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Main Boards => The Bowyer's Bench => Topic started by: eman614 on January 24, 2009, 06:52:00 PM

Title: number of lams
Post by: eman614 on January 24, 2009, 06:52:00 PM
i am confused by the number of lams i am to use. i looked at binghams for the size that i am looking for, and to get the size i want i am going to need 2 .040 glasses, 2 .050 parallels, 1 .030 parallel and 1 .120 taper. the problem is that i don't see anyone else using this many. someone help please.
eric
Title: Re: number of lams
Post by: talkingcabbage on January 24, 2009, 06:56:00 PM
What kind of bow are you trying to build?  We'll need more info to help you.

Joe
Title: Re: number of lams
Post by: eman614 on January 24, 2009, 08:16:00 PM
i'm trying to build a reflex/deflex longbow(pronounced). i am shooting for about 60# but a little lighter would be fine. binghams only has a chart for a take-down so iwas going by it. it says that i will need a thickness of .335. thats how i came up with the lams above. thanks for the help.
eric
Title: Re: number of lams
Post by: talkingcabbage on January 24, 2009, 09:29:00 PM
I'm guessing this:  http://www.binghamprojects.com/drawweight.htm  is where you got the charts?  

I'm just starting my first laminated bow (a 60" takedown recurve).  Kenny M has the best advise for this kind of stuff.  He sells lams, forms, riser blocks, basically everything you'll need.  I'm sure he'll chime in when he gets a chance.  

You might also do a search on paleoplanet.  I'm not sure if they have a chart like that or not, but it's worth a try.

Joe
Title: Re: number of lams
Post by: OH Longbow on January 24, 2009, 09:51:00 PM
Eric,

I have built 2 r/d bows from the Bingham plans.  The first was strictly from their plans and the second I made a little adjustment on the form.  This last time, I used 2-.050 clear glass, 1-.100 taper, 2-.060 parallel, and 1-.062 parallel for a total thickness of .382.  This came out to be about 54# @ 29".  I think the total thickness on the other one was .392 and it came out to be 56# @ 29".  Oh, btw, both bows were 68".

If you're planning on keeping it at 68" in length and using the Bingham plans, I'm guessing that your bow will be somewhere around 50#.

Have fun.

John
Title: Re: number of lams
Post by: BigJim on January 24, 2009, 10:15:00 PM
Eman- the number of lams you use in the limb is not that important. The thickness and makeup are more important.
I use 8 lams in each of my limbs on my RD longbows and they are quite popular. Two clear glass, two veneer exotic wood, two uniweft or core tuff, and two tapered actionboo. Every one will have an opinion on what works for them. I have smooth and fast bows, real quiet too with this set up.
good luck, BigJim
Title: Re: number of lams
Post by: kennym on January 24, 2009, 10:53:00 PM
Like Jim says, number isn't crucial. I've built with 4 to 8 including glass.

 Binghams has a great chart, I've used it a bunch to guess thickness on new forms I've tried.

 You could drop the .030 and use 2 .065 without any problems,I would think.

 One other thing,if that .120 taper is gonna lay on the radius on the belly of your riser(not knowing your design),you might want to go with a thinner taper so it bends easier in the radius. Makes glue lines easier.
Have fun is the main thing!  :thumbsup:
Title: Re: number of lams
Post by: eman614 on January 24, 2009, 11:21:00 PM
thanks everyone.  you have all been a big help. kennym i assume that the radius on the belly is the closest piece to the shooter, i really dont know where im going to put the taper. this will be the first laminated bow i've ever built. is it best to  put the taper in that spot? also i guess that i need to go to your website to get lams and things like that?
Title: Re: number of lams
Post by: kennym on January 25, 2009, 01:45:00 PM
Yep,string side is belly. You can put the taper on the back or belly.Just make sure your riser fits the form with the taper in place,may make the ends gap if you don't. On strait longbows with strait riser,I think that is why most tapers are on the belly side,so the riser and form fit with the lams in place. Wish I could say that more clearly.  :help:
Title: Re: number of lams
Post by: eman614 on January 25, 2009, 07:40:00 PM
alright kennym i think that im ready to make an order from you. i had a question about the different but thicknesses of your lams. are they only available in 1/100 of an inch increments or can i get them in whatever increments that i want, for instance can i get them in .093 or does it have to be .090? thanks.
eric
Title: Re: number of lams
Post by: kennym on January 25, 2009, 08:33:00 PM
Whatever you want, I'll get em as close as I possibly can!
Title: Re: number of lams
Post by: Pennsyltuckey pete on January 26, 2009, 12:26:00 AM
Just one thing to remember about changing  the number of lams in a bow design.  The more lams you are gluing up, the more glue you are going to need to mix.  Do not ask me how I found this out.    :eek:   Big Difference between three heavy lams and five thin ones.
Title: Re: number of lams
Post by: eman614 on January 26, 2009, 06:38:00 PM
which makes a smoother drawing bow, alot of small lams. or a few big lams?
Title: Re: number of lams
Post by: kennym on January 26, 2009, 07:45:00 PM
I can't tell much diff,maybe I'm not sensitive enough! LOL  Probably more in the length and design.
Title: Re: number of lams
Post by: eman614 on January 26, 2009, 09:32:00 PM
i'm sure i'd learn all this if i'd order the instructional material from binghams but that would be to easy. so i got another question. most lams come 36 inches. i assume that i am supposed to glue them together? also what do i use to glue them?
Title: Re: number of lams
Post by: kennym on January 26, 2009, 10:12:00 PM
Here is how I do it,
Grind the ends at a pretty good angle(together for me),lay a small piece of plastic on the edge of your bench(strait edge) or a 6' pc of plywood,board,etc.  With good superglue,wet both skives(angles) it'll take a few seconds to bond.
 Put the angles together,line up on the edge of bench,flip the plastic over it, lay a small block on the joint,and clamp for 20 minutes. Sand off any excess glue and its ready to go.
Or use a dab of smoothon if you need a little more time to work.
Title: Re: number of lams
Post by: eman614 on January 26, 2009, 11:37:00 PM
thanks to everyone for helping. kennym once i get a heatbox built ill be sending an order your way. or if you take walk-ins i might do that. i will be i east st.louis  in a couple of weeks to make sausage with my cousins.if its not too far and you don't mind i'd like to see your operation. thanks again.
eric
Title: Re: number of lams
Post by: kennym on January 28, 2009, 07:38:00 PM
Hey Eric,
I'm about 250 NW of ST Louis,you are welcome to stop by! Call before you come so I can make sure to be here! I work mon thru thurs at my "real" job,then in the shop fri and sat.
Thanks,Kenny
Title: Re: number of lams
Post by: eman614 on January 28, 2009, 08:44:00 PM
that would be awesome. we will be up thursday the 11th through that sunday. friday we won't have much to do, so that will be perfect. if you don't want to put your phone number on the forum then you can send it to me at my email. it is [email protected]. thanks for everything. i can't hardly wait!
eric
Title: Re: number of lams
Post by: kennym on January 28, 2009, 09:04:00 PM
All right here Eric!! Now I gotta clean house(shop)!!


 http://kennyscustomarchery.com/contact.html
Title: Re: number of lams
Post by: eman614 on January 28, 2009, 09:22:00 PM
oh yeah i forgot about the web site. haha don't clean up on my account. did  i mention that i was pumped about seeing the set up.