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Main Boards => The Bowyer's Bench => Topic started by: jvermast on October 06, 2011, 02:16:00 PM

Title: Lam Layout - Input Requested
Post by: jvermast on October 06, 2011, 02:16:00 PM
I am about to put together my first lam - here are the pieces (I am not using glass at this point)

Layer 1 (Back) - 1/8" Hickory tapered to 1/16" at tips
Layer 2 (Core) - 1/16" Maple
Layer 3 (Core)- 12" Power Lam (1/4" tapered to nothing)
Layer 4 (Core) - 1/16" Maple
Layer 5 - 14" Riser Padauk
Layer 6 (Belly) - 1/8" Red Oak tapered to 1/16" at tips.
Layer 7 (Belly) - 1/16" Cherry

I'm aiming for 45-55#

Middle will be 7/16" (.4375 minus power lam) - tips will be 5/16" (0.3125)

What do you guys think? Bingham Projects says .391 for a 55# bow - I think the difference of my thicknesses puts me right about there.

Maybe I should just aim for that exact thickness with a parallel lam and say screw the taper?
Title: Re: Lam Layout - Input Requested
Post by: vanillabear? on October 06, 2011, 03:05:00 PM
Title: Re: Lam Layout - Input Requested
Post by: jvermast on October 06, 2011, 03:28:00 PM
I was kinda taking my queue from this post:

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=40;t=000110

But instead of a 5/16 to 1/4" taper core I'm using multiple lams.
Title: Re: Lam Layout - Input Requested
Post by: Swissbow on October 06, 2011, 03:57:00 PM
How long is your bow going to be and how long is the riser ? What profile are you going to use ? Straight, mild d/r or aggressive d/r-profile ?

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Andy
Title: Re: Lam Layout - Input Requested
Post by: vanillabear? on October 06, 2011, 04:02:00 PM
Title: Re: Lam Layout - Input Requested
Post by: jvermast on October 06, 2011, 05:27:00 PM
QuoteOriginally posted by Swissbow:
How long is your bow going to be and how long is the riser ? What profile are you going to use ? Straight, mild d/r or aggressive d/r-profile ?

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Andy
62" N2N - 14" Riser - Mild d/r
Title: Re: Lam Layout - Input Requested
Post by: okie64 on October 06, 2011, 06:19:00 PM
I have to agree with vanillabear on this one. Hitting that weight and having the bow tillered properly is going to be pretty tough to do with the woods and thicknesses you're planning to use. When I do a trilam I leave the belly lam 9/16" thick to make sure I have plenty of draw weight to play with. I'm not saying you cant do it but everything would have to work out perfectly.
Title: Re: Lam Layout - Input Requested
Post by: jvermast on October 06, 2011, 07:23:00 PM
How do you possibly get a piece of 9/16 wood to flex enough to get into the fade?
Title: Re: Lam Layout - Input Requested
Post by: okie64 on October 06, 2011, 08:55:00 PM
Not sure if I know what you mean. Heres what mine usually look like at the handle area. This one has 1/8" hickory back, 1/4" purpleheart powerlam, 1/8" cherry core, 1/2" hickory belly at the fade and a hickory handle. I was off on my measurement a little, its been a while since I've done a trilam so I went and measured a couple of my old ones and the belly lams were 1/2" thick at the handle and taper to the tips.

(http://i1231.photobucket.com/albums/ee503/Jamey_Burkhart/012.jpg)