Trad Gang

Main Boards => The Bowyer's Bench => Topic started by: scottm on February 12, 2012, 06:07:00 PM

Title: I beam riser?
Post by: scottm on February 12, 2012, 06:07:00 PM
Any chance of some one explaining the process of cutting out and gluing up an I beam style riser?If its not too much to ask some pics would be great.Thanks so much  for your time. Scott
Title: Re: I beam riser?
Post by: Trux Turning on February 12, 2012, 06:30:00 PM
An "I" beam riser is nothing more than 3 pieces glued together- some folks use phonelic in the center to stiffen the riser.
(http://i290.photobucket.com/albums/ll259/truxturning/Tradgang%202012/Tradgang2012021.jpg)
Title: Re: I beam riser?
Post by: scottm on February 12, 2012, 08:21:00 PM
Thanks Trux!
Title: Re: I beam riser?
Post by: kennym on February 12, 2012, 09:08:00 PM
I like to make the beam thick enough that you don't get thru cutting the site window.

You don't have any lam strength then .  Seems most risers break from the corner in the shelf/site window and angle down toward your thumb.

For me , on a 1.5 riser, 3/8" thick beam works pretty well. Spose it depends on how deep you are gonna cut.

Trux, that zebra will pop with finish on it!!
Title: Re: I beam riser?
Post by: scottm on February 12, 2012, 10:47:00 PM
Thanks for the tips Kenny!
Title: Re: I beam riser?
Post by: Bradford on February 12, 2012, 10:54:00 PM
Like Kenny said.. here is a pic of the one I just did.  All the same wood:

(http://i383.photobucket.com/albums/oo273/timberwolf177/Bow%2020/20120211100058.jpg)

So now I will have at least one glue joint running down the wood with the window in it
Title: Re: I beam riser?
Post by: trentcur on February 12, 2012, 11:57:00 PM
Ok and kenny is the "beam" considered to be the center piece???
Title: Re: I beam riser?
Post by: kennym on February 13, 2012, 05:58:00 AM
I guess, not sure why they are named that.

No I to it ,just sandwiched together.

But I sounds better than wich....  :D
Title: Re: I beam riser?
Post by: jtwalsh62 on February 13, 2012, 07:59:00 AM
Why the I beam? Pros/Cons
Title: Re: I beam riser?
Post by: Buzz Killington on February 13, 2012, 08:37:00 AM
I beam risers are laminated with the layers layed from belly to back instead of from left to right. It's called an "I beam" because it's stronger than a regular riser lamination, just as an actual I beam is stronger than a rectanguler beam of equivalant weight. At least that's my understanding of it.
Title: Re: I beam riser?
Post by: tenbrook on February 13, 2012, 09:28:00 AM
An I-Beam adds strength to the riser.

Unlike Kenny I like to make my I-Beams thick.  I go about 5/8" on mine because I like the way the I-Beam shows in the site window.

The choice is yours.

Thick center piece = I-beam visible in sight window

Thin center piece = I-beam does not show in sight window.

Here is a picture of an I-beam riser in one of my bows.  See how the Osage is visible in the sight window section.

Hope this helps.    :thumbsup:    

Tenbrook

More photos of the bow here:

http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=007793;p=1
 
 (http://i90.photobucket.com/albums/k258/matter_daddy/DSCN4825.jpg)
Title: Re: I beam riser?
Post by: scottm on February 14, 2012, 03:31:00 AM
Thanks for the replys fellas.Beautiful work tenbrook !
Title: Re: I beam riser?
Post by: scottm on February 14, 2012, 03:37:00 AM
I was just wondering how these are put together.Its fairly easy for me to come up with 3/4" wood for risers.The thicker stuff is a little harder to come by.I thought maby an I beam riser would be the way for me to go.Thanks again,Scott
Title: Re: I beam riser?
Post by: trentcur on February 14, 2012, 05:26:00 AM
tenbrook........ your ibeam is not layered belly to back is it? It appears that yours are layered from left to right???? If not how do you get your osage showing up in the site window, yet keep coco showing all through the riser from the side profile?

thanks
Title: Re: I beam riser?
Post by: PV on February 14, 2012, 07:00:00 AM
The I beam riser has a full lamination back to belly trentcur. The layers go left to right. These "I Beam" risers have multible laminations with the thickest lam ( 3/4" ) in the middle of the riser.The middle lamination's grain is 1/4 sawn back to belly allowing the greatest strenght or stiffness for the material used.


(http://img.photobucket.com/albums/v488/Shortbldtr/Bows/IMG_1555.jpg)
(http://img.photobucket.com/albums/v488/Shortbldtr/Bows/IMG_1591.jpg)
(http://img.photobucket.com/albums/v488/Shortbldtr/Bows/IMG_1317.jpg)
Title: Re: I beam riser?
Post by: scottm on February 14, 2012, 09:08:00 AM
Nice work PV!
Title: Re: I beam riser?
Post by: Sixby on February 18, 2012, 07:07:00 PM
I do a double I beam. The centered or slightly off centered wood which shows in the sight window and then a !/4 inch piece of phenolic on the back side of that. Wood shows on the outside of the riser and the phenolic I beam keeps me from replacing cracked risers.
I cut and do the entire riser with the wood I beam and all beauty stripes . Then cut and add in the phenolic so that it is full strength and uncut the entire length. It is the last thing added to the riser except overlays.

God bless you, Steve