Hill style bow

[Hophornbean0423]

I want to build a 45# hill style bow I am using a 16" riser and the bow is to be 66" long the glass is. 50 can someone give me some lam thicknesses.

[jsweka]

I typically build them at 68", 0.050 glass, one 0.002 taper, and three parallels.  For a 45# bow, I'd go with a total stack (glass and lams) of 0.405.

Since your bow will be 2" shorter, you'd gain probably 5# for a given total stack, so I'd say a total stack of 0.390 should put you close to 45# @ 28" of draw.

[StanM]

HHB0423,

I've made quite a few bows that fit that description. If you want to save some money and build that bow, buy ONE piece of two-inch glass 0.050, ONE piece of two-inch wide 0.050 parallel core lam and ONE piece of two-inch wide tapered lam with a 0.120 butt thickness and a 0.002 inch per inch taper. Rip all pieces to one inch wide on the bandsaw (this will eat your blade, so use an old one. You can use it over and over on the fiberglass, but it will be shot for wood.)

I glue them up like this - fiberglass, parallel, taper, parallel, riser, parallel then fiberglass. You will need to cut the second piece of fiberglass into two three-foot strips to run up the riser. You can also glue all the lams under the riser if you like the look better.

Taper the last 18" down to 3/8th inch nocks. Bow will be around 45 pounds.

[Hophornbean0423]

Thank you guys that's just what I was looking for

[monterey]

Originally posted by jsweka:
I typically build them at 68", 0.050 glass, one 0.002 taper, and three parallels.

what is the width at fade and width at tip on that?

[onemississipp]

StanM,

It appears you left out a parallel thickness in your stack. As stated your stack total would be .320 with .004 taper your stack at the tips would be .184 or approx. 3/16".

Then in your lay up I found an extra parallel but lost a taper?

[onemississipp]

I would say total stack .380

Go with this!

Glass .050

boo para 0.060

boo para 0.060

boo taper .001 0.080

boo taper .001 0.080

Glass .050

Limb profile: 1.25" at 8" from center of handle then taper to .5" at tips. Start wide and check weight. Narrow as needed or round edges or both.

[StanM]

Originally posted by onemississipp:
StanM,

It appears you left out a parallel thickness in your stack. As stated your stack total would be .320 with .004 taper your stack at the tips would be .184 or approx. 3/16".

Then in your lay up I found an extra parallel but lost a taper?

You are correct, sir. Thank you for pointing that out. It should've read glass, parallel, taper, parallel, riser, taper, glass.

That's what I get for typing on a phone too late at night!

[jsweka]

Hey, hey - onemississipp are pretty close on our recommendations for total stack and total taper.  It's always good to have close agreement on these engineering sorts of guesstimates.  You could split the difference and make your total stack 0.385  

[onemississipp]

No thank you! I thought I was crazy for a minute or two. Had to crunch the numbers.

With the tips being .184, I bet you get a " whip tiller" on that bad boy! Got a pic of one at full draw?

[jsweka]

monterey - I go with 1 1/4" width at the fades and 1/2" at the tips.

Dustin - with 0.002" taper per inch, that's a 0.066 decrease in thickness over a 33" limb (66" bow), so the tips would be 0.324" at the tips if the total stack was 0.390".

My bows are definitely not whip tillered and if anything they might bend too much nearer the fades.  I've been toying with the idea of adding more taper to move the bend farther out.  Here's a couple pics of what they look like.

 

 

[onemississipp]

The whip tiller comment was for StanM, with the .004 taper.

That's a good looking tiller there jsweka.

[onemississipp]

Jsweka,
    What about a power lam, to keep the fades a little more stiff.

[Stefan]

Hello now powerlams on hill style bows,
i make mine 3" parallel from the fades and then straight taper to 3/8 tips,
this give me a well tillered bow .

[jsweka]

Duh - Sorry Dustin. I now see your post was Stan and not me.  Guess I need to read to work on my reading comprehension.

Thanks for the compliment on my bow.

[StanM]

I will get a pic up this weekend!

[MoeM]

I still wonder about my taper sled... my Hillies got a 6mm/m total taper- if I`m not totally confused that means same as 0.06" per inch!?
But they seem to bend same/close as Johns
     
Don`t they??
If I would look at a tiller with a total of 0.02 and try to imagine same one with a three times higher tiller I`d expect a real whip.
But my D/R with 4mm/m is way far from bending to close so sleds can`t be that wrong anyway...

[bowhntineverythingnh03743]

The boys won't steer you wrong... I like thin limbs on my Hill bows. Made this one to be 1 1/8 inch at the fade which straight taper to 1/2 tips. Love the look of it when it is complete... Not such a yard stick look to them.

This was my last one I finished and gave as a trade bow to Juan who's builder didn't produce for him.

Justin

 
 

[onemississipp]

MoeM,
  That's a fine looking tiller. Your sled seems to giving you, without really digging in the weeds, a taper of about .0057 or there about.

[onemississipp]

With all the taper talk it helps for some to see it, so here is a .002 taper, inch position on the left.

0   0.400
1   0.398
2   0.396
3   0.394
4   0.392
5   0.390
6   0.388
7   0.386
8   0.384
9   0.382
10   0.380
11   0.378
12   0.376
13   0.374
14   0.372
15   0.370
16   0.368
17   0.366
18   0.364
19   0.362
20   0.360
21   0.358
22   0.356
23   0.354
24   0.352
25   0.350
26   0.348
27   0.346
28   0.344
29   0.342
30   0.340
31   0.338
32   0.336
33   0.334
34   0.332