Stack Question

[mwosborn]

Planning my swap bow and have a question...

I made a recurve form this past winter and have made 2 bows on it.  The first came in heavier than I wanted at #58.  I reduced the stack and the second came in at #49 - just as the lam stack calculator predicted.

I want to make a #40 bow on my 3rd attempt and need to reduce the stack by .03.  My question is if it makes a difference if I take this off of the parallel lam or the tapered lam?

Here are my first two stacks:

Bow 1 - .280 total
Glass - .04 x2
Parallel - .07
.003 taper - .130


Bow 2 - .265 total
Glass - .04 x2
Parallel - .06
.003 taper - .125

Thanks,

Mitch

[Robertfishes]

you might have to take some from both parallel and taper.. Some vendors don't like to grind a 003 tapers thinner than 0.125

[kennym]

If .015 took off 9#, you want to take off .030 to go 9# more?

I'm not much of a recurve guy but that sounds like a lot. But the stack calc worked the first time!

I won't go less than .010 over the lam's taper which on a .003 taper is .108 so .118 is minimum for a .003.

That should give Roy a decimal headache!

[Roy from Pa]

OMG..

Help, I just fell off my chair... LOL

[kennym]

LOL

[Bvas]

You could also cut your tapers to length off of the thick end  instead of the thin end to reduce stack.

[mwosborn]

Thanks Kenny and Robert -

Kenny - I meant .03 from the original stack so the 3rd attempt would be .250 total.  How's this look?

3rd bow - .250 total
glass - .04 x2
parallel - .05
.003 taper - .120

Sorry Roy!

[Robertfishes]

Yes, Bvas nailed it. that's what I do too. Some times you have to make stack height  adjustments using the tapers since 040 fiberglass is sometimes not 040..I have seen it run 038 to 043. Same with grinding parallels, A good accurate dial caliper is a must have tool for me. I used to use digital calipers but switched over to dials 2 years ago.

[Mad Max]

Originally posted by Robertfishes:
Yes, Bvas nailed it. that's what I do too. Some times you have to make stack height  adjustments using the tapers since 040 fiberglass is sometimes not 040..I have seen it run 038 to 043. Same with grinding parallels, A good accurate dial caliper is a must have tool for me. I used to use digital calipers but switched over to dials 2 years ago.

X2
Be quite Kenny, your going to mess him up.  

[Roy from Pa]

You could also cut your tapers to length off of the thick end instead of the thin end to reduce stack.

That's how I make gwass bows too, Bvasy...

Robert, I hear ya dude. Gwass is not always what they say. That's why I quit making gwass bows...

Mitch, it's ok bro... I've been going to school for them decimal thing ah mah jigs...

[mwosborn]

Cutting off the thick end should work just fine - thanks. I have a digital caliper that will have to do!      

Roy - can you get those bamboo backings down to .04?  Be just like glass then!     :D

[kennym]

:D

[Robertfishes]

Nothing wrong with a digital, I still use my igaging digital when I build ILF limbs and wedges..but I got a good deal on 2 used Mitutoyo dials and they seem to be more user friendly for laminations..

[kennym]

I prefer dial calipers too. Not sure why, just do.

More traditional I suppose...  

[mwosborn]

quote:Originally posted by kennym:
I prefer dial calipers too. Not sure why, just do.

More traditional I suppose...    

Emailed you an order Kenny.