Riser Twist? What Now?

[SenterShot]

I saw build-along in which arrow shafts were used to check for limb twist. Thought I'd try it here on my second recurve project, so I clamped four arrows on perpendicular to the bow: one on each notch line, and one at each fadeout tip.

While I was busy cogitatin' on what fixin's I might have laying around to make a pair of tiller blocks (another trick I saw in the build-along), I noticed that I've got some twist in this new bow even before I've had a chance to brace it up. Both limbs twist the same amount in the same direction--or another way of putting it is, my riser is listing to port about 2 or 3 degrees.

You can see in the photo that the top two arrows, which are clamped at the riser fadeouts, are parallel. So are the two limb tip arrows (photo makes it look like there is a slight twist between the two ends, but I think it's a camera illusion). Now if only all four were parallel! (Must investigate the laminating form to figure out why this happened.)

My question is, if the two limb tips track perfectly parellel when I get a pair of tillering blocks on them, should I try to correct the built-in twist, or just accept it and finish out my riser?

 

[JamesV]

There are a lot of factors to consider. First I don't think any wood is stable forever, it all shrinks, distorts over time. The natural stress inside the wood and the change in moisture are two that are working inside the riser along with the heating (curing) inside the oven. The more laminations used in the riser itself could help along with the choice of materials used. In short there are probably not very many "perfect" bows alive today.

James

[beachbowhunter]

James, no truer words!  Do you have a drum sander you can use or borrow to straighten it out?

[Glunt]

Since I started building I look at bows totally different.   I used to think I owned 3-4 customs that were flawless.  Come to find out I own zero and its common to find a little something on many, many well-known bows.  But, flawless isn't required to function fantastic.  Hard to say from a pic, but I'm guessing once you finish it out it will be fine.

[Robertfishes]

When I built my 3 forms I cut them out with a router with a 2 inch bit, then checked it with a square, I made  sure top of form was square with the side of  form, then I glued on my taper and glass  to form. I have not noticed any twists. I once tried to use a 3 inch  drum sander like the Binghams video  shows..i just couldnt get tne form perfect then I found kennym's web sight showing the router method,  I did   modify his method by using a router table and a 2 inch bottom bearing bit..

[kennym]

If both limbs turn the same direction, check your limb pads on riser for square to side of block  if a TD and your form if a one pc.

I'm bettin it shoot just fine!!