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Main Boards => The Bowyer's Bench => Topic started by: Bryan Adolphe on June 08, 2024, 05:38:32 PM

Title: Strength in a footed riser
Post by: Bryan Adolphe on June 08, 2024, 05:38:32 PM
Question! On a footed riser i have 4 laminations of wood on the back….. adding glass or phenolic …. what would be the best for strength?
Title: Re: Strength in a footed riser
Post by: buckeyebowhunter on June 08, 2024, 05:53:19 PM
Is it a takedown riser or one piece?
Title: Re: Strength in a footed riser
Post by: kennym on June 08, 2024, 07:24:38 PM
Glass will be stiffer than phen
Title: Re: Strength in a footed riser
Post by: Crooked Stic on June 08, 2024, 09:39:09 PM
Glass better a form of glass G10 better yet.
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 08, 2024, 09:55:07 PM
Is it a takedown riser or one piece?
sorry yes a T/D ,
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 08, 2024, 10:05:49 PM
I remember seeing a site window getting cut out and temporarily replaced before the back overlays get installed, me bandsaw not set up to cut glass much....might need to invest in a new blade sometime. $$$
Title: Re: Strength in a footed riser
Post by: buckeyebowhunter on June 08, 2024, 10:23:45 PM
I recently built a footed riser with just two glass accents at 0.030" and then a strip of action wood also 0.030" and it's holding up well.

Yes if you plan to cut a lot of glass and phenolic you will need to bite the bullet and get a lenox tri master blade.

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Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 09, 2024, 09:14:36 AM
I have a sheet of 1/16 g10 just have not wanted to wreck any blades yet :biglaugh:
Title: Re: Strength in a footed riser
Post by: Crooked Stic on June 09, 2024, 01:44:36 PM
If your sawing strips a concrete blade on tables awhile will work. But then when youdoe the risercutting prolly need bandsaw
Title: Re: Strength in a footed riser
Post by: buckeyebowhunter on June 09, 2024, 02:10:14 PM
If you're just cutting strips just use a hacksaw. Do not try to use a miter saw. Bandsaw you need the tri master to cut the riser. The worst part is cutting the sight window. I've been experimenting with taking little chops with the miter saw then using my edge sander to shape the sight window. That cut can be pretty tough even with the carbide tooth blade on a bandsaw.
Title: Re: Strength in a footed riser
Post by: Kirkll on June 10, 2024, 11:01:36 AM
Question! On a footed riser i have 4 laminations of wood on the back….. adding glass or phenolic …. what would be the best for strength?

It depends on the shape of your riser on what is best for strength. If it’s a full radius back, using glass will be stronger than phenolic. But keep in mind…. The laminations of that footing itself is adding strength to the riser. If you are doing an S shape on the back, you just need to cap any end grain run out, and typically hardwood will do that fine….   How about posting a picture of the finished riser shape? That would be helpful…..   Kirk
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 10, 2024, 02:06:22 PM
Hey Kirk heres a pic . Its pretty much as simple as it gets for a footed riser, but it’s a start… A fair bit of work building jigs just to do this. I may use technology.lol To do anything more complicated  :biglaugh: [ You are not allowed to view attachments ]
Title: Re: Strength in a footed riser
Post by: Kirkll on June 10, 2024, 02:41:08 PM
Well its kinda tough to comment on overlays without seeing how you plan to shape the back of the riser.  but.... if you are doing an S shape and do not get into the footing line ends like this photo, i see no need for overlays at all on that riser unless you want them for aesthetics. then i would apply them first, then do your limb pad overlays to cap the end grain.

Now if your S shape goes past that footing line and exposes it to the back of the riser. you Definitely need overlays to cap it. But wood overlays is all you need for strength.... Glass isn't going to add much strength to an S shape.

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Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 10, 2024, 02:51:45 PM
 Sorry the back is radius not s- shaped. :thumbsup:
Title: Re: Strength in a footed riser
Post by: Kirkll on June 10, 2024, 09:01:16 PM
Really?   Typically you build your footings so they center up on the grip. I was looking at your marked area for the deepest part of the grip, and guessing where the standard 1.75” depth would be…

I’m not sure that footing shape is going to work well with a radius back riser without cutting through your footing lines…. That looks seriously thick through the center to me.  What is the measurement from the deepest part of your grip to the back of the riser that is shown in your photo? 
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 10, 2024, 10:26:33 PM
Kinda deceiving right now Kirk cause i haven't finish sanding the radius just cut the limb pads so will see but the plan was not to get into the footing , the drawn grip should be were it ends up at 1 3/4” ….. :thumbsup:
Title: Re: Strength in a footed riser
Post by: Kirkll on June 12, 2024, 08:38:42 PM
On a radius back shape, I always shape the back and the limb pads at the same time, and wrap my overlay full length. I typically use linen phenolic, but have used hardwood from time to time…. You’ll have to post some photos when you get it dialed in….

Kirk
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on June 15, 2024, 11:53:11 AM
On a radius back shape, I always shape the back and the limb pads at the same time, and wrap my overlay full length. I typically use linen phenolic, but have used hardwood from time to time…. You’ll have to post some photos when you get it dialed in….

Kirk
I will do that …. You bet !  :thumbsup:
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on July 05, 2024, 04:15:35 PM
Here it is all finished up pecan and black Limba , maple limb core. It finished a bit heavy for me @ 50# so I’ve only been able to short draw it to shoot , it really does smoke a 560 grain arrow i’m quite happy with the way it shoots.  [ You are not allowed to view attachments ]  [ You are not allowed to view attachments ]  [ You are not allowed to view attachments ]  [ You are not allowed to view attachments ]
Title: Re: Strength in a footed riser
Post by: Jon Lipovac on July 05, 2024, 05:12:57 PM
Looks great Bryan!  :clapper: :clapper:
Title: Re: Strength in a footed riser
Post by: Kirkll on July 06, 2024, 10:08:44 AM
Hey Bryan,

I’m not trying to be critical….. but you might want to avoid rounding the end of your riser at the very end. Believe it or not, there is a huge amount of pressure put on that point that should be distributed evenly across the full width of the limb.

Now you may be ok on lighter weight bows, but I have had glass actually fracture at that point on seriously heavy limbs. I started using a piece of 1/16” G-10 on the base of my limbs that extended past the riser 1/4”  to keep it from happening again.

Check the limb pads on this one…. It has 96# and 115# limbs

https://photos.app.goo.gl/MbpkpzAXqq6y3VB28
Title: Re: Strength in a footed riser
Post by: Bryan Adolphe on July 06, 2024, 05:36:33 PM
Not a problem at all Kirk I appreciate tips tricks and ideas from all ... this is how we learn,  I have built this riser design both ways and like them both equally I am still  trying new ideas I think either way I would Use a limb butt overlay  on future limbs just to take away that potential stress on Glass right there ,  I am going to adjust my riser laminations to centre up on the shelf more which will extend the laminations out closer to the end of the riser  which should make the riser stronger .
Title: Re: Strength in a footed riser
Post by: Kirkll on July 07, 2024, 07:38:59 PM
You got some good stuff going Bryan…. I just like to share some of my boo boo’s when Ive gone into mad scientist mode from time to time. Sometimes a new mouse trap works outstanding!  Sometimes not so much.  It seems like we are either the hero or the goat sometimes. But that’s ok with me. If you aren’t thinking outside the box and tryin* new stuff now and then, it get boring real quick.   :thumbsup: