 26, 2015 7:11 pm

The one photo of the glue up... not much interesting going on here.
Bamboo back trilam glue up 1 (480x640).jpg
Bamboo back trilam glue up 1 (480x640).jpg (196.34 KiB) Viewed 5132 times
Colin

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Re: Bamboo backed tri-lam ELB

#3 Post by hunterguy1991 » Fri Mar 27, 2015 11:05 am

Lots of progress last night and this morning.

Last night :

Stave was taken out of glue up and cleaned up to square and no glue on edges.

Yesterday I fixed up an old No 5 Bailey Stanley hand plane I got from my grandad. Just needed a touch up and tune. I am sick of filing the glue squeeze out off and figured the plane was worth a go. What a dream to use that was!! Its definitely my new favourite tool I own!!

I then proceeded to mark out the bows plan on the blank ready to plane down this morning.

This morning:

Got stuck in early and planed down the bow stave to its width plan. Again I used the plane and had it all done in no time :biggrin: Big sense of satisfaction in using hand tools for me.

Next up I prepped the piece of bamboo I had selected for the back. Again hand tools were used (draw knife and my medieval bowyers stand) to flatten the bamboo off ready to be marked out and shaped to the bow plan.

Once flat I then marked it while it was clamped to the stave and then used a Spoke shave to get it down to the line.

Back on the bowyers stand I then proceeded to further thin it, particularly towards the tips (as Daryl always advises :smile: ) with the draw knife.

I then gave it a quick run over on my belt sander mounted upside down in the vice to make sure it was nice and flat at the nodes and also a bit rough for the glue to take a good hold.

Next was the glue up, same as normal. Glue applied to stave, backing placed, taped, cling wrapped, rubber strapped up and set back in the form.

Bit of teaser of the colours in the bow for you all...
Bamboo back glue up, sneak peak at colours (640x480).jpg
Bamboo back glue up, sneak peak at colours (640x480).jpg (139.78 KiB) Viewed 5111 times
Hope its a shooter because its going to look pretty nice I think.

Out over the weekend so no more progress till Sunday arvo/ Monday.

Colin

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Re: Bamboo backed tri-lam ELB

#4 Post by greybeard » Fri Mar 27, 2015 2:43 pm

hunterguy1991 wrote:........Bit of teaser of the colours in the bow for you all......
Colin, the stave is coming along nicely, did you put much taper into the ironbark core?
hunterguy1991 wrote:......Again hand tools were used (draw knife and my medieval bowyers stand).....
Can you put up a photo of your medieval bowyers stand?

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

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Re: Bamboo backed tri-lam ELB

#5 Post by hunterguy1991 » Fri Mar 27, 2015 4:36 pm

Thanks Daryl.

I wasn't really able to accurately taper the core so I didn't worry about it. It may end up being the bows downfall but only time will tell I guess.

I will post a photo of it on Sunday when I get home. Out for the weekend so no more will be done till Monday I think.

I did manage to get the belly tapers marked out today before I left so I will plane them done as the next step then round the belly with the spoke shave ready for tillering.

The techni glue hardens up quite quickly when left to dry in the sun and the bow is holding about 1 inch of reflex which I'm happy with.

Colin

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Re: Bamboo backed tri-lam ELB

#6 Post by Dennis La Varenne » Fri Mar 27, 2015 11:01 pm

Waiting for the next exciting episode.

I am interested in the effect of the bamboo as a backing on the much lower MoR rated American Ash on an ELWB and whether or not the back can be radiused successfully and by how much.

With regard to tapering a core lam and the belly, the glass bowyers use a master taper under their lams to put a specific taper into them which should also work for a core lam and the belly wood. You just start thicker in the middle and have a very fast taper like 8 or 10 thou per inch.

Having a taper built in the components at the glue-up would yield a blank which would start to bend immediately out of the former wouldn't it? It does with glassed bows.

This won't be one of your BIG bows, Colin, judging from the dimensions. It will lose most of its reflex during tillering because of its cross-section, but it should still be very quick. Don't be surprised if it comes out with even more whip-ending than your usual and a bit flatter through the middle.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

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Re: Bamboo backed tri-lam ELB

#7 Post by hunterguy1991 » Sat Mar 28, 2015 11:05 am

I don't possess the right tools for sanding tapers at the moment so its not really possible for me to do it. Once I transition into glass bows I will have all the right kit to do it.

The natural pole bamboo does have some radius to it but its only very slight at the ends. Not sure what I'm going to do there just yet.

as to the effect of the tapered core on the tiller shape, I have no idea. I think after just feeling this one a little after it was glued up, even still at full thickness the whole length, its going to bend a good circular arc quite evenly. I'm hoping that the reflex will force the thinner tips to go early as the handle loads up

This bow was designed to be a hunting weight, around 60lbs or so, but very light in hand and hopefully quite fast.

We'll see what happens once I start tillering it.

Colin

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Re: Bamboo backed tri-lam ELB

#8 Post by greybeard » Sun Mar 29, 2015 2:31 pm

Colin,

Finding the complimentary ratio for the laminations in a tri laminate English style longbow can take some experimentation.

I believe the main mistake I made was having the back lamination a little too thick and tapering outboard of mid limb to the tips. Combined with a tapered core meant that whip ended limbs were a distinct possibility.
Fortunately I had enough belly wood available to help minimise this outcome.

A parallel back lamination and a tapered core accounting for about 45% to 50% of the total limb thickness at the nock appears to work well.
hunterguy1991 wrote:I wasn't really able to accurately taper the core so I didn't worry about it. It may end up being the bows downfall but only time will tell I guess.
It will be interesting to see the outcome of a tapered back and parallel core, I think it will work.

For what it is worth, because reflex has been built in I have found it beneficial to get the section between the mid limbs moving before removing too much material from mid limb to the tips.

Keeping the belly timber full thickness before glue up helps to maintain reflex in the blank and I have witnessed the amount of reflex increasing as belly wood is removed during the tapering process.

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

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Re: Bamboo backed tri-lam ELB

#9 Post by hunterguy1991 » Sun Mar 29, 2015 8:32 pm

Evening Daryl,

This one was a big experiment because of the bamboo back and reflex... I will just work slow and steady to get it to do what I want (if I can that is)

The bamboo on this bow is very thin compared to others I have seen from American and European bow makers, I think because they do not thin the tips as you and I do after the bamboo is cut to profile.

Im hoping to remove very little to no timber from the belly around the handle as the tips are quite a bit thicker (3mm) than what I would normally make them. I did this in an attempt to push a little more bend into the handle region without removing wood.

I had noticed that some of my other bows had lost weight because I had to remove more timber in the handle section than I wanted to get the bend I needed so I thickened the tips a little to make the handle bend more. Always better to have more wood than you need than not enough.

Colin

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Re: Bamboo backed tri-lam ELB

#10 Post by Dennis La Varenne » Mon Mar 30, 2015 1:36 am

Daryl and Colin,

I also concur with your thinking here. I have noticed much the same thing with my ELBs in the past.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

hunterguy1991
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Re: Bamboo backed tri-lam ELB

#11 Post by hunterguy1991 » Mon Mar 30, 2015 7:06 pm

Well gents, we have a shooter!!

After work was cancelled on me today and I got an order of arrows knocked out I figured it was time to get this bow all tillered up.

As I had planned, the tips took some time to get moving but eventually I did and once the short string went on they came round very nicely.

I just have to do a little bit of fine tuning and check the tiller when being shot tomorrow and I'll get some photos up for you all to look over.

I like to tiller my bows a little soft in the upper limb as the bottom limb is often stressed a little more due to hand placement at the handle.

I managed to get away with not tapering the core lamination in this bow but for lighter versions either a much thinner core lam or a tapered lam would be necessary, otherwise I'd have gone close to running out of belly wood at the tips.

I was aiming for 55-65lbs and build to handle stack to what I thought would be close to the middle of that range, however, the bow came in at nearly 70lbs. Its not a problem for me to shoot but more care will be needed when building a bow for someone else...

It still needs a nice fast flight string, which I will make tomorrow if I have enough left to make it and then adjust the brace height to the sweet spot. I"m a little suss on putting the brace height too far over 6 inches as I don't want to over stress the belly.

More tomorrow.

Colin

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Re: Bamboo backed tri-lam ELB

#12 Post by Dennis La Varenne » Mon Mar 30, 2015 8:31 pm

hunterguy1991 wrote:otherwise I'd have gone close to running out of belly wood at the tips
Collin,

So long as there is enough material for nocks or horns, functionally, this should not really matter. It is more of a cosmetic thing really.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

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Re: Bamboo backed tri-lam ELB

#13 Post by mikaluger » Mon Mar 30, 2015 8:49 pm

Pics pls,......

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Re: Bamboo backed tri-lam ELB

#14 Post by hunterguy1991 » Tue Mar 31, 2015 12:09 pm

Finally got around to getting some photos of it for you all!!

First shot is un braced. Has very little set at all, maybe 1/4-1/2 inch at the tips.
DSCN0775 (640x480).jpg
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Second shot is at brace, around 6 inches, maybe a little under. Took a nice curve and bends more in the handle that what I usually make them. This is easy to tell as the brace profile is a smooth bend the whole length, rather than being a little more straight through the handle as a slightly whip tillered bow would be. I think the top tip is to the left in the photos.
DSCN0776 (640x480).jpg
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Last shot is of the timbers in it. This is un-sanded and un finished. Will come up sweet after a sand and some varnish is applied.
DSCN0777 (640x480).jpg
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Cant decide what I want to do with the tips, horns or just an overlay... either would look nice and suit the bow. It will most likely get horns tho, possibly side nocked.

Let me know what you guys think.

More photos to come when its sanded and finished.

Colin

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Re: Bamboo backed tri-lam ELB

#15 Post by greybeard » Tue Mar 31, 2015 12:45 pm

Hi Colin,

The bow has turned out well. It will be interesting to see how the bow holds up after several hundred shots.
greybeard wrote:It will be interesting to see the outcome of a tapered back and parallel core, I think it will work.
It would appear that the taper in the bamboo compensated for the parallel core.
hunterguy1991 wrote:.... Cant decide what I want to do with the tips, horns or just an overlay... either would look nice and suit the bow. It will most likely get horns tho, possibly side nocked.....Let me know what you guys think.....
If its going to be a knock about bow for the bush perhaps horn overlays, otherwise full horn nocks.

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

hunterguy1991
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Re: Bamboo backed tri-lam ELB

#16 Post by hunterguy1991 » Tue Mar 31, 2015 1:26 pm

Thanks Daryl,

I will let you know how its going when I've put some good shooting sessions through it.

I think on the next one I make I will leave the tips a little smaller to begin with, although, tillering this didn't take very long, it just needed quite a bit taken off the last 12 -8 inches to get them to bend properly.

I will most likely put some horn (or black plastic) nocks on it, but I very much doubt it will ever see the bush... just for target shooting and displays. Tts a bit long for in the bush hunting.

Colin

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Re: Bamboo backed tri-lam ELB

#17 Post by hunterguy1991 » Wed Apr 01, 2015 3:15 pm

Managed to get a photo of full draw between the showers of rain today...

I think its got a nice curve myself.
Full draw on centre (480x640).jpg
Full draw on centre (480x640).jpg (200.65 KiB) Viewed 4982 times
Much more a circular bend than a whip tiller on this bow compared to others I've made but that's what I was aiming for with this bow so I'm happy with it. I have decided to fit it with horn tips not overlays and will most likely do side nocks as they're easy to push pull string in a hurry if I need to. I will use a stringer in preference of course.

Colin

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Re: Bamboo backed tri-lam ELB

#18 Post by greybeard » Wed Apr 01, 2015 4:54 pm

Colin, full horn nocks should set the bow off nicely.
hunterguy1991 wrote:....Much more a circular bend than a whip tiller on this bow compared to others I've made.....
I find that the circular/elliptical tiller is more pleasing to the eye than whip ended tillering.

Well done,

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

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Re: Bamboo backed tri-lam ELB

#19 Post by Dennis La Varenne » Tue Apr 07, 2015 8:14 pm

SIGH!!!

I prefer the look of a modest whip-ended bow myself of course. To my eye, these look more circular in bend that the bendy handle bows, but that is mere nitpickery on my part. Love to know its cast at the long draw though.

Interestingly, as an aside, I cannot recall a single use of the words 'circle' or 'circular' in Ascham anywhere. Whenever he seems to refer to anything having curvature, he tends to use the word 'compass', viz. the shape of a drawn bow and the shape of an arrow's trajectory.

Nor does he ever comment that bows bending in a 'compass' shape actually bend through the grip area, which is only a modern assumption on our part and never his instruction anywhere that I can find.

I have noted that many modern ELB makers very often make assumptions drawn from interpretations of his advice, many of which I find remarkably generous.
Dennis La Varénne

Have the courage to argue your beliefs with conviction, but the humility to accept that you may be wrong.

QVIS CVSTODIET IPSOS CVSTODES (Who polices the police?) - DECIMVS IVNIVS IVVENALIS (Juvenal) - Satire VI, lines 347–8

What is the difference between free enterprise capitalism and organised crime?

HOMO LVPVS HOMINIS - Man is his own predator.

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Re: Bamboo backed tri-lam ELB

#20 Post by hunterguy1991 » Tue Apr 07, 2015 8:35 pm

Dennis,

I too prefer the slightly whipped look, but for this bow with this timber combination I decided against it. There will be many more whipped bows come out of my workshop don't you worry, maybe even a Pacific Yew warbow in the near future :biggrin:

This bow probably wont ever see the longer draw length as I don't want to risk fretting the belly, as it was designed as a target bow so theres no need. I am going to test its cast with a 28" draw and see how far I can get a target arrow.

The bow comes back to perfectly flat after letting it sit for a few hours which Im very happy with and takes quite some effort to string so I think its storing plenty of energy.

Will be dressing it with some black (plastic) horns tomorrow ready for finishing.

Colin

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Re: Bamboo backed tri-lam ELB

#21 Post by mikaluger » Tue Apr 07, 2015 9:42 pm

Bring on the horns and a little oil, I say.............. :biggrin:

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Re: Bamboo backed tri-lam ELB

#22 Post by hunterguy1991 » Sun Apr 19, 2015 7:35 pm

Finally got this sucker finished!!

Black Acetal Plastic side nocks are fitted (could be fitted and blended a bit better but this bows for me and I don't mind)

Colours came out really nice I think.
DSCN0814 (640x480).jpg
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DSCN0817 (640x480).jpg
DSCN0817 (640x480).jpg (194.34 KiB) Viewed 4904 times
One more coat of varnish and tune the brace height now. Its rocket fast and has no set at all.

Colin

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Re: Bamboo backed tri-lam ELB

#23 Post by mikaluger » Sun Apr 19, 2015 7:50 pm

Nice one Col, thats a cracker!!!

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Re: Bamboo backed tri-lam ELB

#24 Post by hunterguy1991 » Sun Apr 19, 2015 7:54 pm

Thanks mate!! Very happy with it :biggrin:

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Re: Bamboo backed tri-lam ELB

#25 Post by greybeard » Mon Apr 20, 2015 8:52 am

Well done Colin,

Do you have any concerns about the string slipping off the side nocks?

Daryl.
"And you must not stick for a groat or twelvepence more than another man would give, if it be a good bow.
For a good bow twice paid for, is better than an ill bow once broken.
[Ascham]

“If a cluttered desk is a sign of a cluttered mind, of what, then, is an empty desk a sign?” [Einstein]

I am old enough to make my own decisions....Just not young enough to remember what I decided!....

hunterguy1991
Posts: 859
Joined: Mon Jul 09, 2012 10:18 am
Location: Woodford Queensland

Re: Bamboo backed tri-lam ELB

#26 Post by hunterguy1991 » Mon Apr 20, 2015 9:13 am

Thanks Daryl!

From what I have seen on the net with regards to side nocks (normally on high weight warbows) the nocks are cut quite deep compared to that of a Victorian style nock... because they're quite deep I don't think it should be a problem, however, I'm yet to do a good shooting session with it so I will know more soon.

It is rather odd looking along the length of a side nocked bow tho as the string crosses from one side of the bow to the other, but is in the centre at the midpoint where the arrow is nocked.

Colin

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