horsebow build

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Brainbruise · #1 Post by **Brainbruise** » Mon Mar 05, 2007 3:03 pm

Well here is my latest bow project.
Materials:
Hickory riser, siyhas
2 .05 glass lams
2 ash lams
1 bamboo lam

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*NOTE- The lovely glass of Guinness

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greybeard · #2 Post by **greybeard** » Mon Mar 05, 2007 6:48 pm

Hi Brainbruise,
The project is looking good so far.

How thick are the laminations and how wide will the limbs at maximum and also their length?

Please keep us Aussies updated on your progress. Hope all goes well,
Daryl.
(It is amazing how a little Guinness improves ones perceptions, I love the stuff.)

archangel · #3 Post by **archangel** » Mon Mar 05, 2007 7:08 pm

Brain,

Another horsebow fan! Good looking start - using combination of a pressed former and inner tube strips to glue up the parallel laminations. I notice that you have stepped the siyahs and will be looking forward to watch how you splice them in to the limbs. Like Greybeard, I'd like to hear more of the dimensions. Keep the pictures coming!

Graeme K · #4 Post by **Graeme K** » Mon Mar 05, 2007 9:09 pm

Hi Brainbruise
Interesting project.
I notice in the photo that you have some woven glass matt, does this mean you are using this as the glass in your bow rathe rthan pre made glass lams.
Also how thick are your core lams and what is the length and width of the limbs.
Graeme

Brainbruise · #5 Post by **Brainbruise** » Mon Mar 05, 2007 11:57 pm

The three lams are 1/16 thick and 1 1/2 inches wide. The bow will be 58 inches long NTN. I found an interesting way to utilize the glass cloth. I seperate the strands, which is very, very easy to do, and make bundles that are 3 foot long. This gives me unidirectional glass "sinew" to reinforce the handle section and siyhas.

Graeme K · #6 Post by **Graeme K** » Tue Mar 06, 2007 9:12 am

Hi Brainbruise
Yes that is a good idea for the glass. I have a roll of what is called 'Rovings' which is sort of a rope made up of the fibers before they are woven that I use for the same sort of thing.
Your limbs seem quite wide and thin --- must be a bit less than 5/16" ---- but I dont know much about using parallel lams as I taper all mine. will be interested to see photos of the splices for the siyhas.

Graeme

Brainbruise · #7 Post by **Brainbruise** » Tue Mar 06, 2007 1:48 pm

The limbs are 1 1/2 inches wide. I will cut an arrow shelf and obviously taper to the siyhas. The limbs right now are 70 inches but they will be cut down and once the siyhas are added, be 58 inches NTN. Good warm day here, which heated my work shed up perfectly. I was concerned about not using a heat source to cure it. Any and all feel free to throw in advice, tips, etc. Oh, and can I get the correct spelling of "siyhas"?

yeoman · #8 Post by **yeoman** » Wed Mar 07, 2007 10:34 am

"Siyah"

John Allan · #9 Post by **John Allan** » Wed Mar 07, 2007 5:56 pm

Hi Brainbruise,
I had a go at one using the same design you have. as it reached 28" on the tiller it laminated at the center of the handle. I had used flax thread and epoxy to wrap the ends of the handle riser. The wraps at each end held but the stress blew out the laminations in the center of the riser. The scale showed 53# as it approached 28". I feel that if I had wrapped more of the riser (all but the 4" of hand grip) I may have got away with it. I see you are using glass for the wrap so that will be strong. I do not mean to spread gloom just pointing out potential pitfalls.
Best of luck with the project.

Brainbruise · #10 Post by **Brainbruise** » Thu Mar 08, 2007 12:16 am

John,

Yep, the riser area is my main concern. I will defiantly keep in mind your experience, and appreciate the "gloom". It will take me at least another week to get this finished (married) and we will see how she turns out.

Brainbruise · #11 Post by **Brainbruise** » Sun Mar 11, 2007 2:37 am

Well I miscalculated on the poundage. It will take seriouse beveling to get it down to at least 75 to 80 which I was shooting for. Here she is afetr the glue up. I am heading to the father in laws and his well stocked woodshop to make some cuts to the riser and taper the limbs. More pics tonight..

*NOTE- The glass of GUINNESS is only used for size reference

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Brainbruise · #12 Post by **Brainbruise** » Sun Mar 11, 2007 5:57 am

A few more cuts

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Brainbruise · #13 Post by **Brainbruise** » Sun Mar 11, 2007 4:28 pm

Siyahs glued on with more bike tube bands.

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Artemis · #14 Post by **Artemis** » Tue Mar 13, 2007 4:15 am

like the look of that one, will have to get a kit myself !

Brainbruise · #15 Post by **Brainbruise** » Tue Mar 13, 2007 3:00 pm

Siyahs glued, not re-enforced yet. Riser re-enforced with singlestrand glass, then covered with fiberglass cloth, plactic wrapped and "molded" down with more bike tubes.

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greybeard · #16 Post by **greybeard** » Tue Mar 13, 2007 7:22 pm

Hi Brainbruise,
The bow is looking good. Have you had any problems getting the siyahs to line up through the handle? My previous attempts didn't include glass in the laminations and the slightest bit of limb twist threw the siyahs out of alignment.
Keep up the good work,
Daryl.

archangel · #17 Post by **archangel** » Tue Mar 13, 2007 9:12 pm

Brainbruise

Coming along really well. The attachment of the siyahs looks very interesting and I am looking forward to seeing how they turn out once the rubber comes off. Like Greybeard, I had the same problem with limb twist occuring with the siyahs being out of alignment. However your work so far is doing the job. No-one has mentioned the bows in the background ... could you share a few details about those as well? I like the look of the bamboo-backed (?) semi-recurve on top.

Brainbruise · #18 Post by **Brainbruise** » Tue Mar 13, 2007 11:51 pm

The bottom bow is boo backed ipe longbow. That sweetheart pulls at about 72lbs. The top bow is a heat tempered boo backed hickory reflex/deflex longbow with a partial cherry riser and antler tip overlays. It pull at about 55lbs. It was much faster to build compared to this horsebow. I am concerned about limb twist. However my first mistake was to use to many lams. Now I will have to tiller it like an all wood bow, which really sux. But I think this will allow me to compensate if there is any twist and bring them back in line

The Gnome! · #19 Post by **The Gnome!** » Wed Mar 14, 2007 12:29 pm

Brainbruise siad,

The bottom bow is boo backed ipe longbow.

What is IPE?

By the way they look/sound sweeeeet too.

Yours In Archery,

Gnome!

Brainbruise · #20 Post by **Brainbruise** » Wed Mar 14, 2007 1:51 pm

Ipe is a south american hardwood, very similar to osage orange in compression, elastisity and toughness.

The Gnome! · #21 Post by **The Gnome!** » Wed Mar 14, 2007 2:01 pm

Cool thanks Brainbruise,

Is/was the Ipe as hard to work with in comparison to Ossage?

Yours In Archery,

Gnome!

Brainbruise · #22 Post by **Brainbruise** » Thu Mar 15, 2007 11:28 am

It is about the same as osage. Whatever tools you use must be sharp. I know it works amazing as a longbow, I have not heard of anyone puting any serious reflex in it. As a longbow wood it is top notch.

Brainbruise · #23 Post by **Brainbruise** » Thu Mar 15, 2007 12:37 pm

OK, the next steps are to re-enforce the siyahs with single strand glass, then a layer of cloth over that, plastic wrapped and "bike tubed" to flatten it out smooth. I did this on the riser as you can see and will touch it up by sanding it a bit before wrapping with silk or maybe hemp. I will probably put more glass on the riser just to make sure. After all this I will finally sting it and get the limbs and string aligned.

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Out of GUINNESS at the moment!!!!

Brainbruise · #24 Post by **Brainbruise** » Sun Mar 18, 2007 2:29 pm

Ready for glass re-enforcement of the siyahs

[img][img]http://i121.photobucket.com/albums/o239 ... se7004.jpg[/img][/img]

Brainbruise · #25 Post by **Brainbruise** » Sat Mar 24, 2007 4:09 pm

Getting closer. A funny thing happened, one of the glass lams on the belly popped off while stringing. The draw weight was indeed to heavy. I scraped the other side off and presto, 58@28. I guess that spot of bad glueing actually was a benefit.

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Graeme K · #26 Post by **Graeme K** » Sat Mar 24, 2007 6:31 pm

Hi Brainbruse
Sorry to hear about the belly lam. I think you may have trouble with only having glass on the back as the glass is an enormous amount stronger than any wood so you may find that you get compression damage on the belly side. Hope I am wrong but I would advise you to keep a close eye on it .

Graeme

archangel · #27 Post by **archangel** » Sat Mar 24, 2007 8:14 pm

Brainbruise

Looking great with the string on and the reinforcing around the base of the siyahs looks like it is holding. Regarding the delamination of the glass, it should not be a worry if the belly lam is bamboo. This should take the compression on its own - ash could be more susceptible to crystalising. Have you thought about adding string bridges at the point where the string sits on the siyahs? This seems to make the release much quicker, as the kinetic energy is transferred to the the arrow and spits it off the string.

wheres the myrtle · #28 Post by **wheres the myrtle** » Sat Mar 24, 2007 8:53 pm

Yup looking very good.

I'd concur with Archangel if that belly lam is anything but boo i'd say given the weight and the amount of bend its gonna have when drawn compression fractures are an almost certainty.

greybeard · #29 Post by **greybeard** » Sat Mar 24, 2007 10:34 pm

Hi,
The bow is looking good. Are the secondary grooves in the siyahs an aid to stringing the bow or did you shorten the nock to nock length to increase the draw weight?

Daryl.

Brainbruise · #30 Post by **Brainbruise** » Sun Mar 25, 2007 2:53 am

Thanks guys for all the input. The core is ash, boo,ash. I have cut my arrow shelf in and I think I will add string bridges. She shoots smooth as warm butter but i do have a little tuneing to do. the glass strands really saved my can. The wood lams seem to be fine so far. I plan to use artificial sinew/black silk combo to wrap with.