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Main Boards => The Bowyer's Bench => Topic started by: pditto613 on May 08, 2021, 11:37:00 PM

Title: Shortening riser?
Post by: pditto613 on May 08, 2021, 11:37:00 PM
Made my first take down recurve.   Turned out nice but came in a little light @46#
If I put the same limbs on a 2” shorter riser how much draw weight do you think it will add?
Title: Re: Shortening riser?
Post by: Roy from Pa on May 09, 2021, 04:44:18 AM
About 5 #.
Title: Re: Shortening riser?
Post by: Mad Max on May 09, 2021, 06:49:18 AM
About 5 #.

yep
Title: Re: Shortening riser?
Post by: pditto613 on May 09, 2021, 07:11:01 AM
That’s what I thought.  Thanks
Title: Re: Shortening riser?
Post by: Crooked Stic on May 09, 2021, 02:41:58 PM
Last time I shortened a riser 2 inches only gain 2 lbs.  So I would be interested to see how you come out. Think you gain more with shorter limbs
Title: Re: Shortening riser?
Post by: Bow Bender on May 09, 2021, 03:16:21 PM
You can make a pair of tapered wedges to go between the limbs and riser.  You can experiment with different tapers until you find the correct one.
Title: Re: Shortening riser?
Post by: pditto613 on May 09, 2021, 08:40:58 PM
Bender you mean use wedges to change the pad angle?   If I took off 2 degrees how much of a change do you think that would make?
Title: Re: Shortening riser?
Post by: Bow Bender on May 09, 2021, 10:33:21 PM
Yes. That's what I mean. I don't remember who it was but once upon a time there was a bow manufacturer that made wedges just for the purpose of changing the draw weight on their take down bows. Maybe someone else remembers who it was and can chime in here. For those that don't know, the poundage and tiller is adjusted on wheelie bows by adjusting the limb bolts up or down . To make a durable set of wedges take a couple scrap pieces of fiberglass that you probably have leftover from making the limbs, cut the length and width to match the limb pad and laminate a piece of wood to one side of each. They should be thick enough to end up with a thick end and ground down to thin at the other end creating a wedge.  Probably should drill limb bolt and alignment pin holes before tapering.  Having the wood laminated to the fiberglass makes it durable and prevents splitting. Make the thick end whatever thickness you want to change the limb pad angle,  just make both the same. Experiment with different wedge angles.  Wedge can be made so they are reversible allowing you to increase or decrease poundage. These can be very useful in making changes in poundage to help fine tune a bow/arrow combination.
Title: Re: Shortening riser?
Post by: Bow Bender on May 09, 2021, 10:55:05 PM
I don't know what the poundage change would be for a 2 degree change,  that isn't very much.  Start with 1/4 inch difference from thin to thick end. They  can always be ground down.
Title: Re: Shortening riser?
Post by: pditto613 on May 09, 2021, 11:09:44 PM
I have some 1/4” phenolic that I could use.  Will probably have to replace the alignment pins with longer ones to make it work.  I will play with that tomorrow
Title: Re: Shortening riser?
Post by: Bow Bender on May 09, 2021, 11:18:13 PM
 :thumbsup:
Keep us posted.
Title: Re: Shortening riser?
Post by: pditto613 on May 11, 2021, 11:26:45 AM
Limb pad wedge
Title: Re: Shortening riser?
Post by: pditto613 on May 11, 2021, 11:33:15 AM
First, I was wrong about the weight of the bow.   It is 50# not 46#. Didn’t check zero on my scale.    The first wedge tapered from 1/16” to 1/4”.  It was just under 5 degrees.   It moved the limb tips forward 1 1/16” and increased the draw to 56#.   More than I was looking for.   Second try changed it to a 3 degree taper and increased to draw to 53#.  This is closer to what I was after.
Title: Re: Shortening riser?
Post by: Flem on May 11, 2021, 12:14:33 PM
What wood did you make that riser from? Looks nice :thumbsup:
Title: Re: Shortening riser?
Post by: Mad Max on May 11, 2021, 12:31:47 PM
Awesome :thumbsup:
Title: Re: Shortening riser?
Post by: Bow Bender on May 11, 2021, 01:37:13 PM
Great!  As long as changing the limb pad angle doesn't move the limb tips so far that the poundage starts to stack at your draw length this is an easy fix.  If this is the poundage that you want you can permanently install the wedges on the riser or the limbs or leave them removable to experiment with on future builds. Now wasn't that a lot easier than making a new riser? And look at what has been learned about just a small change in pad angle for designing your next riser. :thumbsup:
Title: Re: Shortening riser?
Post by: pditto613 on May 11, 2021, 10:44:35 PM
Bender I believe you are right about the stacking when it was an extra 5 degrees.  It hit a wall around 27”. Wish my chronograph still worked it would be interesting to see the speed difference. Flem  that riser is laminated red oak.   It was a prototype first build and I didn’t want to use the good stuff.   So I stained it as dark With minwax true black.  Now I kind of like the simplicity of it.  I will post some pics tomorrow, it is hanging in my spray area drying right now
Title: Re: Shortening riser?
Post by: pditto613 on May 13, 2021, 12:20:51 PM
58” take down.  53# with wedges.  50# without
Title: Re: Shortening riser?
Post by: pditto613 on May 13, 2021, 12:24:00 PM
.
Title: Re: Shortening riser?
Post by: Mad Max on May 13, 2021, 01:39:03 PM
Nice :thumbsup:
Title: Re: Shortening riser?
Post by: Longcruise on May 13, 2021, 03:09:05 PM
A good example of getting a good look out of an everyday wood.  :thumbsup:
Title: Re: Shortening riser?
Post by: Crooked Stic on May 13, 2021, 08:27:40 PM
You should do full draw pics with and without wedges.
Title: Re: Shortening riser?
Post by: Flem on May 13, 2021, 08:33:44 PM
A good example of getting a good look out of an everyday wood.  :thumbsup:

No kidding, its got a great look to it :thumbsup: Except I'm going to stop now cause its hurting my neck :wavey: