First Crack at a warbow (build along)

[Dennis La Varenne]

Rod,

I have done the same thing with rigid handled bows where I put the focus of the arc at the end of the fadeout and drew the arc around it. With this kind of bow, even though is has a very slightly bendy handle, arguably you could place the foci at imaginary top and bottom handle positions, say, perhaps on inch above the where the bow is actually gripped. That would probably be a bit more accurate. Using the arrow pass or more likely the position of the ball of the thumb to place the focus would certainly apply if the bow was genuinely circular I would guess. Have a look at this drawing of a rigid handled bow I did once.

68-inch-longbow-schematic_2.gif (40.76 KiB) Viewed 5115 times

[rodlonq]

Hello Dennis,

Sorry, I misinterpreted your meaning of focal point. In fact, for circular arcs the focal point is the centre of the circle, which is the case for your diagram. For elliptical arcs the focal point moves away from the centre towards the end of the major axis.

I believe there are two things to consider. Unless a bow is tillered for a perfect circle then the limbs should bend in a parabolic in shape (i.e no hinges, no flat spots but more bend in the inner third than the outer). The other point that I didn't make very clearly is the chord between the "origin" of the bend (the fadeout in the case of your last diagram) and the nock gets shorter as the limb bends more, so the nock cannot flow a circular path, but instead follows an elliptical path. This remains true regardless of whether the tiller is circular or parabolic.

It is over-exaggerated to make the point clearer, but perhaps the attached diagram will help.
Cheers... Rod

Screen Shot 2014-08-26 at 5.52.04 pm.png (166.26 KiB) Viewed 5110 times

[hunterguy1991]

Well I attempted a second hickory backed Silver Ash today with the exact dimensions of the template...

Same result as the first one...

So I've decided to scrap the Silver Ash as a belly, but I might try it as a backing material yet on a smaller light weight bow and see how it goes. Splinters don't seem to lift very easily in the stuff and the grain seems very fibrous and interwoven so will be an interesting experiment. Also I have put aside some to be used in a hall table as legs. Very much enjoy doing joinery so will be good.

Have taken Dennis's suggestion and I will be getting some spotted gum late this week so hopefully all goes well with it.

I am going to attempt to salvage the hickory back off the bow I made today and try to reuse it if possible.

Colin

[Dennis La Varenne]

Rod,
Yes, I take your point. Strangely, just after posting, I was looking at my drawing and thought that something about it did not look right. Now I understand why. I should also have used the correct terminology - focal point, not focus.


Colin,
Pity about the Silver Ash, but there you have it. The backing idea may be the way. I have a strip of the stuff here which I have had for years and it does have an interlocking grain structure, but so does Spotted Gum and Red Ironbark. I don't think that is the problem. Silver Ash is just not good in compression. I still think you did well to get as far as you did with the other bow though. With the template you used, it should have come out heavier, but the Air Dried Density (ADD) rating for the stuff is not very high depending if it is Northern, Southern or Queensland variety. Southern (NSW) rates 620 (Bootle), Northern rates at 680 and Queensland at 700kg/m^3, so higher density yields a heavier bow for the same dimensions of course.

[mikaluger]

Colin,
When you want some more Hickory, I will throw in an Ash stave for you. I am going to get more of both this week. I hope.

You can always wait till that Red Ash seasons,.................. you can put me down for a piece of that when its ready too!!!!!!

See if you can get some Malas decking, they may have some up there, use some bamboo for a core, and do a Tri Lam!!!!!!!

You have nothin to lose............... Keep having fun,

Mick.

[hunterguy1991]

Thanks Dennis,

Was a pity about the one that failed today because the tiller was looking really good to start with, nice whip ends and a stiff handle section.

I think the difference between the spotty or ironbark and the ash as far as an interlocked grain goes is that the ironbark and spotty will pull a splinter but because of their density and hardness the splinters follow the grain relatively easily and crack very quickly right through the stave/board... however, when you do manage to lift a splinter in the ash its like pulling duct tape off glass and eventually the interlocked grain just stops you pulling it up altogether. I will let you all know what happens with it that's for sure. I think i'll grab a spotty decking board and have a go at a light bow using ash as the back.

Cheers Mick!

Put me down for another 5 or 6 backing strips of hickory and the ash stave... AND PM me your bank details so I can fix you up for them this time!! haha

Once the Red Ash seasons (think ill give it 6 months or so at least) I will definitely send a few split staves down for you to have a play around with.

Unfortunately the only decking you can get up here is spotty, red gum, merbau/kwila and engineered fibre stuff. I have sourced some Red ironbark from a timber yard and a mate is getting me some spotty on thursday to use in his warbow when I get a prototype right.

Definitely having fun making these, and S*#t's gonna get wild when I crack the 90lbs with a good one haha.

Thanks for all the advice and support so far guys! Really appreciate it!

Colin

[Gringa Bows]

Ah Dennis ,its 2.5 c.m. is an inch or 25mm

[hunterguy1991]

That might be the scale of the picture Rod...

Dennis can you confirm for us please?

[Dennis La Varenne]

Rod and Colin,
It's actually 25.4mm to the inch to be exact, but yes that was the original scale of the picture. I drew it full size originally and had to reduce it somewhat to post here. Sorry about that, Rod if it threw you a bit.

Regards,

[hunterguy1991]

Right, an update!

Some Red Ironbark and some spotty will be acquired on the weekend. Round 3 here we go!

Photos as I go for this one since its a new timber for me.

Plan will be 82" total length 80"n-t-n, 30mm wide for handle section and 25mm thick (20mm ironbark belly and 5mm hickory back). Straight taper to 12mm tips as per Dennis's template.

Lets see what weight this sucker comes in at! Much Less than 90lbs will add some thickness for the next one, very close to or over 90lbs and we're on the money!

Colin

[hunterguy1991]

Evening all,

So yesterday morning I salvaged the back off the second ash bow I made and glued it to a nice piece of Red Ironbark, today I managed to get the belly rounded nicely after a LOT of filing... Dam that stuff is hard!! But I'm already loving the colour of it!!

I made a very slight blue when trimming the ironbark down to the hickory (slightly nicked into it... Boy was I sh*%^y at myself for that!!) so I will be keeping this one if all goes well or someone insists they must have it...

Will be dressing it with Black horn nocks which will compliment the timbers well I think.

At the moment I have it at a low brace height and can see one limb is slightly stiffer than the other, so that will be tomorrows task. Even out the limbs and tiller to full draw.

Photos tomorrow.

Colin

[hunterguy1991]

Photos as promised!!

Hickory backed Red Ironback - brace (640x480).jpg (188.49 KiB) Viewed 5072 times

Bow at brace (about 5 inches here. I have increased it a little further since and may tweak it more when the new string goes on)

Hickory backed Red Ironbark - shooting (480x640).jpg (166.87 KiB) Viewed 5072 times

Full draw shot.

The bow has settled in 50lbs at 28 inches, is 77" n-t-n and has been fitted with horn nocks. I really like the combination of Red Ironbark and Hickory so I think I will have a crack at a heavier one for myself in this combo.

Colin

[Stickbow Hunter]

Looking good mate!

Jeff

[mikaluger]

Huzzzzah!!!!!

[greybeard]

The bow has settled in 50lbs at 28 inches, is 77" n-t-n and has been fitted with horn nocks.

Colin, the bow has turned out very well.

It may be an optical illusion or the n to n length but the limbs appear quite thick for 50#.

Did the ironbark work relatively easy and was lifting splinters an issue?

Daryl.

[hunterguy1991]

Thanks all!!

Pretty chuffed with how this one turned out.

Daryl, I think the glare on the bow makes it appear thicker. The handle is 22mm thick including the 5mm thick hickory backing, which made the 50 lbs about what I was expecting. The thickness tapers down to 12mm at the very tips of the stave. I could easily increase the weight,on the next,one by shortening it but i like that length as it does not over,stress the timber and has taken very little set.

rounding the ironbark belly was an experience I'll say!! That stuff is hard! Took me about 2 and a half hours of filing to finish the round and had to be very careful not to bite too much when doing the bulk removal as its easy to pull big chunks out by mistake.

[hunterguy1991]

What's the best type/way to seal these bows?

So far I have been using an oil based polyurethane which seems to hold up ok but I was wondering what everyone else uses?

Have heard of rubbing them with bees wax and 0000 steel wool, or a simple coat or 2 of Danish oil...

Cheers guys,

Colin

[greybeard]

So yesterday morning I salvaged the back off the second ash bow I made and glued it to a nice piece of Red Ironbark.....

Colin, had you have used Danish Oil chances you could have had a gluing issue. This happened to me when I tried replacing the back of an all bamboo bow that had been given a couple of coats of Danish Oil.

I am happy with the Minwax sealer and if I have to carry out modifications to the bow the finish is easily re coated.

Daryl.

[hunterguy1991]

Hi Daryl,

The backing that was salvaged was unfinished... The bow it was on chrysalled badly in the belly during tillering so I cut it off and used it on the Ironbark one... I don't do any finishing coats until I have run a fair few arrows through the bow with no issues... until then they are only scraped not final sanded or finished.

Since this bow has not developed any problems I wanted to final seal it to keep any moisture out. For this I have used the oil based polyurethane and will do 3 or 4 coats with a light sand between each.

Just wanted to see if I was on the right track and what everyone else is using.

Cheers,

Colin

[mikaluger]

yep minwax........... or truoil.......

[hunterguy1991]

Well I started another one yesterday!!

This one is going to be a proper warbow! Im using hickory backing on a red ironbark belly.

Rough dimensions are as follows:

Total length 84 inches

Handle thickness 32mm, handle width 35mm, Full thickness handle length is 6 inches (3 inches either side of centre)

Thickness taper is straight from handle to tips, tip thickness is 12mm (half inch)

Width is full for the middle quarter (as per Dennis's template) then goes to 3/4 of full width 10.5 inches in from the tips, then straight to 12mm tips.

I will be crowning the back.

Will post photos as I go with the shaping and whatnot.

Cheers,

Colin

[greybeard]

Well I started another one yesterday!!Will post photos as I go with the shaping and whatnot.

Can you start a new post for this one?

Daryl.

[hunterguy1991]

Will do Daryl!!

Cheers,

Colin

[Dennis La Varenne]

Still like those curves, Colin. The bow looks decidely underworked at that draw length though doesn't it?