Help me Design My Next Bow

[Bowjunkie]

Yep Ben, basically ambush bows. I was just fondling this one as I was taking measurements and holy crap she's a little temptress... just BEGGING to be hunted with. Had a lot of bows speak to me, but none thataway. Probably the best-balanced bow I've ever held, and best balanced I've shot. But when I hunt, it's selfbows I carry. I'm cursed   :rolleyes:

Ya know I might... might, consider taking her to the mountains in a couple weeks. For what I'm doing, she's actually perfectly suited in all ways.

[Bowjunkie]

I tried posting more pictures but my computer is old and tired and photobucket isn't jiving with it. Sure wish we could post pictures directly here.

[Roy from Pa]

I guess it's ok uncle bow junk...  LMAO    

[bowhunter15]

Cool, so I think I've got a pretty good start with shape and construction now. For wood choices, I want to do bamboo and osage for the back and belly, however, I really like the contrast in the core and handle like the bows that Ben posted. I found that there's a couple stores near my place that stock exotic and domestic boards in 1/8" thicknesses. I want a nice dark wood to contrast the lighter back and belly, and complimenting the yellow of the osage would be a plus.

The woods I like on their site are: walnut, padauk, purpleheart, bolivian rosewood, katalox, and wenge. Would any of those work just fine for core, tip overlay, and possibly riser? Seems like they range from medium to very dense. The purpleheart might give it sort of a Minnesota Gophers theme. Gonna have to buy some colored pencils and start brainstorming how I want everything to look lol.

This will still be a bit down the road. I haven't bought a sander or band saw yet.

[bowhunter15]

I'm thinking maybe a profile like this?

 

[LittleBen]

Profile looks good. But I can assure you a riser as thick as pictured is a recipe for trouble.

I would shy away from the heavier core materials. It's not life or death, but walnut is going to give better performance than wenge for sure. Cherry or maple also look good and work well as a core.

FWIW, if you don't already own the core material it might be worth just buying a pair of laminations which are already ground to a taper like .002. It's not critical because you're going to have to tiller it anyway, just means a little less scraping. A set of walnut (or other domestic wood) tapers shouldn't cost much ... Maybe $10-20.

Generally core materials should be light, and riser materials and tip overlay materials should be very strong.

If you use a relatively thick riser like I do, you need to REALLY REALLY make sure the fades are ground very smoothly down to PAPER THIN! If not you will get hinging at the fades. You can hedge your bet a little by ALSO adding a very thin (maybe only .125") power lam maybe 3-4" longer than the riser. With a riser like that it would also be wise to use a gap filling glue like Urac or smooth-on.

I might recommend a riser of 10-12" and a very thin power lam of say 14". But others might have other ideas.

Lastly, adding a thick riser like that is a bit of a challenge in itself to get right. It might be worth considering just building this one the way you built the first one in terms of riser, and focussing on a clean tiller since the bow will already be much shorter and thereby more challenging. There's always next time to add more complexity.

Sorry for the essay ...

[bowhunter15]

Thanks for the essay. The riser is deceptive in its thickness I believe. I drew it so that its depth from the belly to the deepest part of the handle is 1 5/8", which is exactly the same as my last bow. The difference is, my last bow had the handle entirely on the belly side and no riser (similar to Bowjunkies pic too) whereas this one is more "forward handle" in design. Do you think that if I simply shifted that entire region towards the belly (meaning less riser thickness and more handle thickness) that would help and make it easier to build? The only reason I was thinking forward handle was to model it after other short bows on the market. It's my understanding that forward handle is more forgiving, but standard handle is faster because of the brace height differences. If the riser is longer than the handle, doesn't the riser itself act as a power lam? I could split the riser into multiple pieces instead of one big block.

I've got no issues with ordering tapers. Looks like Bingham has a decent selection in the $16-23 range + shipping unless anyone has other vendors they like. I found a post by Bowjukie from a couple years ago:
   

   Posted by Bowjunkie (Member # 482) on July 20, 2011 07:26 AM:
 
I've used cherry in glass bows as well as backed them with hickory. I love that stuff... works easily and doesn't load up or dull tools, not oily and glues up and finishes readily, very pretty flat grain under clear glass(sometimes looks a lot like yew), diffuse porous rings with moderately closed grain, readily available. No problem with weight, it holds it's own. The last cherry glass bow I made was 70# @ 28", as predicted.

In selfbows or backed all-wooden bows, it's barely acceptable in my opinion. The good thing about THAT is, it will force you to refine your design and tillering skills.

I haven't done it yet, but I'm guessing it would be the perfect wood to put between boo and osage in a tri-lam.

[mikkekeswick]

I was just wondering how many bows you've made?
Is this your first foray into this sort of design?

[LittleBen]

Garrett, yes if the riser is longer than the handle it acts as a powerlam. The reason I suggested an additional power lam is because grinding out the fades of the riser can be a bear to get right. A thin powerlam in addition which is longer than the riser helps smooth the transition into the bending limbs.

And yes you could just shift it towards the belly side.

I only made the point about the thickness of the riser because I've built many like this and it is a real pain.

I think you need to take one step at a time. Build a short bow first, then add then complication of the fancy forward handle later on another build.

That's just one man's .02

[bowhunter15]

Originally posted by mikkekeswick:
I was just wondering how many bows you've made?
Is this your first foray into this sort of design?

I've made one 68" R/D BBI. First attempt at a tri-lam or a shorter bow.

[bowhunter15]

Originally posted by LittleBen:
Garrett, yes if the riser is longer than the handle it acts as a powerlam. The reason I suggested an additional power lam is because grinding out the fades of the riser can be a bear to get right. A thin powerlam in addition which is longer than the riser helps smooth the transition into the bending limbs.

And yes you could just shift it towards the belly side.

I only made the point about the thickness of the riser because I've built many like this and it is a real pain.

I think you need to take one step at a time. Build a short bow first, then add then complication of the fancy forward handle later on another build.

That's just one man's .02

Okay, would you still suggest a power lam anyways if I move the handle all to the belly side? Something a few inches longer than the handle between the backing and core, .125" in the center down to a feather taper, made of the same hard wood as the bulk of the handle? I need to have some protection from the handle popping off. My last bow had fades build into a thicker 8" center that I glued the handle onto.

[LittleBen]

Yes to the power lam. I'd probably go thicker than .125" in that case though. Maybe 1/4" ....

Anyone who uses a lot of power lams wanna comment?

[Wolftrail]

Makes sense LittleBen to use the power lam.

[bowhunter15]

Another quick question... if I have the belly lams stay on the belly side of the handle, as shown in the sketch below, would I still need a power lam or are those two options basically there to solve the same problem?